From: "matz (Yukihiro Matsumoto)" <matz@...>
Date: 2014-01-03T11:38:08+09:00
Subject: [ruby-core:59493] [ruby-trunk - Feature #9347] Accept non callable	argument to detect


Issue #9347 has been updated by matz (Yukihiro Matsumoto).


I am afraid that kind of conditional behavior could error prone (e.g. accidental misbehavior when one forget having #call in argument object).  I'd rather have #detect with keyword argument, like ary.detect(ifnone: :notfound).

Matz.

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Feature #9347: Accept non callable argument to detect
https://bugs.ruby-lang.org/issues/9347#change-44041

Author: marcandre (Marc-Andre Lafortune)
Status: Open
Priority: Normal
Assignee: matz (Yukihiro Matsumoto)
Category: core
Target version: current: 2.2.0


Currently, the only argument that `Enumerable#detect` accepts is a callable object.

Shouldn't we accept non callable objects too?

    [42].detect(:not_found){} # => NoMethodError: undefined method `call' for :not_found:Symbol
     # would return :not_found instead.

I'd suggest that if the given argument does not `respond_to? :call`, then it would be returned as is instead of raising an error as currently.
Wouldn't this be more flexible and possibly more performant?

Inspired by http://stackoverflow.com/questions/20883414/why-does-enumerabledetect-need-a-proc-lambda


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