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.
- .load_const(const_name, relpath) ⇒ Object
-
.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`.
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# File 'lib/rouge/lexer.rb', line 323 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.
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# File 'lib/rouge/lexer.rb', line 271 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.
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# File 'lib/rouge/lexer.rb', line 97 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.
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# File 'lib/rouge/lexer.rb', line 426 def self.analyze_text(text) 0 end |
.assert_utf8!(str) ⇒ Object
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# File 'lib/rouge/lexer.rb', line 298 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
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# File 'lib/rouge/lexer.rb', line 27 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
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# File 'lib/rouge/lexer.rb', line 90 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).
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# File 'lib/rouge/lexer.rb', line 83 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.
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# File 'lib/rouge/lexer.rb', line 73 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.
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# File 'lib/rouge/lexer.rb', line 283 def filenames(*fnames) (@filenames ||= []).concat(fnames) end |
.find(name) ⇒ Object
Given a string, return the correct lexer class.
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# File 'lib/rouge/lexer.rb', line 34 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.
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# File 'lib/rouge/lexer.rb', line 52 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.
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# File 'lib/rouge/lexer.rb', line 150 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
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# File 'lib/rouge/lexer.rb', line 163 def guess_by_filename(fname) guess :filename => fname end |
.guess_by_mimetype(mt) ⇒ Object
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# File 'lib/rouge/lexer.rb', line 159 def guess_by_mimetype(mt) guess :mimetype => mt end |
.guess_by_source(source) ⇒ Object
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# File 'lib/rouge/lexer.rb', line 167 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.
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# File 'lib/rouge/lexer.rb', line 106 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.
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# File 'lib/rouge/lexer.rb', line 16 def lex(stream, opts={}, &b) new(opts).lex(stream, &b) end |
.load_const(const_name, relpath) ⇒ Object
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# File 'lib/rouge/lexer.rb', line 20 def load_const(const_name, relpath) return if Lexers.const_defined?(const_name) root = Pathname.new(__FILE__).dirname.join('lexers') load root.join(relpath) end |
.mimetypes(*mts) ⇒ Object
Specify a list of mimetypes associated with this lexer.
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# File 'lib/rouge/lexer.rb', line 293 def mimetypes(*mts) (@mimetypes ||= []).concat(mts) end |
.tag(t = nil) ⇒ Object
Used to specify or get the canonical name of this lexer class.
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# File 'lib/rouge/lexer.rb', line 255 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.
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# File 'lib/rouge/lexer.rb', line 357 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.
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# File 'lib/rouge/lexer.rb', line 374 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
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# File 'lib/rouge/lexer.rb', line 337 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.
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# File 'lib/rouge/lexer.rb', line 330 def (o={}) (@options ||= {}).merge!(o) self.class..merge(@options) end |
#reset! ⇒ Object
Called after each lex is finished. The default implementation is a noop.
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# File 'lib/rouge/lexer.rb', line 366 def reset! end |
#stream_tokens(stream, &b) ⇒ Object
Yield ‘[token, chunk]` pairs, given a prepared input stream. This must be implemented.
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# File 'lib/rouge/lexer.rb', line 412 def stream_tokens(stream, &b) raise 'abstract' end |
#tag ⇒ Object
delegated to tag
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# File 'lib/rouge/lexer.rb', line 401 def tag self.class.tag end |