From: "naruse (Yui NARUSE)" <naruse@...>
Date: 2013-04-09T16:08:19+09:00
Subject: [ruby-core:54131] [ruby-trunk - Feature #8229] extend Hash.include?


Issue #8229 has been updated by naruse (Yui NARUSE).

Description updated
Category changed from misc to core
Assignee changed from nobu (Nobuyoshi Nakada) to matz (Yukihiro Matsumoto)


----------------------------------------
Feature #8229: extend Hash.include?
https://bugs.ruby-lang.org/issues/8229#change-38384

Author: eike.rb (Eike Dierks)
Status: Open
Priority: Normal
Assignee: matz (Yukihiro Matsumoto)
Category: core
Target version: Next Major


I'd like to suggest to extend the Hash.include? method.

Currently Hash.include? can only be used to ask for a key,
I believe it should be extended to ask for a (key value) pair.

I believe this extension can be done without breaking prior api.

I suggest to extend the signature of Hash.include?
to Hash.include?(key, value)

That message should return true,
if the receiving object does have an object at key which is equal to value.

It would be a simple replacement for:
    h.include?(key) && h[key] == value

But I do not want to stop there.
I'm heading for h.include_all?(other_hash)
and h.include_any?(other_hash)

and it would be valuable to have h.intersect(other_hash) etc

I believe these to be useful primitives when working with hashes.

I'd like to have the api of the Set class available for the Hash class as well,
but there working on key/value matching.

Obviously any change to such the substantial class as the Hash class
needs a lot of thought for compatibility.

But I believe this can be done without breaking any prior code,
and it could add a lot of new out of the box functionality.

This probably needs some more thought.
We might come up with some dsl like thing like
h.includes.any? or h.includes.all? or h.includes.none?
to be used cross all collection classes.

Someone must be in charge for the Hash class,
my 2p


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