[ruby-core:79927] [Ruby trunk Misc#13283] Disable `&' interpreted as argument prefix warning when passing symbol to Enumerable#map

Issue #13283 has been updated by Dan Allen.


If the warning can't be removed, can we find some other way to write this statement without the need for parentheses?

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Misc #13283: Disable `&' interpreted as argument prefix warning when passing symbol to Enumerable#map
https://bugs.ruby-lang.org/issues/13283#change-63356

* Author: Dan Allen
* Status: Open
* Priority: Normal
* Assignee: 
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A common idiom in Ruby is to pass a symbol reference to `Enumerable#map`, which in turn invokes the corresponding method on each entry.

Case in point:

~~~
%(a b c).map &:upcase
~~~

Yet, when warnings are enabled, this line produces the following warning:

~~~
warning: `&' interpreted as argument prefix
~~~

Perhaps we can all agree that's what this statement *should* do, and in fact Ruby does it. So there's really no reason for this warning. The alternative, a bitwise operation on a symbol, makes little sense. That's especially when the bitwise operator is directly adjacent to the symbol.

The workaround to squelch the warning is to add parentheses:

~~~
%(a b c).map(&:upcase)
~~~

However, it's one of the few cases in Ruby where parentheses are mandatory (for an isolated statement). For those of us who prefer to drop parentheses for code style, this is an irritation. It's also one of the most common warnings I've seen Ruby report when warnings are enabled, so it's also just noisy.

Can this warning be removed?



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