OK, I see how this works now, but I can't figure out how to get extra args in there, i.e. something like [1, 2, 3].collect(&:modulo, 2) doesn't work because it's improper Ruby syntax. I assume there's a reason extra args are allowed, so could someone give a brief illustration of the calling convention?
Thanks in advance, Ken On Feb 5, 2009, at 6:13 PM, [email protected] wrote: > > It is not possible in "plain" ruby because Rails extends the Symbol > class with the possibility of converting it into a Proc (that's what > happens when you precede something with a &). From the Rails source > code: > > unless :to_proc.respond_to?(:to_proc) > class Symbol > # Turns the symbol into a simple proc, which is especially useful > for enumerations. Examples: > # > # # The same as people.collect { |p| p.name } > # people.collect(&:name) > # > # # The same as people.select { |p| p.manager? }.collect { |p| > p.salary } > # people.select(&:manager?).collect(&:salary) > def to_proc > Proc.new { |*args| args.shift.__send__(self, *args) } > end > end > end > > And it does come very handy indeed. > Balint > > On Feb 6, 1:07 am, Kenneth McDonald <[email protected]> > wrote: >> I've seen a claim on the web that &:f is just Ruby shorthand for >> &proc >> { |i| i.f }, but I've certainly never been able to get this &:f >> notation to work in standard ruby. >> >> Thanks, >> Ken > > --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "Ruby on Rails: Talk" group. To post to this group, send email to [email protected] To unsubscribe from this group, send email to [email protected] For more options, visit this group at http://groups.google.com/group/rubyonrails-talk?hl=en -~----------~----~----~----~------~----~------~--~---
