clp

command line syntax highlighter
git clone git://jeskin.net/clp.git
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commit 18ef45115f944672b49383e9aaf899c45e43eda8
parent 1318913ff4e5084a30d33d22f0c87f61dabf59de
Author: Jon Eskin <eskinjp@gmail.com>
Date:   Fri, 22 Jul 2022 04:00:28 -0400

Merge pull request #6 from Nomarian/lexerfix

makes lexer.lua work
Diffstat:
Alua/lexer.lua | 1835+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Dlua/lexers/lexer.lua | 1855-------------------------------------------------------------------------------
2 files changed, 1835 insertions(+), 1855 deletions(-)

diff --git a/lua/lexer.lua b/lua/lexer.lua @@ -0,0 +1,1835 @@ +-- Copyright 2006-2022 Mitchell. See LICENSE. + +local M = {} + +--[=[ This comment is for LuaDoc. +--- +-- Lexes Scintilla documents and source code with Lua and LPeg. +-- +-- ### Writing Lua Lexers +-- +-- Lexers highlight the syntax of source code. Scintilla (the editing component behind +-- [Textadept][] and [SciTE][]) traditionally uses static, compiled C++ lexers which are +-- notoriously difficult to create and/or extend. On the other hand, Lua makes it easy to to +-- rapidly create new lexers, extend existing ones, and embed lexers within one another. Lua +-- lexers tend to be more readable than C++ lexers too. +-- +-- Lexers are Parsing Expression Grammars, or PEGs, composed with the Lua [LPeg library][]. The +-- following table comes from the LPeg documentation and summarizes all you need to know about +-- constructing basic LPeg patterns. This module provides convenience functions for creating +-- and working with other more advanced patterns and concepts. +-- +-- Operator | Description +-- -|- +-- `lpeg.P(string)` | Matches `string` literally. +-- `lpeg.P(`_`n`_`)` | Matches exactly _`n`_ number of characters. +-- `lpeg.S(string)` | Matches any character in set `string`. +-- `lpeg.R("`_`xy`_`")`| Matches any character between range `x` and `y`. +-- `patt^`_`n`_ | Matches at least _`n`_ repetitions of `patt`. +-- `patt^-`_`n`_ | Matches at most _`n`_ repetitions of `patt`. +-- `patt1 * patt2` | Matches `patt1` followed by `patt2`. +-- `patt1 + patt2` | Matches `patt1` or `patt2` (ordered choice). +-- `patt1 - patt2` | Matches `patt1` if `patt2` does not also match. +-- `-patt` | Equivalent to `("" - patt)`. +-- `#patt` | Matches `patt` but consumes no input. +-- +-- The first part of this document deals with rapidly constructing a simple lexer. The next part +-- deals with more advanced techniques, such as custom coloring and embedding lexers within one +-- another. Following that is a discussion about code folding, or being able to tell Scintilla +-- which code blocks are "foldable" (temporarily hideable from view). After that are instructions +-- on how to use Lua lexers with the aforementioned Textadept and SciTE editors. Finally there +-- are comments on lexer performance and limitations. +-- +-- [LPeg library]: http://www.inf.puc-rio.br/~roberto/lpeg/lpeg.html +-- [Textadept]: https://orbitalquark.github.io/textadept +-- [SciTE]: https://scintilla.org/SciTE.html +-- +-- ### Lexer Basics +-- +-- The *lexers/* directory contains all lexers, including your new one. Before attempting to +-- write one from scratch though, first determine if your programming language is similar to +-- any of the 100+ languages supported. If so, you may be able to copy and modify that lexer, +-- saving some time and effort. The filename of your lexer should be the name of your programming +-- language in lower case followed by a *.lua* extension. For example, a new Lua lexer has the +-- name *lua.lua*. +-- +-- Note: Try to refrain from using one-character language names like "c", "d", or "r". For +-- example, Scintillua uses "ansi_c", "dmd", and "rstats", respectively. +-- +-- #### New Lexer Template +-- +-- There is a *lexers/template.txt* file that contains a simple template for a new lexer. Feel +-- free to use it, replacing the '?'s with the name of your lexer. Consider this snippet from +-- the template: +-- +-- -- ? LPeg lexer. +-- +-- local lexer = require('lexer') +-- local token, word_match = lexer.token, lexer.word_match +-- local P, S = lpeg.P, lpeg.S +-- +-- local lex = lexer.new('?') +-- +-- -- Whitespace. +-- local ws = token(lexer.WHITESPACE, lexer.space^1) +-- lex:add_rule('whitespace', ws) +-- +-- [...] +-- +-- return lex +-- +-- The first 3 lines of code simply define often used convenience variables. The fourth and +-- last lines [define](#lexer.new) and return the lexer object Scintilla uses; they are very +-- important and must be part of every lexer. The fifth line defines something called a "token", +-- an essential building block of lexers. You will learn about tokens shortly. The sixth line +-- defines a lexer grammar rule, which you will learn about later, as well as token styles. (Be +-- aware that it is common practice to combine these two lines for short rules.) Note, however, +-- the `local` prefix in front of variables, which is needed so-as not to affect Lua's global +-- environment. All in all, this is a minimal, working lexer that you can build on. +-- +-- #### Tokens +-- +-- Take a moment to think about your programming language's structure. What kind of key +-- elements does it have? In the template shown earlier, one predefined element all languages +-- have is whitespace. Your language probably also has elements like comments, strings, and +-- keywords. Lexers refer to these elements as "tokens". Tokens are the fundamental "building +-- blocks" of lexers. Lexers break down source code into tokens for coloring, which results +-- in the syntax highlighting familiar to you. It is up to you how specific your lexer is +-- when it comes to tokens. Perhaps only distinguishing between keywords and identifiers is +-- necessary, or maybe recognizing constants and built-in functions, methods, or libraries is +-- desirable. The Lua lexer, for example, defines 11 tokens: whitespace, keywords, built-in +-- functions, constants, built-in libraries, identifiers, strings, comments, numbers, labels, +-- and operators. Even though constants, built-in functions, and built-in libraries are subsets +-- of identifiers, Lua programmers find it helpful for the lexer to distinguish between them +-- all. It is perfectly acceptable to just recognize keywords and identifiers. +-- +-- In a lexer, tokens consist of a token name and an LPeg pattern that matches a sequence of +-- characters recognized as an instance of that token. Create tokens using the [`lexer.token()`]() +-- function. Let us examine the "whitespace" token defined in the template shown earlier: +-- +-- local ws = token(lexer.WHITESPACE, lexer.space^1) +-- +-- At first glance, the first argument does not appear to be a string name and the second +-- argument does not appear to be an LPeg pattern. Perhaps you expected something like: +-- +-- local ws = token('whitespace', S('\t\v\f\n\r ')^1) +-- +-- The `lexer` module actually provides a convenient list of common token names and common LPeg +-- patterns for you to use. Token names include [`lexer.DEFAULT`](), [`lexer.WHITESPACE`](), +-- [`lexer.COMMENT`](), [`lexer.STRING`](), [`lexer.NUMBER`](), [`lexer.KEYWORD`](), +-- [`lexer.IDENTIFIER`](), [`lexer.OPERATOR`](), [`lexer.ERROR`](), [`lexer.PREPROCESSOR`](), +-- [`lexer.CONSTANT`](), [`lexer.VARIABLE`](), [`lexer.FUNCTION`](), [`lexer.CLASS`](), +-- [`lexer.TYPE`](), [`lexer.LABEL`](), [`lexer.REGEX`](), and [`lexer.EMBEDDED`](). Patterns +-- include [`lexer.any`](), [`lexer.alpha`](), [`lexer.digit`](), [`lexer.alnum`](), +-- [`lexer.lower`](), [`lexer.upper`](), [`lexer.xdigit`](), [`lexer.graph`](), [`lexer.print`](), +-- [`lexer.punct`](), [`lexer.space`](), [`lexer.newline`](), [`lexer.nonnewline`](), +-- [`lexer.dec_num`](), [`lexer.hex_num`](), [`lexer.oct_num`](), [`lexer.integer`](), +-- [`lexer.float`](), [`lexer.number`](), and [`lexer.word`](). You may use your own token names +-- if none of the above fit your language, but an advantage to using predefined token names is +-- that your lexer's tokens will inherit the universal syntax highlighting color theme used by +-- your text editor. +-- +-- ##### Example Tokens +-- +-- So, how might you define other tokens like keywords, comments, and strings? Here are some +-- examples. +-- +-- **Keywords** +-- +-- Instead of matching _n_ keywords with _n_ `P('keyword_`_`n`_`')` ordered choices, use another +-- convenience function: [`lexer.word_match()`](). It is much easier and more efficient to +-- write word matches like: +-- +-- local keyword = token(lexer.KEYWORD, lexer.word_match{ +-- 'keyword_1', 'keyword_2', ..., 'keyword_n' +-- }) +-- +-- local case_insensitive_keyword = token(lexer.KEYWORD, lexer.word_match({ +-- 'KEYWORD_1', 'keyword_2', ..., 'KEYword_n' +-- }, true)) +-- +-- local hyphened_keyword = token(lexer.KEYWORD, lexer.word_match{ +-- 'keyword-1', 'keyword-2', ..., 'keyword-n' +-- }) +-- +-- For short keyword lists, you can use a single string of words. For example: +-- +-- local keyword = token(lexer.KEYWORD, lexer.word_match('key_1 key_2 ... key_n')) +-- +-- **Comments** +-- +-- Line-style comments with a prefix character(s) are easy to express with LPeg: +-- +-- local shell_comment = token(lexer.COMMENT, lexer.to_eol('#')) +-- local c_line_comment = token(lexer.COMMENT, lexer.to_eol('//', true)) +-- +-- The comments above start with a '#' or "//" and go to the end of the line. The second comment +-- recognizes the next line also as a comment if the current line ends with a '\' escape character. +-- +-- C-style "block" comments with a start and end delimiter are also easy to express: +-- +-- local c_comment = token(lexer.COMMENT, lexer.range('/*', '*/')) +-- +-- This comment starts with a "/\*" sequence and contains anything up to and including an ending +-- "\*/" sequence. The ending "\*/" is optional so the lexer can recognize unfinished comments +-- as comments and highlight them properly. +-- +-- **Strings** +-- +-- Most programming languages allow escape sequences in strings such that a sequence like +-- "\\&quot;" in a double-quoted string indicates that the '&quot;' is not the end of the +-- string. [`lexer.range()`]() handles escapes inherently. +-- +-- local dq_str = lexer.range('"') +-- local sq_str = lexer.range("'") +-- local string = token(lexer.STRING, dq_str + sq_str) +-- +-- In this case, the lexer treats '\' as an escape character in a string sequence. +-- +-- **Numbers** +-- +-- Most programming languages have the same format for integer and float tokens, so it might +-- be as simple as using a predefined LPeg pattern: +-- +-- local number = token(lexer.NUMBER, lexer.number) +-- +-- However, some languages allow postfix characters on integers. +-- +-- local integer = P('-')^-1 * (lexer.dec_num * S('lL')^-1) +-- local number = token(lexer.NUMBER, lexer.float + lexer.hex_num + integer) +-- +-- Your language may need other tweaks, but it is up to you how fine-grained you want your +-- highlighting to be. After all, you are not writing a compiler or interpreter! +-- +-- #### Rules +-- +-- Programming languages have grammars, which specify valid token structure. For example, +-- comments usually cannot appear within a string. Grammars consist of rules, which are simply +-- combinations of tokens. Recall from the lexer template the [`lexer.add_rule()`]() call, +-- which adds a rule to the lexer's grammar: +-- +-- lex:add_rule('whitespace', ws) +-- +-- Each rule has an associated name, but rule names are completely arbitrary and serve only to +-- identify and distinguish between different rules. Rule order is important: if text does not +-- match the first rule added to the grammar, the lexer tries to match the second rule added, and +-- so on. Right now this lexer simply matches whitespace tokens under a rule named "whitespace". +-- +-- To illustrate the importance of rule order, here is an example of a simplified Lua lexer: +-- +-- lex:add_rule('whitespace', token(lexer.WHITESPACE, ...)) +-- lex:add_rule('keyword', token(lexer.KEYWORD, ...)) +-- lex:add_rule('identifier', token(lexer.IDENTIFIER, ...)) +-- lex:add_rule('string', token(lexer.STRING, ...)) +-- lex:add_rule('comment', token(lexer.COMMENT, ...)) +-- lex:add_rule('number', token(lexer.NUMBER, ...)) +-- lex:add_rule('label', token(lexer.LABEL, ...)) +-- lex:add_rule('operator', token(lexer.OPERATOR, ...)) +-- +-- Note how identifiers come after keywords. In Lua, as with most programming languages, +-- the characters allowed in keywords and identifiers are in the same set (alphanumerics +-- plus underscores). If the lexer added the "identifier" rule before the "keyword" rule, +-- all keywords would match identifiers and thus incorrectly highlight as identifiers instead +-- of keywords. The same idea applies to function, constant, etc. tokens that you may want to +-- distinguish between: their rules should come before identifiers. +-- +-- So what about text that does not match any rules? For example in Lua, the '!' character is +-- meaningless outside a string or comment. Normally the lexer skips over such text. If instead +-- you want to highlight these "syntax errors", add an additional end rule: +-- +-- lex:add_rule('whitespace', ws) +-- ... +-- lex:add_rule('error', token(lexer.ERROR, lexer.any)) +-- +-- This identifies and highlights any character not matched by an existing rule as a `lexer.ERROR` +-- token. +-- +-- Even though the rules defined in the examples above contain a single token, rules may +-- consist of multiple tokens. For example, a rule for an HTML tag could consist of a tag token +-- followed by an arbitrary number of attribute tokens, allowing the lexer to highlight all +-- tokens separately. That rule might look something like this: +-- +-- lex:add_rule('tag', tag_start * (ws * attributes)^0 * tag_end^-1) +-- +-- Note however that lexers with complex rules like these are more prone to lose track of their +-- state, especially if they span multiple lines. +-- +-- #### Summary +-- +-- Lexers primarily consist of tokens and grammar rules. At your disposal are a number of +-- convenience patterns and functions for rapidly creating a lexer. If you choose to use +-- predefined token names for your tokens, you do not have to define how the lexer highlights +-- them. The tokens will inherit the default syntax highlighting color theme your editor uses. +-- +-- ### Advanced Techniques +-- +-- #### Styles and Styling +-- +-- The most basic form of syntax highlighting is assigning different colors to different +-- tokens. Instead of highlighting with just colors, Scintilla allows for more rich highlighting, +-- or "styling", with different fonts, font sizes, font attributes, and foreground and background +-- colors, just to name a few. The unit of this rich highlighting is called a "style". Styles +-- are simply Lua tables of properties. By default, lexers associate predefined token names like +-- `lexer.WHITESPACE`, `lexer.COMMENT`, `lexer.STRING`, etc. with particular styles as part +-- of a universal color theme. These predefined styles are contained in [`lexer.styles`](), +-- and you may define your own styles. See that table's documentation for more information. As +-- with token names, LPeg patterns, and styles, there is a set of predefined color names, +-- but they vary depending on the current color theme in use. Therefore, it is generally not +-- a good idea to manually define colors within styles in your lexer since they might not fit +-- into a user's chosen color theme. Try to refrain from even using predefined colors in a +-- style because that color may be theme-specific. Instead, the best practice is to either use +-- predefined styles or derive new color-agnostic styles from predefined ones. For example, Lua +-- "longstring" tokens use the existing `lexer.styles.string` style instead of defining a new one. +-- +-- ##### Example Styles +-- +-- Defining styles is pretty straightforward. An empty style that inherits the default theme +-- settings is simply an empty table: +-- +-- local style_nothing = {} +-- +-- A similar style but with a bold font face looks like this: +-- +-- local style_bold = {bold = true} +-- +-- You can derive new styles from predefined ones without having to rewrite them. This operation +-- leaves the old style unchanged. For example, if you had a "static variable" token whose +-- style you wanted to base off of `lexer.styles.variable`, it would probably look like: +-- +-- local style_static_var = lexer.styles.variable .. {italics = true} +-- +-- The color theme files in the *lexers/themes/* folder give more examples of style definitions. +-- +-- #### Token Styles +-- +-- Lexers use the [`lexer.add_style()`]() function to assign styles to particular tokens. Recall +-- the token definition and from the lexer template: +-- +-- local ws = token(lexer.WHITESPACE, lexer.space^1) +-- lex:add_rule('whitespace', ws) +-- +-- Why is a style not assigned to the `lexer.WHITESPACE` token? As mentioned earlier, lexers +-- automatically associate tokens that use predefined token names with a particular style. Only +-- tokens with custom token names need manual style associations. As an example, consider a +-- custom whitespace token: +-- +-- local ws = token('custom_whitespace', lexer.space^1) +-- +-- Assigning a style to this token looks like: +-- +-- lex:add_style('custom_whitespace', lexer.styles.whitespace) +-- +-- Do not confuse token names with rule names. They are completely different entities. In the +-- example above, the lexer associates the "custom_whitespace" token with the existing style +-- for `lexer.WHITESPACE` tokens. If instead you prefer to color the background of whitespace +-- a shade of grey, it might look like: +-- +-- lex:add_style('custom_whitespace', lexer.styles.whitespace .. {back = lexer.colors.grey}) +-- +-- Remember to refrain from assigning specific colors in styles, but in this case, all user +-- color themes probably define `colors.grey`. +-- +-- #### Line Lexers +-- +-- By default, lexers match the arbitrary chunks of text passed to them by Scintilla. These +-- chunks may be a full document, only the visible part of a document, or even just portions +-- of lines. Some lexers need to match whole lines. For example, a lexer for the output of a +-- file "diff" needs to know if the line started with a '+' or '-' and then style the entire +-- line accordingly. To indicate that your lexer matches by line, create the lexer with an +-- extra parameter: +-- +-- local lex = lexer.new('?', {lex_by_line = true}) +-- +-- Now the input text for the lexer is a single line at a time. Keep in mind that line lexers +-- do not have the ability to look ahead at subsequent lines. +-- +-- #### Embedded Lexers +-- +-- Lexers embed within one another very easily, requiring minimal effort. In the following +-- sections, the lexer being embedded is called the "child" lexer and the lexer a child is +-- being embedded in is called the "parent". For example, consider an HTML lexer and a CSS +-- lexer. Either lexer stands alone for styling their respective HTML and CSS files. However, CSS +-- can be embedded inside HTML. In this specific case, the CSS lexer is the "child" lexer with +-- the HTML lexer being the "parent". Now consider an HTML lexer and a PHP lexer. This sounds +-- a lot like the case with CSS, but there is a subtle difference: PHP _embeds itself into_ +-- HTML while CSS is _embedded in_ HTML. This fundamental difference results in two types of +-- embedded lexers: a parent lexer that embeds other child lexers in it (like HTML embedding CSS), +-- and a child lexer that embeds itself into a parent lexer (like PHP embedding itself in HTML). +-- +-- ##### Parent Lexer +-- +-- Before embedding a child lexer into a parent lexer, the parent lexer needs to load the child +-- lexer. This is done with the [`lexer.load()`]() function. For example, loading the CSS lexer +-- within the HTML lexer looks like: +-- +-- local css = lexer.load('css') +-- +-- The next part of the embedding process is telling the parent lexer when to switch over +-- to the child lexer and when to switch back. The lexer refers to these indications as the +-- "start rule" and "end rule", respectively, and are just LPeg patterns. Continuing with the +-- HTML/CSS example, the transition from HTML to CSS is when the lexer encounters a "style" +-- tag with a "type" attribute whose value is "text/css": +-- +-- local css_tag = P('<style') * P(function(input, index) +-- if input:find('^[^>]+type="text/css"', index) then return index end +-- end) +-- +-- This pattern looks for the beginning of a "style" tag and searches its attribute list for +-- the text "`type="text/css"`". (In this simplified example, the Lua pattern does not consider +-- whitespace between the '=' nor does it consider that using single quotes is valid.) If there +-- is a match, the functional pattern returns a value instead of `nil`. In this case, the value +-- returned does not matter because we ultimately want to style the "style" tag as an HTML tag, +-- so the actual start rule looks like this: +-- +-- local css_start_rule = #css_tag * tag +-- +-- Now that the parent knows when to switch to the child, it needs to know when to switch +-- back. In the case of HTML/CSS, the switch back occurs when the lexer encounters an ending +-- "style" tag, though the lexer should still style the tag as an HTML tag: +-- +-- local css_end_rule = #P('</style>') * tag +-- +-- Once the parent loads the child lexer and defines the child's start and end rules, it embeds +-- the child with the [`lexer.embed()`]() function: +-- +-- lex:embed(css, css_start_rule, css_end_rule) +-- +-- ##### Child Lexer +-- +-- The process for instructing a child lexer to embed itself into a parent is very similar to +-- embedding a child into a parent: first, load the parent lexer into the child lexer with the +-- [`lexer.load()`]() function and then create start and end rules for the child lexer. However, +-- in this case, call [`lexer.embed()`]() with switched arguments. For example, in the PHP lexer: +-- +-- local html = lexer.load('html') +-- local php_start_rule = token('php_tag', '<?php ') +-- local php_end_rule = token('php_tag', '?>') +-- lex:add_style('php_tag', lexer.styles.embedded) +-- html:embed(lex, php_start_rule, php_end_rule) +-- +-- #### Lexers with Complex State +-- +-- A vast majority of lexers are not stateful and can operate on any chunk of text in a +-- document. However, there may be rare cases where a lexer does need to keep track of some +-- sort of persistent state. Rather than using `lpeg.P` function patterns that set state +-- variables, it is recommended to make use of Scintilla's built-in, per-line state integers via +-- [`lexer.line_state`](). It was designed to accommodate up to 32 bit flags for tracking state. +-- [`lexer.line_from_position()`]() will return the line for any position given to an `lpeg.P` +-- function pattern. (Any positions derived from that position argument will also work.) +-- +-- Writing stateful lexers is beyond the scope of this document. +-- +-- ### Code Folding +-- +-- When reading source code, it is occasionally helpful to temporarily hide blocks of code like +-- functions, classes, comments, etc. This is the concept of "folding". In the Textadept and +-- SciTE editors for example, little indicators in the editor margins appear next to code that +-- can be folded at places called "fold points". When the user clicks an indicator, the editor +-- hides the code associated with the indicator until the user clicks the indicator again. The +-- lexer specifies these fold points and what code exactly to fold. +-- +-- The fold points for most languages occur on keywords or character sequences. Examples of +-- fold keywords are "if" and "end" in Lua and examples of fold character sequences are '{', +-- '}', "/\*", and "\*/" in C for code block and comment delimiters, respectively. However, +-- these fold points cannot occur just anywhere. For example, lexers should not recognize fold +-- keywords that appear within strings or comments. The [`lexer.add_fold_point()`]() function +-- allows you to conveniently define fold points with such granularity. For example, consider C: +-- +-- lex:add_fold_point(lexer.OPERATOR, '{', '}') +-- lex:add_fold_point(lexer.COMMENT, '/*', '*/') +-- +-- The first assignment states that any '{' or '}' that the lexer recognized as an `lexer.OPERATOR` +-- token is a fold point. Likewise, the second assignment states that any "/\*" or "\*/" that +-- the lexer recognizes as part of a `lexer.COMMENT` token is a fold point. The lexer does +-- not consider any occurrences of these characters outside their defined tokens (such as in +-- a string) as fold points. How do you specify fold keywords? Here is an example for Lua: +-- +-- lex:add_fold_point(lexer.KEYWORD, 'if', 'end') +-- lex:add_fold_point(lexer.KEYWORD, 'do', 'end') +-- lex:add_fold_point(lexer.KEYWORD, 'function', 'end') +-- lex:add_fold_point(lexer.KEYWORD, 'repeat', 'until') +-- +-- If your lexer has case-insensitive keywords as fold points, simply add a +-- `case_insensitive_fold_points = true` option to [`lexer.new()`](), and specify keywords in +-- lower case. +-- +-- If your lexer needs to do some additional processing in order to determine if a token is +-- a fold point, pass a function that returns an integer to `lex:add_fold_point()`. Returning +-- `1` indicates the token is a beginning fold point and returning `-1` indicates the token is +-- an ending fold point. Returning `0` indicates the token is not a fold point. For example: +-- +-- local function fold_strange_token(text, pos, line, s, symbol) +-- if ... then +-- return 1 -- beginning fold point +-- elseif ... then +-- return -1 -- ending fold point +-- end +-- return 0 +-- end +-- +-- lex:add_fold_point('strange_token', '|', fold_strange_token) +-- +-- Any time the lexer encounters a '|' that is a "strange_token", it calls the `fold_strange_token` +-- function to determine if '|' is a fold point. The lexer calls these functions with the +-- following arguments: the text to identify fold points in, the beginning position of the +-- current line in the text to fold, the current line's text, the position in the current line +-- the fold point text starts at, and the fold point text itself. +-- +-- #### Fold by Indentation +-- +-- Some languages have significant whitespace and/or no delimiters that indicate fold points. If +-- your lexer falls into this category and you would like to mark fold points based on changes +-- in indentation, create the lexer with a `fold_by_indentation = true` option: +-- +-- local lex = lexer.new('?', {fold_by_indentation = true}) +-- +-- ### Using Lexers +-- +-- **Textadept** +-- +-- Put your lexer in your *~/.textadept/lexers/* directory so you do not overwrite it when +-- upgrading Textadept. Also, lexers in this directory override default lexers. Thus, Textadept +-- loads a user *lua* lexer instead of the default *lua* lexer. This is convenient for tweaking +-- a default lexer to your liking. Then add a [file type](#textadept.file_types) for your lexer +-- if necessary. +-- +-- **SciTE** +-- +-- Create a *.properties* file for your lexer and `import` it in either your *SciTEUser.properties* +-- or *SciTEGlobal.properties*. The contents of the *.properties* file should contain: +-- +-- file.patterns.[lexer_name]=[file_patterns] +-- lexer.$(file.patterns.[lexer_name])=[lexer_name] +-- +-- where `[lexer_name]` is the name of your lexer (minus the *.lua* extension) and +-- `[file_patterns]` is a set of file extensions to use your lexer for. +-- +-- Please note that Lua lexers ignore any styling information in *.properties* files. Your +-- theme file in the *lexers/themes/* directory contains styling information. +-- +-- ### Migrating Legacy Lexers +-- +-- Legacy lexers are of the form: +-- +-- local l = require('lexer') +-- local token, word_match = l.token, l.word_match +-- local P, R, S = lpeg.P, lpeg.R, lpeg.S +-- +-- local M = {_NAME = '?'} +-- +-- [... token and pattern definitions ...] +-- +-- M._rules = { +-- {'rule', pattern}, +-- [...] +-- } +-- +-- M._tokenstyles = { +-- 'token' = 'style', +-- [...] +-- } +-- +-- M._foldsymbols = { +-- _patterns = {...}, +-- ['token'] = {['start'] = 1, ['end'] = -1}, +-- [...] +-- } +-- +-- return M +-- +-- While Scintillua will handle such legacy lexers just fine without any changes, it is +-- recommended that you migrate yours. The migration process is fairly straightforward: +-- +-- 1. Replace all instances of `l` with `lexer`, as it's better practice and results in less +-- confusion. +-- 2. Replace `local M = {_NAME = '?'}` with `local lex = lexer.new('?')`, where `?` is the +-- name of your legacy lexer. At the end of the lexer, change `return M` to `return lex`. +-- 3. Instead of defining rules towards the end of your lexer, define your rules as you define +-- your tokens and patterns using [`lex:add_rule()`](#lexer.add_rule). +-- 4. Similarly, any custom token names should have their styles immediately defined using +-- [`lex:add_style()`](#lexer.add_style). +-- 5. Optionally convert any table arguments passed to [`lexer.word_match()`]() to a +-- space-separated string of words. +-- 6. Replace any calls to `lexer.embed(M, child, ...)` and `lexer.embed(parent, M, ...)` with +-- [`lex:embed`](#lexer.embed)`(child, ...)` and `parent:embed(lex, ...)`, respectively. +-- 7. Define fold points with simple calls to [`lex:add_fold_point()`](#lexer.add_fold_point). No +-- need to mess with Lua patterns anymore. +-- 8. Any legacy lexer options such as `M._FOLDBYINDENTATION`, `M._LEXBYLINE`, `M._lexer`, +-- etc. should be added as table options to [`lexer.new()`](). +-- 9. Any external lexer rule fetching and/or modifications via `lexer._RULES` should be changed +-- to use [`lexer.get_rule()`]() and [`lexer.modify_rule()`](). +-- +-- As an example, consider the following sample legacy lexer: +-- +-- local l = require('lexer') +-- local token, word_match = l.token, l.word_match +-- local P, R, S = lpeg.P, lpeg.R, lpeg.S +-- +-- local M = {_NAME = 'legacy'} +-- +-- local ws = token(l.WHITESPACE, l.space^1) +-- local comment = token(l.COMMENT, '#' * l.nonnewline^0) +-- local string = token(l.STRING, l.delimited_range('"')) +-- local number = token(l.NUMBER, l.float + l.integer) +-- local keyword = token(l.KEYWORD, word_match{'foo', 'bar', 'baz'}) +-- local custom = token('custom', P('quux')) +-- local identifier = token(l.IDENTIFIER, l.word) +-- local operator = token(l.OPERATOR, S('+-*/%^=<>,.()[]{}')) +-- +-- M._rules = { +-- {'whitespace', ws}, +-- {'keyword', keyword}, +-- {'custom', custom}, +-- {'identifier', identifier}, +-- {'string', string}, +-- {'comment', comment}, +-- {'number', number}, +-- {'operator', operator} +-- } +-- +-- M._tokenstyles = { +-- 'custom' = l.STYLE_KEYWORD .. ',bold' +-- } +-- +-- M._foldsymbols = { +-- _patterns = {'[{}]'}, +-- [l.OPERATOR] = {['{'] = 1, ['}'] = -1} +-- } +-- +-- return M +-- +-- Following the migration steps would yield: +-- +-- local lexer = require('lexer') +-- local token, word_match = lexer.token, lexer.word_match +-- local P, S = lpeg.P, lpeg.S +-- +-- local lex = lexer.new('legacy') +-- +-- lex:add_rule('whitespace', token(lexer.WHITESPACE, lexer.space^1)) +-- lex:add_rule('keyword', token(lexer.KEYWORD, word_match('foo bar baz'))) +-- lex:add_rule('custom', token('custom', 'quux')) +-- lex:add_style('custom', lexer.styles.keyword .. {bold = true}) +-- lex:add_rule('identifier', token(lexer.IDENTIFIER, lexer.word)) +-- lex:add_rule('string', token(lexer.STRING, lexer.range('"'))) +-- lex:add_rule('comment', token(lexer.COMMENT, lexer.to_eol('#'))) +-- lex:add_rule('number', token(lexer.NUMBER, lexer.number)) +-- lex:add_rule('operator', token(lexer.OPERATOR, S('+-*/%^=<>,.()[]{}'))) +-- +-- lex:add_fold_point(lexer.OPERATOR, '{', '}') +-- +-- return lex +-- +-- ### Considerations +-- +-- #### Performance +-- +-- There might be some slight overhead when initializing a lexer, but loading a file from disk +-- into Scintilla is usually more expensive. On modern computer systems, I see no difference in +-- speed between Lua lexers and Scintilla's C++ ones. Optimize lexers for speed by re-arranging +-- `lexer.add_rule()` calls so that the most common rules match first. Do keep in mind that +-- order matters for similar rules. +-- +-- In some cases, folding may be far more expensive than lexing, particularly in lexers with a +-- lot of potential fold points. If your lexer is exhibiting signs of slowness, try disabling +-- folding in your text editor first. If that speeds things up, you can try reducing the number +-- of fold points you added, overriding `lexer.fold()` with your own implementation, or simply +-- eliminating folding support from your lexer. +-- +-- #### Limitations +-- +-- Embedded preprocessor languages like PHP cannot completely embed in their parent languages +-- in that the parent's tokens do not support start and end rules. This mostly goes unnoticed, +-- but code like +-- +-- <div id="<?php echo $id; ?>"> +-- +-- will not style correctly. +-- +-- #### Troubleshooting +-- +-- Errors in lexers can be tricky to debug. Lexers print Lua errors to `io.stderr` and `_G.print()` +-- statements to `io.stdout`. Running your editor from a terminal is the easiest way to see +-- errors as they occur. +-- +-- #### Risks +-- +-- Poorly written lexers have the ability to crash Scintilla (and thus its containing application), +-- so unsaved data might be lost. However, I have only observed these crashes in early lexer +-- development, when syntax errors or pattern errors are present. Once the lexer actually starts +-- styling text (either correctly or incorrectly, it does not matter), I have not observed +-- any crashes. +-- +-- #### Acknowledgements +-- +-- Thanks to Peter Odding for his [lexer post][] on the Lua mailing list that provided inspiration, +-- and thanks to Roberto Ierusalimschy for LPeg. +-- +-- [lexer post]: http://lua-users.org/lists/lua-l/2007-04/msg00116.html +-- @field DEFAULT (string) +-- The token name for default tokens. +-- @field WHITESPACE (string) +-- The token name for whitespace tokens. +-- @field COMMENT (string) +-- The token name for comment tokens. +-- @field STRING (string) +-- The token name for string tokens. +-- @field NUMBER (string) +-- The token name for number tokens. +-- @field KEYWORD (string) +-- The token name for keyword tokens. +-- @field IDENTIFIER (string) +-- The token name for identifier tokens. +-- @field OPERATOR (string) +-- The token name for operator tokens. +-- @field ERROR (string) +-- The token name for error tokens. +-- @field PREPROCESSOR (string) +-- The token name for preprocessor tokens. +-- @field CONSTANT (string) +-- The token name for constant tokens. +-- @field VARIABLE (string) +-- The token name for variable tokens. +-- @field FUNCTION (string) +-- The token name for function tokens. +-- @field CLASS (string) +-- The token name for class tokens. +-- @field TYPE (string) +-- The token name for type tokens. +-- @field LABEL (string) +-- The token name for label tokens. +-- @field REGEX (string) +-- The token name for regex tokens. +-- @field any (pattern) +-- A pattern that matches any single character. +-- @field ascii (pattern) +-- A pattern that matches any ASCII character (codes 0 to 127). +-- @field extend (pattern) +-- A pattern that matches any ASCII extended character (codes 0 to 255). +-- @field alpha (pattern) +-- A pattern that matches any alphabetic character ('A'-'Z', 'a'-'z'). +-- @field digit (pattern) +-- A pattern that matches any digit ('0'-'9'). +-- @field alnum (pattern) +-- A pattern that matches any alphanumeric character ('A'-'Z', 'a'-'z', '0'-'9'). +-- @field lower (pattern) +-- A pattern that matches any lower case character ('a'-'z'). +-- @field upper (pattern) +-- A pattern that matches any upper case character ('A'-'Z'). +-- @field xdigit (pattern) +-- A pattern that matches any hexadecimal digit ('0'-'9', 'A'-'F', 'a'-'f'). +-- @field cntrl (pattern) +-- A pattern that matches any control character (ASCII codes 0 to 31). +-- @field graph (pattern) +-- A pattern that matches any graphical character ('!' to '~'). +-- @field print (pattern) +-- A pattern that matches any printable character (' ' to '~'). +-- @field punct (pattern) +-- A pattern that matches any punctuation character ('!' to '/', ':' to '@', '[' to ''', +-- '{' to '~'). +-- @field space (pattern) +-- A pattern that matches any whitespace character ('\t', '\v', '\f', '\n', '\r', space). +-- @field newline (pattern) +-- A pattern that matches a sequence of end of line characters. +-- @field nonnewline (pattern) +-- A pattern that matches any single, non-newline character. +-- @field dec_num (pattern) +-- A pattern that matches a decimal number. +-- @field hex_num (pattern) +-- A pattern that matches a hexadecimal number. +-- @field oct_num (pattern) +-- A pattern that matches an octal number. +-- @field integer (pattern) +-- A pattern that matches either a decimal, hexadecimal, or octal number. +-- @field float (pattern) +-- A pattern that matches a floating point number. +-- @field number (pattern) +-- A pattern that matches a typical number, either a floating point, decimal, hexadecimal, +-- or octal number. +-- @field word (pattern) +-- A pattern that matches a typical word. Words begin with a letter or underscore and consist +-- of alphanumeric and underscore characters. +-- @field FOLD_BASE (number) +-- The initial (root) fold level. +-- @field FOLD_BLANK (number) +-- Flag indicating that the line is blank. +-- @field FOLD_HEADER (number) +-- Flag indicating the line is fold point. +-- @field fold_level (table, Read-only) +-- Table of fold level bit-masks for line numbers starting from 1. +-- Fold level masks are composed of an integer level combined with any of the following bits: +-- +-- * `lexer.FOLD_BASE` +-- The initial fold level. +-- * `lexer.FOLD_BLANK` +-- The line is blank. +-- * `lexer.FOLD_HEADER` +-- The line is a header, or fold point. +-- @field indent_amount (table, Read-only) +-- Table of indentation amounts in character columns, for line numbers starting from 1. +-- @field line_state (table) +-- Table of integer line states for line numbers starting from 1. +-- Line states can be used by lexers for keeping track of persistent states. +-- @field property (table) +-- Map of key-value string pairs. +-- @field property_expanded (table, Read-only) +-- Map of key-value string pairs with `$()` and `%()` variable replacement performed in values. +-- @field property_int (table, Read-only) +-- Map of key-value pairs with values interpreted as numbers, or `0` if not found. +-- @field style_at (table, Read-only) +-- Table of style names at positions in the buffer starting from 1. +-- @field folding (boolean) +-- Whether or not folding is enabled for the lexers that support it. +-- This option is disabled by default. +-- This is an alias for `lexer.property['fold'] = '1|0'`. +-- @field fold_on_zero_sum_lines (boolean) +-- Whether or not to mark as a fold point lines that contain both an ending and starting fold +-- point. For example, `} else {` would be marked as a fold point. +-- This option is disabled by default. This is an alias for +-- `lexer.property['fold.on.zero.sum.lines'] = '1|0'`. +-- @field fold_compact (boolean) +-- Whether or not blank lines after an ending fold point are included in that +-- fold. +-- This option is disabled by default. +-- This is an alias for `lexer.property['fold.compact'] = '1|0'`. +-- @field fold_by_indentation (boolean) +-- Whether or not to fold based on indentation level if a lexer does not have +-- a folder. +-- Some lexers automatically enable this option. It is disabled by default. +-- This is an alias for `lexer.property['fold.by.indentation'] = '1|0'`. +-- @field fold_line_groups (boolean) +-- Whether or not to fold multiple, consecutive line groups (such as line comments and import +-- statements) and only show the top line. +-- This option is disabled by default. +-- This is an alias for `lexer.property['fold.line.groups'] = '1|0'`. +module('lexer')]=] + +local print = function(...) + io.stderr:write( + string.format( + string.rep("%s", select("#",...), " ") + , ... ) + ,"\n" + ) +end + +lpeg = require('lpeg') +local lpeg_P, lpeg_R, lpeg_S, lpeg_V = lpeg.P, lpeg.R, lpeg.S, lpeg.V +local lpeg_Ct, lpeg_Cc, lpeg_Cp = lpeg.Ct, lpeg.Cc, lpeg.Cp +local lpeg_Cmt, lpeg_C = lpeg.Cmt, lpeg.C +local lpeg_match = lpeg.match + +--- +-- Map of color name strings to color values in `0xBBGGRR` or `"#RRGGBB"` format. +-- Note: for applications running within a terminal emulator, only 16 color values are recognized, +-- regardless of how many colors a user's terminal actually supports. (A terminal emulator's +-- settings determines how to actually display these recognized color values, which may end up +-- being mapped to a completely different color set.) In order to use the light variant of a +-- color, some terminals require a style's `bold` attribute must be set along with that normal +-- color. Recognized color values are black (0x000000), red (0x000080), green (0x008000), yellow +-- (0x008080), blue (0x800000), magenta (0x800080), cyan (0x808000), white (0xC0C0C0), light black +-- (0x404040), light red (0x0000FF), light green (0x00FF00), light yellow (0x00FFFF), light blue +-- (0xFF0000), light magenta (0xFF00FF), light cyan (0xFFFF00), and light white (0xFFFFFF). +-- @name colors +-- @class table +M.colors = setmetatable({}, { + __index = function(_, name) + local color = M.property['color.' .. name] + return tonumber(color) or color + end, __newindex = function(_, name, color) M.property['color.' .. name] = color end +}) + +-- A style object that distills into a property string that can be read by the LPeg lexer. +local style_obj = {} +style_obj.__index = style_obj + +-- Create a style object from a style name, property table, or legacy style string. +function style_obj.new(name_or_props) + local prop_string = tostring(name_or_props) + if type(name_or_props) == 'string' and name_or_props:find('^[%w_]+$') then + prop_string = string.format('$(style.%s)', name_or_props) + elseif type(name_or_props) == 'table' then + local settings = {} + for k, v in pairs(name_or_props) do + settings[#settings + 1] = type(v) ~= 'boolean' and string.format('%s:%s', k, v) or + string.format('%s%s', v and '' or 'not', k) + end + prop_string = table.concat(settings, ',') + end + return setmetatable({prop_string = prop_string}, style_obj) +end + +-- Returns a new style based on this one with the properties defined in the given table or +-- legacy style string. +function style_obj.__concat(self, props) + if type(props) == 'table' then props = tostring(style_obj.new(props)) end + return setmetatable({prop_string = string.format('%s,%s', self.prop_string, props)}, style_obj) +end + +-- Returns this style object as property string for use with the LPeg lexer. +function style_obj.__tostring(self) return self.prop_string end + +--- +-- Map of style names to style definition tables. +-- +-- Style names consist of the following default names as well as the token names defined by lexers. +-- +-- * `default`: The default style all others are based on. +-- * `line_number`: The line number margin style. +-- * `control_char`: The style of control character blocks. +-- * `indent_guide`: The style of indentation guides. +-- * `call_tip`: The style of call tip text. Only the `font`, `size`, `fore`, and `back` style +-- definition fields are supported. +-- * `fold_display_text`: The style of text displayed next to folded lines. +-- * `class`, `comment`, `constant`, `embedded`, `error`, `function`, `identifier`, `keyword`, +-- `label`, `number`, `operator`, `preprocessor`, `regex`, `string`, `type`, `variable`, +-- `whitespace`: Some token names used by lexers. Some lexers may define more token names, +-- so this list is not exhaustive. +-- * *`lang`*`_whitespace`: A special style for whitespace tokens in lexer name *lang*. It +-- inherits from `whitespace`, and is used in place of it for all lexers. +-- +-- Style definition tables may contain the following fields: +-- +-- * `font`: String font name. +-- * `size`: Integer font size. +-- * `bold`: Whether or not the font face is bold. The default value is `false`. +-- * `weight`: Integer weight or boldness of a font, between 1 and 999. +-- * `italics`: Whether or not the font face is italic. The default value is `false`. +-- * `underlined`: Whether or not the font face is underlined. The default value is `false`. +-- * `fore`: Font face foreground color in `0xBBGGRR` or `"#RRGGBB"` format. +-- * `back`: Font face background color in `0xBBGGRR` or `"#RRGGBB"` format. +-- * `eolfilled`: Whether or not the background color extends to the end of the line. The +-- default value is `false`. +-- * `case`: Font case: `'u'` for upper, `'l'` for lower, and `'m'` for normal, mixed case. The +-- default value is `'m'`. +-- * `visible`: Whether or not the text is visible. The default value is `true`. +-- * `changeable`: Whether the text is changeable instead of read-only. The default value is +-- `true`. +-- @class table +-- @name styles +M.styles = setmetatable({}, { + __index = function(_, name) return style_obj.new(name) end, __newindex = function(_, name, style) + if getmetatable(style) ~= style_obj then style = style_obj.new(style) end + M.property['style.' .. name] = tostring(style) + end +}) + +-- Default styles. +local default = { + 'nothing', 'whitespace', 'comment', 'string', 'number', 'keyword', 'identifier', 'operator', + 'error', 'preprocessor', 'constant', 'variable', 'function', 'class', 'type', 'label', 'regex', + 'embedded' +} +for _, name in ipairs(default) do + M[name:upper()] = name + M['STYLE_' .. name:upper()] = style_obj.new(name) -- backward compatibility +end +-- Predefined styles. +local predefined = { + 'default', 'line_number', 'brace_light', 'brace_bad', 'control_char', 'indent_guide', 'call_tip', + 'fold_display_text' +} +for _, name in ipairs(predefined) do + M[name:upper()] = name + M['STYLE_' .. name:upper()] = style_obj.new(name) -- backward compatibility +end + +--- +-- Adds pattern *rule* identified by string *id* to the ordered list of rules for lexer *lexer*. +-- @param lexer The lexer to add the given rule to. +-- @param id The id associated with this rule. It does not have to be the same as the name +-- passed to `token()`. +-- @param rule The LPeg pattern of the rule. +-- @see modify_rule +-- @name add_rule +function M.add_rule(lexer, id, rule) + if lexer._lexer then lexer = lexer._lexer end -- proxy; get true parent + if not lexer._RULES then + lexer._RULES = {} + -- Contains an ordered list (by numerical index) of rule names. This is used in conjunction + -- with lexer._RULES for building _TOKENRULE. + lexer._RULEORDER = {} + end + lexer._RULES[id] = rule + lexer._RULEORDER[#lexer._RULEORDER + 1] = id + lexer:build_grammar() +end + +--- +-- Replaces in lexer *lexer* the existing rule identified by string *id* with pattern *rule*. +-- @param lexer The lexer to modify. +-- @param id The id associated with this rule. +-- @param rule The LPeg pattern of the rule. +-- @name modify_rule +function M.modify_rule(lexer, id, rule) + if lexer._lexer then lexer = lexer._lexer end -- proxy; get true parent + lexer._RULES[id] = rule + lexer:build_grammar() +end + +--- +-- Returns the rule identified by string *id*. +-- @param lexer The lexer to fetch a rule from. +-- @param id The id of the rule to fetch. +-- @return pattern +-- @name get_rule +function M.get_rule(lexer, id) + if lexer._lexer then lexer = lexer._lexer end -- proxy; get true parent + return lexer._RULES[id] +end + +--- +-- Associates string *token_name* in lexer *lexer* with style table *style*. +-- *style* may have the following fields: +-- +-- * `font`: String font name. +-- * `size`: Integer font size. +-- * `bold`: Whether or not the font face is bold. The default value is `false`. +-- * `weight`: Integer weight or boldness of a font, between 1 and 999. +-- * `italics`: Whether or not the font face is italic. The default value is `false`. +-- * `underlined`: Whether or not the font face is underlined. The default value is `false`. +-- * `fore`: Font face foreground color in `0xBBGGRR` or `"#RRGGBB"` format. +-- * `back`: Font face background color in `0xBBGGRR` or `"#RRGGBB"` format. +-- * `eolfilled`: Whether or not the background color extends to the end of the line. The +-- default value is `false`. +-- * `case`: Font case, `'u'` for upper, `'l'` for lower, and `'m'` for normal, mixed case. The +-- default value is `'m'`. +-- * `visible`: Whether or not the text is visible. The default value is `true`. +-- * `changeable`: Whether the text is changeable instead of read-only. The default value is +-- `true`. +-- +-- Field values may also contain "$(property.name)" expansions for properties defined in Scintilla, +-- theme files, etc. +-- @param lexer The lexer to add a style to. +-- @param token_name The name of the token to associated with the style. +-- @param style A style string for Scintilla. +-- @usage lex:add_style('longstring', lexer.styles.string) +-- @usage lex:add_style('deprecated_func', lexer.styles['function'] .. {italics = true} +-- @usage lex:add_style('visible_ws', lexer.styles.whitespace .. {back = lexer.colors.grey} +-- @name add_style +function M.add_style(lexer, token_name, style) + local num_styles = lexer._numstyles + if num_styles == 33 then num_styles = num_styles + 8 end -- skip predefined + if num_styles >= 256 then print('Too many styles defined (256 MAX)') end + lexer._TOKENSTYLES[token_name], lexer._numstyles = num_styles, num_styles + 1 + if type(style) == 'table' and not getmetatable(style) then style = style_obj.new(style) end + lexer._EXTRASTYLES[token_name] = tostring(style) + -- If the lexer is a proxy or a child that embedded itself, copy this style to the parent lexer. + if lexer._lexer then lexer._lexer:add_style(token_name, style) end +end + +--- +-- Adds to lexer *lexer* a fold point whose beginning and end tokens are string *token_name* +-- tokens with string content *start_symbol* and *end_symbol*, respectively. +-- In the event that *start_symbol* may or may not be a fold point depending on context, and that +-- additional processing is required, *end_symbol* may be a function that ultimately returns +-- `1` (indicating a beginning fold point), `-1` (indicating an ending fold point), or `0` +-- (indicating no fold point). That function is passed the following arguments: +-- +-- * `text`: The text being processed for fold points. +-- * `pos`: The position in *text* of the beginning of the line currently being processed. +-- * `line`: The text of the line currently being processed. +-- * `s`: The position of *start_symbol* in *line*. +-- * `symbol`: *start_symbol* itself. +-- @param lexer The lexer to add a fold point to. +-- @param token_name The token name of text that indicates a fold point. +-- @param start_symbol The text that indicates the beginning of a fold point. +-- @param end_symbol Either the text that indicates the end of a fold point, or a function that +-- returns whether or not *start_symbol* is a beginning fold point (1), an ending fold point +-- (-1), or not a fold point at all (0). +-- @usage lex:add_fold_point(lexer.OPERATOR, '{', '}') +-- @usage lex:add_fold_point(lexer.KEYWORD, 'if', 'end') +-- @usage lex:add_fold_point(lexer.COMMENT, lexer.fold_consecutive_lines('#')) +-- @usage lex:add_fold_point('custom', function(text, pos, line, s, symbol) ... end) +-- @name add_fold_point +function M.add_fold_point(lexer, token_name, start_symbol, end_symbol) + if not lexer._FOLDPOINTS then lexer._FOLDPOINTS = {_SYMBOLS = {}} end + local symbols = lexer._FOLDPOINTS._SYMBOLS + if not lexer._FOLDPOINTS[token_name] then lexer._FOLDPOINTS[token_name] = {} end + if lexer._CASEINSENSITIVEFOLDPOINTS then + start_symbol = start_symbol:lower() + if type(end_symbol) == 'string' then end_symbol = end_symbol:lower() end + end + if type(end_symbol) == 'string' then + if not symbols[end_symbol] then symbols[#symbols + 1], symbols[end_symbol] = end_symbol, true end + lexer._FOLDPOINTS[token_name][start_symbol] = 1 + lexer._FOLDPOINTS[token_name][end_symbol] = -1 + else + lexer._FOLDPOINTS[token_name][start_symbol] = end_symbol -- function or int + end + if not symbols[start_symbol] then + symbols[#symbols + 1], symbols[start_symbol] = start_symbol, true + end + -- If the lexer is a proxy or a child that embedded itself, copy this fold point to the + -- parent lexer. + if lexer._lexer then lexer._lexer:add_fold_point(token_name, start_symbol, end_symbol) end +end + +-- (Re)constructs `lexer._TOKENRULE`. +local function join_tokens(lexer) + local patterns, order = lexer._RULES, lexer._RULEORDER + local token_rule = patterns[order[1]] + for i = 2, #order do token_rule = token_rule + patterns[order[i]] end + lexer._TOKENRULE = token_rule + M.token(M.DEFAULT, M.any) + return lexer._TOKENRULE +end + +-- Metatable for Scintillua grammars. +-- These grammars are just tables ultimately passed to `lpeg.P()`. +local grammar_mt = { + __index = { + -- Adds lexer *lexer* and any of its embedded lexers to this grammar. + -- @param lexer The lexer to add. + add_lexer = function(self, lexer) + local lexer_name = lexer._PARENTNAME or lexer._NAME + local token_rule = lexer:join_tokens() + for _, child in ipairs(lexer._CHILDREN) do + if child._CHILDREN then self:add_lexer(child) end + local rules = child._EMBEDDEDRULES[lexer_name] + local rules_token_rule = self['__' .. child._NAME] or rules.token_rule + self[child._NAME] = (-rules.end_rule * rules_token_rule)^0 * rules.end_rule^-1 * + lpeg_V(lexer_name) + local embedded_child = '_' .. child._NAME + self[embedded_child] = rules.start_rule * (-rules.end_rule * rules_token_rule)^0 * + rules.end_rule^-1 + token_rule = lpeg_V(embedded_child) + token_rule + end + self['__' .. lexer_name] = token_rule -- can contain embedded lexer rules + self[lexer_name] = token_rule^0 + end + } +} + +-- (Re)constructs `lexer._GRAMMAR`. +-- @param initial_rule The name of the rule to start lexing with. The default value is +-- `lexer._NAME`. Multilang lexers use this to start with a child rule if necessary. +local function build_grammar(lexer, initial_rule) + if not lexer._RULES then return end + if lexer._CHILDREN then + if not initial_rule then initial_rule = lexer._NAME end + local grammar = setmetatable({initial_rule}, grammar_mt) + grammar:add_lexer(lexer) + lexer._INITIALRULE = initial_rule + lexer._GRAMMAR = lpeg_Ct(lpeg_P(grammar)) + else + lexer._GRAMMAR = lpeg_Ct(lexer:join_tokens()^0) + end +end + +--- +-- Embeds child lexer *child* in parent lexer *lexer* using patterns *start_rule* and *end_rule*, +-- which signal the beginning and end of the embedded lexer, respectively. +-- @param lexer The parent lexer. +-- @param child The child lexer. +-- @param start_rule The pattern that signals the beginning of the embedded lexer. +-- @param end_rule The pattern that signals the end of the embedded lexer. +-- @usage html:embed(css, css_start_rule, css_end_rule) +-- @usage html:embed(lex, php_start_rule, php_end_rule) -- from php lexer +-- @name embed +function M.embed(lexer, child, start_rule, end_rule) + if lexer._lexer then lexer = lexer._lexer end -- proxy; get true parent + -- Add child rules. + if not child._EMBEDDEDRULES then child._EMBEDDEDRULES = {} end + if not child._RULES then error('Cannot embed lexer with no rules') end + child._EMBEDDEDRULES[lexer._NAME] = { + start_rule = start_rule, token_rule = child:join_tokens(), end_rule = end_rule + } + if not lexer._CHILDREN then lexer._CHILDREN = {} end + local children = lexer._CHILDREN + children[#children + 1] = child + -- Add child styles. + for token, style in pairs(child._EXTRASTYLES) do lexer:add_style(token, style) end + -- Add child fold symbols. + if child._FOLDPOINTS then + for token_name, symbols in pairs(child._FOLDPOINTS) do + if token_name ~= '_SYMBOLS' then + for symbol, v in pairs(symbols) do lexer:add_fold_point(token_name, symbol, v) end + end + end + end + lexer:build_grammar() + child._lexer = lexer -- use parent's tokens if child is embedding itself +end + +--- +-- Lexes a chunk of text *text* (that has an initial style number of *init_style*) using lexer +-- *lexer*, returning a table of token names and positions. +-- @param lexer The lexer to lex text with. +-- @param text The text in the buffer to lex. +-- @param init_style The current style. Multiple-language lexers use this to determine which +-- language to start lexing in. +-- @return table of token names and positions. +-- @name lex +function M.lex(lexer, text, init_style) + if not lexer._GRAMMAR then return {M.DEFAULT, #text + 1} end + if not lexer._LEXBYLINE then + -- For multilang lexers, build a new grammar whose initial_rule is the current language. + if lexer._CHILDREN then + for style, style_num in pairs(lexer._TOKENSTYLES) do + if style_num == init_style then + local lexer_name = style:match('^(.+)_whitespace') or lexer._PARENTNAME or lexer._NAME + if lexer._INITIALRULE ~= lexer_name then lexer:build_grammar(lexer_name) end + break + end + end + end + return lpeg_match(lexer._GRAMMAR, text) + else + local function append(tokens, line_tokens, offset) + for i = 1, #line_tokens, 2 do + tokens[#tokens + 1] = line_tokens[i] + tokens[#tokens + 1] = line_tokens[i + 1] + offset + end + end + local tokens = {} + local offset = 0 + local grammar = lexer._GRAMMAR + for line in text:gmatch('[^\r\n]*\r?\n?') do + local line_tokens = lpeg_match(grammar, line) + if line_tokens then append(tokens, line_tokens, offset) end + offset = offset + #line + -- Use the default style to the end of the line if none was specified. + if tokens[#tokens] ~= offset then + tokens[#tokens + 1], tokens[#tokens + 2] = 'default', offset + 1 + end + end + return tokens + end +end + +--- +-- Determines fold points in a chunk of text *text* using lexer *lexer*, returning a table of +-- fold levels associated with line numbers. +-- *text* starts at position *start_pos* on line number *start_line* with a beginning fold +-- level of *start_level* in the buffer. +-- @param lexer The lexer to fold text with. +-- @param text The text in the buffer to fold. +-- @param start_pos The position in the buffer *text* starts at, counting from 1. +-- @param start_line The line number *text* starts on, counting from 1. +-- @param start_level The fold level *text* starts on. +-- @return table of fold levels associated with line numbers. +-- @name fold +function M.fold(lexer, text, start_pos, start_line, start_level) + local folds = {} + if text == '' then return folds end + local fold = M.property_int['fold'] > 0 + local FOLD_BASE = M.FOLD_BASE + local FOLD_HEADER, FOLD_BLANK = M.FOLD_HEADER, M.FOLD_BLANK + if fold and lexer._FOLDPOINTS then + local lines = {} + for p, l in (text .. '\n'):gmatch('()(.-)\r?\n') do lines[#lines + 1] = {p, l} end + local fold_zero_sum_lines = M.property_int['fold.on.zero.sum.lines'] > 0 + local fold_compact = M.property_int['fold.compact'] > 0 + local fold_points = lexer._FOLDPOINTS + local fold_point_symbols = fold_points._SYMBOLS + local style_at, fold_level = M.style_at, M.fold_level + local line_num, prev_level = start_line, start_level + local current_level = prev_level + for _, captures in ipairs(lines) do + local pos, line = captures[1], captures[2] + if line ~= '' then + if lexer._CASEINSENSITIVEFOLDPOINTS then line = line:lower() end + local ranges = {} + local function is_valid_range(s, e) + if not s or not e then return false end + for i = 1, #ranges - 1, 2 do + local range_s, range_e = ranges[i], ranges[i + 1] + if s >= range_s and s <= range_e or e >= range_s and e <= range_e then + return false + end + end + ranges[#ranges + 1] = s + ranges[#ranges + 1] = e + return true + end + local level_decreased = false + for _, symbol in ipairs(fold_point_symbols) do + local word = not symbol:find('[^%w_]') + local s, e = line:find(symbol, 1, true) + while is_valid_range(s, e) do + -- if not word or line:find('^%f[%w_]' .. symbol .. '%f[^%w_]', s) then + local word_before = s > 1 and line:find('^[%w_]', s - 1) + local word_after = line:find('^[%w_]', e + 1) + if not word or not (word_before or word_after) then + local symbols = fold_points[style_at[start_pos + pos - 1 + s - 1]] + local level = symbols and symbols[symbol] + if type(level) == 'function' then + level = level(text, pos, line, s, symbol) + end + if type(level) == 'number' then + current_level = current_level + level + if level < 0 and current_level < prev_level then + -- Potential zero-sum line. If the level were to go back up on the same line, + -- the line may be marked as a fold header. + level_decreased = true + end + end + end + s, e = line:find(symbol, s + 1, true) + end + end + folds[line_num] = prev_level + if current_level > prev_level then + folds[line_num] = prev_level + FOLD_HEADER + elseif level_decreased and current_level == prev_level and fold_zero_sum_lines then + if line_num > start_line then + folds[line_num] = prev_level - 1 + FOLD_HEADER + else + -- Typing within a zero-sum line. + local level = fold_level[line_num] - 1 + if level > FOLD_HEADER then level = level - FOLD_HEADER end + if level > FOLD_BLANK then level = level - FOLD_BLANK end + folds[line_num] = level + FOLD_HEADER + current_level = current_level + 1 + end + end + if current_level < FOLD_BASE then current_level = FOLD_BASE end + prev_level = current_level + else + folds[line_num] = prev_level + (fold_compact and FOLD_BLANK or 0) + end + line_num = line_num + 1 + end + elseif fold and (lexer._FOLDBYINDENTATION or M.property_int['fold.by.indentation'] > 0) then + -- Indentation based folding. + -- Calculate indentation per line. + local indentation = {} + for indent, line in (text .. '\n'):gmatch('([\t ]*)([^\r\n]*)\r?\n') do + indentation[#indentation + 1] = line ~= '' and #indent + end + -- Find the first non-blank line before start_line. If the current line is indented, make + -- that previous line a header and update the levels of any blank lines inbetween. If the + -- current line is blank, match the level of the previous non-blank line. + local current_level = start_level + for i = start_line, 1, -1 do + local level = M.fold_level[i] + if level >= FOLD_HEADER then level = level - FOLD_HEADER end + if level < FOLD_BLANK then + local indent = M.indent_amount[i] + if indentation[1] and indentation[1] > indent then + folds[i] = FOLD_BASE + indent + FOLD_HEADER + for j = i + 1, start_line - 1 do folds[j] = start_level + FOLD_BLANK end + elseif not indentation[1] then + current_level = FOLD_BASE + indent + end + break + end + end + -- Iterate over lines, setting fold numbers and fold flags. + for i = 1, #indentation do + if indentation[i] then + current_level = FOLD_BASE + indentation[i] + folds[start_line + i - 1] = current_level + for j = i + 1, #indentation do + if indentation[j] then + if FOLD_BASE + indentation[j] > current_level then + folds[start_line + i - 1] = current_level + FOLD_HEADER + current_level = FOLD_BASE + indentation[j] -- for any blanks below + end + break + end + end + else + folds[start_line + i - 1] = current_level + FOLD_BLANK + end + end + else + -- No folding, reset fold levels if necessary. + local current_line = start_line + for _ in text:gmatch('\r?\n') do + folds[current_line] = start_level + current_line = current_line + 1 + end + end + return folds +end + +--- +-- Creates a returns a new lexer with the given name. +-- @param name The lexer's name. +-- @param opts Table of lexer options. Options currently supported: +-- * `lex_by_line`: Whether or not the lexer only processes whole lines of text (instead of +-- arbitrary chunks of text) at a time. Line lexers cannot look ahead to subsequent lines. +-- The default value is `false`. +-- * `fold_by_indentation`: Whether or not the lexer does not define any fold points and that +-- fold points should be calculated based on changes in line indentation. The default value +-- is `false`. +-- * `case_insensitive_fold_points`: Whether or not fold points added via +-- `lexer.add_fold_point()` ignore case. The default value is `false`. +-- * `inherit`: Lexer to inherit from. The default value is `nil`. +-- @usage lexer.new('rhtml', {inherit = lexer.load('html')}) +-- @name new +function M.new(name, opts) + local lexer = { + _NAME = assert(name, 'lexer name expected'), _LEXBYLINE = opts and opts['lex_by_line'], + _FOLDBYINDENTATION = opts and opts['fold_by_indentation'], + _CASEINSENSITIVEFOLDPOINTS = opts and opts['case_insensitive_fold_points'], + _lexer = opts and opts['inherit'] + } + + -- Create the initial maps for token names to style numbers and styles. + local token_styles = {} + for i = 1, #default do token_styles[default[i]] = i end + for i = 1, #predefined do token_styles[predefined[i]] = i + 32 end + lexer._TOKENSTYLES, lexer._numstyles = token_styles, #default + 1 + lexer._EXTRASTYLES = {} + + return setmetatable(lexer, { + __index = { + add_rule = M.add_rule, modify_rule = M.modify_rule, get_rule = M.get_rule, + add_style = M.add_style, add_fold_point = M.add_fold_point, join_tokens = join_tokens, + build_grammar = build_grammar, embed = M.embed, lex = M.lex, fold = M.fold + } + }) +end + +-- Legacy support for older lexers. +-- Processes the `lex._rules`, `lex._tokenstyles`, and `lex._foldsymbols` tables. Since legacy +-- lexers may be processed up to twice, ensure their default styles and rules are not processed +-- more than once. +local function process_legacy_lexer(lexer) + local function warn(msg) --[[io.stderr:write(msg, "\n")]]end + if not lexer._LEGACY then + lexer._LEGACY = true + warn("lexers as tables are deprecated; use 'lexer.new()'") + local token_styles = {} + for i = 1, #default do token_styles[default[i]] = i end + for i = 1, #predefined do token_styles[predefined[i]] = i + 32 end + lexer._TOKENSTYLES, lexer._numstyles = token_styles, #default + 1 + lexer._EXTRASTYLES = {} + setmetatable(lexer, getmetatable(M.new(''))) + if lexer._rules then + warn("lexer '_rules' table is deprecated; use 'add_rule()'") + for _, rule in ipairs(lexer._rules) do lexer:add_rule(rule[1], rule[2]) end + end + end + if lexer._tokenstyles then + warn("lexer '_tokenstyles' table is deprecated; use 'add_style()'") + for token, style in pairs(lexer._tokenstyles) do + -- If this legacy lexer is being processed a second time, only add styles added since + -- the first processing. + if not lexer._TOKENSTYLES[token] then lexer:add_style(token, style) end + end + end + if lexer._foldsymbols then + warn("lexer '_foldsymbols' table is deprecated; use 'add_fold_point()'") + for token_name, symbols in pairs(lexer._foldsymbols) do + if type(symbols) == 'table' and token_name ~= '_patterns' then + for symbol, v in pairs(symbols) do lexer:add_fold_point(token_name, symbol, v) end + end + end + if lexer._foldsymbols._case_insensitive then lexer._CASEINSENSITIVEFOLDPOINTS = true end + elseif lexer._fold then + lexer.fold = function(self, ...) return lexer._fold(...) end + end +end + +local lexers = {} -- cache of loaded lexers +--- +-- Initializes or loads and returns the lexer of string name *name*. +-- Scintilla calls this function in order to load a lexer. Parent lexers also call this function +-- in order to load child lexers and vice-versa. The user calls this function in order to load +-- a lexer when using Scintillua as a Lua library. +-- @param name The name of the lexing language. +-- @param alt_name The alternate name of the lexing language. This is useful for embedding the +-- same child lexer with multiple sets of start and end tokens. +-- @param cache Flag indicating whether or not to load lexers from the cache. This should only +-- be `true` when initially loading a lexer (e.g. not from within another lexer for embedding +-- purposes). The default value is `false`. +-- @return lexer object +-- @name load +function M.load(name, alt_name, cache) + if cache and lexers[alt_name or name] then return lexers[alt_name or name] end + + -- When using Scintillua as a stand-alone module, the `property`, `property_int`, and + -- `property_expanded` tables do not exist (they are not useful). Create them in order prevent + -- errors from occurring. + if not M.property then + M.property = setmetatable( + {} + ,{ + __index = function() return '' end, + __newindex = function(t, k, v) rawset(t, k, tostring(v)) end + } + ) + M.property_int = setmetatable({}, { + __index = function(t, k) return tonumber(M.property[k]) or 0 end, + __newindex = function() error('read-only property') end + }) + M.property_expanded = setmetatable({}, { + __index = function(t, key) + return M.property[key]:gsub('[$%%](%b())', function(key) return t[key:sub(2, -2)] end) + end, __newindex = function() error('read-only property') end + }) + end + + -- Load the language lexer with its rules, styles, etc. + -- However, replace the default `WHITESPACE` style name with a unique whitespace style name + -- (and then automatically add it afterwards), since embedded lexing relies on these unique + -- whitespace style names. Note that loading embedded lexers changes `WHITESPACE` again, + -- so when adding it later, do not reference the potentially incorrect value. + M.WHITESPACE = (alt_name or name) .. '_whitespace' + local lexer = require("lexers/" .. name) + assert(lexer, string.format("'%s.lua' did not return a lexer", name)) + if alt_name then lexer._NAME = alt_name end + if not getmetatable(lexer) or lexer._LEGACY then + -- A legacy lexer may need to be processed a second time in order to pick up any `_tokenstyles` + -- or `_foldsymbols` added after `lexer.embed_lexer()`. + process_legacy_lexer(lexer) + if lexer._lexer and lexer._lexer._LEGACY then + process_legacy_lexer(lexer._lexer) -- mainly for `_foldsymbols` edits + end + end + lexer:add_style((alt_name or name) .. '_whitespace', M.styles.whitespace) + + -- If the lexer is a proxy or a child that embedded itself, set the parent to be the main + -- lexer. Keep a reference to the old parent name since embedded child rules reference and + -- use that name. + if lexer._lexer then + lexer = lexer._lexer + lexer._PARENTNAME, lexer._NAME = lexer._NAME, alt_name or name + end + + if cache then lexers[alt_name or name] = lexer end + return lexer +end + +-- The following are utility functions lexers will have access to. + +-- Common patterns. +M.any = lpeg_P(1) +M.alpha = lpeg_R('AZ', 'az') +M.digit = lpeg_R('09') +M.alnum = lpeg_R('AZ', 'az', '09') +M.lower = lpeg_R('az') +M.upper = lpeg_R('AZ') +M.xdigit = lpeg_R('09', 'AF', 'af') +M.graph = lpeg_R('!~') +M.punct = lpeg_R('!/', ':@', '[\'', '{~') +M.space = lpeg_S('\t\v\f\n\r ') + +M.newline = lpeg_P('\r')^-1 * '\n' +M.nonnewline = 1 - M.newline + +M.dec_num = M.digit^1 +M.hex_num = '0' * lpeg_S('xX') * M.xdigit^1 +M.oct_num = '0' * lpeg_R('07')^1 +M.integer = lpeg_S('+-')^-1 * (M.hex_num + M.oct_num + M.dec_num) +M.float = lpeg_S('+-')^-1 * + ((M.digit^0 * '.' * M.digit^1 + M.digit^1 * '.' * M.digit^0 * -lpeg_P('.')) * + (lpeg_S('eE') * lpeg_S('+-')^-1 * M.digit^1)^-1 + + (M.digit^1 * lpeg_S('eE') * lpeg_S('+-')^-1 * M.digit^1)) +M.number = M.float + M.integer + +M.word = (M.alpha + '_') * (M.alnum + '_')^0 + +-- Deprecated. +M.nonnewline_esc = 1 - (M.newline + '\\') + '\\' * M.any +M.ascii = lpeg_R('\000\127') +M.extend = lpeg_R('\000\255') +M.cntrl = lpeg_R('\000\031') +M.print = lpeg_R(' ~') + +--- +-- Creates and returns a token pattern with token name *name* and pattern *patt*. +-- If *name* is not a predefined token name, its style must be defined via `lexer.add_style()`. +-- @param name The name of token. If this name is not a predefined token name, then a style +-- needs to be assiciated with it via `lexer.add_style()`. +-- @param patt The LPeg pattern associated with the token. +-- @return pattern +-- @usage local ws = token(lexer.WHITESPACE, lexer.space^1) +-- @usage local annotation = token('annotation', '@' * lexer.word) +-- @name token +function M.token(name, patt) + return lpeg_Cc(name) * patt * lpeg_Cp() +end + +--- +-- Creates and returns a pattern that matches from string or pattern *prefix* until the end of +-- the line. +-- *escape* indicates whether the end of the line can be escaped with a '\' character. +-- @param prefix String or pattern prefix to start matching at. +-- @param escape Optional flag indicating whether or not newlines can be escaped by a '\' +-- character. The default value is `false`. +-- @return pattern +-- @usage local line_comment = lexer.to_eol('//') +-- @usage local line_comment = lexer.to_eol(S('#;')) +-- @name to_eol +function M.to_eol(prefix, escape) + return prefix * (not escape and M.nonnewline or M.nonnewline_esc)^0 +end + +--- +-- Creates and returns a pattern that matches a range of text bounded by strings or patterns *s* +-- and *e*. +-- This is a convenience function for matching more complicated ranges like strings with escape +-- characters, balanced parentheses, and block comments (nested or not). *e* is optional and +-- defaults to *s*. *single_line* indicates whether or not the range must be on a single line; +-- *escapes* indicates whether or not to allow '\' as an escape character; and *balanced* +-- indicates whether or not to handle balanced ranges like parentheses, and requires *s* and *e* +-- to be different. +-- @param s String or pattern start of a range. +-- @param e Optional string or pattern end of a range. The default value is *s*. +-- @param single_line Optional flag indicating whether or not the range must be on a single +-- line. The default value is `false`. +-- @param escapes Optional flag indicating whether or not the range end may be escaped by a '\' +-- character. The default value is `false` unless *s* and *e* are identical, single-character +-- strings. In that case, the default value is `true`. +-- @param balanced Optional flag indicating whether or not to match a balanced range, like the +-- "%b" Lua pattern. This flag only applies if *s* and *e* are different. +-- @return pattern +-- @usage local dq_str_escapes = lexer.range('"') +-- @usage local dq_str_noescapes = lexer.range('"', false, false) +-- @usage local unbalanced_parens = lexer.range('(', ')') +-- @usage local balanced_parens = lexer.range('(', ')', false, false, true) +-- @name range +function M.range(s, e, single_line, escapes, balanced) + if type(e) ~= 'string' and type(e) ~= 'userdata' then + e, single_line, escapes, balanced = s, e, single_line, escapes + end + local any = M.any - e + if single_line then any = any - '\n' end + if balanced then any = any - s end + if escapes == nil then + -- Only allow escapes by default for ranges with identical, single-character string delimiters. + escapes = type(s) == 'string' and #s == 1 and s == e + end + if escapes then any = any - '\\' + '\\' * M.any end + if balanced and s ~= e then + return lpeg_P{s * (any + lpeg_V(1))^0 * lpeg_P(e)^-1} + else + return s * any^0 * lpeg_P(e)^-1 + end +end + +-- Deprecated function. Use `lexer.range()` instead. +-- Creates and returns a pattern that matches a range of text bounded by *chars* characters. +-- This is a convenience function for matching more complicated delimited ranges like strings +-- with escape characters and balanced parentheses. *single_line* indicates whether or not the +-- range must be on a single line, *no_escape* indicates whether or not to ignore '\' as an +-- escape character, and *balanced* indicates whether or not to handle balanced ranges like +-- parentheses and requires *chars* to be composed of two characters. +-- @param chars The character(s) that bound the matched range. +-- @param single_line Optional flag indicating whether or not the range must be on a single line. +-- @param no_escape Optional flag indicating whether or not the range end character may be +-- escaped by a '\\' character. +-- @param balanced Optional flag indicating whether or not to match a balanced range, like the +-- "%b" Lua pattern. This flag only applies if *chars* consists of two different characters +-- (e.g. "()"). +-- @return pattern +-- @usage local dq_str_escapes = lexer.delimited_range('"') +-- @usage local dq_str_noescapes = lexer.delimited_range('"', false, true) +-- @usage local unbalanced_parens = lexer.delimited_range('()') +-- @usage local balanced_parens = lexer.delimited_range('()', false, false, true) +-- @see range +-- @name delimited_range +function M.delimited_range(chars, single_line, no_escape, balanced) + print("lexer.delimited_range() is deprecated, use lexer.range()") + local s = chars:sub(1, 1) + local e = #chars == 2 and chars:sub(2, 2) or s + local range + local b = balanced and s or '' + local n = single_line and '\n' or '' + if no_escape then + local invalid = lpeg_S(e .. n .. b) + range = M.any - invalid + else + local invalid = lpeg_S(e .. n .. b) + '\\' + range = M.any - invalid + '\\' * M.any + end + if balanced and s ~= e then + return lpeg_P{s * (range + lpeg_V(1))^0 * e} + else + return s * range^0 * lpeg_P(e)^-1 + end +end + +--- +-- Creates and returns a pattern that matches pattern *patt* only at the beginning of a line. +-- @param patt The LPeg pattern to match on the beginning of a line. +-- @return pattern +-- @usage local preproc = token(lexer.PREPROCESSOR, lexer.starts_line(lexer.to_eol('#'))) +-- @name starts_line +function M.starts_line(patt) + return lpeg_Cmt(lpeg_C(patt), function(input, index, match, ...) + local pos = index - #match + if pos == 1 then return index, ... end + local char = input:sub(pos - 1, pos - 1) + if char == '\n' or char == '\r' or char == '\f' then return index, ... end + end) +end + +--- +-- Creates and returns a pattern that verifies the first non-whitespace character behind the +-- current match position is in string set *s*. +-- @param s String character set like one passed to `lpeg.S()`. +-- @return pattern +-- @usage local regex = lexer.last_char_includes('+-*!%^&|=,([{') * lexer.range('/') +-- @name last_char_includes +function M.last_char_includes(s) + s = string.format('[%s]', s:gsub('[-%%%[]', '%%%1')) + return lpeg_P(function(input, index) + if index == 1 then return index end + local i = index + while input:sub(i - 1, i - 1):match('[ \t\r\n\f]') do i = i - 1 end + if input:sub(i - 1, i - 1):match(s) then return index end + end) +end + +-- Deprecated function. Use `lexer.range()` instead. +-- Returns a pattern that matches a balanced range of text that starts with string *start_chars* +-- and ends with string *end_chars*. +-- With single-character delimiters, this function is identical to `delimited_range(start_chars .. +-- end_chars, false, true, true)`. +-- @param start_chars The string starting a nested sequence. +-- @param end_chars The string ending a nested sequence. +-- @return pattern +-- @usage local nested_comment = lexer.nested_pair('/*', '*/') +-- @see range +-- @name nested_pair +function M.nested_pair(start_chars, end_chars) + print("lexer.nested_pair() is deprecated, use lexer.range()") + local s, e = start_chars, lpeg_P(end_chars)^-1 + return lpeg_P{s * (M.any - s - end_chars + lpeg_V(1))^0 * e} +end + +--- +-- Creates and returns a pattern that matches any single word in list or string *words*. +-- *case_insensitive* indicates whether or not to ignore case when matching words. +-- This is a convenience function for simplifying a set of ordered choice word patterns. +-- @param word_list A list of words or a string list of words separated by spaces. +-- @param case_insensitive Optional boolean flag indicating whether or not the word match is +-- case-insensitive. The default value is `false`. +-- @param word_chars Unused legacy parameter. +-- @return pattern +-- @usage local keyword = token(lexer.KEYWORD, word_match{'foo', 'bar', 'baz'}) +-- @usage local keyword = token(lexer.KEYWORD, word_match({'foo-bar', 'foo-baz', 'bar-foo', +-- 'bar-baz', 'baz-foo', 'baz-bar'}, true)) +-- @usage local keyword = token(lexer.KEYWORD, word_match('foo bar baz')) +-- @name word_match +function M.word_match(word_list, case_insensitive, word_chars) + if type(case_insensitive) == 'string' or type(word_chars) == 'boolean' then + -- Legacy `word_match(word_list, word_chars, case_insensitive)` form. + word_chars, case_insensitive = case_insensitive, word_chars + elseif type(word_list) == 'string' then + local words = word_list -- space-separated list of words + word_list = {} + for word in words:gsub('%-%-[^\n]+', ''):gmatch('%S+') do word_list[#word_list + 1] = word end + end + if not word_chars then word_chars = '' end + for _, word in ipairs(word_list) do + word_list[case_insensitive and word:lower() or word] = true + for char in word:gmatch('[^%w_%s]') do + if not word_chars:find(char, 1, true) then word_chars = word_chars .. char end + end + end + local chars = M.alnum + '_' + if word_chars ~= '' then chars = chars + lpeg_S(word_chars) end + return lpeg_Cmt(chars^1, function(input, index, word) + if case_insensitive then word = word:lower() end + return word_list[word] and index or nil + end) +end + +-- Deprecated legacy function. Use `parent:embed()` instead. +-- Embeds child lexer *child* in parent lexer *parent* using patterns *start_rule* and *end_rule*, +-- which signal the beginning and end of the embedded lexer, respectively. +-- @param parent The parent lexer. +-- @param child The child lexer. +-- @param start_rule The pattern that signals the beginning of the embedded lexer. +-- @param end_rule The pattern that signals the end of the embedded lexer. +-- @usage lexer.embed_lexer(M, css, css_start_rule, css_end_rule) +-- @usage lexer.embed_lexer(html, M, php_start_rule, php_end_rule) +-- @usage lexer.embed_lexer(html, ruby, ruby_start_rule, ruby_end_rule) +-- @see embed +-- @name embed_lexer +function M.embed_lexer(parent, child, start_rule, end_rule) + if not getmetatable(parent) then process_legacy_lexer(parent) end + if not getmetatable(child) then process_legacy_lexer(child) end + parent:embed(child, start_rule, end_rule) +end + +-- Determines if the previous line is a comment. +-- This is used for determining if the current comment line is a fold point. +-- @param prefix The prefix string defining a comment. +-- @param text The text passed to a fold function. +-- @param pos The pos passed to a fold function. +-- @param line The line passed to a fold function. +-- @param s The s passed to a fold function. +local function prev_line_is_comment(prefix, text, pos, line, s) + local start = line:find('%S') + if start < s and not line:find(prefix, start, true) then return false end + local p = pos - 1 + if text:sub(p, p) == '\n' then + p = p - 1 + if text:sub(p, p) == '\r' then p = p - 1 end + if text:sub(p, p) ~= '\n' then + while p > 1 and text:sub(p - 1, p - 1) ~= '\n' do p = p - 1 end + while text:sub(p, p):find('^[\t ]$') do p = p + 1 end + return text:sub(p, p + #prefix - 1) == prefix + end + end + return false +end + +-- Determines if the next line is a comment. +-- This is used for determining if the current comment line is a fold point. +-- @param prefix The prefix string defining a comment. +-- @param text The text passed to a fold function. +-- @param pos The pos passed to a fold function. +-- @param line The line passed to a fold function. +-- @param s The s passed to a fold function. +local function next_line_is_comment(prefix, text, pos, line, s) + local p = text:find('\n', pos + s) + if p then + p = p + 1 + while text:sub(p, p):find('^[\t ]$') do p = p + 1 end + return text:sub(p, p + #prefix - 1) == prefix + end + return false +end + +--- +-- Returns for `lexer.add_fold_point()` the parameters needed to fold consecutive lines that +-- start with string *prefix*. +-- @param prefix The prefix string (e.g. a line comment). +-- @usage lex:add_fold_point(lexer.COMMENT, lexer.fold_consecutive_lines('--')) +-- @usage lex:add_fold_point(lexer.COMMENT, lexer.fold_consecutive_lines('//')) +-- @usage lex:add_fold_point(lexer.KEYWORD, lexer.fold_consecutive_lines('import')) +-- @name fold_consecutive_lines +function M.fold_consecutive_lines(prefix) + local property_int = M.property_int + return prefix, function(text, pos, line, s) + if property_int['fold.line.groups'] == 0 then return 0 end + if s > 1 and line:match('^%s*()') < s then return 0 end + local prev_line_comment = prev_line_is_comment(prefix, text, pos, line, s) + local next_line_comment = next_line_is_comment(prefix, text, pos, line, s) + if not prev_line_comment and next_line_comment then return 1 end + if prev_line_comment and not next_line_comment then return -1 end + return 0 + end +end + +-- Deprecated legacy function. Use `lexer.fold_consecutive_lines()` instead. +-- Returns a fold function (to be passed to `lexer.add_fold_point()`) that folds consecutive +-- line comments that start with string *prefix*. +-- @param prefix The prefix string defining a line comment. +-- @usage lex:add_fold_point(lexer.COMMENT, '--', lexer.fold_line_comments('--')) +-- @usage lex:add_fold_point(lexer.COMMENT, '//', lexer.fold_line_comments('//')) +-- @name fold_line_comments +function M.fold_line_comments(prefix) + print('lexer.fold_line_comments() is deprecated, use lexer.fold_consecutive_lines()') + return select(2, M.fold_consecutive_lines(prefix)) +end + +--[[ The functions and fields below were defined in C. + +--- +-- Returns the line number (starting from 1) of the line that contains position *pos*, which +-- starts from 1. +-- @param pos The position to get the line number of. +-- @return number +local function line_from_position(pos) end +]] + +return M diff --git a/lua/lexers/lexer.lua b/lua/lexers/lexer.lua @@ -1,1855 +0,0 @@ --- Copyright 2006-2022 Mitchell. See LICENSE. - -local M = {} - ---[=[ This comment is for LuaDoc. ---- --- Lexes Scintilla documents and source code with Lua and LPeg. --- --- ### Writing Lua Lexers --- --- Lexers highlight the syntax of source code. Scintilla (the editing component behind --- [Textadept][] and [SciTE][]) traditionally uses static, compiled C++ lexers which are --- notoriously difficult to create and/or extend. On the other hand, Lua makes it easy to to --- rapidly create new lexers, extend existing ones, and embed lexers within one another. Lua --- lexers tend to be more readable than C++ lexers too. --- --- Lexers are Parsing Expression Grammars, or PEGs, composed with the Lua [LPeg library][]. The --- following table comes from the LPeg documentation and summarizes all you need to know about --- constructing basic LPeg patterns. This module provides convenience functions for creating --- and working with other more advanced patterns and concepts. --- --- Operator | Description --- -|- --- `lpeg.P(string)` | Matches `string` literally. --- `lpeg.P(`_`n`_`)` | Matches exactly _`n`_ number of characters. --- `lpeg.S(string)` | Matches any character in set `string`. --- `lpeg.R("`_`xy`_`")`| Matches any character between range `x` and `y`. --- `patt^`_`n`_ | Matches at least _`n`_ repetitions of `patt`. --- `patt^-`_`n`_ | Matches at most _`n`_ repetitions of `patt`. --- `patt1 * patt2` | Matches `patt1` followed by `patt2`. --- `patt1 + patt2` | Matches `patt1` or `patt2` (ordered choice). --- `patt1 - patt2` | Matches `patt1` if `patt2` does not also match. --- `-patt` | Equivalent to `("" - patt)`. --- `#patt` | Matches `patt` but consumes no input. --- --- The first part of this document deals with rapidly constructing a simple lexer. The next part --- deals with more advanced techniques, such as custom coloring and embedding lexers within one --- another. Following that is a discussion about code folding, or being able to tell Scintilla --- which code blocks are "foldable" (temporarily hideable from view). After that are instructions --- on how to use Lua lexers with the aforementioned Textadept and SciTE editors. Finally there --- are comments on lexer performance and limitations. --- --- [LPeg library]: http://www.inf.puc-rio.br/~roberto/lpeg/lpeg.html --- [Textadept]: https://orbitalquark.github.io/textadept --- [SciTE]: https://scintilla.org/SciTE.html --- --- ### Lexer Basics --- --- The *lexers/* directory contains all lexers, including your new one. Before attempting to --- write one from scratch though, first determine if your programming language is similar to --- any of the 100+ languages supported. If so, you may be able to copy and modify that lexer, --- saving some time and effort. The filename of your lexer should be the name of your programming --- language in lower case followed by a *.lua* extension. For example, a new Lua lexer has the --- name *lua.lua*. --- --- Note: Try to refrain from using one-character language names like "c", "d", or "r". For --- example, Scintillua uses "ansi_c", "dmd", and "rstats", respectively. --- --- #### New Lexer Template --- --- There is a *lexers/template.txt* file that contains a simple template for a new lexer. Feel --- free to use it, replacing the '?'s with the name of your lexer. Consider this snippet from --- the template: --- --- -- ? LPeg lexer. --- --- local lexer = require('lexer') --- local token, word_match = lexer.token, lexer.word_match --- local P, S = lpeg.P, lpeg.S --- --- local lex = lexer.new('?') --- --- -- Whitespace. --- local ws = token(lexer.WHITESPACE, lexer.space^1) --- lex:add_rule('whitespace', ws) --- --- [...] --- --- return lex --- --- The first 3 lines of code simply define often used convenience variables. The fourth and --- last lines [define](#lexer.new) and return the lexer object Scintilla uses; they are very --- important and must be part of every lexer. The fifth line defines something called a "token", --- an essential building block of lexers. You will learn about tokens shortly. The sixth line --- defines a lexer grammar rule, which you will learn about later, as well as token styles. (Be --- aware that it is common practice to combine these two lines for short rules.) Note, however, --- the `local` prefix in front of variables, which is needed so-as not to affect Lua's global --- environment. All in all, this is a minimal, working lexer that you can build on. --- --- #### Tokens --- --- Take a moment to think about your programming language's structure. What kind of key --- elements does it have? In the template shown earlier, one predefined element all languages --- have is whitespace. Your language probably also has elements like comments, strings, and --- keywords. Lexers refer to these elements as "tokens". Tokens are the fundamental "building --- blocks" of lexers. Lexers break down source code into tokens for coloring, which results --- in the syntax highlighting familiar to you. It is up to you how specific your lexer is --- when it comes to tokens. Perhaps only distinguishing between keywords and identifiers is --- necessary, or maybe recognizing constants and built-in functions, methods, or libraries is --- desirable. The Lua lexer, for example, defines 11 tokens: whitespace, keywords, built-in --- functions, constants, built-in libraries, identifiers, strings, comments, numbers, labels, --- and operators. Even though constants, built-in functions, and built-in libraries are subsets --- of identifiers, Lua programmers find it helpful for the lexer to distinguish between them --- all. It is perfectly acceptable to just recognize keywords and identifiers. --- --- In a lexer, tokens consist of a token name and an LPeg pattern that matches a sequence of --- characters recognized as an instance of that token. Create tokens using the [`lexer.token()`]() --- function. Let us examine the "whitespace" token defined in the template shown earlier: --- --- local ws = token(lexer.WHITESPACE, lexer.space^1) --- --- At first glance, the first argument does not appear to be a string name and the second --- argument does not appear to be an LPeg pattern. Perhaps you expected something like: --- --- local ws = token('whitespace', S('\t\v\f\n\r ')^1) --- --- The `lexer` module actually provides a convenient list of common token names and common LPeg --- patterns for you to use. Token names include [`lexer.DEFAULT`](), [`lexer.WHITESPACE`](), --- [`lexer.COMMENT`](), [`lexer.STRING`](), [`lexer.NUMBER`](), [`lexer.KEYWORD`](), --- [`lexer.IDENTIFIER`](), [`lexer.OPERATOR`](), [`lexer.ERROR`](), [`lexer.PREPROCESSOR`](), --- [`lexer.CONSTANT`](), [`lexer.VARIABLE`](), [`lexer.FUNCTION`](), [`lexer.CLASS`](), --- [`lexer.TYPE`](), [`lexer.LABEL`](), [`lexer.REGEX`](), and [`lexer.EMBEDDED`](). Patterns --- include [`lexer.any`](), [`lexer.alpha`](), [`lexer.digit`](), [`lexer.alnum`](), --- [`lexer.lower`](), [`lexer.upper`](), [`lexer.xdigit`](), [`lexer.graph`](), [`lexer.print`](), --- [`lexer.punct`](), [`lexer.space`](), [`lexer.newline`](), [`lexer.nonnewline`](), --- [`lexer.dec_num`](), [`lexer.hex_num`](), [`lexer.oct_num`](), [`lexer.integer`](), --- [`lexer.float`](), [`lexer.number`](), and [`lexer.word`](). You may use your own token names --- if none of the above fit your language, but an advantage to using predefined token names is --- that your lexer's tokens will inherit the universal syntax highlighting color theme used by --- your text editor. --- --- ##### Example Tokens --- --- So, how might you define other tokens like keywords, comments, and strings? Here are some --- examples. --- --- **Keywords** --- --- Instead of matching _n_ keywords with _n_ `P('keyword_`_`n`_`')` ordered choices, use another --- convenience function: [`lexer.word_match()`](). It is much easier and more efficient to --- write word matches like: --- --- local keyword = token(lexer.KEYWORD, lexer.word_match{ --- 'keyword_1', 'keyword_2', ..., 'keyword_n' --- }) --- --- local case_insensitive_keyword = token(lexer.KEYWORD, lexer.word_match({ --- 'KEYWORD_1', 'keyword_2', ..., 'KEYword_n' --- }, true)) --- --- local hyphened_keyword = token(lexer.KEYWORD, lexer.word_match{ --- 'keyword-1', 'keyword-2', ..., 'keyword-n' --- }) --- --- For short keyword lists, you can use a single string of words. For example: --- --- local keyword = token(lexer.KEYWORD, lexer.word_match('key_1 key_2 ... key_n')) --- --- **Comments** --- --- Line-style comments with a prefix character(s) are easy to express with LPeg: --- --- local shell_comment = token(lexer.COMMENT, lexer.to_eol('#')) --- local c_line_comment = token(lexer.COMMENT, lexer.to_eol('//', true)) --- --- The comments above start with a '#' or "//" and go to the end of the line. The second comment --- recognizes the next line also as a comment if the current line ends with a '\' escape character. --- --- C-style "block" comments with a start and end delimiter are also easy to express: --- --- local c_comment = token(lexer.COMMENT, lexer.range('/*', '*/')) --- --- This comment starts with a "/\*" sequence and contains anything up to and including an ending --- "\*/" sequence. The ending "\*/" is optional so the lexer can recognize unfinished comments --- as comments and highlight them properly. --- --- **Strings** --- --- Most programming languages allow escape sequences in strings such that a sequence like --- "\\&quot;" in a double-quoted string indicates that the '&quot;' is not the end of the --- string. [`lexer.range()`]() handles escapes inherently. --- --- local dq_str = lexer.range('"') --- local sq_str = lexer.range("'") --- local string = token(lexer.STRING, dq_str + sq_str) --- --- In this case, the lexer treats '\' as an escape character in a string sequence. --- --- **Numbers** --- --- Most programming languages have the same format for integer and float tokens, so it might --- be as simple as using a predefined LPeg pattern: --- --- local number = token(lexer.NUMBER, lexer.number) --- --- However, some languages allow postfix characters on integers. --- --- local integer = P('-')^-1 * (lexer.dec_num * S('lL')^-1) --- local number = token(lexer.NUMBER, lexer.float + lexer.hex_num + integer) --- --- Your language may need other tweaks, but it is up to you how fine-grained you want your --- highlighting to be. After all, you are not writing a compiler or interpreter! --- --- #### Rules --- --- Programming languages have grammars, which specify valid token structure. For example, --- comments usually cannot appear within a string. Grammars consist of rules, which are simply --- combinations of tokens. Recall from the lexer template the [`lexer.add_rule()`]() call, --- which adds a rule to the lexer's grammar: --- --- lex:add_rule('whitespace', ws) --- --- Each rule has an associated name, but rule names are completely arbitrary and serve only to --- identify and distinguish between different rules. Rule order is important: if text does not --- match the first rule added to the grammar, the lexer tries to match the second rule added, and --- so on. Right now this lexer simply matches whitespace tokens under a rule named "whitespace". --- --- To illustrate the importance of rule order, here is an example of a simplified Lua lexer: --- --- lex:add_rule('whitespace', token(lexer.WHITESPACE, ...)) --- lex:add_rule('keyword', token(lexer.KEYWORD, ...)) --- lex:add_rule('identifier', token(lexer.IDENTIFIER, ...)) --- lex:add_rule('string', token(lexer.STRING, ...)) --- lex:add_rule('comment', token(lexer.COMMENT, ...)) --- lex:add_rule('number', token(lexer.NUMBER, ...)) --- lex:add_rule('label', token(lexer.LABEL, ...)) --- lex:add_rule('operator', token(lexer.OPERATOR, ...)) --- --- Note how identifiers come after keywords. In Lua, as with most programming languages, --- the characters allowed in keywords and identifiers are in the same set (alphanumerics --- plus underscores). If the lexer added the "identifier" rule before the "keyword" rule, --- all keywords would match identifiers and thus incorrectly highlight as identifiers instead --- of keywords. The same idea applies to function, constant, etc. tokens that you may want to --- distinguish between: their rules should come before identifiers. --- --- So what about text that does not match any rules? For example in Lua, the '!' character is --- meaningless outside a string or comment. Normally the lexer skips over such text. If instead --- you want to highlight these "syntax errors", add an additional end rule: --- --- lex:add_rule('whitespace', ws) --- ... --- lex:add_rule('error', token(lexer.ERROR, lexer.any)) --- --- This identifies and highlights any character not matched by an existing rule as a `lexer.ERROR` --- token. --- --- Even though the rules defined in the examples above contain a single token, rules may --- consist of multiple tokens. For example, a rule for an HTML tag could consist of a tag token --- followed by an arbitrary number of attribute tokens, allowing the lexer to highlight all --- tokens separately. That rule might look something like this: --- --- lex:add_rule('tag', tag_start * (ws * attributes)^0 * tag_end^-1) --- --- Note however that lexers with complex rules like these are more prone to lose track of their --- state, especially if they span multiple lines. --- --- #### Summary --- --- Lexers primarily consist of tokens and grammar rules. At your disposal are a number of --- convenience patterns and functions for rapidly creating a lexer. If you choose to use --- predefined token names for your tokens, you do not have to define how the lexer highlights --- them. The tokens will inherit the default syntax highlighting color theme your editor uses. --- --- ### Advanced Techniques --- --- #### Styles and Styling --- --- The most basic form of syntax highlighting is assigning different colors to different --- tokens. Instead of highlighting with just colors, Scintilla allows for more rich highlighting, --- or "styling", with different fonts, font sizes, font attributes, and foreground and background --- colors, just to name a few. The unit of this rich highlighting is called a "style". Styles --- are simply Lua tables of properties. By default, lexers associate predefined token names like --- `lexer.WHITESPACE`, `lexer.COMMENT`, `lexer.STRING`, etc. with particular styles as part --- of a universal color theme. These predefined styles are contained in [`lexer.styles`](), --- and you may define your own styles. See that table's documentation for more information. As --- with token names, LPeg patterns, and styles, there is a set of predefined color names, --- but they vary depending on the current color theme in use. Therefore, it is generally not --- a good idea to manually define colors within styles in your lexer since they might not fit --- into a user's chosen color theme. Try to refrain from even using predefined colors in a --- style because that color may be theme-specific. Instead, the best practice is to either use --- predefined styles or derive new color-agnostic styles from predefined ones. For example, Lua --- "longstring" tokens use the existing `lexer.styles.string` style instead of defining a new one. --- --- ##### Example Styles --- --- Defining styles is pretty straightforward. An empty style that inherits the default theme --- settings is simply an empty table: --- --- local style_nothing = {} --- --- A similar style but with a bold font face looks like this: --- --- local style_bold = {bold = true} --- --- You can derive new styles from predefined ones without having to rewrite them. This operation --- leaves the old style unchanged. For example, if you had a "static variable" token whose --- style you wanted to base off of `lexer.styles.variable`, it would probably look like: --- --- local style_static_var = lexer.styles.variable .. {italics = true} --- --- The color theme files in the *lexers/themes/* folder give more examples of style definitions. --- --- #### Token Styles --- --- Lexers use the [`lexer.add_style()`]() function to assign styles to particular tokens. Recall --- the token definition and from the lexer template: --- --- local ws = token(lexer.WHITESPACE, lexer.space^1) --- lex:add_rule('whitespace', ws) --- --- Why is a style not assigned to the `lexer.WHITESPACE` token? As mentioned earlier, lexers --- automatically associate tokens that use predefined token names with a particular style. Only --- tokens with custom token names need manual style associations. As an example, consider a --- custom whitespace token: --- --- local ws = token('custom_whitespace', lexer.space^1) --- --- Assigning a style to this token looks like: --- --- lex:add_style('custom_whitespace', lexer.styles.whitespace) --- --- Do not confuse token names with rule names. They are completely different entities. In the --- example above, the lexer associates the "custom_whitespace" token with the existing style --- for `lexer.WHITESPACE` tokens. If instead you prefer to color the background of whitespace --- a shade of grey, it might look like: --- --- lex:add_style('custom_whitespace', lexer.styles.whitespace .. {back = lexer.colors.grey}) --- --- Remember to refrain from assigning specific colors in styles, but in this case, all user --- color themes probably define `colors.grey`. --- --- #### Line Lexers --- --- By default, lexers match the arbitrary chunks of text passed to them by Scintilla. These --- chunks may be a full document, only the visible part of a document, or even just portions --- of lines. Some lexers need to match whole lines. For example, a lexer for the output of a --- file "diff" needs to know if the line started with a '+' or '-' and then style the entire --- line accordingly. To indicate that your lexer matches by line, create the lexer with an --- extra parameter: --- --- local lex = lexer.new('?', {lex_by_line = true}) --- --- Now the input text for the lexer is a single line at a time. Keep in mind that line lexers --- do not have the ability to look ahead at subsequent lines. --- --- #### Embedded Lexers --- --- Lexers embed within one another very easily, requiring minimal effort. In the following --- sections, the lexer being embedded is called the "child" lexer and the lexer a child is --- being embedded in is called the "parent". For example, consider an HTML lexer and a CSS --- lexer. Either lexer stands alone for styling their respective HTML and CSS files. However, CSS --- can be embedded inside HTML. In this specific case, the CSS lexer is the "child" lexer with --- the HTML lexer being the "parent". Now consider an HTML lexer and a PHP lexer. This sounds --- a lot like the case with CSS, but there is a subtle difference: PHP _embeds itself into_ --- HTML while CSS is _embedded in_ HTML. This fundamental difference results in two types of --- embedded lexers: a parent lexer that embeds other child lexers in it (like HTML embedding CSS), --- and a child lexer that embeds itself into a parent lexer (like PHP embedding itself in HTML). --- --- ##### Parent Lexer --- --- Before embedding a child lexer into a parent lexer, the parent lexer needs to load the child --- lexer. This is done with the [`lexer.load()`]() function. For example, loading the CSS lexer --- within the HTML lexer looks like: --- --- local css = lexer.load('css') --- --- The next part of the embedding process is telling the parent lexer when to switch over --- to the child lexer and when to switch back. The lexer refers to these indications as the --- "start rule" and "end rule", respectively, and are just LPeg patterns. Continuing with the --- HTML/CSS example, the transition from HTML to CSS is when the lexer encounters a "style" --- tag with a "type" attribute whose value is "text/css": --- --- local css_tag = P('<style') * P(function(input, index) --- if input:find('^[^>]+type="text/css"', index) then return index end --- end) --- --- This pattern looks for the beginning of a "style" tag and searches its attribute list for --- the text "`type="text/css"`". (In this simplified example, the Lua pattern does not consider --- whitespace between the '=' nor does it consider that using single quotes is valid.) If there --- is a match, the functional pattern returns a value instead of `nil`. In this case, the value --- returned does not matter because we ultimately want to style the "style" tag as an HTML tag, --- so the actual start rule looks like this: --- --- local css_start_rule = #css_tag * tag --- --- Now that the parent knows when to switch to the child, it needs to know when to switch --- back. In the case of HTML/CSS, the switch back occurs when the lexer encounters an ending --- "style" tag, though the lexer should still style the tag as an HTML tag: --- --- local css_end_rule = #P('</style>') * tag --- --- Once the parent loads the child lexer and defines the child's start and end rules, it embeds --- the child with the [`lexer.embed()`]() function: --- --- lex:embed(css, css_start_rule, css_end_rule) --- --- ##### Child Lexer --- --- The process for instructing a child lexer to embed itself into a parent is very similar to --- embedding a child into a parent: first, load the parent lexer into the child lexer with the --- [`lexer.load()`]() function and then create start and end rules for the child lexer. However, --- in this case, call [`lexer.embed()`]() with switched arguments. For example, in the PHP lexer: --- --- local html = lexer.load('html') --- local php_start_rule = token('php_tag', '<?php ') --- local php_end_rule = token('php_tag', '?>') --- lex:add_style('php_tag', lexer.styles.embedded) --- html:embed(lex, php_start_rule, php_end_rule) --- --- #### Lexers with Complex State --- --- A vast majority of lexers are not stateful and can operate on any chunk of text in a --- document. However, there may be rare cases where a lexer does need to keep track of some --- sort of persistent state. Rather than using `lpeg.P` function patterns that set state --- variables, it is recommended to make use of Scintilla's built-in, per-line state integers via --- [`lexer.line_state`](). It was designed to accommodate up to 32 bit flags for tracking state. --- [`lexer.line_from_position()`]() will return the line for any position given to an `lpeg.P` --- function pattern. (Any positions derived from that position argument will also work.) --- --- Writing stateful lexers is beyond the scope of this document. --- --- ### Code Folding --- --- When reading source code, it is occasionally helpful to temporarily hide blocks of code like --- functions, classes, comments, etc. This is the concept of "folding". In the Textadept and --- SciTE editors for example, little indicators in the editor margins appear next to code that --- can be folded at places called "fold points". When the user clicks an indicator, the editor --- hides the code associated with the indicator until the user clicks the indicator again. The --- lexer specifies these fold points and what code exactly to fold. --- --- The fold points for most languages occur on keywords or character sequences. Examples of --- fold keywords are "if" and "end" in Lua and examples of fold character sequences are '{', --- '}', "/\*", and "\*/" in C for code block and comment delimiters, respectively. However, --- these fold points cannot occur just anywhere. For example, lexers should not recognize fold --- keywords that appear within strings or comments. The [`lexer.add_fold_point()`]() function --- allows you to conveniently define fold points with such granularity. For example, consider C: --- --- lex:add_fold_point(lexer.OPERATOR, '{', '}') --- lex:add_fold_point(lexer.COMMENT, '/*', '*/') --- --- The first assignment states that any '{' or '}' that the lexer recognized as an `lexer.OPERATOR` --- token is a fold point. Likewise, the second assignment states that any "/\*" or "\*/" that --- the lexer recognizes as part of a `lexer.COMMENT` token is a fold point. The lexer does --- not consider any occurrences of these characters outside their defined tokens (such as in --- a string) as fold points. How do you specify fold keywords? Here is an example for Lua: --- --- lex:add_fold_point(lexer.KEYWORD, 'if', 'end') --- lex:add_fold_point(lexer.KEYWORD, 'do', 'end') --- lex:add_fold_point(lexer.KEYWORD, 'function', 'end') --- lex:add_fold_point(lexer.KEYWORD, 'repeat', 'until') --- --- If your lexer has case-insensitive keywords as fold points, simply add a --- `case_insensitive_fold_points = true` option to [`lexer.new()`](), and specify keywords in --- lower case. --- --- If your lexer needs to do some additional processing in order to determine if a token is --- a fold point, pass a function that returns an integer to `lex:add_fold_point()`. Returning --- `1` indicates the token is a beginning fold point and returning `-1` indicates the token is --- an ending fold point. Returning `0` indicates the token is not a fold point. For example: --- --- local function fold_strange_token(text, pos, line, s, symbol) --- if ... then --- return 1 -- beginning fold point --- elseif ... then --- return -1 -- ending fold point --- end --- return 0 --- end --- --- lex:add_fold_point('strange_token', '|', fold_strange_token) --- --- Any time the lexer encounters a '|' that is a "strange_token", it calls the `fold_strange_token` --- function to determine if '|' is a fold point. The lexer calls these functions with the --- following arguments: the text to identify fold points in, the beginning position of the --- current line in the text to fold, the current line's text, the position in the current line --- the fold point text starts at, and the fold point text itself. --- --- #### Fold by Indentation --- --- Some languages have significant whitespace and/or no delimiters that indicate fold points. If --- your lexer falls into this category and you would like to mark fold points based on changes --- in indentation, create the lexer with a `fold_by_indentation = true` option: --- --- local lex = lexer.new('?', {fold_by_indentation = true}) --- --- ### Using Lexers --- --- **Textadept** --- --- Put your lexer in your *~/.textadept/lexers/* directory so you do not overwrite it when --- upgrading Textadept. Also, lexers in this directory override default lexers. Thus, Textadept --- loads a user *lua* lexer instead of the default *lua* lexer. This is convenient for tweaking --- a default lexer to your liking. Then add a [file type](#textadept.file_types) for your lexer --- if necessary. --- --- **SciTE** --- --- Create a *.properties* file for your lexer and `import` it in either your *SciTEUser.properties* --- or *SciTEGlobal.properties*. The contents of the *.properties* file should contain: --- --- file.patterns.[lexer_name]=[file_patterns] --- lexer.$(file.patterns.[lexer_name])=[lexer_name] --- --- where `[lexer_name]` is the name of your lexer (minus the *.lua* extension) and --- `[file_patterns]` is a set of file extensions to use your lexer for. --- --- Please note that Lua lexers ignore any styling information in *.properties* files. Your --- theme file in the *lexers/themes/* directory contains styling information. --- --- ### Migrating Legacy Lexers --- --- Legacy lexers are of the form: --- --- local l = require('lexer') --- local token, word_match = l.token, l.word_match --- local P, R, S = lpeg.P, lpeg.R, lpeg.S --- --- local M = {_NAME = '?'} --- --- [... token and pattern definitions ...] --- --- M._rules = { --- {'rule', pattern}, --- [...] --- } --- --- M._tokenstyles = { --- 'token' = 'style', --- [...] --- } --- --- M._foldsymbols = { --- _patterns = {...}, --- ['token'] = {['start'] = 1, ['end'] = -1}, --- [...] --- } --- --- return M --- --- While Scintillua will handle such legacy lexers just fine without any changes, it is --- recommended that you migrate yours. The migration process is fairly straightforward: --- --- 1. Replace all instances of `l` with `lexer`, as it's better practice and results in less --- confusion. --- 2. Replace `local M = {_NAME = '?'}` with `local lex = lexer.new('?')`, where `?` is the --- name of your legacy lexer. At the end of the lexer, change `return M` to `return lex`. --- 3. Instead of defining rules towards the end of your lexer, define your rules as you define --- your tokens and patterns using [`lex:add_rule()`](#lexer.add_rule). --- 4. Similarly, any custom token names should have their styles immediately defined using --- [`lex:add_style()`](#lexer.add_style). --- 5. Optionally convert any table arguments passed to [`lexer.word_match()`]() to a --- space-separated string of words. --- 6. Replace any calls to `lexer.embed(M, child, ...)` and `lexer.embed(parent, M, ...)` with --- [`lex:embed`](#lexer.embed)`(child, ...)` and `parent:embed(lex, ...)`, respectively. --- 7. Define fold points with simple calls to [`lex:add_fold_point()`](#lexer.add_fold_point). No --- need to mess with Lua patterns anymore. --- 8. Any legacy lexer options such as `M._FOLDBYINDENTATION`, `M._LEXBYLINE`, `M._lexer`, --- etc. should be added as table options to [`lexer.new()`](). --- 9. Any external lexer rule fetching and/or modifications via `lexer._RULES` should be changed --- to use [`lexer.get_rule()`]() and [`lexer.modify_rule()`](). --- --- As an example, consider the following sample legacy lexer: --- --- local l = require('lexer') --- local token, word_match = l.token, l.word_match --- local P, R, S = lpeg.P, lpeg.R, lpeg.S --- --- local M = {_NAME = 'legacy'} --- --- local ws = token(l.WHITESPACE, l.space^1) --- local comment = token(l.COMMENT, '#' * l.nonnewline^0) --- local string = token(l.STRING, l.delimited_range('"')) --- local number = token(l.NUMBER, l.float + l.integer) --- local keyword = token(l.KEYWORD, word_match{'foo', 'bar', 'baz'}) --- local custom = token('custom', P('quux')) --- local identifier = token(l.IDENTIFIER, l.word) --- local operator = token(l.OPERATOR, S('+-*/%^=<>,.()[]{}')) --- --- M._rules = { --- {'whitespace', ws}, --- {'keyword', keyword}, --- {'custom', custom}, --- {'identifier', identifier}, --- {'string', string}, --- {'comment', comment}, --- {'number', number}, --- {'operator', operator} --- } --- --- M._tokenstyles = { --- 'custom' = l.STYLE_KEYWORD .. ',bold' --- } --- --- M._foldsymbols = { --- _patterns = {'[{}]'}, --- [l.OPERATOR] = {['{'] = 1, ['}'] = -1} --- } --- --- return M --- --- Following the migration steps would yield: --- --- local lexer = require('lexer') --- local token, word_match = lexer.token, lexer.word_match --- local P, S = lpeg.P, lpeg.S --- --- local lex = lexer.new('legacy') --- --- lex:add_rule('whitespace', token(lexer.WHITESPACE, lexer.space^1)) --- lex:add_rule('keyword', token(lexer.KEYWORD, word_match('foo bar baz'))) --- lex:add_rule('custom', token('custom', 'quux')) --- lex:add_style('custom', lexer.styles.keyword .. {bold = true}) --- lex:add_rule('identifier', token(lexer.IDENTIFIER, lexer.word)) --- lex:add_rule('string', token(lexer.STRING, lexer.range('"'))) --- lex:add_rule('comment', token(lexer.COMMENT, lexer.to_eol('#'))) --- lex:add_rule('number', token(lexer.NUMBER, lexer.number)) --- lex:add_rule('operator', token(lexer.OPERATOR, S('+-*/%^=<>,.()[]{}'))) --- --- lex:add_fold_point(lexer.OPERATOR, '{', '}') --- --- return lex --- --- ### Considerations --- --- #### Performance --- --- There might be some slight overhead when initializing a lexer, but loading a file from disk --- into Scintilla is usually more expensive. On modern computer systems, I see no difference in --- speed between Lua lexers and Scintilla's C++ ones. Optimize lexers for speed by re-arranging --- `lexer.add_rule()` calls so that the most common rules match first. Do keep in mind that --- order matters for similar rules. --- --- In some cases, folding may be far more expensive than lexing, particularly in lexers with a --- lot of potential fold points. If your lexer is exhibiting signs of slowness, try disabling --- folding in your text editor first. If that speeds things up, you can try reducing the number --- of fold points you added, overriding `lexer.fold()` with your own implementation, or simply --- eliminating folding support from your lexer. --- --- #### Limitations --- --- Embedded preprocessor languages like PHP cannot completely embed in their parent languages --- in that the parent's tokens do not support start and end rules. This mostly goes unnoticed, --- but code like --- --- <div id="<?php echo $id; ?>"> --- --- will not style correctly. --- --- #### Troubleshooting --- --- Errors in lexers can be tricky to debug. Lexers print Lua errors to `io.stderr` and `_G.print()` --- statements to `io.stdout`. Running your editor from a terminal is the easiest way to see --- errors as they occur. --- --- #### Risks --- --- Poorly written lexers have the ability to crash Scintilla (and thus its containing application), --- so unsaved data might be lost. However, I have only observed these crashes in early lexer --- development, when syntax errors or pattern errors are present. Once the lexer actually starts --- styling text (either correctly or incorrectly, it does not matter), I have not observed --- any crashes. --- --- #### Acknowledgements --- --- Thanks to Peter Odding for his [lexer post][] on the Lua mailing list that provided inspiration, --- and thanks to Roberto Ierusalimschy for LPeg. --- --- [lexer post]: http://lua-users.org/lists/lua-l/2007-04/msg00116.html --- @field DEFAULT (string) --- The token name for default tokens. --- @field WHITESPACE (string) --- The token name for whitespace tokens. --- @field COMMENT (string) --- The token name for comment tokens. --- @field STRING (string) --- The token name for string tokens. --- @field NUMBER (string) --- The token name for number tokens. --- @field KEYWORD (string) --- The token name for keyword tokens. --- @field IDENTIFIER (string) --- The token name for identifier tokens. --- @field OPERATOR (string) --- The token name for operator tokens. --- @field ERROR (string) --- The token name for error tokens. --- @field PREPROCESSOR (string) --- The token name for preprocessor tokens. --- @field CONSTANT (string) --- The token name for constant tokens. --- @field VARIABLE (string) --- The token name for variable tokens. --- @field FUNCTION (string) --- The token name for function tokens. --- @field CLASS (string) --- The token name for class tokens. --- @field TYPE (string) --- The token name for type tokens. --- @field LABEL (string) --- The token name for label tokens. --- @field REGEX (string) --- The token name for regex tokens. --- @field any (pattern) --- A pattern that matches any single character. --- @field ascii (pattern) --- A pattern that matches any ASCII character (codes 0 to 127). --- @field extend (pattern) --- A pattern that matches any ASCII extended character (codes 0 to 255). --- @field alpha (pattern) --- A pattern that matches any alphabetic character ('A'-'Z', 'a'-'z'). --- @field digit (pattern) --- A pattern that matches any digit ('0'-'9'). --- @field alnum (pattern) --- A pattern that matches any alphanumeric character ('A'-'Z', 'a'-'z', '0'-'9'). --- @field lower (pattern) --- A pattern that matches any lower case character ('a'-'z'). --- @field upper (pattern) --- A pattern that matches any upper case character ('A'-'Z'). --- @field xdigit (pattern) --- A pattern that matches any hexadecimal digit ('0'-'9', 'A'-'F', 'a'-'f'). --- @field cntrl (pattern) --- A pattern that matches any control character (ASCII codes 0 to 31). --- @field graph (pattern) --- A pattern that matches any graphical character ('!' to '~'). --- @field print (pattern) --- A pattern that matches any printable character (' ' to '~'). --- @field punct (pattern) --- A pattern that matches any punctuation character ('!' to '/', ':' to '@', '[' to ''', --- '{' to '~'). --- @field space (pattern) --- A pattern that matches any whitespace character ('\t', '\v', '\f', '\n', '\r', space). --- @field newline (pattern) --- A pattern that matches a sequence of end of line characters. --- @field nonnewline (pattern) --- A pattern that matches any single, non-newline character. --- @field dec_num (pattern) --- A pattern that matches a decimal number. --- @field hex_num (pattern) --- A pattern that matches a hexadecimal number. --- @field oct_num (pattern) --- A pattern that matches an octal number. --- @field integer (pattern) --- A pattern that matches either a decimal, hexadecimal, or octal number. --- @field float (pattern) --- A pattern that matches a floating point number. --- @field number (pattern) --- A pattern that matches a typical number, either a floating point, decimal, hexadecimal, --- or octal number. --- @field word (pattern) --- A pattern that matches a typical word. Words begin with a letter or underscore and consist --- of alphanumeric and underscore characters. --- @field FOLD_BASE (number) --- The initial (root) fold level. --- @field FOLD_BLANK (number) --- Flag indicating that the line is blank. --- @field FOLD_HEADER (number) --- Flag indicating the line is fold point. --- @field fold_level (table, Read-only) --- Table of fold level bit-masks for line numbers starting from 1. --- Fold level masks are composed of an integer level combined with any of the following bits: --- --- * `lexer.FOLD_BASE` --- The initial fold level. --- * `lexer.FOLD_BLANK` --- The line is blank. --- * `lexer.FOLD_HEADER` --- The line is a header, or fold point. --- @field indent_amount (table, Read-only) --- Table of indentation amounts in character columns, for line numbers starting from 1. --- @field line_state (table) --- Table of integer line states for line numbers starting from 1. --- Line states can be used by lexers for keeping track of persistent states. --- @field property (table) --- Map of key-value string pairs. --- @field property_expanded (table, Read-only) --- Map of key-value string pairs with `$()` and `%()` variable replacement performed in values. --- @field property_int (table, Read-only) --- Map of key-value pairs with values interpreted as numbers, or `0` if not found. --- @field style_at (table, Read-only) --- Table of style names at positions in the buffer starting from 1. --- @field folding (boolean) --- Whether or not folding is enabled for the lexers that support it. --- This option is disabled by default. --- This is an alias for `lexer.property['fold'] = '1|0'`. --- @field fold_on_zero_sum_lines (boolean) --- Whether or not to mark as a fold point lines that contain both an ending and starting fold --- point. For example, `} else {` would be marked as a fold point. --- This option is disabled by default. This is an alias for --- `lexer.property['fold.on.zero.sum.lines'] = '1|0'`. --- @field fold_compact (boolean) --- Whether or not blank lines after an ending fold point are included in that --- fold. --- This option is disabled by default. --- This is an alias for `lexer.property['fold.compact'] = '1|0'`. --- @field fold_by_indentation (boolean) --- Whether or not to fold based on indentation level if a lexer does not have --- a folder. --- Some lexers automatically enable this option. It is disabled by default. --- This is an alias for `lexer.property['fold.by.indentation'] = '1|0'`. --- @field fold_line_groups (boolean) --- Whether or not to fold multiple, consecutive line groups (such as line comments and import --- statements) and only show the top line. --- This option is disabled by default. --- This is an alias for `lexer.property['fold.line.groups'] = '1|0'`. -module('lexer')]=] - -if not require then - -- Substitute for Lua's require() function, which does not require the package module to - -- be loaded. - -- Note: all modules must be in the global namespace, which is the case in LexerLPeg's default - -- Lua State. - function require(name) return name == 'lexer' and M or _G[name] end -end - -local print = function(...) - local args = table.pack(...) - local msg = {} - for i = 1, args.n do - msg[#msg + 1] = tostring(args[i]) - end - vis:info(table.concat(msg, ' ')) -end - -lpeg = require('lpeg') -local lpeg_P, lpeg_R, lpeg_S, lpeg_V = lpeg.P, lpeg.R, lpeg.S, lpeg.V -local lpeg_Ct, lpeg_Cc, lpeg_Cp = lpeg.Ct, lpeg.Cc, lpeg.Cp -local lpeg_Cmt, lpeg_C = lpeg.Cmt, lpeg.C -local lpeg_match = lpeg.match - --- Searches for the given *name* in the given *path*. --- This is a safe implementation of Lua 5.2's `package.searchpath()` function that does not --- require the package module to be loaded. -local function searchpath(name, path) - local tried = {} - for part in path:gmatch('[^;]+') do - local filename = part:gsub('%?', name) - local ok, errmsg = loadfile(filename) - if ok or not errmsg:find('cannot open') then return filename end - tried[#tried + 1] = string.format("no file '%s'", filename) - end - return nil, table.concat(tried, '\n') -end - ---- --- Map of color name strings to color values in `0xBBGGRR` or `"#RRGGBB"` format. --- Note: for applications running within a terminal emulator, only 16 color values are recognized, --- regardless of how many colors a user's terminal actually supports. (A terminal emulator's --- settings determines how to actually display these recognized color values, which may end up --- being mapped to a completely different color set.) In order to use the light variant of a --- color, some terminals require a style's `bold` attribute must be set along with that normal --- color. Recognized color values are black (0x000000), red (0x000080), green (0x008000), yellow --- (0x008080), blue (0x800000), magenta (0x800080), cyan (0x808000), white (0xC0C0C0), light black --- (0x404040), light red (0x0000FF), light green (0x00FF00), light yellow (0x00FFFF), light blue --- (0xFF0000), light magenta (0xFF00FF), light cyan (0xFFFF00), and light white (0xFFFFFF). --- @name colors --- @class table -M.colors = setmetatable({}, { - __index = function(_, name) - local color = M.property['color.' .. name] - return tonumber(color) or color - end, __newindex = function(_, name, color) M.property['color.' .. name] = color end -}) - --- A style object that distills into a property string that can be read by the LPeg lexer. -local style_obj = {} -style_obj.__index = style_obj - --- Create a style object from a style name, property table, or legacy style string. -function style_obj.new(name_or_props) - local prop_string = tostring(name_or_props) - if type(name_or_props) == 'string' and name_or_props:find('^[%w_]+$') then - prop_string = string.format('$(style.%s)', name_or_props) - elseif type(name_or_props) == 'table' then - local settings = {} - for k, v in pairs(name_or_props) do - settings[#settings + 1] = type(v) ~= 'boolean' and string.format('%s:%s', k, v) or - string.format('%s%s', v and '' or 'not', k) - end - prop_string = table.concat(settings, ',') - end - return setmetatable({prop_string = prop_string}, style_obj) -end - --- Returns a new style based on this one with the properties defined in the given table or --- legacy style string. -function style_obj.__concat(self, props) - if type(props) == 'table' then props = tostring(style_obj.new(props)) end - return setmetatable({prop_string = string.format('%s,%s', self.prop_string, props)}, style_obj) -end - --- Returns this style object as property string for use with the LPeg lexer. -function style_obj.__tostring(self) return self.prop_string end - ---- --- Map of style names to style definition tables. --- --- Style names consist of the following default names as well as the token names defined by lexers. --- --- * `default`: The default style all others are based on. --- * `line_number`: The line number margin style. --- * `control_char`: The style of control character blocks. --- * `indent_guide`: The style of indentation guides. --- * `call_tip`: The style of call tip text. Only the `font`, `size`, `fore`, and `back` style --- definition fields are supported. --- * `fold_display_text`: The style of text displayed next to folded lines. --- * `class`, `comment`, `constant`, `embedded`, `error`, `function`, `identifier`, `keyword`, --- `label`, `number`, `operator`, `preprocessor`, `regex`, `string`, `type`, `variable`, --- `whitespace`: Some token names used by lexers. Some lexers may define more token names, --- so this list is not exhaustive. --- * *`lang`*`_whitespace`: A special style for whitespace tokens in lexer name *lang*. It --- inherits from `whitespace`, and is used in place of it for all lexers. --- --- Style definition tables may contain the following fields: --- --- * `font`: String font name. --- * `size`: Integer font size. --- * `bold`: Whether or not the font face is bold. The default value is `false`. --- * `weight`: Integer weight or boldness of a font, between 1 and 999. --- * `italics`: Whether or not the font face is italic. The default value is `false`. --- * `underlined`: Whether or not the font face is underlined. The default value is `false`. --- * `fore`: Font face foreground color in `0xBBGGRR` or `"#RRGGBB"` format. --- * `back`: Font face background color in `0xBBGGRR` or `"#RRGGBB"` format. --- * `eolfilled`: Whether or not the background color extends to the end of the line. The --- default value is `false`. --- * `case`: Font case: `'u'` for upper, `'l'` for lower, and `'m'` for normal, mixed case. The --- default value is `'m'`. --- * `visible`: Whether or not the text is visible. The default value is `true`. --- * `changeable`: Whether the text is changeable instead of read-only. The default value is --- `true`. --- @class table --- @name styles -M.styles = setmetatable({}, { - __index = function(_, name) return style_obj.new(name) end, __newindex = function(_, name, style) - if getmetatable(style) ~= style_obj then style = style_obj.new(style) end - M.property['style.' .. name] = tostring(style) - end -}) - --- Default styles. -local default = { - 'nothing', 'whitespace', 'comment', 'string', 'number', 'keyword', 'identifier', 'operator', - 'error', 'preprocessor', 'constant', 'variable', 'function', 'class', 'type', 'label', 'regex', - 'embedded' -} -for _, name in ipairs(default) do - M[name:upper()] = name - M['STYLE_' .. name:upper()] = style_obj.new(name) -- backward compatibility -end --- Predefined styles. -local predefined = { - 'default', 'line_number', 'brace_light', 'brace_bad', 'control_char', 'indent_guide', 'call_tip', - 'fold_display_text' -} -for _, name in ipairs(predefined) do - M[name:upper()] = name - M['STYLE_' .. name:upper()] = style_obj.new(name) -- backward compatibility -end - ---- --- Adds pattern *rule* identified by string *id* to the ordered list of rules for lexer *lexer*. --- @param lexer The lexer to add the given rule to. --- @param id The id associated with this rule. It does not have to be the same as the name --- passed to `token()`. --- @param rule The LPeg pattern of the rule. --- @see modify_rule --- @name add_rule -function M.add_rule(lexer, id, rule) - if lexer._lexer then lexer = lexer._lexer end -- proxy; get true parent - if not lexer._RULES then - lexer._RULES = {} - -- Contains an ordered list (by numerical index) of rule names. This is used in conjunction - -- with lexer._RULES for building _TOKENRULE. - lexer._RULEORDER = {} - end - lexer._RULES[id] = rule - lexer._RULEORDER[#lexer._RULEORDER + 1] = id - lexer:build_grammar() -end - ---- --- Replaces in lexer *lexer* the existing rule identified by string *id* with pattern *rule*. --- @param lexer The lexer to modify. --- @param id The id associated with this rule. --- @param rule The LPeg pattern of the rule. --- @name modify_rule -function M.modify_rule(lexer, id, rule) - if lexer._lexer then lexer = lexer._lexer end -- proxy; get true parent - lexer._RULES[id] = rule - lexer:build_grammar() -end - ---- --- Returns the rule identified by string *id*. --- @param lexer The lexer to fetch a rule from. --- @param id The id of the rule to fetch. --- @return pattern --- @name get_rule -function M.get_rule(lexer, id) - if lexer._lexer then lexer = lexer._lexer end -- proxy; get true parent - return lexer._RULES[id] -end - ---- --- Associates string *token_name* in lexer *lexer* with style table *style*. --- *style* may have the following fields: --- --- * `font`: String font name. --- * `size`: Integer font size. --- * `bold`: Whether or not the font face is bold. The default value is `false`. --- * `weight`: Integer weight or boldness of a font, between 1 and 999. --- * `italics`: Whether or not the font face is italic. The default value is `false`. --- * `underlined`: Whether or not the font face is underlined. The default value is `false`. --- * `fore`: Font face foreground color in `0xBBGGRR` or `"#RRGGBB"` format. --- * `back`: Font face background color in `0xBBGGRR` or `"#RRGGBB"` format. --- * `eolfilled`: Whether or not the background color extends to the end of the line. The --- default value is `false`. --- * `case`: Font case, `'u'` for upper, `'l'` for lower, and `'m'` for normal, mixed case. The --- default value is `'m'`. --- * `visible`: Whether or not the text is visible. The default value is `true`. --- * `changeable`: Whether the text is changeable instead of read-only. The default value is --- `true`. --- --- Field values may also contain "$(property.name)" expansions for properties defined in Scintilla, --- theme files, etc. --- @param lexer The lexer to add a style to. --- @param token_name The name of the token to associated with the style. --- @param style A style string for Scintilla. --- @usage lex:add_style('longstring', lexer.styles.string) --- @usage lex:add_style('deprecated_func', lexer.styles['function'] .. {italics = true} --- @usage lex:add_style('visible_ws', lexer.styles.whitespace .. {back = lexer.colors.grey} --- @name add_style -function M.add_style(lexer, token_name, style) - local num_styles = lexer._numstyles - if num_styles == 33 then num_styles = num_styles + 8 end -- skip predefined - if num_styles >= 256 then print('Too many styles defined (256 MAX)') end - lexer._TOKENSTYLES[token_name], lexer._numstyles = num_styles, num_styles + 1 - if type(style) == 'table' and not getmetatable(style) then style = style_obj.new(style) end - lexer._EXTRASTYLES[token_name] = tostring(style) - -- If the lexer is a proxy or a child that embedded itself, copy this style to the parent lexer. - if lexer._lexer then lexer._lexer:add_style(token_name, style) end -end - ---- --- Adds to lexer *lexer* a fold point whose beginning and end tokens are string *token_name* --- tokens with string content *start_symbol* and *end_symbol*, respectively. --- In the event that *start_symbol* may or may not be a fold point depending on context, and that --- additional processing is required, *end_symbol* may be a function that ultimately returns --- `1` (indicating a beginning fold point), `-1` (indicating an ending fold point), or `0` --- (indicating no fold point). That function is passed the following arguments: --- --- * `text`: The text being processed for fold points. --- * `pos`: The position in *text* of the beginning of the line currently being processed. --- * `line`: The text of the line currently being processed. --- * `s`: The position of *start_symbol* in *line*. --- * `symbol`: *start_symbol* itself. --- @param lexer The lexer to add a fold point to. --- @param token_name The token name of text that indicates a fold point. --- @param start_symbol The text that indicates the beginning of a fold point. --- @param end_symbol Either the text that indicates the end of a fold point, or a function that --- returns whether or not *start_symbol* is a beginning fold point (1), an ending fold point --- (-1), or not a fold point at all (0). --- @usage lex:add_fold_point(lexer.OPERATOR, '{', '}') --- @usage lex:add_fold_point(lexer.KEYWORD, 'if', 'end') --- @usage lex:add_fold_point(lexer.COMMENT, lexer.fold_consecutive_lines('#')) --- @usage lex:add_fold_point('custom', function(text, pos, line, s, symbol) ... end) --- @name add_fold_point -function M.add_fold_point(lexer, token_name, start_symbol, end_symbol) - if not lexer._FOLDPOINTS then lexer._FOLDPOINTS = {_SYMBOLS = {}} end - local symbols = lexer._FOLDPOINTS._SYMBOLS - if not lexer._FOLDPOINTS[token_name] then lexer._FOLDPOINTS[token_name] = {} end - if lexer._CASEINSENSITIVEFOLDPOINTS then - start_symbol = start_symbol:lower() - if type(end_symbol) == 'string' then end_symbol = end_symbol:lower() end - end - if type(end_symbol) == 'string' then - if not symbols[end_symbol] then symbols[#symbols + 1], symbols[end_symbol] = end_symbol, true end - lexer._FOLDPOINTS[token_name][start_symbol] = 1 - lexer._FOLDPOINTS[token_name][end_symbol] = -1 - else - lexer._FOLDPOINTS[token_name][start_symbol] = end_symbol -- function or int - end - if not symbols[start_symbol] then - symbols[#symbols + 1], symbols[start_symbol] = start_symbol, true - end - -- If the lexer is a proxy or a child that embedded itself, copy this fold point to the - -- parent lexer. - if lexer._lexer then lexer._lexer:add_fold_point(token_name, start_symbol, end_symbol) end -end - --- (Re)constructs `lexer._TOKENRULE`. -local function join_tokens(lexer) - local patterns, order = lexer._RULES, lexer._RULEORDER - local token_rule = patterns[order[1]] - for i = 2, #order do token_rule = token_rule + patterns[order[i]] end - lexer._TOKENRULE = token_rule + M.token(M.DEFAULT, M.any) - return lexer._TOKENRULE -end - --- Metatable for Scintillua grammars. --- These grammars are just tables ultimately passed to `lpeg.P()`. -local grammar_mt = { - __index = { - -- Adds lexer *lexer* and any of its embedded lexers to this grammar. - -- @param lexer The lexer to add. - add_lexer = function(self, lexer) - local lexer_name = lexer._PARENTNAME or lexer._NAME - local token_rule = lexer:join_tokens() - for _, child in ipairs(lexer._CHILDREN) do - if child._CHILDREN then self:add_lexer(child) end - local rules = child._EMBEDDEDRULES[lexer_name] - local rules_token_rule = self['__' .. child._NAME] or rules.token_rule - self[child._NAME] = (-rules.end_rule * rules_token_rule)^0 * rules.end_rule^-1 * - lpeg_V(lexer_name) - local embedded_child = '_' .. child._NAME - self[embedded_child] = rules.start_rule * (-rules.end_rule * rules_token_rule)^0 * - rules.end_rule^-1 - token_rule = lpeg_V(embedded_child) + token_rule - end - self['__' .. lexer_name] = token_rule -- can contain embedded lexer rules - self[lexer_name] = token_rule^0 - end - } -} - --- (Re)constructs `lexer._GRAMMAR`. --- @param initial_rule The name of the rule to start lexing with. The default value is --- `lexer._NAME`. Multilang lexers use this to start with a child rule if necessary. -local function build_grammar(lexer, initial_rule) - if not lexer._RULES then return end - if lexer._CHILDREN then - if not initial_rule then initial_rule = lexer._NAME end - local grammar = setmetatable({initial_rule}, grammar_mt) - grammar:add_lexer(lexer) - lexer._INITIALRULE = initial_rule - lexer._GRAMMAR = lpeg_Ct(lpeg_P(grammar)) - else - lexer._GRAMMAR = lpeg_Ct(lexer:join_tokens()^0) - end -end - ---- --- Embeds child lexer *child* in parent lexer *lexer* using patterns *start_rule* and *end_rule*, --- which signal the beginning and end of the embedded lexer, respectively. --- @param lexer The parent lexer. --- @param child The child lexer. --- @param start_rule The pattern that signals the beginning of the embedded lexer. --- @param end_rule The pattern that signals the end of the embedded lexer. --- @usage html:embed(css, css_start_rule, css_end_rule) --- @usage html:embed(lex, php_start_rule, php_end_rule) -- from php lexer --- @name embed -function M.embed(lexer, child, start_rule, end_rule) - if lexer._lexer then lexer = lexer._lexer end -- proxy; get true parent - -- Add child rules. - if not child._EMBEDDEDRULES then child._EMBEDDEDRULES = {} end - if not child._RULES then error('Cannot embed lexer with no rules') end - child._EMBEDDEDRULES[lexer._NAME] = { - start_rule = start_rule, token_rule = child:join_tokens(), end_rule = end_rule - } - if not lexer._CHILDREN then lexer._CHILDREN = {} end - local children = lexer._CHILDREN - children[#children + 1] = child - -- Add child styles. - for token, style in pairs(child._EXTRASTYLES) do lexer:add_style(token, style) end - -- Add child fold symbols. - if child._FOLDPOINTS then - for token_name, symbols in pairs(child._FOLDPOINTS) do - if token_name ~= '_SYMBOLS' then - for symbol, v in pairs(symbols) do lexer:add_fold_point(token_name, symbol, v) end - end - end - end - lexer:build_grammar() - child._lexer = lexer -- use parent's tokens if child is embedding itself -end - ---- --- Lexes a chunk of text *text* (that has an initial style number of *init_style*) using lexer --- *lexer*, returning a table of token names and positions. --- @param lexer The lexer to lex text with. --- @param text The text in the buffer to lex. --- @param init_style The current style. Multiple-language lexers use this to determine which --- language to start lexing in. --- @return table of token names and positions. --- @name lex -function M.lex(lexer, text, init_style) - if not lexer._GRAMMAR then return {M.DEFAULT, #text + 1} end - if not lexer._LEXBYLINE then - -- For multilang lexers, build a new grammar whose initial_rule is the current language. - if lexer._CHILDREN then - for style, style_num in pairs(lexer._TOKENSTYLES) do - if style_num == init_style then - local lexer_name = style:match('^(.+)_whitespace') or lexer._PARENTNAME or lexer._NAME - if lexer._INITIALRULE ~= lexer_name then lexer:build_grammar(lexer_name) end - break - end - end - end - return lpeg_match(lexer._GRAMMAR, text) - else - local function append(tokens, line_tokens, offset) - for i = 1, #line_tokens, 2 do - tokens[#tokens + 1] = line_tokens[i] - tokens[#tokens + 1] = line_tokens[i + 1] + offset - end - end - local tokens = {} - local offset = 0 - local grammar = lexer._GRAMMAR - for line in text:gmatch('[^\r\n]*\r?\n?') do - local line_tokens = lpeg_match(grammar, line) - if line_tokens then append(tokens, line_tokens, offset) end - offset = offset + #line - -- Use the default style to the end of the line if none was specified. - if tokens[#tokens] ~= offset then - tokens[#tokens + 1], tokens[#tokens + 2] = 'default', offset + 1 - end - end - return tokens - end -end - ---- --- Determines fold points in a chunk of text *text* using lexer *lexer*, returning a table of --- fold levels associated with line numbers. --- *text* starts at position *start_pos* on line number *start_line* with a beginning fold --- level of *start_level* in the buffer. --- @param lexer The lexer to fold text with. --- @param text The text in the buffer to fold. --- @param start_pos The position in the buffer *text* starts at, counting from 1. --- @param start_line The line number *text* starts on, counting from 1. --- @param start_level The fold level *text* starts on. --- @return table of fold levels associated with line numbers. --- @name fold -function M.fold(lexer, text, start_pos, start_line, start_level) - local folds = {} - if text == '' then return folds end - local fold = M.property_int['fold'] > 0 - local FOLD_BASE = M.FOLD_BASE - local FOLD_HEADER, FOLD_BLANK = M.FOLD_HEADER, M.FOLD_BLANK - if fold and lexer._FOLDPOINTS then - local lines = {} - for p, l in (text .. '\n'):gmatch('()(.-)\r?\n') do lines[#lines + 1] = {p, l} end - local fold_zero_sum_lines = M.property_int['fold.on.zero.sum.lines'] > 0 - local fold_compact = M.property_int['fold.compact'] > 0 - local fold_points = lexer._FOLDPOINTS - local fold_point_symbols = fold_points._SYMBOLS - local style_at, fold_level = M.style_at, M.fold_level - local line_num, prev_level = start_line, start_level - local current_level = prev_level - for _, captures in ipairs(lines) do - local pos, line = captures[1], captures[2] - if line ~= '' then - if lexer._CASEINSENSITIVEFOLDPOINTS then line = line:lower() end - local ranges = {} - local function is_valid_range(s, e) - if not s or not e then return false end - for i = 1, #ranges - 1, 2 do - local range_s, range_e = ranges[i], ranges[i + 1] - if s >= range_s and s <= range_e or e >= range_s and e <= range_e then - return false - end - end - ranges[#ranges + 1] = s - ranges[#ranges + 1] = e - return true - end - local level_decreased = false - for _, symbol in ipairs(fold_point_symbols) do - local word = not symbol:find('[^%w_]') - local s, e = line:find(symbol, 1, true) - while is_valid_range(s, e) do - -- if not word or line:find('^%f[%w_]' .. symbol .. '%f[^%w_]', s) then - local word_before = s > 1 and line:find('^[%w_]', s - 1) - local word_after = line:find('^[%w_]', e + 1) - if not word or not (word_before or word_after) then - local symbols = fold_points[style_at[start_pos + pos - 1 + s - 1]] - local level = symbols and symbols[symbol] - if type(level) == 'function' then - level = level(text, pos, line, s, symbol) - end - if type(level) == 'number' then - current_level = current_level + level - if level < 0 and current_level < prev_level then - -- Potential zero-sum line. If the level were to go back up on the same line, - -- the line may be marked as a fold header. - level_decreased = true - end - end - end - s, e = line:find(symbol, s + 1, true) - end - end - folds[line_num] = prev_level - if current_level > prev_level then - folds[line_num] = prev_level + FOLD_HEADER - elseif level_decreased and current_level == prev_level and fold_zero_sum_lines then - if line_num > start_line then - folds[line_num] = prev_level - 1 + FOLD_HEADER - else - -- Typing within a zero-sum line. - local level = fold_level[line_num] - 1 - if level > FOLD_HEADER then level = level - FOLD_HEADER end - if level > FOLD_BLANK then level = level - FOLD_BLANK end - folds[line_num] = level + FOLD_HEADER - current_level = current_level + 1 - end - end - if current_level < FOLD_BASE then current_level = FOLD_BASE end - prev_level = current_level - else - folds[line_num] = prev_level + (fold_compact and FOLD_BLANK or 0) - end - line_num = line_num + 1 - end - elseif fold and (lexer._FOLDBYINDENTATION or M.property_int['fold.by.indentation'] > 0) then - -- Indentation based folding. - -- Calculate indentation per line. - local indentation = {} - for indent, line in (text .. '\n'):gmatch('([\t ]*)([^\r\n]*)\r?\n') do - indentation[#indentation + 1] = line ~= '' and #indent - end - -- Find the first non-blank line before start_line. If the current line is indented, make - -- that previous line a header and update the levels of any blank lines inbetween. If the - -- current line is blank, match the level of the previous non-blank line. - local current_level = start_level - for i = start_line, 1, -1 do - local level = M.fold_level[i] - if level >= FOLD_HEADER then level = level - FOLD_HEADER end - if level < FOLD_BLANK then - local indent = M.indent_amount[i] - if indentation[1] and indentation[1] > indent then - folds[i] = FOLD_BASE + indent + FOLD_HEADER - for j = i + 1, start_line - 1 do folds[j] = start_level + FOLD_BLANK end - elseif not indentation[1] then - current_level = FOLD_BASE + indent - end - break - end - end - -- Iterate over lines, setting fold numbers and fold flags. - for i = 1, #indentation do - if indentation[i] then - current_level = FOLD_BASE + indentation[i] - folds[start_line + i - 1] = current_level - for j = i + 1, #indentation do - if indentation[j] then - if FOLD_BASE + indentation[j] > current_level then - folds[start_line + i - 1] = current_level + FOLD_HEADER - current_level = FOLD_BASE + indentation[j] -- for any blanks below - end - break - end - end - else - folds[start_line + i - 1] = current_level + FOLD_BLANK - end - end - else - -- No folding, reset fold levels if necessary. - local current_line = start_line - for _ in text:gmatch('\r?\n') do - folds[current_line] = start_level - current_line = current_line + 1 - end - end - return folds -end - ---- --- Creates a returns a new lexer with the given name. --- @param name The lexer's name. --- @param opts Table of lexer options. Options currently supported: --- * `lex_by_line`: Whether or not the lexer only processes whole lines of text (instead of --- arbitrary chunks of text) at a time. Line lexers cannot look ahead to subsequent lines. --- The default value is `false`. --- * `fold_by_indentation`: Whether or not the lexer does not define any fold points and that --- fold points should be calculated based on changes in line indentation. The default value --- is `false`. --- * `case_insensitive_fold_points`: Whether or not fold points added via --- `lexer.add_fold_point()` ignore case. The default value is `false`. --- * `inherit`: Lexer to inherit from. The default value is `nil`. --- @usage lexer.new('rhtml', {inherit = lexer.load('html')}) --- @name new -function M.new(name, opts) - local lexer = { - _NAME = assert(name, 'lexer name expected'), _LEXBYLINE = opts and opts['lex_by_line'], - _FOLDBYINDENTATION = opts and opts['fold_by_indentation'], - _CASEINSENSITIVEFOLDPOINTS = opts and opts['case_insensitive_fold_points'], - _lexer = opts and opts['inherit'] - } - - -- Create the initial maps for token names to style numbers and styles. - local token_styles = {} - for i = 1, #default do token_styles[default[i]] = i end - for i = 1, #predefined do token_styles[predefined[i]] = i + 32 end - lexer._TOKENSTYLES, lexer._numstyles = token_styles, #default + 1 - lexer._EXTRASTYLES = {} - - return setmetatable(lexer, { - __index = { - add_rule = M.add_rule, modify_rule = M.modify_rule, get_rule = M.get_rule, - add_style = M.add_style, add_fold_point = M.add_fold_point, join_tokens = join_tokens, - build_grammar = build_grammar, embed = M.embed, lex = M.lex, fold = M.fold - } - }) -end - --- Legacy support for older lexers. --- Processes the `lex._rules`, `lex._tokenstyles`, and `lex._foldsymbols` tables. Since legacy --- lexers may be processed up to twice, ensure their default styles and rules are not processed --- more than once. -local function process_legacy_lexer(lexer) - local function warn(msg) --[[io.stderr:write(msg, "\n")]]end - if not lexer._LEGACY then - lexer._LEGACY = true - warn("lexers as tables are deprecated; use 'lexer.new()'") - local token_styles = {} - for i = 1, #default do token_styles[default[i]] = i end - for i = 1, #predefined do token_styles[predefined[i]] = i + 32 end - lexer._TOKENSTYLES, lexer._numstyles = token_styles, #default + 1 - lexer._EXTRASTYLES = {} - setmetatable(lexer, getmetatable(M.new(''))) - if lexer._rules then - warn("lexer '_rules' table is deprecated; use 'add_rule()'") - for _, rule in ipairs(lexer._rules) do lexer:add_rule(rule[1], rule[2]) end - end - end - if lexer._tokenstyles then - warn("lexer '_tokenstyles' table is deprecated; use 'add_style()'") - for token, style in pairs(lexer._tokenstyles) do - -- If this legacy lexer is being processed a second time, only add styles added since - -- the first processing. - if not lexer._TOKENSTYLES[token] then lexer:add_style(token, style) end - end - end - if lexer._foldsymbols then - warn("lexer '_foldsymbols' table is deprecated; use 'add_fold_point()'") - for token_name, symbols in pairs(lexer._foldsymbols) do - if type(symbols) == 'table' and token_name ~= '_patterns' then - for symbol, v in pairs(symbols) do lexer:add_fold_point(token_name, symbol, v) end - end - end - if lexer._foldsymbols._case_insensitive then lexer._CASEINSENSITIVEFOLDPOINTS = true end - elseif lexer._fold then - lexer.fold = function(self, ...) return lexer._fold(...) end - end -end - -local lexers = {} -- cache of loaded lexers ---- --- Initializes or loads and returns the lexer of string name *name*. --- Scintilla calls this function in order to load a lexer. Parent lexers also call this function --- in order to load child lexers and vice-versa. The user calls this function in order to load --- a lexer when using Scintillua as a Lua library. --- @param name The name of the lexing language. --- @param alt_name The alternate name of the lexing language. This is useful for embedding the --- same child lexer with multiple sets of start and end tokens. --- @param cache Flag indicating whether or not to load lexers from the cache. This should only --- be `true` when initially loading a lexer (e.g. not from within another lexer for embedding --- purposes). The default value is `false`. --- @return lexer object --- @name load -function M.load(name, alt_name, cache) - if cache and lexers[alt_name or name] then return lexers[alt_name or name] end - - -- When using Scintillua as a stand-alone module, the `property`, `property_int`, and - -- `property_expanded` tables do not exist (they are not useful). Create them in order prevent - -- errors from occurring. - if not M.property then - M.property = setmetatable({['lexer.lpeg.home'] = package.path:gsub('/%?%.lua', '')}, { - __index = function() return '' end, - __newindex = function(t, k, v) rawset(t, k, tostring(v)) end - }) - M.property_int = setmetatable({}, { - __index = function(t, k) return tonumber(M.property[k]) or 0 end, - __newindex = function() error('read-only property') end - }) - M.property_expanded = setmetatable({}, { - __index = function(t, key) - return M.property[key]:gsub('[$%%](%b())', function(key) return t[key:sub(2, -2)] end) - end, __newindex = function() error('read-only property') end - }) - end - - -- Load the language lexer with its rules, styles, etc. - -- However, replace the default `WHITESPACE` style name with a unique whitespace style name - -- (and then automatically add it afterwards), since embedded lexing relies on these unique - -- whitespace style names. Note that loading embedded lexers changes `WHITESPACE` again, - -- so when adding it later, do not reference the potentially incorrect value. - M.WHITESPACE = (alt_name or name) .. '_whitespace' - local path = M.property['lexer.lpeg.home']:gsub(';', '/?.lua;') .. '/?.lua' - local lexer = dofile(assert(searchpath('lexers/'..name, path))) - assert(lexer, string.format("'%s.lua' did not return a lexer", name)) - if alt_name then lexer._NAME = alt_name end - if not getmetatable(lexer) or lexer._LEGACY then - -- A legacy lexer may need to be processed a second time in order to pick up any `_tokenstyles` - -- or `_foldsymbols` added after `lexer.embed_lexer()`. - process_legacy_lexer(lexer) - if lexer._lexer and lexer._lexer._LEGACY then - process_legacy_lexer(lexer._lexer) -- mainly for `_foldsymbols` edits - end - end - lexer:add_style((alt_name or name) .. '_whitespace', M.styles.whitespace) - - -- If the lexer is a proxy or a child that embedded itself, set the parent to be the main - -- lexer. Keep a reference to the old parent name since embedded child rules reference and - -- use that name. - if lexer._lexer then - lexer = lexer._lexer - lexer._PARENTNAME, lexer._NAME = lexer._NAME, alt_name or name - end - - if cache then lexers[alt_name or name] = lexer end - return lexer -end - --- The following are utility functions lexers will have access to. - --- Common patterns. -M.any = lpeg_P(1) -M.alpha = lpeg_R('AZ', 'az') -M.digit = lpeg_R('09') -M.alnum = lpeg_R('AZ', 'az', '09') -M.lower = lpeg_R('az') -M.upper = lpeg_R('AZ') -M.xdigit = lpeg_R('09', 'AF', 'af') -M.graph = lpeg_R('!~') -M.punct = lpeg_R('!/', ':@', '[\'', '{~') -M.space = lpeg_S('\t\v\f\n\r ') - -M.newline = lpeg_P('\r')^-1 * '\n' -M.nonnewline = 1 - M.newline - -M.dec_num = M.digit^1 -M.hex_num = '0' * lpeg_S('xX') * M.xdigit^1 -M.oct_num = '0' * lpeg_R('07')^1 -M.integer = lpeg_S('+-')^-1 * (M.hex_num + M.oct_num + M.dec_num) -M.float = lpeg_S('+-')^-1 * - ((M.digit^0 * '.' * M.digit^1 + M.digit^1 * '.' * M.digit^0 * -lpeg_P('.')) * - (lpeg_S('eE') * lpeg_S('+-')^-1 * M.digit^1)^-1 + - (M.digit^1 * lpeg_S('eE') * lpeg_S('+-')^-1 * M.digit^1)) -M.number = M.float + M.integer - -M.word = (M.alpha + '_') * (M.alnum + '_')^0 - --- Deprecated. -M.nonnewline_esc = 1 - (M.newline + '\\') + '\\' * M.any -M.ascii = lpeg_R('\000\127') -M.extend = lpeg_R('\000\255') -M.cntrl = lpeg_R('\000\031') -M.print = lpeg_R(' ~') - ---- --- Creates and returns a token pattern with token name *name* and pattern *patt*. --- If *name* is not a predefined token name, its style must be defined via `lexer.add_style()`. --- @param name The name of token. If this name is not a predefined token name, then a style --- needs to be assiciated with it via `lexer.add_style()`. --- @param patt The LPeg pattern associated with the token. --- @return pattern --- @usage local ws = token(lexer.WHITESPACE, lexer.space^1) --- @usage local annotation = token('annotation', '@' * lexer.word) --- @name token -function M.token(name, patt) - return lpeg_Cc(name) * patt * lpeg_Cp() -end - ---- --- Creates and returns a pattern that matches from string or pattern *prefix* until the end of --- the line. --- *escape* indicates whether the end of the line can be escaped with a '\' character. --- @param prefix String or pattern prefix to start matching at. --- @param escape Optional flag indicating whether or not newlines can be escaped by a '\' --- character. The default value is `false`. --- @return pattern --- @usage local line_comment = lexer.to_eol('//') --- @usage local line_comment = lexer.to_eol(S('#;')) --- @name to_eol -function M.to_eol(prefix, escape) - return prefix * (not escape and M.nonnewline or M.nonnewline_esc)^0 -end - ---- --- Creates and returns a pattern that matches a range of text bounded by strings or patterns *s* --- and *e*. --- This is a convenience function for matching more complicated ranges like strings with escape --- characters, balanced parentheses, and block comments (nested or not). *e* is optional and --- defaults to *s*. *single_line* indicates whether or not the range must be on a single line; --- *escapes* indicates whether or not to allow '\' as an escape character; and *balanced* --- indicates whether or not to handle balanced ranges like parentheses, and requires *s* and *e* --- to be different. --- @param s String or pattern start of a range. --- @param e Optional string or pattern end of a range. The default value is *s*. --- @param single_line Optional flag indicating whether or not the range must be on a single --- line. The default value is `false`. --- @param escapes Optional flag indicating whether or not the range end may be escaped by a '\' --- character. The default value is `false` unless *s* and *e* are identical, single-character --- strings. In that case, the default value is `true`. --- @param balanced Optional flag indicating whether or not to match a balanced range, like the --- "%b" Lua pattern. This flag only applies if *s* and *e* are different. --- @return pattern --- @usage local dq_str_escapes = lexer.range('"') --- @usage local dq_str_noescapes = lexer.range('"', false, false) --- @usage local unbalanced_parens = lexer.range('(', ')') --- @usage local balanced_parens = lexer.range('(', ')', false, false, true) --- @name range -function M.range(s, e, single_line, escapes, balanced) - if type(e) ~= 'string' and type(e) ~= 'userdata' then - e, single_line, escapes, balanced = s, e, single_line, escapes - end - local any = M.any - e - if single_line then any = any - '\n' end - if balanced then any = any - s end - if escapes == nil then - -- Only allow escapes by default for ranges with identical, single-character string delimiters. - escapes = type(s) == 'string' and #s == 1 and s == e - end - if escapes then any = any - '\\' + '\\' * M.any end - if balanced and s ~= e then - return lpeg_P{s * (any + lpeg_V(1))^0 * lpeg_P(e)^-1} - else - return s * any^0 * lpeg_P(e)^-1 - end -end - --- Deprecated function. Use `lexer.range()` instead. --- Creates and returns a pattern that matches a range of text bounded by *chars* characters. --- This is a convenience function for matching more complicated delimited ranges like strings --- with escape characters and balanced parentheses. *single_line* indicates whether or not the --- range must be on a single line, *no_escape* indicates whether or not to ignore '\' as an --- escape character, and *balanced* indicates whether or not to handle balanced ranges like --- parentheses and requires *chars* to be composed of two characters. --- @param chars The character(s) that bound the matched range. --- @param single_line Optional flag indicating whether or not the range must be on a single line. --- @param no_escape Optional flag indicating whether or not the range end character may be --- escaped by a '\\' character. --- @param balanced Optional flag indicating whether or not to match a balanced range, like the --- "%b" Lua pattern. This flag only applies if *chars* consists of two different characters --- (e.g. "()"). --- @return pattern --- @usage local dq_str_escapes = lexer.delimited_range('"') --- @usage local dq_str_noescapes = lexer.delimited_range('"', false, true) --- @usage local unbalanced_parens = lexer.delimited_range('()') --- @usage local balanced_parens = lexer.delimited_range('()', false, false, true) --- @see range --- @name delimited_range -function M.delimited_range(chars, single_line, no_escape, balanced) - print("lexer.delimited_range() is deprecated, use lexer.range()") - local s = chars:sub(1, 1) - local e = #chars == 2 and chars:sub(2, 2) or s - local range - local b = balanced and s or '' - local n = single_line and '\n' or '' - if no_escape then - local invalid = lpeg_S(e .. n .. b) - range = M.any - invalid - else - local invalid = lpeg_S(e .. n .. b) + '\\' - range = M.any - invalid + '\\' * M.any - end - if balanced and s ~= e then - return lpeg_P{s * (range + lpeg_V(1))^0 * e} - else - return s * range^0 * lpeg_P(e)^-1 - end -end - ---- --- Creates and returns a pattern that matches pattern *patt* only at the beginning of a line. --- @param patt The LPeg pattern to match on the beginning of a line. --- @return pattern --- @usage local preproc = token(lexer.PREPROCESSOR, lexer.starts_line(lexer.to_eol('#'))) --- @name starts_line -function M.starts_line(patt) - return lpeg_Cmt(lpeg_C(patt), function(input, index, match, ...) - local pos = index - #match - if pos == 1 then return index, ... end - local char = input:sub(pos - 1, pos - 1) - if char == '\n' or char == '\r' or char == '\f' then return index, ... end - end) -end - ---- --- Creates and returns a pattern that verifies the first non-whitespace character behind the --- current match position is in string set *s*. --- @param s String character set like one passed to `lpeg.S()`. --- @return pattern --- @usage local regex = lexer.last_char_includes('+-*!%^&|=,([{') * lexer.range('/') --- @name last_char_includes -function M.last_char_includes(s) - s = string.format('[%s]', s:gsub('[-%%%[]', '%%%1')) - return lpeg_P(function(input, index) - if index == 1 then return index end - local i = index - while input:sub(i - 1, i - 1):match('[ \t\r\n\f]') do i = i - 1 end - if input:sub(i - 1, i - 1):match(s) then return index end - end) -end - --- Deprecated function. Use `lexer.range()` instead. --- Returns a pattern that matches a balanced range of text that starts with string *start_chars* --- and ends with string *end_chars*. --- With single-character delimiters, this function is identical to `delimited_range(start_chars .. --- end_chars, false, true, true)`. --- @param start_chars The string starting a nested sequence. --- @param end_chars The string ending a nested sequence. --- @return pattern --- @usage local nested_comment = lexer.nested_pair('/*', '*/') --- @see range --- @name nested_pair -function M.nested_pair(start_chars, end_chars) - print("lexer.nested_pair() is deprecated, use lexer.range()") - local s, e = start_chars, lpeg_P(end_chars)^-1 - return lpeg_P{s * (M.any - s - end_chars + lpeg_V(1))^0 * e} -end - ---- --- Creates and returns a pattern that matches any single word in list or string *words*. --- *case_insensitive* indicates whether or not to ignore case when matching words. --- This is a convenience function for simplifying a set of ordered choice word patterns. --- @param word_list A list of words or a string list of words separated by spaces. --- @param case_insensitive Optional boolean flag indicating whether or not the word match is --- case-insensitive. The default value is `false`. --- @param word_chars Unused legacy parameter. --- @return pattern --- @usage local keyword = token(lexer.KEYWORD, word_match{'foo', 'bar', 'baz'}) --- @usage local keyword = token(lexer.KEYWORD, word_match({'foo-bar', 'foo-baz', 'bar-foo', --- 'bar-baz', 'baz-foo', 'baz-bar'}, true)) --- @usage local keyword = token(lexer.KEYWORD, word_match('foo bar baz')) --- @name word_match -function M.word_match(word_list, case_insensitive, word_chars) - if type(case_insensitive) == 'string' or type(word_chars) == 'boolean' then - -- Legacy `word_match(word_list, word_chars, case_insensitive)` form. - word_chars, case_insensitive = case_insensitive, word_chars - elseif type(word_list) == 'string' then - local words = word_list -- space-separated list of words - word_list = {} - for word in words:gsub('%-%-[^\n]+', ''):gmatch('%S+') do word_list[#word_list + 1] = word end - end - if not word_chars then word_chars = '' end - for _, word in ipairs(word_list) do - word_list[case_insensitive and word:lower() or word] = true - for char in word:gmatch('[^%w_%s]') do - if not word_chars:find(char, 1, true) then word_chars = word_chars .. char end - end - end - local chars = M.alnum + '_' - if word_chars ~= '' then chars = chars + lpeg_S(word_chars) end - return lpeg_Cmt(chars^1, function(input, index, word) - if case_insensitive then word = word:lower() end - return word_list[word] and index or nil - end) -end - --- Deprecated legacy function. Use `parent:embed()` instead. --- Embeds child lexer *child* in parent lexer *parent* using patterns *start_rule* and *end_rule*, --- which signal the beginning and end of the embedded lexer, respectively. --- @param parent The parent lexer. --- @param child The child lexer. --- @param start_rule The pattern that signals the beginning of the embedded lexer. --- @param end_rule The pattern that signals the end of the embedded lexer. --- @usage lexer.embed_lexer(M, css, css_start_rule, css_end_rule) --- @usage lexer.embed_lexer(html, M, php_start_rule, php_end_rule) --- @usage lexer.embed_lexer(html, ruby, ruby_start_rule, ruby_end_rule) --- @see embed --- @name embed_lexer -function M.embed_lexer(parent, child, start_rule, end_rule) - if not getmetatable(parent) then process_legacy_lexer(parent) end - if not getmetatable(child) then process_legacy_lexer(child) end - parent:embed(child, start_rule, end_rule) -end - --- Determines if the previous line is a comment. --- This is used for determining if the current comment line is a fold point. --- @param prefix The prefix string defining a comment. --- @param text The text passed to a fold function. --- @param pos The pos passed to a fold function. --- @param line The line passed to a fold function. --- @param s The s passed to a fold function. -local function prev_line_is_comment(prefix, text, pos, line, s) - local start = line:find('%S') - if start < s and not line:find(prefix, start, true) then return false end - local p = pos - 1 - if text:sub(p, p) == '\n' then - p = p - 1 - if text:sub(p, p) == '\r' then p = p - 1 end - if text:sub(p, p) ~= '\n' then - while p > 1 and text:sub(p - 1, p - 1) ~= '\n' do p = p - 1 end - while text:sub(p, p):find('^[\t ]$') do p = p + 1 end - return text:sub(p, p + #prefix - 1) == prefix - end - end - return false -end - --- Determines if the next line is a comment. --- This is used for determining if the current comment line is a fold point. --- @param prefix The prefix string defining a comment. --- @param text The text passed to a fold function. --- @param pos The pos passed to a fold function. --- @param line The line passed to a fold function. --- @param s The s passed to a fold function. -local function next_line_is_comment(prefix, text, pos, line, s) - local p = text:find('\n', pos + s) - if p then - p = p + 1 - while text:sub(p, p):find('^[\t ]$') do p = p + 1 end - return text:sub(p, p + #prefix - 1) == prefix - end - return false -end - ---- --- Returns for `lexer.add_fold_point()` the parameters needed to fold consecutive lines that --- start with string *prefix*. --- @param prefix The prefix string (e.g. a line comment). --- @usage lex:add_fold_point(lexer.COMMENT, lexer.fold_consecutive_lines('--')) --- @usage lex:add_fold_point(lexer.COMMENT, lexer.fold_consecutive_lines('//')) --- @usage lex:add_fold_point(lexer.KEYWORD, lexer.fold_consecutive_lines('import')) --- @name fold_consecutive_lines -function M.fold_consecutive_lines(prefix) - local property_int = M.property_int - return prefix, function(text, pos, line, s) - if property_int['fold.line.groups'] == 0 then return 0 end - if s > 1 and line:match('^%s*()') < s then return 0 end - local prev_line_comment = prev_line_is_comment(prefix, text, pos, line, s) - local next_line_comment = next_line_is_comment(prefix, text, pos, line, s) - if not prev_line_comment and next_line_comment then return 1 end - if prev_line_comment and not next_line_comment then return -1 end - return 0 - end -end - --- Deprecated legacy function. Use `lexer.fold_consecutive_lines()` instead. --- Returns a fold function (to be passed to `lexer.add_fold_point()`) that folds consecutive --- line comments that start with string *prefix*. --- @param prefix The prefix string defining a line comment. --- @usage lex:add_fold_point(lexer.COMMENT, '--', lexer.fold_line_comments('--')) --- @usage lex:add_fold_point(lexer.COMMENT, '//', lexer.fold_line_comments('//')) --- @name fold_line_comments -function M.fold_line_comments(prefix) - print('lexer.fold_line_comments() is deprecated, use lexer.fold_consecutive_lines()') - return select(2, M.fold_consecutive_lines(prefix)) -end - ---[[ The functions and fields below were defined in C. - ---- --- Returns the line number (starting from 1) of the line that contains position *pos*, which --- starts from 1. --- @param pos The position to get the line number of. --- @return number -local function line_from_position(pos) end -]] - -return M