From: Perry Smith <pedzsan@...>
Date: 2012-12-24T04:40:32+09:00
Subject: [ruby-core:51103] Re: [ruby-trunk - Feature #7612] Enumerators take a proc

Great!  I tried something similar but I must have botched it somehow.

Oh.... I bet I tried e(&p1)

On Dec 23, 2012, at 1:15 PM, trans (Thomas Sawyer) wrote:

> 
> Issue #7612 has been updated by trans (Thomas Sawyer).
> 
> 
> =begin
> Use `&`:
> 
>  e.each(&p1)
>  e.each(&m2)
>  e.each(&p2)
> =end
> 
> ----------------------------------------
> Feature #7612: Enumerators take a proc
> https://bugs.ruby-lang.org/issues/7612#change-35034
> 
> Author: pedz (Perry Smith)
> Status: Open
> Priority: Normal
> Assignee: 
> Category: 
> Target version: 
> 
> 
> If there is already a clean syntax for this, I apologize.  I sure could not find it.
> 
> class Foo
>  def initialize
>    @inst = 18
>  end
> 
>  def meth(a, b)
>    puts "method #{@inst} #{a} #{b}"
>  end
> end
> 
> foo = Foo.new
> 
> e = %w{a b c}.each_with_index
> p1 = Proc.new { |a, b| puts "proc #{a} #{b}" }
> m2 = foo.method(:meth)
> p2 = m2.to_proc
> 
> # Current Syntax possibilities
> e.each { |a, b| puts "direct #{a} #{b}" }
> e.each { |a, b| foo.meth(a, b) }
> e.each { |a, b| p1.call(a,b) }
> e.each { |a, b| m2.call(a,b) }
> e.each { |a, b| p2.call(a,b) }
> 
> # Proposed Addition
> 
> e.each(p1) # same as e.each { |a, b| p1.call(a,b) }
> e.each(m2) # same as e.each { |a, b| m2.call(a,b) }
> e.each(p2) # same as e.each { |a, b| p2.call(a,b) }
> 
> # In the case of a method or lambda, the arguments are checked and possible errors thrown.
> # In the case of a proc, the proc "tricks" apply
> 
> To add readability, an "apply_to" method could be added:
> 
> e.apply_to(p1)
> 
> The extra "each" bothers me since the enumerator already has an "each" associated with it.
> 
> 
> 
> -- 
> http://bugs.ruby-lang.org/
>