From: Rick DeNatale <rick.denatale@...>
Date: 2008-01-11T03:55:33+09:00
Subject: Re: Array#count returning an enumerator

On 1/10/08, Yukihiro Matsumoto <matz@ruby-lang.org> wrote:
> Hi,
>
> In message "Re: Array#count returning an enumerator"
>     on Thu, 10 Jan 2008 20:16:08 +0900, "David A. Black" <dblack@rubypal.com> writes:
>
> |>  ary.count.with_index{|x,i|...}
> |
> |What does that give you that's different from ary.each.with_index?
>
> It returns count of items for which block gives true.
>
>   ary = [1,2,3,4]
>   p ary.count.with_index{|x,i| i%2 == 0}  # => 2
>   p ary.each.with_index{|x,i| i%2 == 0}   # => [1,2,3,4]

Matz,

The RDOC indicates that Enumerable#count returns an int in all cases.
Or at least it did for the version of Ruby 1.9 from just before the
1.9.0 release.

Unfortunately, I dont know what it says now because I refreshed from
SVN yesterday and now I get:

shadowfax:~ rick$ ri1.9 Enumerable#count
/usr/local/lib/ruby/1.9.0/rdoc/ri/driver.rb:321:in `block in
populate_class_cache': undefined method `[]' for
#<YAML::Object:0x7538fc> (NoMethodError)
        from /usr/local/lib/ruby/1.9.0/rdoc/ri/driver.rb:319:in `each'
        from /usr/local/lib/ruby/1.9.0/rdoc/ri/driver.rb:319:in
`populate_class_cache'
        from /usr/local/lib/ruby/1.9.0/rdoc/ri/driver.rb:237:in `class_cache'
        from /usr/local/lib/ruby/1.9.0/rdoc/ri/driver.rb:354:in `block in run'
        from /usr/local/lib/ruby/1.9.0/rdoc/ri/driver.rb:351:in `each'
        from /usr/local/lib/ruby/1.9.0/rdoc/ri/driver.rb:351:in `run'
        from /usr/local/lib/ruby/1.9.0/rdoc/ri/driver.rb:200:in `run'
        from /usr/local/bin/ri1.9:5:in `<main>'
shadowfax:~ rick$ ri1.9
/usr/local/lib/ruby/1.9.0/rdoc/ri/driver.rb:321:in `block in
populate_class_cache': undefined method `[]' for
#<YAML::Object:0x7539d8> (NoMethodError)
        from /usr/local/lib/ruby/1.9.0/rdoc/ri/driver.rb:319:in `each'
        from /usr/local/lib/ruby/1.9.0/rdoc/ri/driver.rb:319:in
`populate_class_cache'
        from /usr/local/lib/ruby/1.9.0/rdoc/ri/driver.rb:237:in `class_cache'
        from /usr/local/lib/ruby/1.9.0/rdoc/ri/driver.rb:382:in `select_classes'
        from /usr/local/lib/ruby/1.9.0/rdoc/ri/driver.rb:349:in `run'
        from /usr/local/lib/ruby/1.9.0/rdoc/ri/driver.rb:200:in `run'
        from /usr/local/bin/ri1.9:5:in `<main>'

shadowfax:~ rick$ ri1.9 -v
ri1.9 2.0.0
shadowfax:~ rick$ ruby1.9 -v
ruby 1.9.0 (2008-01-10 revision 0) [i686-darwin8.11.1]



-- 
Rick DeNatale

My blog on Ruby
http://talklikeaduck.denhaven2.com/