Class: HH::Syntax::Ruby

Inherits:
Tokenizer show all
Defined in:
lib/ext/highlighter/lang/ruby.rb

Overview

A tokenizer for the Ruby language. It recognizes all common syntax (and some less common syntax) but because it is not a true lexer, it will make mistakes on some ambiguous cases.

Constant Summary collapse

KEYWORDS =

The list of all identifiers recognized as keywords.

%w{if then elsif else end begin do rescue ensure while for
class module def yield raise until unless and or not when
case super undef break next redo retry in return alias
defined?}

Instance Attribute Summary

Attributes inherited from Tokenizer

#chunk, #group

Instance Method Summary collapse

Methods inherited from Tokenizer

#finish, #option, #set, #start, #teardown, #tokenize

Instance Method Details

#setupObject

Perform ruby-specific setup



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# File 'lib/ext/highlighter/lang/ruby.rb', line 17

def setup
  @selector = false
  @allow_operator = false
  @heredocs = []
end

#stepObject

Step through a single iteration of the tokenization process.



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# File 'lib/ext/highlighter/lang/ruby.rb', line 24

def step
  case
    when bol? && check( /=begin/ )
      start_group( :comment, scan_until( /^=end#{EOL}/ ) )
    when bol? && check( /__END__#{EOL}/ )
      start_group( :comment, scan_until( /\Z/ ) )
  else
    case
      when check( /def\s+/ )
        start_group :keyword, scan( /def\s+/ )
        start_group :method,  scan_until( /(?=[;(\s]|#{EOL})/ )
      when check( /class\s+/ )
        start_group :keyword, scan( /class\s+/ )
        start_group :class,  scan_until( /(?=[;\s<]|#{EOL})/ )
      when check( /module\s+/ )
        start_group :keyword, scan( /module\s+/ )
        start_group :module,  scan_until( /(?=[;\s]|#{EOL})/ )
      when check( /::/ )
        start_group :punct, scan(/::/)
      when check( /:"/ )
        start_group :symbol, scan(/:/)
        scan_delimited_region :symbol, :symbol, "", true
        @allow_operator = true
      when check( /:'/ )
        start_group :symbol, scan(/:/)
        scan_delimited_region :symbol, :symbol, "", false
        @allow_operator = true
      when scan( /:[_a-zA-Z@$][$@\w]*[=!?]?/ )
        start_group :symbol, matched
        @allow_operator = true
      when scan( /\?(\\[^\n\r]|[^\\\n\r\s])/ )
        start_group :char, matched
        @allow_operator = true
      when check( /(__FILE__|__LINE__|true|false|nil|self)[?!]?/ )
        if @selector || matched[-1] == ?? || matched[-1] == ?!
          start_group :ident,
            scan(/(__FILE__|__LINE__|true|false|nil|self)[?!]?/)
        else
          start_group :constant,
            scan(/(__FILE__|__LINE__|true|false|nil|self)/)
        end
        @selector = false
        @allow_operator = true
      when scan(/0([bB][01]+|[oO][0-7]+|[dD][0-9]+|[xX][0-9a-fA-F]+)/)
        start_group :number, matched
        @allow_operator = true
      else
        case peek(2)
          when "%r"
            scan_delimited_region :punct, :regex, scan( /../ ), true
            @allow_operator = true
          when "%w", "%q"
            scan_delimited_region :punct, :string, scan( /../ ), false
            @allow_operator = true
          when "%s"
            scan_delimited_region :punct, :symbol, scan( /../ ), false
            @allow_operator = true
          when "%W", "%Q", "%x"
            scan_delimited_region :punct, :string, scan( /../ ), true
            @allow_operator = true
          when /%[^\sa-zA-Z0-9]/
            scan_delimited_region :punct, :string, scan( /./ ), true
            @allow_operator = true
          when "<<"
            saw_word = ( chunk[-1,1] =~ /[\w!?]/ )
            start_group :punct, scan( /<</ )
            if saw_word
              @allow_operator = false
              return
            end

            float_right = scan( /-/ )
            append "-" if float_right
            if ( type = scan( /['"]/ ) )
              append type
              delim = scan_until( /(?=#{type})/ )
              if delim.nil?
                append scan_until( /\Z/ )
                return
              end
            else
              delim = scan( /\w+/ ) or return
            end
            start_group :constant, delim
            start_group :punct, scan( /#{type}/ ) if type
            @heredocs << [ float_right, type, delim ]
            @allow_operator = true
          else
            case peek(1)
              when /[\n\r]/
                unless @heredocs.empty?
                  scan_heredoc(*@heredocs.shift)
                else
                  start_group :normal, scan( /\s+/ )
                end
                @allow_operator = false
              when /\s/
                start_group :normal, scan( /\s+/ )
              when "#"
                start_group :comment, scan( /#[^\n\r]*/ )
              when /[A-Z]/
                start_group @selector ? :ident : :constant, scan( /\w+/ )
                @allow_operator = true
              when /[a-z_]/
                word = scan( /\w+[?!]?/ )
                if !@selector && KEYWORDS.include?( word )
                  start_group :keyword, word
                  @allow_operator = false
                elsif
                  start_group :ident, word
                  @allow_operator = true
                end
                @selector = false
              when /\d/
                start_group :number,
                  scan( /[\d_]+(\.[\d_]+)?([eE][\d_]+)?/ )
                @allow_operator = true
              when '"'
                scan_delimited_region :punct, :string, "", true
                @allow_operator = true
              when '/'
                if @allow_operator
                  start_group :punct, scan(%r{/})
                  @allow_operator = false
                else
                  scan_delimited_region :punct, :regex, "", true
                  @allow_operator = true
                end
              when "'"
                scan_delimited_region :punct, :string, "", false
                @allow_operator = true
              when "."
                dots = scan( /\.{1,3}/ )
                start_group :punct, dots
                @selector = ( dots.length == 1 )
              when /[@]/
                start_group :attribute, scan( /@{1,2}\w*/ )
                @allow_operator = true
              when /[$]/
                start_group :global, scan(/\$/)
                start_group :global, scan( /\w+|./ ) if check(/./)
                @allow_operator = true
              when /[-!?*\/+=<>(\[\{}:;,&|%]/
                start_group :punct, scan(/./)
                @allow_operator = false
              when /[)\]]/
                start_group :punct, scan(/./)
                @allow_operator = true
              else
                # all else just falls through this, to prevent
                # infinite loops...
                append getch
            end
        end
    end
  end
end