Others explained that not all builtins' APIs can be copied by using prototypes.

But if you are willing to combine your rank with another modifier sub like by with prototype, you could form compound statements like

rank LIST;

rank by BLOCK LIST;

rank by {SUBNAME} LIST;

[download]

I find this more readable than your original approach.

If acceptable, I could elaborate further on a clean implementation.

Cheers Rolf
(addicted to the Perl Programming Language and ☆☆☆☆ :)
Wikisyntax for the Monastery

In reply to Re^2: Prototype like sort()? by LanX
in thread Prototype like sort()? by perlancar

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