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William James schrieb:
> zslevi wrote:
>
>> foo = lambda {|x|
>> return lambda {|y| return x+y}}
>>
>> puts (foo.call(3)).call(4)
>>
>> It works finally, but it's just too verbose.
>> Can anyone suggest a shorter, programmer friendlier way of writing
>> this?
>
> Can you see that "proc" is shorter than "lambda"?
>
> foo = proc{|x| proc{|y| x+y}}
> ==>#<Proc:0x02824eb4@(irb):20>
> foo[3][4]
> ==>7

Javascript:
3+4


André
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On Thu, Jan 15, 2009 at 5:54 AM, William James <> wrote:

> Can you see that "proc" is shorter than "lambda"?
>
> foo = proc{|x| proc{|y| x+y}}
> ==>#<Proc:0x02824eb4@(irb):20>
> foo[3][4]
> ==>7

But also not the same thing on Ruby 1.9, so it's important to be
careful about this generally, even if it works fine with either in the
above example.

>> def foo
>> proc { return }.call
>> puts "Never gets printed"
>> end
=> nil
>> foo
=> nil
>> def bar
>> lambda { return }.call
>> puts "Gets Printed"
>> end
=> nil
>> bar
Gets Printed
=> nil
>> RUBY_VERSION
=> "1.9.1"



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Gregory Brown wrote:
> But also not the same thing on Ruby 1.9, so it's important to be
> careful about this generally, even if it works fine with either in the
> above example.

Yep, it's best to avoid proc{} entirely, since in ruby 1.8 it's an alias
for lambda{}, but in ruby 1.9 it has changed to be an alias for
Proc.new{}.

For the full gory details see
http://innig.net/software/ruby/closures-in-ruby.rb
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