脳ざらし紀行

_ irb + irb/completion + ri

Irb/TipsAndTricksだと全てのシンボルが補完候補として出てきてしまう。以下のようなスクリプト(irbri.rb)を用意して、

require 'irb/completion'

module Kernel
  def r(arg)
    puts `ri #{arg}`
  end
  private :r
end

class Module
  def i(meth = nil)
    if meth
      puts `ri #{self}##{meth}`
     else
      puts `ri #{self}`
    end
  end

  def c(meth = nil)
    if meth
      puts `ri #{self}::#{meth}`
    else
      puts `ri #{self}`
    end
  end
end

RICompletionProc = proc{|input|
  bind = IRB.conf[:MAIN_CONTEXT].workspace.binding
  case input
  when /(\s*([A-Z].*)\.([ic])\s*):(.*)/
    pre = $1
    receiver = $2
    ic = $3
    meth = $4 ? /\A#{Regexp.quote($4)}/ : /./ #}
    begin
      if ic == 'i'
        candidates = eval("#{receiver}.instance_methods(false)", bind)
      else
        candidates = eval("#{receiver}.methods(false)", bind) + ['new']
      end
      candidates = candidates.grep(meth)
      candidates.map{|s| pre + ':' + s }
    rescue Exception
      candidates = []
    end
  when /([A-Z]\w+)#(\w*)/ #}
    klass = $1
    meth = $2 ? /\A#{Regexp.quote($2)}/ : /./
    candidates = eval("#{klass}.instance_methods", bind)
    p meth
    candidates = candidates.grep(meth)
    p candidates
    candidates.map{|s| klass + '#' + s }
  else
    IRB::InputCompletor::CompletionProc.call(input)
  end
}
Readline.basic_word_break_characters= " \t\n\"\\'`><=;|&{("
Readline.completion_proc = RICompletionProc

irb を実行すると、

$ irb -r irbri.rb
irb(main):001:0>String.i:s[TAB] #<= ここでTABをうつ。
String.i:scan       String.i:split      String.i:strip!     String.i:succ!
String.i:size       String.i:squeeze    String.i:sub        String.i:sum
String.i:slice      String.i:squeeze!   String.i:sub!       String.i:swapcase
String.i:slice!     String.i:strip      String.i:succ       String.i:swapcase!
irb(main):001:0> String.i:sum
------------------------------------------------------------- String#sum
     str.sum(n=16)   => integer
------------------------------------------------------------------------
     Returns a basic _n_-bit checksum of the characters in _str_, where
     _n_ is the optional +Fixnum+ parameter, defaulting to 16. The
     result is simply the sum of the binary value of each character in
     _str_ modulo +2n - 1+. This is not a particularly good checksum.

=> nil
irb(main):002:0>

とStringのインスタンスメソッドしか補完候補にならない。クラスメソッドは.cでok。

色々欠陥はあるけど。