SoundSoftware Code Site

module CodeRay

module Scanners

  class JavaScript < Scanner

    include Streamable

    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

    ]

    PREDEFINED_CONSTANTS = %w[

      false null true undefined

    ]

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

    KEYWORDS_EXPECTING_VALUE = WordList.new.add %w[

      case delete in instanceof new return throw typeof with

    ]

    # 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

    ]

    IDENT_KIND = WordList.new(:ident).

      add(RESERVED_WORDS, :reserved).

      add(PREDEFINED_CONSTANTS, :pre_constant).

      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,

    }

    def scan_tokens tokens, options

      state = :initial

      string_delimiter = nil

      value_expected = true

      key_expected = false

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

            # FIXME: scan over nested tags

            xml_scanner.tokenize match

            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

            kind = :operator

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

            function_expected = 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]

            # 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

          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 $CODERAY_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

  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