Module: IRB::InputCompletor

# File 'lib/irb/completion.rb', line 45

def self.retrieve_completion_data(input, bind: IRB.conf[:MAIN_CONTEXT].workspace.binding, doc_namespace: false)
  case input
  when /^((["'`]).*\2)\.([^.]*)$/
    # String
    receiver = $1
    message = Regexp.quote($3)

    candidates = String.instance_methods.collect{|m| m.to_s}
    if doc_namespace
      "String.#{message}"
    else
      select_message(receiver, message, candidates)
    end

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

    candidates = Regexp.instance_methods.collect{|m| m.to_s}
    if doc_namespace
      "Regexp.#{message}"
    else
      select_message(receiver, message, candidates)
    end

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

    candidates = Array.instance_methods.collect{|m| m.to_s}
    if doc_namespace
      "Array.#{message}"
    else
      select_message(receiver, message, candidates)
    end

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

    proc_candidates = Proc.instance_methods.collect{|m| m.to_s}
    hash_candidates = Hash.instance_methods.collect{|m| m.to_s}
    if doc_namespace
      ["Proc.#{message}", "Hash.#{message}"]
    else
      select_message(receiver, message, proc_candidates | hash_candidates)
    end

  when /^(:[^:.]*)$/
    # Symbol
    return nil if doc_namespace
    sym = $1
    candidates = Symbol.all_symbols.collect do |s|
      ":" + s.id2name.encode(Encoding.default_external)
    rescue Encoding::UndefinedConversionError
      # ignore
    end
    candidates.grep(/^#{Regexp.quote(sym)}/)

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

  when /^([A-Z].*)::([^:.]*)$/
    # Constant or class methods
    receiver = $1
    message = Regexp.quote($2)
    begin
      candidates = eval("#{receiver}.constants.collect{|m| m.to_s}", bind)
      candidates |= eval("#{receiver}.methods.collect{|m| m.to_s}", bind)
    rescue Exception
      candidates = []
    end
    if doc_namespace
      "#{receiver}::#{message}"
    else
      select_message(receiver, message, candidates, "::")
    end

  when /^(:[^:.]+)(\.|::)([^.]*)$/
    # Symbol
    receiver = $1
    sep = $2
    message = Regexp.quote($3)

    candidates = Symbol.instance_methods.collect{|m| m.to_s}
    if doc_namespace
      "Symbol.#{message}"
    else
      select_message(receiver, message, candidates, sep)
    end

  when /^(?<num>-?(?:0[dbo])?[0-9_](?:\.[0-9_])?(?:(?:[eE][-]?[0-9])?i?|r)?)(?<sep>\.|::)(?<mes>[^.]*)$/
    # Numeric
    receiver = $~[:num]
    sep = $~[:sep]
    message = Regexp.quote($~[:mes])

    begin
      instance = eval(receiver, bind)
      if doc_namespace
        "#{instance.class.name}.#{message}"
      else
        candidates = instance.methods.collect{|m| m.to_s}
        select_message(receiver, message, candidates, sep)
      end
    rescue Exception
      if doc_namespace
        nil
      else
        candidates = []
      end
    end

  when /^(-?0x[0-9a-fA-F_]+)(\.|::)([^.]*)$/
    # Numeric(0xFFFF)
    receiver = $1
    sep = $2
    message = Regexp.quote($3)

    begin
      instance = eval(receiver, bind)
      if doc_namespace
        "#{instance.class.name}.#{message}"
      else
        candidates = instance.methods.collect{|m| m.to_s}
        select_message(receiver, message, candidates, sep)
      end
    rescue Exception
      if doc_namespace
        nil
      else
        candidates = []
      end
    end

  when /^(\$[^.]*)$/
    # global var
    gvar = $1
    all_gvars = global_variables.collect{|m| m.to_s}
    if doc_namespace
      all_gvars.find{ |i| i == gvar }
    else
      all_gvars.grep(Regexp.new(Regexp.quote(gvar)))
    end

  when /^([^."].*)(\.|::)([^.]*)$/
    # variable.func or func.func
    receiver = $1
    sep = $2
    message = Regexp.quote($3)

    gv = eval("global_variables", bind).collect{|m| m.to_s}.push("true", "false", "nil")
    lv = eval("local_variables", bind).collect{|m| m.to_s}
    iv = eval("instance_variables", bind).collect{|m| m.to_s}
    cv = eval("self.class.constants", bind).collect{|m| m.to_s}

    if (gv | lv | iv | cv).include?(receiver) or /^[A-Z]/ =~ receiver && /\./ !~ receiver
      # foo.func and foo is var. OR
      # foo::func and foo is var. OR
      # foo::Const and foo is var. OR
      # Foo::Bar.func
      begin
        candidates = []
        rec = eval(receiver, bind)
        if sep == "::" and rec.kind_of?(Module)
          candidates = rec.constants.collect{|m| m.to_s}
        end
        candidates |= rec.methods.collect{|m| m.to_s}
      rescue Exception
        candidates = []
      end
    else
      # func1.func2
      candidates = []
      to_ignore = ignored_modules
      ObjectSpace.each_object(Module){|m|
        next if (to_ignore.include?(m) rescue true)
        candidates.concat m.instance_methods(false).collect{|x| x.to_s}
      }
      candidates.sort!
      candidates.uniq!
    end
    if doc_namespace
      "#{rec.class.name}#{sep}#{candidates.find{ |i| i == message }}"
    else
      select_message(receiver, message, candidates, sep)
    end

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

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

    candidates = String.instance_methods(true).collect{|m| m.to_s}
    if doc_namespace
      "String.#{candidates.find{ |i| i == message }}"
    else
      select_message(receiver, message, candidates)
    end

  else
    candidates = eval("methods | private_methods | local_variables | instance_variables | self.class.constants", bind).collect{|m| m.to_s}
    candidates |= ReservedWords

    if doc_namespace
      candidates.find{ |i| i == input }
    else
      candidates.grep(/^#{Regexp.quote(input)}/)
    end
  end
end

# File 'lib/irb/completion.rb', line 296

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