Class: Rouge::Lexer Abstract
- Inherits:
-
Object
- Object
- Rouge::Lexer
- Includes:
- Token::Tokens
- Defined in:
- lib/rouge/lexer.rb
Overview
A lexer transforms text into a stream of ‘[token, chunk]` pairs.
Direct Known Subclasses
Defined Under Namespace
Classes: AmbiguousGuess
Constant Summary
Constants included from Token::Tokens
Token::Tokens::Num, Token::Tokens::Str
Class Method Summary collapse
-
.aliases(*args) ⇒ Object
Used to specify alternate names this lexer class may be found by.
-
.all ⇒ Object
A list of all lexers.
-
.analyze_text(text) ⇒ Object
abstract
Return a number between 0 and 1 indicating the likelihood that the text given should be lexed with this lexer.
- .assert_utf8!(str) ⇒ Object
- .default_options(o = {}) ⇒ Object
-
.demo(arg = :absent) ⇒ Object
Specify or get a small demo string for this lexer.
-
.demo_file(arg = :absent) ⇒ Object
Specify or get the path name containing a small demo for this lexer (can be overriden by Lexer.demo).
-
.desc(arg = :absent) ⇒ Object
Specify or get this lexer’s description.
-
.filenames(*fnames) ⇒ Object
Specify a list of filename globs associated with this lexer.
-
.find(name) ⇒ Object
Given a string, return the correct lexer class.
-
.find_fancy(str, code = nil) ⇒ Object
Find a lexer, with fancy shiny features.
-
.guess(info = {}) ⇒ Object
Guess which lexer to use based on a hash of info.
- .guess_by_filename(fname) ⇒ Object
- .guess_by_mimetype(mt) ⇒ Object
- .guess_by_source(source) ⇒ Object
-
.guesses(info = {}) ⇒ Object
Guess which lexer to use based on a hash of info.
-
.lex(stream, opts = {}, &b) ⇒ Object
Lexes ‘stream` with the given options.
-
.mimetypes(*mts) ⇒ Object
Specify a list of mimetypes associated with this lexer.
-
.tag(t = nil) ⇒ Object
Used to specify or get the canonical name of this lexer class.
Instance Method Summary collapse
- #debug ⇒ Object deprecated Deprecated.
-
#initialize(opts = {}) ⇒ Lexer
constructor
Create a new lexer with the given options.
-
#lex(string, opts = {}, &b) ⇒ Object
Given a string, yield [token, chunk] pairs.
-
#option(k, v = :absent) ⇒ Object
get or specify one option for this lexer.
-
#options(o = {}) ⇒ Object
get and/or specify the options for this lexer.
-
#reset! ⇒ Object
abstract
Called after each lex is finished.
-
#stream_tokens(stream, &b) ⇒ Object
abstract
Yield ‘[token, chunk]` pairs, given a prepared input stream.
-
#tag ⇒ Object
delegated to Lexer.tag.
Methods included from Token::Tokens
Constructor Details
#initialize(opts = {}) ⇒ Lexer
Create a new lexer with the given options. Individual lexers may specify extra options. The only current globally accepted option is ‘:debug`.
316 317 318 319 320 |
# File 'lib/rouge/lexer.rb', line 316 def initialize(opts={}) (opts) @debug = option(:debug) end |
Class Method Details
.aliases(*args) ⇒ Object
Used to specify alternate names this lexer class may be found by.
264 265 266 267 268 |
# File 'lib/rouge/lexer.rb', line 264 def aliases(*args) args.map!(&:to_s) args.each { |arg| Lexer.register(arg, self) } (@aliases ||= []).concat(args) end |
.all ⇒ Object
Returns a list of all lexers.
90 91 92 |
# File 'lib/rouge/lexer.rb', line 90 def all registry.values.uniq end |
.analyze_text(text) ⇒ Object
Return a number between 0 and 1 indicating the likelihood that the text given should be lexed with this lexer. The default implementation returns 0. Values under 0.5 will only be used to disambiguate filename or mimetype matches.
419 420 421 |
# File 'lib/rouge/lexer.rb', line 419 def self.analyze_text(text) 0 end |
.assert_utf8!(str) ⇒ Object
291 292 293 294 295 296 297 |
# File 'lib/rouge/lexer.rb', line 291 def assert_utf8!(str) return if %w(US-ASCII UTF-8).include? str.encoding.name raise EncodingError.new( "Bad encoding: #{str.encoding.names.join(',')}. " + "Please convert your string to UTF-8." ) end |
.default_options(o = {}) ⇒ Object
20 21 22 23 24 |
# File 'lib/rouge/lexer.rb', line 20 def (o={}) @default_options ||= {} @default_options.merge!(o) @default_options end |
.demo(arg = :absent) ⇒ Object
Specify or get a small demo string for this lexer
83 84 85 86 87 |
# File 'lib/rouge/lexer.rb', line 83 def demo(arg=:absent) return @demo = arg unless arg == :absent @demo = File.read(demo_file) end |
.demo_file(arg = :absent) ⇒ Object
Specify or get the path name containing a small demo for this lexer (can be overriden by demo).
76 77 78 79 80 |
# File 'lib/rouge/lexer.rb', line 76 def demo_file(arg=:absent) return @demo_file = Pathname.new(arg) unless arg == :absent @demo_file = Pathname.new(__FILE__).dirname.join('demos', tag) end |
.desc(arg = :absent) ⇒ Object
Specify or get this lexer’s description.
66 67 68 69 70 71 72 |
# File 'lib/rouge/lexer.rb', line 66 def desc(arg=:absent) if arg == :absent @desc else @desc = arg end end |
.filenames(*fnames) ⇒ Object
Specify a list of filename globs associated with this lexer.
276 277 278 |
# File 'lib/rouge/lexer.rb', line 276 def filenames(*fnames) (@filenames ||= []).concat(fnames) end |
.find(name) ⇒ Object
Given a string, return the correct lexer class.
27 28 29 |
# File 'lib/rouge/lexer.rb', line 27 def find(name) registry[name.to_s] end |
.find_fancy(str, code = nil) ⇒ Object
Find a lexer, with fancy shiny features.
-
The string you pass can include CGI-style options
Lexer.find_fancy('erb?parent=tex')
-
You can pass the special name ‘guess’ so we guess for you, and you can pass a second argument of the code to guess by
Lexer.find_fancy('guess', "#!/bin/bash\necho Hello, world")
This is used in the Redcarpet plugin as well as Rouge’s own markdown lexer for highlighting internal code blocks.
45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 |
# File 'lib/rouge/lexer.rb', line 45 def find_fancy(str, code=nil) name, opts = str ? str.split('?', 2) : [nil, ''] # parse the options hash from a cgi-style string opts = CGI.parse(opts || '').map do |k, vals| [ k.to_sym, vals.empty? ? true : vals[0] ] end opts = Hash[opts] lexer_class = case name when 'guess', nil self.guess(:source => code, :mimetype => opts[:mimetype]) when String self.find(name) end lexer_class && lexer_class.new(opts) end |
.guess(info = {}) ⇒ Object
Guess which lexer to use based on a hash of info.
143 144 145 146 147 148 149 150 |
# File 'lib/rouge/lexer.rb', line 143 def guess(info={}) lexers = guesses(info) return Lexers::PlainText if lexers.empty? return lexers[0] if lexers.size == 1 raise AmbiguousGuess.new(lexers) end |
.guess_by_filename(fname) ⇒ Object
156 157 158 |
# File 'lib/rouge/lexer.rb', line 156 def guess_by_filename(fname) guess :filename => fname end |
.guess_by_mimetype(mt) ⇒ Object
152 153 154 |
# File 'lib/rouge/lexer.rb', line 152 def guess_by_mimetype(mt) guess :mimetype => mt end |
.guess_by_source(source) ⇒ Object
160 161 162 |
# File 'lib/rouge/lexer.rb', line 160 def guess_by_source(source) guess :source => source end |
.guesses(info = {}) ⇒ Object
Guess which lexer to use based on a hash of info.
This accepts the same arguments as Lexer.guess, but will never throw an error. It will return a (possibly empty) list of potential lexers to use.
99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 |
# File 'lib/rouge/lexer.rb', line 99 def guesses(info={}) mimetype, filename, source = info.values_at(:mimetype, :filename, :source) lexers = registry.values.uniq total_size = lexers.size lexers = filter_by_mimetype(lexers, mimetype) if mimetype return lexers if lexers.size == 1 lexers = filter_by_filename(lexers, filename) if filename return lexers if lexers.size == 1 if source # If we're filtering against *all* lexers, we only use confident return # values from analyze_text. But if we've filtered down already, we can trust # the analysis more. source_threshold = lexers.size < total_size ? 0 : 0.5 return [best_by_source(lexers, source, source_threshold)].compact end [] end |
.lex(stream, opts = {}, &b) ⇒ Object
Lexes ‘stream` with the given options. The lex is delegated to a new instance.
16 17 18 |
# File 'lib/rouge/lexer.rb', line 16 def lex(stream, opts={}, &b) new(opts).lex(stream, &b) end |
.mimetypes(*mts) ⇒ Object
Specify a list of mimetypes associated with this lexer.
286 287 288 |
# File 'lib/rouge/lexer.rb', line 286 def mimetypes(*mts) (@mimetypes ||= []).concat(mts) end |
.tag(t = nil) ⇒ Object
Used to specify or get the canonical name of this lexer class.
248 249 250 251 252 253 |
# File 'lib/rouge/lexer.rb', line 248 def tag(t=nil) return @tag if t.nil? @tag = t.to_s Lexer.register(@tag, self) end |
Instance Method Details
#debug ⇒ Object
Instead of ‘debug { “foo” }`, simply `puts “foo” if @debug`.
Leave a debug message if the ‘:debug` option is set. The message is given as a block because some debug messages contain calculated information that is unnecessary for lexing in the real world.
Calls to this method should be guarded with “if @debug” for best performance when debugging is turned off.
350 351 352 353 |
# File 'lib/rouge/lexer.rb', line 350 def debug warn "Lexer#debug is deprecated. Simply puts if @debug instead." puts yield if @debug end |
#lex(string, opts = {}, &b) ⇒ Object
Given a string, yield [token, chunk] pairs. If no block is given, an enumerator is returned.
367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 |
# File 'lib/rouge/lexer.rb', line 367 def lex(string, opts={}, &b) return enum_for(:lex, string) unless block_given? Lexer.assert_utf8!(string) reset! unless opts[:continue] # consolidate consecutive tokens of the same type last_token = nil last_val = nil stream_tokens(string) do |tok, val| next if val.empty? if tok == last_token last_val << val next end b.call(last_token, last_val) if last_token last_token = tok last_val = val end b.call(last_token, last_val) if last_token end |
#option(k, v = :absent) ⇒ Object
get or specify one option for this lexer
330 331 332 333 334 335 336 |
# File 'lib/rouge/lexer.rb', line 330 def option(k, v=:absent) if v == :absent [k] else ({ k => v }) end end |
#options(o = {}) ⇒ Object
get and/or specify the options for this lexer.
323 324 325 326 327 |
# File 'lib/rouge/lexer.rb', line 323 def (o={}) (@options ||= {}).merge!(o) self.class..merge(@options) end |
#reset! ⇒ Object
Called after each lex is finished. The default implementation is a noop.
359 360 |
# File 'lib/rouge/lexer.rb', line 359 def reset! end |
#stream_tokens(stream, &b) ⇒ Object
Yield ‘[token, chunk]` pairs, given a prepared input stream. This must be implemented.
405 406 407 |
# File 'lib/rouge/lexer.rb', line 405 def stream_tokens(stream, &b) raise 'abstract' end |
#tag ⇒ Object
delegated to tag
394 395 396 |
# File 'lib/rouge/lexer.rb', line 394 def tag self.class.tag end |