From: sowieso@...
Date: 2014-01-31T08:19:50+00:00
Subject: [ruby-core:60381] [ruby-trunk - Feature #8987] map/collect extension which handles arguments

Issue #8987 has been updated by So Wieso.


Matthew Kerwin wrote:
> On 31 January 2014 15:48, SASADA Koichi <ko1@atdot.net> wrote:
>  
>  >     p [1, 2, 3, 4].map(&4.method(:+)) #=> [5, 6, 7, 8]
>  >     p [1, 2, 3, 4].map(&��{|x| 4+x})  #=> [5, 6, 7, 8]
>  >     p [1, 2, 3, 4].map(&��(4, :+))    #=> [5, 6, 7, 8]
>  >     p [1, 2, 3, 4].map(&��("4+"))     #=> [5, 6, 7, 8]
>  >     p [1, 2, 3, 4].map(&��{4+_})      #=> [5, 6, 7, 8] (doesn't run)
>  >
>  
>  Are any of these actually better than:
>  
>      p [1, 2, 3, 4].map{|x| 4+x }
>  
>  ?
>  
>  
>  -- 
>    Matthew Kerwin
>    http://matthew.kerwin.net.au/

Actually I believe the most readable form would be

`p [1,2,3,4].map{ 4 + _ }  # when there is no |���|, set block params to _ `

Many blocks in realworld-code are so easy, that it is really a barrier to have to think about a name, and therefore one uses often non-verbose names like you used x. Where is the point in being forced to think of a name, when you don't set the name to something meaningful. I guess this was the idea why the to_proc convention was introduced. The problem with it is, that it is really limiting because you cannot use parameters (and the presence of a parameter doesn't necessarily make problems so complex to justify a name).



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Feature #8987: map/collect extension which handles arguments
https://bugs.ruby-lang.org/issues/8987#change-44856

* Author: So Wieso
* Status: Open
* Priority: Normal
* Assignee: 
* Category: core
* Target version: current: 2.2.0
----------------------------------------
Please consider extending map/collect by allowing additional arguments to be passed to proc, like:
A: [1,2,3,4].map :+, 4
and/or
B: [1,2,3,4].map 4, &:+

=> [5, 6, 7, 8]

Variant A is probably more readable. Variant B is more versatile (allows arbitrary arguments to be passed to block).


---Files--------------------------------
mappi.rb (410 Bytes)


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