[ruby-core:60024] [ruby-trunk - Feature #9442] [Rejected] Multiple comparison construction with `==` and `===`

Issue #9442 has been updated by Yukihiro Matsumoto.

Status changed from Open to Rejected

I am sorry but the proposed syntax conflicts with the existing syntax, especially the equal operator one.
You have proposed improvement on case statement, but it still conflicts.

So (until someone come up with the new non-conflicting syntax), I have to reject this proposal.

Matz.


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Feature #9442: Multiple comparison construction with `==` and `===`
https://bugs.ruby-lang.org/issues/9442#change-44544

* Author: Tsuyoshi Sawada
* Status: Rejected
* Priority: Normal
* Assignee: 
* Category: 
* Target version: 
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I often want to write a condition that depends on multiple variables like this:

    if a == 1 and b == 2 then ...
    elsif a == 2 and b == 1 then ...
    elsif a == 2 and b == 2 then ...
    ...

In order to make this compact, I sometimes write these cases like this:

    case [a, b]
    when [1, 2] then ...
    when [2, 1] then ...
    when [2, 2] then ...
    ...

or even

    if [a, b] == [1, 2] then ...
    elsif [a, b] == [2, 1] then ...
    elsif [a, b] == [2, 2] then ...
    ...

but I feel that constructing these arrays is a waste of resource, as well as is not elegant to write.

I request a syntax feature that allows multiple comparison using `==` and `===` in the spirit of multiple assignment with `=` :

    x, y, z = :foo, :bar, :baz

so that the two examples above would be respectively written as:

    case a, b
    when 1, 2 then ...
    when 2, 1 then ...
    when 2, 2 then ...
    ...

and

    if a, b == 1, 2 then ...
    elsif a, b == 2, 1 then ...
    elsif a, b == 2, 2 then ...
    ...




-- 
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