From: timr <timrandg@...>
Date: 2010-08-28T04:12:29+09:00
Subject: Re: how about Array#collect_until

Thanks everyone for the great ideas. I ended up slightly modifying
Senault's suggestion (see below), though I learned from all the
various approaches. In my particular case I do need an inclusive
collect (long story, but using this to do some DNA fuzzy expression
matching that smartly knows when it has found a good solution and
breaks rather than finishing all the other possible calculations, and
I need to see the solution). And though the inject is a great
suggestion, I would prefer keeping the code blocks for determining
endpoint grammatically separated from the processing block, rather
than embedded.
Arigato Ruby Community,
Tim

#collects items processed through block until a solution satisfies the
function test (lambda{})
class Array
  def collect_until(fn, &block)
    results = []
    self.each do |x|
      result = (yield x)
      results << result
      break if fn.call(result)
    end
    results
  end
end
p %w[ find out if that  this  but not the other mother
mouth].collect_until(lambda {|word| word[-2,2] == 'st' }){|item| item
+ "t" }

puts "another attempt"

p [1,6,7,5,3,0,10,12,14].collect_until(Proc.new {|num| num > 25 }){|
item| item * 4 }

puts "another attempt"
p [1,2,3].collect_until(Proc.new {|x| x%2 == 0}) {|item| item + 10}




On Aug 27, 1:47 am, "F. Senault" <f...@lacave.net> wrote:
> Le 27 août à 08:29, timr a écrit :
>
> > [1,2,3].collect{|item| item + 10} # => [11,12,13]
> > [1,2,3].collect_until({|x| x%2 == 0}) {|item| item + 10} # => [11,12]
>
> Why not something like this :
>
> class Array
>   defcollect_until
>     n = []
>     self.each do |e|
>       r, brk = yield e
>       n << r
>       break if brk
>     end
>     n
>   end
> end
>
> Used like this :
>
> >> [1,2,3].collect_until{ |x| [ x + 10 , (x % 2 == 0) ] }
>
> => [11, 12]
>
> Not very pretty, but it does the job.
>
> Fred
> --
> Actual dialogue from the end of the battle:
> Cleric:  "Keep hitting it!"
> Paladin: "It's dead."
> Fighter: "Yeah, but it's not dead enough."  (David P. Murphy in the SDM)