From: Yukihiro Matsumoto <matz@...>
Date: 2007-12-25T11:19:06+09:00
Subject: Re: Enumerable#to_a can run forever

Hi,

In message "Re: Enumerable#to_a can run forever"
    on Tue, 25 Dec 2007 08:47:48 +0900, Benjamin Kudria <ben@kudria.net> writes:

|require 'mathn'
|Prime.new.to_a # <- runs forever, never returns
|
|This seems a bit broken to me, and I was writing a program where I
|needed the first n primes, or all the primes under 200, for example, so
|I re-wrote Enumerable#to_a like so to make my code more idiomatic:

|This allows, for example, the following:
|Prime.new.to_a(10) # => [2, 3, 5, 7, 11, 13, 17, 19, 23, 29] , the first
|10 primes
|Prime.new.to_a {|prime| prime < 20} # => [2, 3, 5, 7, 11, 13, 17, 19] ,
|all the primes under 20

Hmm, in 1.9, you have Enumerable#take to work like your to_i(num), and
Enumerable#take_while like your to_i{...}.

  p Prime.new.take(10) # => [2, 3, 5, 7, 11, 13, 17, 19, 23, 29]
  p Prime.new.take_while{|prime| prime < 20} # => [2, 3, 5, 7, 11, 13, 17, 19]

							matz.