From: Steve Litt <slitt@...>
Date: 2005-12-09T07:36:51+09:00
Subject: Re: do/end vs braces

On Thursday 08 December 2005 10:07 am, Daniel Schierbeck wrote:
> Steve Litt wrote:
> > Hi all,
> >
> > It looks to me like when you use an iterator (each for instance), you can
> > make the block either from a do/end pair, or from curly braces. All
> > things being equal, I'd greatly prefer to use do/end. Are there any
> > differences in runtime speed, capabilities, or Rubyness?
>
> There's a slight difference in how they're parsed.
>
>    foo bar { block }
>
> is the same as
>
>    foo(bar { block })
>
> while
>
>    foo bar do
>      block
>    end
>
> is the same as
>
>    foo(bar) do
>      block
>    end
>
> or
>
>    foo(bar) { block }
>
> but it's only an issue when you leave out the parantheses.

Except I can't put in the parentheses:

#!/usr/bin/ruby
my_array = ["alpha", "beta", "gamma"]
puts (my_array.collect do
	|word|
	word.capitalize
end)

Output:
[slitt@mydesk slitt]$ ./test.rb
./test.rb:3: syntax error
./test.rb:6: syntax error
[slitt@mydesk slitt]$

Thanks

SteveT


> The styling 
> convention is that the curly braces are used for one-line blocks and the
> do..end for multi-line blocks
>
>    foo { make_me_a_bar }
>    bar do
>      foo = Foo.new
>      pass_the_foo(foo)
>      do_something_else
>    end
>
>
> Cheers,
> Daniel

-- 
Steve Litt
http://www.troubleshooters.com
slitt@troubleshooters.com