[Chicago-talk] appending hashes

[Andy_Bach at wiwb.uscourts.gov]

Interestingly (???) the map method:
 'mapappend' => sub
         {
                 %a = %b;
                 %a = map {$_ => $c{$_} }  keys(%c);
         },

is slower and gets worse as the hashes get bigger. I bumped up c to:
%c = map(($_, $_), 0 .. 6750);
and:
Benchmark: timing 1000 iterations of append, baseline, mapappend...
    append: 36 wallclock secs (33.94 usr +  0.22 sys = 34.16 CPU) @ 
29.27/s (n=1000)
  baseline:  2 wallclock secs ( 2.08 usr +  0.02 sys =  2.10 CPU) @ 
476.19/s (n=1000)
 mapappend: 65 wallclock secs (61.32 usr +  0.58 sys = 61.90 CPU) @ 
16.16/s (n=1000)

(left off unroll as it was really slow).  Looks like slices are the way to 
go.

a

Andy Bach, Sys. Mangler
Internet: andy_bach at wiwb.uscourts.gov 
VOICE: (608) 261-5738  FAX 264-5030


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