SoundSoftware Code Site

module CodeRay

module Scanners

  # Scanner for JavaScript.

  # 

  # Aliases: +ecmascript+, +ecma_script+, +javascript+

  class JavaScript < Scanner

    register_for :java_script

    file_extension 'js'

    # The actual JavaScript keywords.

    KEYWORDS = %w[

      break case catch continue default delete do else

      finally for function if in instanceof new

      return switch throw try typeof var void while with

    ]  # :nodoc:

    PREDEFINED_CONSTANTS = %w[

      false null true undefined NaN Infinity

    ]  # :nodoc:

    MAGIC_VARIABLES = %w[ this arguments ]  # :nodoc: arguments was introduced in JavaScript 1.4

    KEYWORDS_EXPECTING_VALUE = WordList.new.add %w[

      case delete in instanceof new return throw typeof with

    ]  # :nodoc:

    # Reserved for future use.

    RESERVED_WORDS = %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

    ]  # :nodoc:

    IDENT_KIND = WordList.new(:ident).

      add(RESERVED_WORDS, :reserved).

      add(PREDEFINED_CONSTANTS, :predefined_constant).

      add(MAGIC_VARIABLES, :local_variable).

      add(KEYWORDS, :keyword)  # :nodoc:

    ESCAPE = / [bfnrtv\n\\'"] | x[a-fA-F0-9]{1,2} | [0-7]{1,3} /x  # :nodoc:

    UNICODE_ESCAPE =  / u[a-fA-F0-9]{4} | U[a-fA-F0-9]{8} /x  # :nodoc:

    REGEXP_ESCAPE =  / [bBdDsSwW] /x  # :nodoc:

    STRING_CONTENT_PATTERN = {

      "'" => /[^\\']+/,

      '"' => /[^\\"]+/,

      '/' => /[^\\\/]+/,

    }  # :nodoc:

    KEY_CHECK_PATTERN = {

      "'" => / (?> [^\\']* (?: \\. [^\\']* )* ) ' \s* : /mx,

      '"' => / (?> [^\\"]* (?: \\. [^\\"]* )* ) " \s* : /mx,

    }  # :nodoc:

  protected

    def scan_tokens encoder, options

      state = :initial

      string_delimiter = nil

      value_expected = true

      key_expected = false

      function_expected = false

      until eos?

        case state

        when :initial

          if match = scan(/ \s+ | \\\n /x)

            value_expected = true if !value_expected && match.index(?\n)

            encoder.text_token match, :space

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

            value_expected = true

            encoder.text_token match, :comment

          elsif check(/\.?\d/)

            key_expected = value_expected = false

            if match = scan(/0[xX][0-9A-Fa-f]+/)

              encoder.text_token match, :hex

            elsif match = scan(/(?>0[0-7]+)(?![89.eEfF])/)

              encoder.text_token match, :octal

            elsif match = scan(/\d+[fF]|\d*\.\d+(?:[eE][+-]?\d+)?[fF]?|\d+[eE][+-]?\d+[fF]?/)

              encoder.text_token match, :float

            elsif match = scan(/\d+/)

              encoder.text_token match, :integer

            end

          elsif value_expected && match = scan(/<([[:alpha:]]\w*) (?: [^\/>]*\/> | .*?<\/\1>)/xim)

            # TODO: scan over nested tags

            xml_scanner.tokenize match, :tokens => encoder

            value_expected = false

            next

          elsif match = scan(/ [-+*=<>?:;,!&^|(\[{~%]+ | \.(?!\d) /x)

            value_expected = true

            last_operator = match[-1]

            key_expected = (last_operator == ?{) || (last_operator == ?,)

            function_expected = false

            encoder.text_token match, :operator

          elsif match = scan(/ [)\]}]+ /x)

            function_expected = key_expected = value_expected = false

            encoder.text_token match, :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]

            # TODO: labels

            if kind == :ident

              if match.index(?$)  # $ allowed inside an identifier

                kind = :predefined

              elsif function_expected

                kind = :function

              elsif check(/\s*[=:]\s*function\b/)

                kind = :function

              elsif key_expected && check(/\s*:/)

                kind = :key

              end

            end

            function_expected = (kind == :keyword) && (match == 'function')

            key_expected = false

            encoder.text_token match, kind

          elsif match = scan(/["']/)

            if key_expected && check(KEY_CHECK_PATTERN[match])

              state = :key

            else

              state = :string

            end

            encoder.begin_group state

            string_delimiter = match

            encoder.text_token match, :delimiter

          elsif value_expected && (match = scan(/\//))

            encoder.begin_group :regexp

            state = :regexp

            string_delimiter = '/'

            encoder.text_token match, :delimiter

          elsif match = scan(/ \/ /x)

            value_expected = true

            key_expected = false

            encoder.text_token match, :operator

          else

            encoder.text_token getch, :error

          end

        when :string, :regexp, :key

          if match = scan(STRING_CONTENT_PATTERN[string_delimiter])

            encoder.text_token match, :content

          elsif match = scan(/["'\/]/)

            encoder.text_token match, :delimiter

            if state == :regexp

              modifiers = scan(/[gim]+/)

              encoder.text_token modifiers, :modifier if modifiers && !modifiers.empty?

            end

            encoder.end_group state

            string_delimiter = nil

            key_expected = value_expected = false

            state = :initial

          elsif state != :regexp && (match = scan(/ \\ (?: #{ESCAPE} | #{UNICODE_ESCAPE} ) /mox))

            if string_delimiter == "'" && !(match == "\\\\" || match == "\\'")

              encoder.text_token match, :content

            else

              encoder.text_token match, :char

            end

          elsif state == :regexp && match = scan(/ \\ (?: #{ESCAPE} | #{REGEXP_ESCAPE} | #{UNICODE_ESCAPE} ) /mox)

            encoder.text_token match, :char

          elsif match = scan(/\\./m)

            encoder.text_token match, :content

          elsif match = scan(/ \\ | $ /x)

            encoder.end_group state

            encoder.text_token match, :error

            key_expected = value_expected = false

            state = :initial

          else

            raise_inspect "else case \" reached; %p not handled." % peek(1), encoder

          end

        else

          raise_inspect 'Unknown state', encoder

        end

      end

      if [:string, :regexp].include? state

        encoder.end_group state

      end

      encoder

    end

  protected

    def reset_instance

      super

      @xml_scanner.reset if defined? @xml_scanner

    end

    def xml_scanner

      @xml_scanner ||= CodeRay.scanner :xml, :tokens => @tokens, :keep_tokens => true, :keep_state => false

    end

  end

end

end