RubyLex

Constants

DEINDENT_CLAUSE
DLtype2Token
ENINDENT_CLAUSE
Ltype2Token
PERCENT_LTYPE
PERCENT_PAREN

Attributes

debug_level[RW]

char_no[R]

exception_on_syntax_error[RW]

indent[R]

line_no[R]

readed_auto_clean_up[RW]

seek[R]

skip_space[RW]

Public Class Methods

debug?() click to toggle source

 
               # File irb/ruby-lex.rb, line 34
def debug?
  @debug_level > 0
end

new() click to toggle source

 
               # File irb/ruby-lex.rb, line 40
def initialize
  lex_init
  set_input(STDIN)

  @seek = 0
  @exp_line_no = @line_no = 1
  @base_char_no = 0
  @char_no = 0
  @rests = []
  @readed = []
  @here_readed = []

  @indent = 0
  @indent_stack = []
  @lex_state = EXPR_BEG
  @space_seen = false
  @here_header = false
  
  @continue = false
  @line = ""

  @skip_space = false
  @readed_auto_clean_up = false
  @exception_on_syntax_error = true

  @prompt = nil
end

Public Instance Methods

each_top_level_statement() click to toggle source

 
               # File irb/ruby-lex.rb, line 227
def each_top_level_statement
  initialize_input
  catch(:TERM_INPUT) do
    loop do
      begin
        @continue = false
        prompt
        unless l = lex
          throw :TERM_INPUT if @line == ''
        else
          #p l
          @line.concat l
          if @ltype or @continue or @indent > 0
            next
          end
        end
        if @line != "\n"
          yield @line, @exp_line_no
        end
        break unless l
        @line = ''
        @exp_line_no = @line_no

        @indent = 0
        @indent_stack = []
        prompt
      rescue TerminateLineInput
        initialize_input
        prompt
        get_readed
      end
    end
  end
end

eof?() click to toggle source

 
               # File irb/ruby-lex.rb, line 132
def eof?
  @io.eof?
end

get_readed() click to toggle source

 
               # File irb/ruby-lex.rb, line 89
def get_readed
  if idx = @readed.reverse.index("\n")
    @base_char_no = idx
  else
    @base_char_no += @readed.size
  end
  
  readed = @readed.join("")
  @readed = []
  readed
end

getc() click to toggle source

 
               # File irb/ruby-lex.rb, line 101
  def getc
    while @rests.empty?
#      return nil unless buf_input
      @rests.push nil unless buf_input
    end
    c = @rests.shift
    if @here_header
      @here_readed.push c
    else
      @readed.push c
    end
    @seek += 1
    if c == "\n"
      @line_no += 1 
      @char_no = 0
    else
      @char_no += 1
    end
    c
  end

getc_of_rests() click to toggle source

 
               # File irb/ruby-lex.rb, line 136
def getc_of_rests
  if @rests.empty?
    nil
  else
    getc
  end
end

gets() click to toggle source

 
               # File irb/ruby-lex.rb, line 122
def gets
  l = ""
  while c = getc
    l.concat(c)
    break if c == "\n"
  end
  return nil if l == "" and c.nil?
  l
end

identify_comment() click to toggle source

 
               # File irb/ruby-lex.rb, line 1085
  def identify_comment
    @ltype = "#"

    while ch = getc
#      if ch == "\\" #"
#       read_escape
#      end
      if ch == "\n"
        @ltype = nil
        ungetc
        break
      end
    end
    return Token(TkCOMMENT)
  end

identify_gvar() click to toggle source

 
               # File irb/ruby-lex.rb, line 746
def identify_gvar
  @lex_state = EXPR_END
  
  case ch = getc
  when /[~_*$?!@\/\;,=:<>".]/   #"
    Token(TkGVAR, "$" + ch)
  when "-"
    Token(TkGVAR, "$-" + getc)
  when "&", "`", "'", "+"
    Token(TkBACK_REF, "$"+ch)
  when /[1-9]/
    while getc =~ /[0-9]/; end
    ungetc
    Token(TkNTH_REF)
  when /\w/
    ungetc
    ungetc
    identify_identifier
  else 
    ungetc
    Token("$")
  end
end

identify_here_document() click to toggle source

 
               # File irb/ruby-lex.rb, line 879
  def identify_here_document
    ch = getc
#    if lt = PERCENT_LTYPE[ch]
    if ch == "-"
      ch = getc
      indent = true
    end
    if /['"`]/ =~ ch
      lt = ch
      quoted = ""
      while (c = getc) && c != lt
        quoted.concat c
      end
    else
      lt = '"'
      quoted = ch.dup
      while (c = getc) && c =~ /\w/
        quoted.concat c
      end
      ungetc
    end

    ltback, @ltype = @ltype, lt
    reserve = []
    while ch = getc
      reserve.push ch
      if ch == "\\"
        reserve.push ch = getc
      elsif ch == "\n"
        break
      end
    end

    @here_header = false
    while l = gets
      l = l.sub(/(:?\r)?\n\z/, '')
      if (indent ? l.strip : l) == quoted
        break
      end
    end

    @here_header = true
    @here_readed.concat reserve
    while ch = reserve.pop
      ungetc ch
    end

    @ltype = ltback
    @lex_state = EXPR_END
    Token(Ltype2Token[lt])
  end

identify_identifier() click to toggle source

 
               # File irb/ruby-lex.rb, line 770
  def identify_identifier
    token = ""
    if peek(0) =~ /[$@]/
      token.concat(c = getc)
      if c == "@" and peek(0) == "@"
        token.concat getc
      end
    end

    while (ch = getc) =~ /\w|_/
      print ":", ch, ":" if RubyLex.debug?
      token.concat ch
    end
    ungetc
    
    if (ch == "!" || ch == "?") && token[0,1] =~ /\w/ && peek(0) != "="
      token.concat getc
    end

    # almost fix token

    case token
    when /^\$/
      return Token(TkGVAR, token)
    when /^\@\@/
      @lex_state = EXPR_END
      # p Token(TkCVAR, token)
      return Token(TkCVAR, token)
    when /^\@/
      @lex_state = EXPR_END
      return Token(TkIVAR, token)
    end
    
    if @lex_state != EXPR_DOT
      print token, "\n" if RubyLex.debug?

      token_c, *trans = TkReading2Token[token]
      if token_c
        # reserved word?

        if (@lex_state != EXPR_BEG &&
            @lex_state != EXPR_FNAME &&
            trans[1])
          # modifiers
          token_c = TkSymbol2Token[trans[1]]
          @lex_state = trans[0]
        else
          if @lex_state != EXPR_FNAME
            if ENINDENT_CLAUSE.include?(token)
              # check for ``class = val'' etc.
              valid = true
              case token
              when "class"
                valid = false unless peek_match?(/^\s*(<<|\w|::)/)
              when "def"
                valid = false if peek_match?(/^\s*(([+-\/*&\|^]|<<|>>|\|\||\&\&)=|\&\&|\|\|)/)
              when "do"
                valid = false if peek_match?(/^\s*([+-\/*]?=|\*|<|>|\&)/)
              when *ENINDENT_CLAUSE
                valid = false if peek_match?(/^\s*([+-\/*]?=|\*|<|>|\&|\|)/)
              else
                # no nothing
              end
              if valid
                if token == "do"
                  if ![TkFOR, TkWHILE, TkUNTIL].include?(@indent_stack.last)
                    @indent += 1
                    @indent_stack.push token_c
                  end
                else
                  @indent += 1
                  @indent_stack.push token_c
                end
#               p @indent_stack
              end

            elsif DEINDENT_CLAUSE.include?(token)
              @indent -= 1
              @indent_stack.pop
            end
            @lex_state = trans[0]
          else
            @lex_state = EXPR_END
          end
        end
        return Token(token_c, token)
      end
    end

    if @lex_state == EXPR_FNAME
      @lex_state = EXPR_END
      if peek(0) == '='
        token.concat getc
      end
    elsif @lex_state == EXPR_BEG || @lex_state == EXPR_DOT
      @lex_state = EXPR_ARG
    else
      @lex_state = EXPR_END
    end

    if token[0, 1] =~ /[A-Z]/
      return Token(TkCONSTANT, token)
    elsif token[token.size - 1, 1] =~ /[!?]/
      return Token(TkFID, token)
    else
      return Token(TkIDENTIFIER, token)
    end
  end

identify_number() click to toggle source

 
               # File irb/ruby-lex.rb, line 949
def identify_number
  @lex_state = EXPR_END

  if peek(0) == "0" && peek(1) !~ /[.eE]/
    getc
    case peek(0)
    when /[xX]/
      ch = getc
      match = /[0-9a-fA-F_]/
    when /[bB]/
      ch = getc
      match = /[01_]/
    when /[oO]/
      ch = getc
      match = /[0-7_]/
    when /[dD]/
      ch = getc
      match = /[0-9_]/
    when /[0-7]/
      match = /[0-7_]/
    when /[89]/
      RubyLex.fail SyntaxError, "Illegal octal digit"
    else 
      return Token(TkINTEGER)
    end
    
    len0 = true
    non_digit = false
    while ch = getc
      if match =~ ch
        if ch == "_"
          if non_digit
            RubyLex.fail SyntaxError, "trailing `#{ch}' in number"
          else
            non_digit = ch
          end
        else
          non_digit = false
          len0 = false
        end
      else
        ungetc
        if len0
          RubyLex.fail SyntaxError, "numeric literal without digits"
        end
        if non_digit
          RubyLex.fail SyntaxError, "trailing `#{non_digit}' in number"
        end
        break
      end
    end
    return Token(TkINTEGER)
  end
  
  type = TkINTEGER
  allow_point = true
  allow_e = true
  non_digit = false
  while ch = getc
    case ch
    when /[0-9]/
      non_digit = false
    when "_"
      non_digit = ch
    when allow_point && "."
      if non_digit
        RubyLex.fail SyntaxError, "trailing `#{non_digit}' in number"
      end
      type = TkFLOAT
      if peek(0) !~ /[0-9]/
        type = TkINTEGER
        ungetc
        break
      end
      allow_point = false
    when allow_e && "e", allow_e && "E"
      if non_digit
        RubyLex.fail SyntaxError, "trailing `#{non_digit}' in number"
      end
      type = TkFLOAT
      if peek(0) =~ /[+-]/
        getc
      end
      allow_e = false
      allow_point = false
      non_digit = ch
    else
      if non_digit
        RubyLex.fail SyntaxError, "trailing `#{non_digit}' in number"
      end
      ungetc
      break
    end
  end
  Token(type)
end

identify_quotation() click to toggle source

 
               # File irb/ruby-lex.rb, line 931
  def identify_quotation
    ch = getc
    if lt = PERCENT_LTYPE[ch]
      ch = getc
    elsif ch =~ /\W/
      lt = "\""
    else
      RubyLex.fail SyntaxError, "unknown type of %string"
    end
#     if ch !~ /\W/
#       ungetc
#       next
#     end
    #@ltype = lt
    @quoted = ch unless @quoted = PERCENT_PAREN[ch]
    identify_string(lt, @quoted)
  end

identify_string(ltype, quoted = ltype) click to toggle source

 
               # File irb/ruby-lex.rb, line 1046
def identify_string(ltype, quoted = ltype)
  @ltype = ltype
  @quoted = quoted
  subtype = nil
  begin
    nest = 0
    while ch = getc
      if @quoted == ch and nest == 0
        break
      elsif @ltype != "'" && @ltype != "]" && @ltype != ":" and ch == "#"
        subtype = true
      elsif ch == '\' #'
        read_escape
      end
      if PERCENT_PAREN.values.include?(@quoted) 
        if PERCENT_PAREN[ch] == @quoted
          nest += 1
        elsif ch == @quoted
          nest -= 1
        end
      end
    end
    if @ltype == "/"
      if peek(0) =~ /i|m|x|o|e|s|u|n/
        getc
      end
    end
    if subtype
      Token(DLtype2Token[ltype])
    else
      Token(Ltype2Token[ltype])
    end
  ensure
    @ltype = nil
    @quoted = nil
    @lex_state = EXPR_END
  end
end

initialize_input() click to toggle source

 
               # File irb/ruby-lex.rb, line 211
def initialize_input
  @ltype = nil
  @quoted = nil
  @indent = 0
  @indent_stack = []
  @lex_state = EXPR_BEG
  @space_seen = false
  @here_header = false
  
  @continue = false
  prompt

  @line = ""
  @exp_line_no = @line_no
end

lex() click to toggle source

 
               # File irb/ruby-lex.rb, line 262
def lex
  until (((tk = token).kind_of?(TkNL) || tk.kind_of?(TkEND_OF_SCRIPT)) &&
           !@continue or
           tk.nil?)
    #p tk
    #p @lex_state
    #p self
  end
  line = get_readed
  #      print self.inspect
  if line == "" and tk.kind_of?(TkEND_OF_SCRIPT) || tk.nil?
    nil
  else
    line
  end
end

lex_init() click to toggle source

 
               # File irb/ruby-lex.rb, line 339
def lex_init()
  @OP = IRB::SLex.new
  @OP.def_rules("\00"", "\0004", "\0032") do |op, io|
    Token(TkEND_OF_SCRIPT)
  end

  @OP.def_rules(" ", "\t", "\f", "\r", "\113"") do |op, io|
    @space_seen = true
    while getc =~ /[ \t\f\r\13]/; end
    ungetc
    Token(TkSPACE)
  end

  @OP.def_rule("#") do |op, io|
    identify_comment
  end

  @OP.def_rule("=begin",
               proc{|op, io| @prev_char_no == 0 && peek(0) =~ /\s/}) do 
    |op, io|
    @ltype = "="
    until getc == "\n"; end
    until peek_equal?("=end") && peek(4) =~ /\s/
      until getc == "\n"; end
    end
    gets
    @ltype = nil
    Token(TkRD_COMMENT)
  end

  @OP.def_rule("\n") do |op, io|
    print "\\n\n" if RubyLex.debug?
    case @lex_state
    when EXPR_BEG, EXPR_FNAME, EXPR_DOT
      @continue = true
    else
      @continue = false
      @lex_state = EXPR_BEG
      until (@indent_stack.empty? || 
             [TkLPAREN, TkLBRACK, TkLBRACE, 
               TkfLPAREN, TkfLBRACK, TkfLBRACE].include?(@indent_stack.last))
        @indent_stack.pop
      end
    end
    @here_header = false
    @here_readed = []
    Token(TkNL)
  end

  @OP.def_rules("*", "**",    
                "=", "==", "===", 
                "=~", "<=>",        
                "<", "<=",
                ">", ">=", ">>") do
    |op, io|
    case @lex_state
    when EXPR_FNAME, EXPR_DOT
      @lex_state = EXPR_ARG
    else
      @lex_state = EXPR_BEG
    end
    Token(op)
  end

  @OP.def_rules("!", "!=", "!~") do
    |op, io|
    @lex_state = EXPR_BEG
    Token(op)
  end

  @OP.def_rules("<<") do
    |op, io|
    tk = nil
    if @lex_state != EXPR_END && @lex_state != EXPR_CLASS &&
        (@lex_state != EXPR_ARG || @space_seen)
      c = peek(0)
      if /\S/ =~ c && (/["'`]/ =~ c || /[\w_]/ =~ c || c == "-")
        tk = identify_here_document
      end
    end
    unless tk
      tk = Token(op)
      case @lex_state
      when EXPR_FNAME, EXPR_DOT
        @lex_state = EXPR_ARG
      else
        @lex_state = EXPR_BEG
      end
    end
    tk
  end

  @OP.def_rules("'", '"') do
    |op, io|
    identify_string(op)
  end

  @OP.def_rules("`") do
    |op, io|
    if @lex_state == EXPR_FNAME
      @lex_state = EXPR_END
      Token(op)
    else
      identify_string(op)
    end
  end

  @OP.def_rules('?') do
    |op, io|
    if @lex_state == EXPR_END
      @lex_state = EXPR_BEG
      Token(TkQUESTION)
    else
      ch = getc
      if @lex_state == EXPR_ARG && ch =~ /\s/
        ungetc
        @lex_state = EXPR_BEG;
        Token(TkQUESTION)
      else
        if (ch == '\') 
          read_escape
        end
        @lex_state = EXPR_END
        Token(TkINTEGER)
      end
    end
  end

  @OP.def_rules("&", "&&", "|", "||") do
    |op, io|
    @lex_state = EXPR_BEG
    Token(op)
  end
  
  @OP.def_rules("+=", "-=", "*=", "**=", 
                "&=", "|=", "^=", "<<=", ">>=", "||=", "&&=") do
    |op, io|
    @lex_state = EXPR_BEG
    op =~ /^(.*)=$/
    Token(TkOPASGN, $1)
  end

  @OP.def_rule("+@", proc{|op, io| @lex_state == EXPR_FNAME}) do
    |op, io|
    @lex_state = EXPR_ARG
    Token(op)
  end

  @OP.def_rule("-@", proc{|op, io| @lex_state == EXPR_FNAME}) do
    |op, io|
    @lex_state = EXPR_ARG
    Token(op)
  end

  @OP.def_rules("+", "-") do
    |op, io|
    catch(:RET) do
      if @lex_state == EXPR_ARG
        if @space_seen and peek(0) =~ /[0-9]/
          throw :RET, identify_number
        else
          @lex_state = EXPR_BEG
        end
      elsif @lex_state != EXPR_END and peek(0) =~ /[0-9]/
        throw :RET, identify_number
      else
        @lex_state = EXPR_BEG
      end
      Token(op)
    end
  end

  @OP.def_rule(".") do
    |op, io|
    @lex_state = EXPR_BEG
    if peek(0) =~ /[0-9]/
      ungetc
      identify_number
    else
      # for "obj.if" etc.
      @lex_state = EXPR_DOT
      Token(TkDOT)
    end
  end

  @OP.def_rules("..", "...") do
    |op, io|
    @lex_state = EXPR_BEG
    Token(op)
  end

  lex_int2
end

lex_int2() click to toggle source

 
               # File irb/ruby-lex.rb, line 533
  def lex_int2
    @OP.def_rules("]", "}", ")") do
      |op, io|
      @lex_state = EXPR_END
      @indent -= 1
      @indent_stack.pop
      Token(op)
    end

    @OP.def_rule(":") do
      |op, io|
      if @lex_state == EXPR_END || peek(0) =~ /\s/
        @lex_state = EXPR_BEG
        Token(TkCOLON)
      else
        @lex_state = EXPR_FNAME;
        Token(TkSYMBEG)
      end
    end

    @OP.def_rule("::") do
       |op, io|
#      p @lex_state.id2name, @space_seen
      if @lex_state == EXPR_BEG or @lex_state == EXPR_ARG && @space_seen
        @lex_state = EXPR_BEG
        Token(TkCOLON3)
      else
        @lex_state = EXPR_DOT
        Token(TkCOLON2)
      end
    end

    @OP.def_rule("/") do
      |op, io|
      if @lex_state == EXPR_BEG || @lex_state == EXPR_MID
        identify_string(op)
      elsif peek(0) == '='
        getc
        @lex_state = EXPR_BEG
        Token(TkOPASGN, "/") #/)
      elsif @lex_state == EXPR_ARG and @space_seen and peek(0) !~ /\s/
        identify_string(op)
      else 
        @lex_state = EXPR_BEG
        Token("/") #/)
      end
    end

    @OP.def_rules("^") do
      |op, io|
      @lex_state = EXPR_BEG
      Token("^")
    end

    #       @OP.def_rules("^=") do
    #   @lex_state = EXPR_BEG
    #   Token(OP_ASGN, :^)
    #       end
    
    @OP.def_rules(",") do
      |op, io|
      @lex_state = EXPR_BEG
      Token(op)
    end

    @OP.def_rules(";") do
      |op, io|
      @lex_state = EXPR_BEG
      until (@indent_stack.empty? || 
             [TkLPAREN, TkLBRACK, TkLBRACE, 
               TkfLPAREN, TkfLBRACK, TkfLBRACE].include?(@indent_stack.last))
        @indent_stack.pop
      end
      Token(op)
    end

    @OP.def_rule("~") do
      |op, io|
      @lex_state = EXPR_BEG
      Token("~")
    end

    @OP.def_rule("~@", proc{|op, io| @lex_state == EXPR_FNAME}) do
      |op, io|
      @lex_state = EXPR_BEG
      Token("~")
    end
    
    @OP.def_rule("(") do
      |op, io|
      @indent += 1
      if @lex_state == EXPR_BEG || @lex_state == EXPR_MID
        @lex_state = EXPR_BEG
        tk_c = TkfLPAREN
      else
        @lex_state = EXPR_BEG
        tk_c = TkLPAREN
      end
      @indent_stack.push tk_c
      tk = Token(tk_c)
    end

    @OP.def_rule("[]", proc{|op, io| @lex_state == EXPR_FNAME}) do
      |op, io|
      @lex_state = EXPR_ARG
      Token("[]")
    end

    @OP.def_rule("[]=", proc{|op, io| @lex_state == EXPR_FNAME}) do
      |op, io|
      @lex_state = EXPR_ARG
      Token("[]=")
    end

    @OP.def_rule("[") do
      |op, io|
      @indent += 1
      if @lex_state == EXPR_FNAME
        tk_c = TkfLBRACK
      else
        if @lex_state == EXPR_BEG || @lex_state == EXPR_MID
          tk_c = TkLBRACK
        elsif @lex_state == EXPR_ARG && @space_seen
          tk_c = TkLBRACK
        else
          tk_c = TkfLBRACK
        end
        @lex_state = EXPR_BEG
      end
      @indent_stack.push tk_c
      Token(tk_c)
    end

    @OP.def_rule("{") do
      |op, io|
      @indent += 1
      if @lex_state != EXPR_END && @lex_state != EXPR_ARG
        tk_c = TkLBRACE
      else
        tk_c = TkfLBRACE
      end
      @lex_state = EXPR_BEG
      @indent_stack.push tk_c
      Token(tk_c)
    end

    @OP.def_rule('\') do
      |op, io|
      if getc == "\n"
        @space_seen = true
        @continue = true
        Token(TkSPACE)
      else
        ungetc
        Token("\\")
      end
    end

    @OP.def_rule('%') do
      |op, io|
      if @lex_state == EXPR_BEG || @lex_state == EXPR_MID
        identify_quotation
      elsif peek(0) == '='
        getc
        Token(TkOPASGN, :%)
      elsif @lex_state == EXPR_ARG and @space_seen and peek(0) !~ /\s/
        identify_quotation
      else
        @lex_state = EXPR_BEG
        Token("%") #))
      end
    end

    @OP.def_rule('$') do
      |op, io|
      identify_gvar
    end

    @OP.def_rule('@') do
      |op, io|
      if peek(0) =~ /[\w_@]/
        ungetc
        identify_identifier
      else
        Token("@")
      end
    end

    #       @OP.def_rule("def", proc{|op, io| /\s/ =~ io.peek(0)}) do 
    #   |op, io|
    #   @indent += 1
    #   @lex_state = EXPR_FNAME
    # # @lex_state = EXPR_END
    # # until @rests[0] == "\n" or @rests[0] == ";"
    # #   rests.shift
    # # end
    #       end

    @OP.def_rule("") do
      |op, io|
      printf "MATCH: start %s: %s\n", op, io.inspect if RubyLex.debug?
      if peek(0) =~ /[0-9]/
        t = identify_number
      elsif peek(0) =~ /[\w_]/
        t = identify_identifier
      end
      printf "MATCH: end %s: %s\n", op, io.inspect if RubyLex.debug?
      t
    end
    
    p @OP if RubyLex.debug?
  end

peek(i = 0) click to toggle source

 
               # File irb/ruby-lex.rb, line 180
def peek(i = 0)
  while @rests.size <= i
    return nil unless buf_input
  end
  @rests[i]
end

peek_equal?(str) click to toggle source

 
               # File irb/ruby-lex.rb, line 165
def peek_equal?(str)
  chrs = str.split(//)
  until @rests.size >= chrs.size
    return false unless buf_input
  end
  @rests[0, chrs.size] == chrs
end

peek_match?(regexp) click to toggle source

 
               # File irb/ruby-lex.rb, line 173
def peek_match?(regexp)
  while @rests.empty?
    return false unless buf_input
  end
  regexp =~ @rests.join("")
end

prompt() click to toggle source

 
               # File irb/ruby-lex.rb, line 205
def prompt
  if @prompt
    @prompt.call(@ltype, @indent, @continue, @line_no)
  end
end

read_escape() click to toggle source

 
               # File irb/ruby-lex.rb, line 1101
def read_escape
  case ch = getc
  when "\n", "\r", "\f"
  when "\\", "n", "t", "r", "f", "v", "a", "e", "b", "s" #"
  when /[0-7]/
    ungetc ch
    3.times do
      case ch = getc
      when /[0-7]/
      when nil
        break
      else
        ungetc
        break
      end
    end
    
  when "x"
    2.times do
      case ch = getc
      when /[0-9a-fA-F]/
      when nil
        break
      else
        ungetc
        break
      end
    end

  when "M"
    if (ch = getc) != '-'
      ungetc
    else
      if (ch = getc) == "\\" #"
        read_escape
      end
    end

  when "C", "c" #, "^"
    if ch == "C" and (ch = getc) != "-"
      ungetc
    elsif (ch = getc) == "\\" #"
      read_escape
    end
  else
    # other characters 
  end
end

set_input(io, p = nil, &block) click to toggle source

io functions

 
               # File irb/ruby-lex.rb, line 78
def set_input(io, p = nil, &block)
  @io = io
  if p.respond_to?(:call)
    @input = p
  elsif block_given?
    @input = block
  else
    @input = Proc.new{@io.gets}
  end
end

set_prompt(p = nil, &block) click to toggle source

 
               # File irb/ruby-lex.rb, line 196
def set_prompt(p = nil, &block)
  p = block if block_given?
  if p.respond_to?(:call)
    @prompt = p
  else
    @prompt = Proc.new{print p}
  end
end

token() click to toggle source

 
               # File irb/ruby-lex.rb, line 279
def token
  #      require "tracer"
  #      Tracer.on
  @prev_seek = @seek
  @prev_line_no = @line_no
  @prev_char_no = @char_no
  begin
    begin
      tk = @OP.match(self)
      @space_seen = tk.kind_of?(TkSPACE)
    rescue SyntaxError
      raise if @exception_on_syntax_error
      tk = TkError.new(@seek, @line_no, @char_no)
    end
  end while @skip_space and tk.kind_of?(TkSPACE)
  if @readed_auto_clean_up
    get_readed
  end
  #      Tracer.off
  tk
end

ungetc(c = nil) click to toggle source

 
               # File irb/ruby-lex.rb, line 144
def ungetc(c = nil)
  if @here_readed.empty?
    c2 = @readed.pop
  else
    c2 = @here_readed.pop
  end
  c = c2 unless c
  @rests.unshift c #c = 
    @seek -= 1
  if c == "\n"
    @line_no -= 1 
    if idx = @readed.reverse.index("\n")
      @char_no = @readed.size - idx
    else
      @char_no = @base_char_no + @readed.size
    end
  else
    @char_no -= 1
  end
end

Commenting is here to help enhance the documentation. For example, code samples, or clarification of the documentation.

If you have questions about Ruby or the documentation, please post to one of the Ruby mailing lists. You will get better, faster, help that way.

If you wish to post a correction of the docs, please do so, but also file bug report so that it can be corrected for the next release. Thank you.

If you want to help improve the Ruby documentation, please see Improve the docs, or visit Documenting-ruby.org.

Home Classes Methods

In Files

Parent

Methods

Included Modules

Class/Module Index

RubyLex

Constants

Attributes

Public Class Methods

Public Instance Methods