I find this syntax for map confusing and always use the curly braces syntax. map{...}

perl -MTime::HiRes=time -wE"my $t=time; my @a=1..1e6;say time-$t;

[download]
is way faster than: 
perl -MTime::HiRes=time -wE"my $t=time; my @a=map $_,1..1e6;say time-$
++t;

[download]
because the map generates an anon array that is an "extra step" and that array is copied to @a.

In your later code, you have a map within a map which is similar to a foreach within a foreach. So it is going to run like 1 million times slower.

On my machine... 

C:\Projects>perl -MTime::HiRes=time -wE"my $t=time; my @a=(1..1e6);say
+ time-$t;"
0.0974979400634766

C:\Projects>perl -MTime::HiRes=time -wE"my $t=time; my @a=map $_,1..1e
+6;say time-$t;"
0.337559938430786

C:\Projects>perl -MTime::HiRes=time -wE"my $t=time; my @a=map {$_}1..1
+e6;say time-$t;"
0.339046001434326

[download]

In reply to Re: What could cause excessive page faults? by Marshall
in thread What could cause excessive page faults? by BrowserUk

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