From: Thomas Sawyer <transfire@...>
Date: 2012-03-17T03:16:50+09:00
Subject: [ruby-core:43353] [ruby-trunk - Bug #6151] ArgumentError of lambda shows wrong location


Issue #6151 has been updated by Thomas Sawyer.


Just to be clear, where both issues fixed? i.e. the fact that an error was raised in this case at all, as well as the location of lambda errors?

----------------------------------------
Bug #6151: ArgumentError of lambda shows wrong location
https://bugs.ruby-lang.org/issues/6151#change-24657

Author: Thomas Sawyer
Status: Closed
Priority: Normal
Assignee: 
Category: core
Target version: 2.0.0
ruby -v: ruby 1.9.3p0 (2011-10-30 revision 33570) [x86_64-linux]


=begin

Perhaps there is a reason, but it sure seems like a bug to me. Given this simple class:

      #
      class BlockParser < BasicObject
        def initialize(data={}, &block)
          @data = data
          instance_eval(&block)
        end

        def method_missing(name, *args, &block)
          if block
            @data[name] = {}
            BlockParser.new(@data[name], &block)
          else
            case args.size
            when 0
              @data[name]
            when 1
              @data[name] = args.first
            else
              @data[name] = args
            end
          end
        end
      end

Then we can do:

      data = {}
      BlockParser.new(data) do
        name 'Tommy'
      end
      data #=> {:name=>'Tommy'}

But,

      data = {}
      blk  = lambda do
        name 'Tommy'
      end
      BlockParser.new(data, &blk)
      ArgumentError: wrong number of arguments (1 for 0)
      	from (irb):44:in `block in irb_binding'
      	from (irb):16:in `instance_eval'
      	from (irb):16:in `initialize'
      	from (irb):46:in `new'
      	from (irb):46
      	from /home/trans/.rbfu/rubies/1.9.3-p0/bin/irb:12:in `<main>'

If I use (({Proc.new})) instead of (({lambda})) it works. But since I am using (({#instance_eval})) to evaluate the Proc, that shouldn't matter.

Note the reported line number of the error corresponds to (({name 'Tommy'})).
=end



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