ruby-core

Issue #11653 has been updated by Martin D端rst.


J旦rg W Mittag wrote:

> This is basically a subset of what I proposed a year ago in #11262.

Commenting on a closed issue won't help much to move an open issue forward. One thing that might help is to split Feature #11262 into smaller issues that can be discussed more easily.

> A `Hash` is basically just a function from keys to elements.

Yes. The most direct case is `Hash.new { |h, k| my_function(k) }`. :-)



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Feature #11653: Add to_proc on Hash
https://bugs.ruby-lang.org/issues/11653#change-59349

* Author: Daniel P. Clark
* Status: Closed
* Priority: Normal
* Assignee: Nobuyoshi Nakada
----------------------------------------
Procs can be called the same way a hash is with `[]`.  But a Hash is not mappable as a Proc.

~~~ruby
    my_hash = ->key{{
      a: 1, b: 2, c: 3, d: 4, e: 5, f: 6
    }[key]}

    my_hash[:a]
    # => 1

    [:e, :a, :b, :f, :c, :d].map(&my_hash) # hash is now mappable
    # => [5, 1, 2, 6, 3, 4]
~~~

This seems so straight forward I believe it should be part of the language itself with the `.to_proc` method call.



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