Select Code to Download

open(FILE "<file.dat") || die "cannot open file";

sub insertQuarter {
    my ($coin) = @_;
...
    initializeGame();
    startGame();
}

# just return a false value and allow the
# calling code to deal with the false return
...
# call stack information, set error variable,
# and return a specific value.
(defined($coin) && $coin == 25) || return errorHandler("You must inser
+t 25 cents");

#!/usr/bin/perl

...
    'Assert'          => sub { eval { Assert($_)          } for (@nums
+) },    
    'Assert2'         => sub { eval { Assert2($_)         } for (@nums
+) },   
});

Benchmark: timing 10000 iterations of Assert, Assert2, IfBlocks, IfSta
+tement, UnlessBlocks, UnlessStatement...
         Assert:  4 wallclock secs ( 2.38 usr +  0.02 sys =  2.40 CPU)
+ @ 4166.67/s (n=10000)
...
IfStatement     1299/s             52%          49%       3%          
+--   -69%    -69%
Assert          4167/s            388%         378%     231%        22
+1%     --     -0%
Assert2         4184/s            390%         380%     233%        22
+2%     0%      --

sub onlyAcceptFooObjects {
    my ($foo) = @_;
...
        || die "This method only accepts Foo objects";
    # ...
}