Re^2: Thread::Queue memory issue with nested maps but not foreach loops...

for (EXPR .. EXPR)
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is an iterator, but
for (CONSTANT .. CONSTANT)
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is actually
my @anon; BEGIN { @anon = (CONSTANT..CONSTANT); } for (@anon)
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Now, for (@anon) is treated more efficiently than generic lists, but I don't remember how so exactly.
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Re^3: Thread::Queue memory issue with nested maps but not foreach loops... by BrowserUk (Patriarch) on Mar 03, 2012 at 09:13 UTC
Sorry, but that simply cannot be true. At least not for large ranges: C:\test>perl -MTime::HiRes=time -E"$t=time; ++$c for 1..1e6; say time- +$t; <>" 0.0741260051727295 5.2 MB C:\test>perl -MTime::HiRes=time -E"$e=1e6;$t=time; ++$c for 1..$e; say + time-$t; <>" 0.0663371086120605 5.3 MB C:\test>perl -MTime::HiRes=time -E"$t=time; ++$c for 1..1e7; say time- +$t; <>" 0.635999917984009 5.2 MB C:\test>perl -MTime::HiRes=time -E"$e=1e7;$t=time; ++$c for 1..$e; say + time-$t; <>" 0.645999908447266 5.3 MB C:\test>perl -MTime::HiRes=time -E"$t=time; ++$c for 1..1e8; say time- +$t; <>" 6.22199988365173 5.2 MB C:\test>perl -MTime::HiRes=time -E"$e=1e8;$t=time; ++$c for 1..$e; say + time-$t; <>" 6.46099996566772 5.3 MB C:\test>perl -MTime::HiRes=time -E"$t=time; ++$c for 1..1e9; say time- +$t; <>" 61.9520001411438 5.2MB C:\test>perl -MTime::HiRes=time -E"$e=1e9;$t=time; ++$c for 1..$e; say + time-$t; <>" 64.4389998912811 5.3 MB [download] There isn't any evidence for it at small range sizes: `C:\test>perl -MTime::HiRes=time -E"$t=time; ++$c for 1..1e2; say time- +$t; <>" 2.09808349609375e-005 5.2 MB C:\test>perl -MTime::HiRes=time -E"$e=1e2;$t=time; ++$c for 1..$e; say + time-$t; <>" 1.9073486328125e-005 5.3 MB` [download] With the rise and rise of 'Social' network sites: 'Computers are making people easier to use everyday' Examine what is said, not who speaks -- Silence betokens consent -- Love the truth but pardon error. "Science is about questioning the status quo. Questioning authority". In the absence of evidence, opinion is indistinguishable from prejudice. The start of some sanity?	[reply] [d/l] [select]
Re^4: Thread::Queue memory issue with nested maps but not foreach loops... by ikegami (Patriarch) on Mar 05, 2012 at 06:55 UTC
I stand corrected. I got two things mingled. It only flattens a constant range at compile-time when it would otherwise be flattened at run-time. (e.g. `my @a = (1..10_000);`)	[reply] [d/l]