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Re: Closure Over Scalar?

by BillKSmith (Monsignor)
on Feb 18, 2021 at 20:29 UTC ( #11128540=note: print w/replies, xml ) Need Help??


in reply to Closure Over Scalar?

This seems to be what use feature 'state' is made for.
#!/usr/bin/env perl # demo of closure around sub, with persistent string use strict; use warnings; use feature 'state'; for my $q ('a'..'g') { do_something($q); print "Done computing\n" } sub do_something { state $FIXED_STRING = 'fixed_string'; state %persistent; my $x = $_[0]; $persistent{$x}{$FIXED_STRING} = rand; END { for my $k (keys %persistent) { print "$k: $persistent{$k}{$FIXED_STRING}\n"; } } }
Bill

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Re^2: Closure Over Scalar?
by QM (Parson) on Feb 19, 2021 at 14:25 UTC
    This seems to be what use feature 'state' is made for.
    Yes, state has fallen out of my lexicon from disuse. A very good point, I don't need a closure, and the assignment happens as expected!

    -QM
    --
    Quantum Mechanics: The dreams stuff is made of

      It is not an issue in your example, but could be in your production code. Initialization of state hash and array variables was not available before v5.28.
      Bill

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