From: matthew@...
Date: 2016-01-20T18:36:39+00:00
Subject: [ruby-core:72991] [Ruby trunk - Feature #11999] MatchData#to_h to get a Hash from named captures

Issue #11999 has been updated by Matthew Kerwin.


Yui NARUSE wrote:
> Yukihiro Matsumoto wrote:
> > I don't think `to_h` is appropriate, because `MatchData` is not always able to convert to Hash/Map.
> > Is there any name candidate?
> 
> I feel it can always convert to Hash because even if it doesn't use named captures, the numbering is 1-origin.
> 
> ```
> irb(main):001:0> /(a)(b)(c)/.match("abc")
> => #<MatchData "abc" 1:"a" 2:"b" 3:"c">
> irb(main):002:0> /(a)(b)(c)/.match("abc").to_h
> => {1=>"a", 2=>"b", 3=>"c"}
> ```

I did some experimenting of my own to this end, and came up with this: https://github.com/phluid61/mug/blob/master/lib/mug/matchdata/hash.rb

The only real weirdness arises from the fact that positional captures don't happen at all if there's a named capture group in the Regexp; but given the resulting mutual exclusivity, the code itself becomes pretty straight-forward.

----------------------------------------
Feature #11999: MatchData#to_h to get a Hash from named captures
https://bugs.ruby-lang.org/issues/11999#change-56211

* Author: sorah Shota Fukumori
* Status: Open
* Priority: Normal
* Assignee: 
----------------------------------------
~~~
class MatchData
  def to_h
    self.names.map { |n| [n, self[n]] }.to_h
  end
end

p '12'.match(/(?<a>.)(?<b>.)(?<c>.)?/).to_h #=> {"a"=>"1", "b"=>"2", "c"=>nil}
~~~

Sometimes I want to get a Hash from named capture, but currently I have to use #names + #captures. How about adding MatchData#to_h for convenience way?



---Files--------------------------------
11999.diff (2.77 KB)


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