completion.rb

#
#   irb/completor.rb -
#       $Release Version: 0.9$
#       $Revision: 11708 $
#       $Date: 2007-02-13 08:01:19 +0900 (Tue, 13 Feb 2007) $
#       by Keiju ISHITSUKA(keiju@ishitsuka.com)
#       From Original Idea of shugo@ruby-lang.org
#

require "readline"

module IRB
  module InputCompletor

    @RCS_ID='-$Id: completion.rb 11708 2007-02-12 23:01:19Z shyouhei $-'

    ReservedWords = [
      "BEGIN", "END",
      "alias", "and",
      "begin", "break",
      "case", "class",
      "def", "defined", "do",
      "else", "elsif", "end", "ensure",
      "false", "for",
      "if", "in",
      "module",
      "next", "nil", "not",
      "or",
      "redo", "rescue", "retry", "return",
      "self", "super",
      "then", "true",
      "undef", "unless", "until",
      "when", "while",
      "yield",
    ]

    CompletionProc = proc { |input|
      bind = IRB.current_context.workspace.binding

      case input
      when %r{^(/[^/]*/)\.([^.]*)$}
        # Regexp
        receiver = $1
        message = Regexp.quote($2)

        candidates = Regexp.instance_methods(true)
        select_message(receiver, message, candidates)

      when /^([^\]]*\])\.([^.]*)$/
        # Array
        receiver = $1
        message = Regexp.quote($2)

        candidates = Array.instance_methods(true)
        select_message(receiver, message, candidates)

      when /^([^\}]*\})\.([^.]*)$/
        # Proc or Hash
        receiver = $1
        message = Regexp.quote($2)

        candidates = Proc.instance_methods(true) | Hash.instance_methods(true)
        select_message(receiver, message, candidates)

      when /^(:[^:.]*)$/
        # Symbol
        Symbol.all_symbols.map(&:inspect).grep(/^#{$1}/)

      when /^::([A-Z][^:\.\(]*)$/
        # Absolute Constant or class methods
        receiver = $1
        candidates = Object.constants
        candidates.grep(/^#{receiver}/).collect{|e| "::" + e}

      when /^(((::)?[A-Z][^:.\(]*)+)::?([^:.]*)$/
        # Constant or class methods
        receiver = $1
        message = Regexp.quote($4)
        begin
          candidates = eval("#{receiver}.constants | #{receiver}.methods", bind)
        rescue Exception
          candidates = []
        end
        candidates.grep(/^#{message}/).collect{|e| receiver + "::" + e}

      when /^(:[^:.]+)\.([^.]*)$/
        # Symbol
        receiver = $1
        message = Regexp.quote($2)

        candidates = Symbol.instance_methods(true)
        select_message(receiver, message, candidates)

      when /^(-?(0[dbo])?[0-9_]+(\.[0-9_]+)?([eE]-?[0-9]+)?)\.([^.]*)$/
        # Numeric
        receiver = $1
        message = Regexp.quote($5)

        begin
          candidates = eval(receiver, bind).methods
        rescue Exception
          candidates = []
        end
        select_message(receiver, message, candidates)

      when /^(-?0x[0-9a-fA-F_]+)\.([^.]*)$/
        # Numeric(0xFFFF)
        receiver = $1
        message = Regexp.quote($2)

        begin
          candidates = eval(receiver, bind).methods
        rescue Exception
          candidates = []
        end
        select_message(receiver, message, candidates)

      when /^(\$[^.]*)$/
        candidates = global_variables.grep(Regexp.new(Regexp.quote($1)))

      when /^((\.?[^.]+)+)\.([^.]*)$/
        # variable
        receiver = $1
        message = Regexp.quote($3)

        gv = eval("global_variables", bind)
        lv = eval("local_variables", bind)
        cv = eval("self.class.constants", bind)

        if (gv | lv | cv).include?(receiver)
          # foo.func and foo is local var.
          candidates = eval("#{receiver}.methods", bind)
        elsif /^[A-Z]/ =~ receiver and /\./ !~ receiver
          # Foo::Bar.func
          begin
            candidates = eval("#{receiver}.methods", bind)
          rescue Exception
            candidates = []
          end
        else
          # func1.func2
          candidates = []
          ObjectSpace.each_object(Module){|m|
            begin
              name = m.name
            rescue Exception
              name = ""
            end
            next if name != "IRB::Context" and
              /^(IRB|SLex|RubyLex|RubyToken)/ =~ name
            candidates.concat m.instance_methods(false)
          }
          candidates.sort!
          candidates.uniq!
        end
        select_message(receiver, message, candidates)

      when /^\.([^.]*)$/
        # unknown(maybe String)

        receiver = ""
        message = Regexp.quote($1)

        candidates = String.instance_methods(true)
        select_message(receiver, message, candidates)

      else
        candidates = eval("methods | private_methods | local_variables | self.class.constants", bind)

        (candidates|ReservedWords).grep(/^#{Regexp.quote(input)}/)
      end
    }

    Operators = ["%", "&", "*", "**", "+",  "-",  "/",
      "<", "<<", "<=", "<=>", "==", "===", "=~", ">", ">=", ">>",
      "[]", "[]=", "^",]

    def self.select_message(receiver, message, candidates)
      candidates.grep(/^#{message}/).collect do |e|
        case e
        when /^[a-zA-Z_]/
          receiver + "." + e
        when /^[0-9]/
        when *Operators
          #receiver + " " + e
        end
      end
    end
  end
end

if Readline.respond_to?("basic_word_break_characters=")
  Readline.basic_word_break_characters= " \t\n\"\\'`><=;|&{("
end
Readline.completion_append_character = nil
Readline.completion_proc = IRB::InputCompletor::CompletionProc