Re: Pass conditions to a subroutine

You could use eval EXPR, but passing a sub reference is safer, clearer and easier.

my $condition = sub { !-d $_[0] };
my $result = checkForDirectory($condition);

sub checkForDirectory
{
    my $condition = shift;
    
    ...
    
    if ($condition->($someDir))
    {
        doSomethingElse();
    }
}
[download]

Comment on Re: Pass conditions to a subroutine Select or Download Code

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Re^2: Pass conditions to a subroutine by Fletch (Bishop) on May 13, 2008 at 19:15 UTC
Of course you could take advantage of one of the few times you would actually want to use a prototype and allow a more streamlined syntax: `sub checkForDirectory (&) { my $cond = shift; ## ... } ## ... my $result = checkForDirectory { ! -d $_[0] }; my $also_result = checkForDirectory sub { -M $_[0] > 2 }` [download] Although doing it this way means that if your coderefs aren't inline (say they're coming from an array or hash based on some other external condition) you'll need to use a leading & to override the prototype check . . . `my $predicate = sub { $_[0] =~ /^\d{4}-\d{2}-\d{2}/ }; my $other_result = &checkForDirectory( $predicate );` [download] The cake is a lie. The cake is a lie. The cake is a lie.	[reply] [d/l] [select]
Re^2: Pass conditions to a subroutine by PerlRob (Sexton) on May 13, 2008 at 18:08 UTC
Thanks to all--exactly what I was looking for!	[reply]