[ruby-core:71327] [Ruby trunk - Feature #11653] [Open] Add to_proc on Hash

[ruby-core:71327] [Ruby trunk - Feature #11653] [Open] Add to_proc on Hash

[6ftdan]

Issue #11653 has been reported by Daniel P. Clark.

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

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

    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.



-- 
https://bugs.ruby-lang.org/

[ruby-core:71329] [Ruby trunk - Feature #11653] Add to_proc on Hash

[duerst]

Issue #11653 has been updated by Martin Dürst.

Assignee set to Yukihiro Matsumoto

I think this is an excellent idea. I hope this can make it into Ruby 2.3.

----------------------------------------
Feature #11653: Add to_proc on Hash
https://bugs.ruby-lang.org/issues/11653#change-54703

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

    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.



-- 
https://bugs.ruby-lang.org/

[ruby-core:71330] [Ruby trunk - Feature #11653] Add to_proc on Hash

[nobu]

Issue #11653 has been updated by Nobuyoshi Nakada.

Description updated

You can write it as:

~~~ruby
[:e, :a, :b, :f, :c, :d].map(&my_hash.method(:[]))
~~~

----------------------------------------
Feature #11653: Add to_proc on Hash
https://bugs.ruby-lang.org/issues/11653#change-54704

* Author: Daniel P. Clark
* Status: Open
* Priority: Normal
* Assignee: Yukihiro Matsumoto
----------------------------------------
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.



-- 
https://bugs.ruby-lang.org/

[ruby-core:71404] [Ruby trunk - Feature #11653] Add to_proc on Hash

[matz]

Issue #11653 has been updated by Yukihiro Matsumoto.

Assignee changed from Yukihiro Matsumoto to Nobuyoshi Nakada

Accepted.

Matz.


----------------------------------------
Feature #11653: Add to_proc on Hash
https://bugs.ruby-lang.org/issues/11653#change-54774

* Author: Daniel P. Clark
* Status: Open
* 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.



-- 
https://bugs.ruby-lang.org/

[ruby-core:71405] [Ruby trunk - Feature #11653] Add to_proc on Hash

[ko1]

Issue #11653 has been updated by Koichi Sasada.


Discussion: https://docs.google.com/document/d/1D0Eo5N7NE_unIySOKG9lVj_eyXf66BQPM4PKp7NvMyQ/pub

Feel free to continue discussion on this ticket.


----------------------------------------
Feature #11653: Add to_proc on Hash
https://bugs.ruby-lang.org/issues/11653#change-54775

* Author: Daniel P. Clark
* Status: Open
* 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.



-- 
https://bugs.ruby-lang.org/

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[Dan Whiteside]

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[ruby-core:76135] [Ruby trunk Feature#11653] Add to_proc on Hash

[Ruby-Lang]

Issue #11653 has been updated by Jörg W Mittag.


Daniel P. Clark wrote:
> 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.

This is basically a subset of what I proposed a year ago in #11262. I additionally proposed that `Hash` also implement `call`. IMO, it doesn't make much sense to have one without the other: both methods basically say "hey, I'm kinda like a function", and a `Hash` is basically just a function from keys to elements. I proposed the same thing for `Array` and `Set`, which are essentially also just functions from indices to elements (`Array`) or elements to booleans (`Set`). However, so far, there has been no interest in that ticket.

----------------------------------------
Feature #11653: Add to_proc on Hash
https://bugs.ruby-lang.org/issues/11653#change-59340

* 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.



-- 
https://bugs.ruby-lang.org/

[ruby-core:76140] [Ruby trunk Feature#11653] Add to_proc on Hash

[duerst]

Issue #11653 has been updated by Martin Dürst.


Jörg 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) }`. :-)



----------------------------------------
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.



-- 
https://bugs.ruby-lang.org/