Hi --
On Wed, 4 Aug 2010, Marnen Laibow-Koser wrote:
...which I do. But for...in just doesn't feel like a good fit for Ruby
to me -- it feels more like syntactic sugar for Perl and PHP
programmers.
Evidence for that can be found in the fact that for is implemented in
terms of each:
obj = Object.new
def obj.each
puts "Here I am in each, about to yield 100!"
yield 100
end
for a in obj
puts a
end
Output:
Here I am in each, about to yield 100!
100
Another demo:
$ ruby -e 'for a in 3; end'
-e:1:in `<main>': undefined method `each' for 3:Fixnum (NoMethodError)
There's a slight difference in how they work, in the sense that each
takes a code block (at least, as usually implemented), while for is in
flat scope, similar to an if-statement:
for a in [1]
b = 100
end
p b # 100
I don't know of any cases where having the flat scope would be so
important as to lead me to use for if I didn't have some other reason to
(which I don't think I ever have).
David
--
David A. Black, Senior Developer, Cyrus Innovation Inc.
The Ruby training with Black/Brown/McAnally
Compleat Philadelphia, PA, October 1-2, 2010
Rubyist http://www.compleatrubyist.com
--
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.
