Re^2: map {} list or do {} for list?

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in reply to Re: map {} list or do {} for list?
in thread map {} list or do {} for list?

That was my feeling about map too. But I have seen it used void in a few bits of code recently, and wondered if there was any solid argument for or against, other than it looks wrong :)

Cheers,
R.

Pereant, qui ante nos nostra dixerunt!

Comment on Re^2: map {} list or do {} for list?

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Re^3: map {} list or do {} for list? by SuicideJunkie (Vicar) on Apr 11, 2014 at 16:06 UTC
Well, it certainly still works, but its misleading. You're building a big list of results and then immediately throwing it away.	[reply]
Re^4: map {} list or do {} for list? by choroba (Cardinal) on Apr 11, 2014 at 16:08 UTC
Wasn't that optimized not to happen in void context? لսႽ† ᥲᥒ⚪⟊Ⴙᘓᖇ Ꮅᘓᖇ⎱ Ⴙᥲ𝇋ƙᘓᖇ	[reply]
Re^5: map {} list or do {} for list? by Anonymous Monk on Apr 11, 2014 at 16:44 UTC
It's a FAQ of its own. Per perl581delta: "map in void context is no longer expensive. map is now context aware, and will not construct a list if called in void context".	[reply]
Re^5: map {} list or do {} for list? by SuicideJunkie (Vicar) on Apr 14, 2014 at 14:30 UTC
Sorry, I didn't mean to imply that it wasn't optimized away. I meant that when reading the code, map says "Hey! Pay attention to the return values of this code block, we're making a list of them."	[reply]
Re^6: map {} list or do {} for list? by jethro (Monsignor) on Apr 15, 2014 at 09:30 UTC
Re^5: map {} list or do {} for list? by Random_Walk (Prior) on Apr 12, 2014 at 12:33 UTC
It looks like it is well optimised. See my benchmarks, currently at the end of the thread. Cheers, R. Pereant, qui ante nos nostra dixerunt!	[reply]

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