From: "nobu (Nobuyoshi Nakada)" Date: 2013-06-10T14:44:58+09:00 Subject: [ruby-core:55398] [ruby-trunk - Feature #8506] Object#iter_for / Object#to_iter Issue #8506 has been updated by nobu (Nobuyoshi Nakada). Description updated You may want to show the implementation in ruby (and tests)? ---------------------------------------- Feature #8506: Object#iter_for / Object#to_iter https://bugs.ruby-lang.org/issues/8506#change-39822 Author: alindeman (Andy Lindeman) Status: Open Priority: Normal Assignee: Category: Target version: =begin Ruby's (({Enumerator})) and (({#enum_for})) methods are very powerful and I use them very often. However, (({Object#enum_for})) requires a method that yields, usually in some sort of loop. Many objects in Ruby have methods that iterate to a "next value," but do not yield. For example, (({Fixnum#next.})) There is no way to use (({Fixnum#next})) with (({#enum_for})) directly that I am aware of. I propose the introduction of (({Object#iter_for})) which--given a method--generates a lazy sequence by continually invoking the method on successive values. I call it (({iter})) or (({iterate})) because it is very similar to clojure's iterate: http://clojure.github.io/clojure/clojure.core-api.html#clojure.core/iterate Proposed API: 0.iter_for(:next).take(5) # => [0, 1, 2, 3, 4] require 'date' Date.new(2013, 1, 1).iter_for(:next_month).take(3) # => [Tue, 01 Jan 2013, Fri, 01 Feb 2013, Fri, 01 Mar 2013] I am especially excited about (({0.iter_for(:next)})) as I find myself using infinite lazy numeric sequences more often lately to solve specific kinds of problems. Right now you are required to write something like: (({Enumerator.new { |y| i = 0; loop { y << i; i += 1 } }})) or (({(0..Float::INFINITY).each})). Neither is especially elegant or happy to the developers' eyes in my opinion. Thank you all :) Ruby is an amazing tool. =end -- http://bugs.ruby-lang.org/