[Chicago-talk] Delete element from array

[Andy_Bach at wiwb.uscourts.gov]

Another cute trick - use a hash for your bad (or good, which ever is easist
to know ahead of time) symbols:
use warnings;
use strict;
my @symbols = qw(foo fiv fib fink fort futz);
my %bad_symbols = (
    foo => 1,
    fort => 1,
);
print "Sym: ", join(", ", @symbols), "\n";
@symbols = grep { not $bad_symbols{$_} } @symbols;
print "Sym: ", join(", ", @symbols), "\n";

In a process like this:
sub symbol_is_bad {
    my $symbol = shift;

    if (foo1) {
        return 1;
    }
    if (foo2) {
        return 1;
    }
    ...

    return;
}

my @good_sym = grep { not symbol_is_bad($_) } @sym;

depending upon the size and repetiveness of the data and dynamicn-ness and
cost of the tests, the  sub is good candidate for 'memoization'. There's a
CPAN module for this, but basically it's a matter of avoiding the retest by
caching the results (in a hash say):
my %bad_symbols;
sub symbol_is_bad {
   my ($test_sym) = @_;
   return 1 if $bad_symbols{$test_sym};
    my $symbol = shift;

    if (foo1) {
        $bad_symbols{$test_symj}++;
        return 1;
    }
    if (foo2) {
        $bad_symbols{$test_symj}++;
        return 1;
    }
    ...


    return;
}

]my @good_sym = grep { not symbol_is_bad($_) } @sym;

Following PBP, you might want to refactor there to remove the various
returns (and set a specific return value for failure) inside the "if" tests
- set a flag and handle it at the end, using elsif to make it case stmt but
....

a



-------------------
Andy Bach
Systems Mangler
Internet: andy_bach at wiwb.uscourts.gov
Voice: (608) 261-5738 Fax: 264-5932

Accordion, n.:        A bagpipe with pleats.