ruby1.9.1 : Override string method
in [Ruby]
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From: Ts on 2 Nov 2009 06:49 The following script doesn't work... Do you have any idea of what is wrong? Is it a ruby bug? (ruby version: ruby 1.9.1p243 (2009-07-16 revision 24175) [i386-darwin9]) require 'time' Time.parse("1999-10-31 16:46:50") # this works class String alias_method :old_sub!, :sub! def sub!(*args, &block) old_sub!(*args, &block) end end Time.parse("1999-10-31 16:46:50") # this crashes # => # # ArgumentError: argument out of range # from /opt/local/lib/ruby1.9/1.9.1/time.rb:202:in `local' # from /opt/local/lib/ruby1.9/1.9.1/time.rb:202:in `make_time' # from /opt/local/lib/ruby1.9/1.9.1/time.rb:261:in `parse' # from (irb):10 # from /opt/local/bin/irb1.9:12:in `<main>' -- Posted via http://www.ruby-forum.com/.
From: Brian Candler on 2 Nov 2009 07:08 Thomas Sevestre wrote: > > The following script doesn't work... > Do you have any idea of what is wrong? There are loads of sub! calls in date/format.rb, but I have no idea why delegating sub! in this way would break it. I note that the same error occurs in 1.8.6 too: ArgumentError: argument out of range from /usr/lib/ruby/1.8/time.rb:184:in `local' from /usr/lib/ruby/1.8/time.rb:184:in `make_time' from /usr/lib/ruby/1.8/time.rb:243:in `parse' from (irb):19 I copied time.rb to my local directory and modified it to puts the arguments to local. I see that it is calling Time.local(1999, 10, 31, 16, 46, 50, 0) before the sub! change, but Time.local(2009,0,1,0,0,0,0) after it. Most bizarre. -- Posted via http://www.ruby-forum.com/.
From: David A. Black on 2 Nov 2009 07:39 Hi -- On Mon, 2 Nov 2009, Brian Candler wrote: > Thomas Sevestre wrote: >> >> The following script doesn't work... >> Do you have any idea of what is wrong? > > There are loads of sub! calls in date/format.rb, but I have no idea why > delegating sub! in this way would break it. > > I note that the same error occurs in 1.8.6 too: > ArgumentError: argument out of range > from /usr/lib/ruby/1.8/time.rb:184:in `local' > from /usr/lib/ruby/1.8/time.rb:184:in `make_time' > from /usr/lib/ruby/1.8/time.rb:243:in `parse' > from (irb):19 > > I copied time.rb to my local directory and modified it to puts the > arguments to local. I see that it is calling > > Time.local(1999, 10, 31, 16, 46, 50, 0) > > before the sub! change, but > > Time.local(2009,0,1,0,0,0,0) > > after it. Most bizarre. I believe it's about the $1, $2... variables: "abc".sub!(/(.)/, "z") p $1 # nil "abc".old_sub!(/(.)/, "z") p $1 # "a" When sub! calls old_sub!, the $n variables inside sub! are not set, but the ones in old_sub! are. When the date parser hits _parse_iso (or whichever of that family of methods it hits), there are calls to sub! followed by usage of the $n variables, which are actually not set because they're two methods removed. A more generic example: def y(str) /(.)/.match(str) p $1 end def x(str) y(str) p $1 end x("abc") => "a" nil David -- The Ruby training with D. Black, G. Brown, J.McAnally Compleat Jan 22-23, 2010, Tampa, FL Rubyist http://www.thecompleatrubyist.com David A. Black/Ruby Power and Light, LLC (http://www.rubypal.com)
From: Brian Candler on 2 Nov 2009 08:23 > A more generic example: So the $~ variables are both thread-local *and* scoped to the enclosing method? That's definitely new to me. Thanks for the explanation. -- Posted via http://www.ruby-forum.com/.
From: Thomas Sevestre on 2 Nov 2009 10:31
Interesting! I wasn't aware of that. Is there any way to make it work? It is feasible in your generic example: def y(str, b) eval "/(.)/.match(str)", b p $1 end def x(str) y(str, binding) p $1 end x("abc") # => # # nil # "a" But in my case, I need to find the caller's binding : class String alias_method :old_sub!, :sub! def sub!(*args, &block) eval "old_sub!(*args, &block)", caller_binding end end But I havn't been able to retrieve it :( Do you have any idea? Thomas -- Posted via http://www.ruby-forum.com/. |