lib/irb/input-method.rb

   1 #
   2 #   irb/input-method.rb - input methods used irb
   3 #       $Release Version: 0.9.5$
   4 #       $Revision$
   5 #       by Keiju ISHITSUKA(keiju@ruby-lang.org)
   6 #
   7 # --
   8 #
   9 #
  10 #
  11 module IRB
  12   #
  13   # InputMethod
  14   #     StdioInputMethod
  15   #     FileInputMethod
  16   #     (ReadlineInputMethod)
  17   #
  18   STDIN_FILE_NAME = "(line)"
  19   class InputMethod
  20     @RCS_ID='-$Id$-'
  21
  22     def initialize(file = STDIN_FILE_NAME)
  23       @file_name = file
  24     end
  25     attr_reader :file_name
  26
  27     attr_accessor :prompt
  28
  29     def gets
  30       IRB.fail NotImplementedError, "gets"
  31     end
  32     public :gets
  33
  34     def readable_atfer_eof?
  35       false
  36     end
  37   end
  38
  39   class StdioInputMethod < InputMethod
  40     def initialize
  41       super
  42       @line_no = 0
  43       @line = []
  44     end
  45
  46     def gets
  47       print @prompt
  48       @line[@line_no += 1] = $stdin.gets
  49     end
  50
  51     def eof?
  52       $stdin.eof?
  53     end
  54
  55     def readable_atfer_eof?
  56       true
  57     end
  58
  59     def line(line_no)
  60       @line[line_no]
  61     end
  62   end
  63
  64   class FileInputMethod < InputMethod
  65     def initialize(file)
  66       super
  67       @io = open(file)
  68     end
  69     attr_reader :file_name
  70
  71     def eof?
  72       @io.eof?
  73     end
  74
  75     def gets
  76       print @prompt
  77       l = @io.gets
  78 #      print @prompt, l
  79       l
  80     end
  81   end
  82
  83   begin
  84     require "readline"
  85     class ReadlineInputMethod < InputMethod
  86       include Readline
  87       def initialize
  88         super
  89
  90         @line_no = 0
  91         @line = []
  92         @eof = false
  93       end
  94
  95       def gets
  96         Readline.input = STDIN
  97         Readline.output = STDOUT
  98         if l = readline(@prompt, false)
  99           HISTORY.push(l) if !l.empty?
 100           @line[@line_no += 1] = l + "\n"
 101         else
 102           @eof = true
 103           l
 104         end
 105       end
 106
 107       def eof?
 108         @eof
 109       end
 110
 111       def readable_atfer_eof?
 112         true
 113       end
 114
 115       def line(line_no)
 116         @line[line_no]
 117       end
 118     end
 119   rescue LoadError
 120   end
 121 end