Class: CodeRay::Scanners::JavaScript

Inherits:
Scanner
  • Object
show all
Includes:
CodeRay::Streamable
Defined in:
lib/coderay/scanners/java_script.rb

Constant Summary collapse

KEYWORDS =

The actual JavaScript keywords.

%w[
  break case catch continue default delete do else
  false finally for function if in instanceof new null
  return switch throw true try typeof var void while with
]
MAGIC_VARIABLES =

arguments was introduced in JavaScript 1.4

%w[ this arguments ]
KEYWORDS_EXPECTING_VALUE = 
WordList.new.add %w[
  case delete in instanceof new return throw typeof while with
]
RESERVED_WORDS =

Reserved for future use.

%w[
  abstract boolean byte char class debugger double enum export extends
  final float goto implements import int interface long native package
  private protected public short static super synchronized throws transient
  volatile
]
IDENT_KIND = 
WordList.new(:ident).
add(RESERVED_WORDS, :reserved).
add(MAGIC_VARIABLES, :local_variable).
add(KEYWORDS, :keyword)
ESCAPE = 
/ [bfnrtv\n\\'"] | x[a-fA-F0-9]{1,2} | [0-7]{1,3} /x
UNICODE_ESCAPE = 
/ u[a-fA-F0-9]{4} | U[a-fA-F0-9]{8} /x
REGEXP_ESCAPE = 
/ [bBdDsSwW] /x
STRING_CONTENT_PATTERN = 
{
  "'" => /[^\\']+/,
  '"' => /[^\\"]+/,
  '/' => /[^\\\/]+/,
}
KEY_CHECK_PATTERN = 
{
  "'" => / [^\\']* (?: \\.? [^\\']* )* '? \s* : /x,
  '"' => / [^\\"]* (?: \\.? [^\\"]* )* "? \s* : /x,
}

Constants inherited from Scanner

Scanner::DEFAULT_OPTIONS, Scanner::ScanError

Instance Method Summary collapse

Methods inherited from Scanner

#column, #each, file_extension, #initialize, #line, normify, #reset, streamable?, #streaming?, #string=, #tokenize, #tokens

Methods included from Plugin

#helper, #included, #plugin_host, #plugin_id, #register_for, #title

Constructor Details

This class inherits a constructor from CodeRay::Scanners::Scanner

Instance Method Details

#scan_tokens(tokens, options) ⇒ Object 



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# File 'lib/coderay/scanners/java_script.rb', line 50

def scan_tokens tokens, options

  state = :initial
  string_delimiter = nil
  value_expected = true
  key_expected = false

  until eos?

    kind = nil
    match = nil
    
    case state

    when :initial

      if match = scan(/ \s+ | \\\n /x)
        value_expected = true if !value_expected && match.index(?\n)
        tokens << [match, :space]
        next

      elsif scan(%r! // [^\n\\]* (?: \\. [^\n\\]* )* | /\* (?: .*? \*/ | .* ) !mx)
        value_expected = true
        kind = :comment

      elsif check(/\d/)
        key_expected = value_expected = false
        if scan(/0[xX][0-9A-Fa-f]+/)
          kind = :hex
        elsif scan(/(?>0[0-7]+)(?![89.eEfF])/)
          kind = :oct
        elsif scan(/\d+[fF]|\d*\.\d+(?:[eE][+-]?\d+)?[fF]?|\d+[eE][+-]?\d+[fF]?/)
          kind = :float
        elsif scan(/\d+/)
          kind = :integer
        end
        
      elsif match = scan(/ [-+*=<>?:;,!&^|(\[{~%]+ | \.(?!\d) /x)
        value_expected = true
        last_operator = match[-1]
        key_expected = (last_operator == ?{) || (last_operator == ?,)
        kind = :operator

      elsif scan(/ [)\]}]+ /x)
        key_expected = value_expected = false
        kind = :operator

      elsif match = scan(/ [$a-zA-Z_][A-Za-z_0-9$]* /x)
        kind = IDENT_KIND[match]
        value_expected = (kind == :keyword) && KEYWORDS_EXPECTING_VALUE[match]
        if kind == :ident
          if match.index(?$)  # $ allowed inside an identifier
            kind = :predefined
          elsif key_expected && check(/\s*:/)
            kind = :key
          end
        end
        key_expected = false
      
      elsif match = scan(/["']/)
        if key_expected && check(KEY_CHECK_PATTERN[match])
          state = :key
        else
          state = :string
        end
        tokens << [:open, state]
        string_delimiter = match
        kind = :delimiter

      elsif value_expected && (match = scan(/\/(?=\S)/))
        tokens << [:open, :regexp]
        state = :regexp
        string_delimiter = '/'
        kind = :delimiter

      elsif scan(/ \/ /x)
        value_expected = true
        key_expected = false
        kind = :operator

      else
        getch
        kind = :error

      end

    when :string, :regexp, :key
      if scan(STRING_CONTENT_PATTERN[string_delimiter])
        kind = :content
      elsif match = scan(/["'\/]/)
        tokens << [match, :delimiter]
        if state == :regexp
          modifiers = scan(/[gim]+/)
          tokens << [modifiers, :modifier] if modifiers && !modifiers.empty?
        end
        tokens << [:close, state]
        string_delimiter = nil
        key_expected = value_expected = false
        state = :initial
        next
      elsif state != :regexp && (match = scan(/ \\ (?: #{ESCAPE} | #{UNICODE_ESCAPE} ) /mox))
        if string_delimiter == "'" && !(match == "\\\\" || match == "\\'")
          kind = :content
        else
          kind = :char
        end
      elsif state == :regexp && scan(/ \\ (?: #{ESCAPE} | #{REGEXP_ESCAPE} | #{UNICODE_ESCAPE} ) /mox)
        kind = :char
      elsif scan(/\\./m)
        kind = :content
      elsif scan(/ \\ | $ /x)
        tokens << [:close, state]
        kind = :error
        key_expected = value_expected = false
        state = :initial
      else
        raise_inspect "else case \" reached; %p not handled." % peek(1), tokens
      end

    else
      raise_inspect 'Unknown state', tokens

    end

    match ||= matched
    if $DEBUG and not kind
      raise_inspect 'Error token %p in line %d' %
        [[match, kind], line], tokens
    end
    raise_inspect 'Empty token', tokens unless match
    
    tokens << [match, kind]

  end

  if [:string, :regexp].include? state
    tokens << [:close, state]
  end

  tokens
end