ch06.087_best

来自「Perl Best Practices the source code」· 087_BEST 代码 · 共 49 行

##############################################################################
##   Code fragment (Recommended) from Chapter 6 of "Perl Best Practices"    ##
##     Copyright (c) O'Reilly & Associates, 2005. All Rights Reserved.      ##
##  See: http://www.oreilly.com/pub/a/oreilly/ask_tim/2001/codepolicy.html  ##
##############################################################################


# Standard modules...
use strict;
use warnings;
use IO::Prompt;
use Carp;
use English qw( -no_match_vars );
use Data::Alias;
use Readonly;

Readonly my $MAX_NUMBER_OF_ATTEMPTS => 10;

sub get_big_int {
    my $tried = 0;
    my $int;
 
    while (!$tried || !is_big($int)) {
        print 'Enter a valid integer: ';
        $int = <>;
 
        chomp $int;
 
        $tried = 1;
    }
 
    return $int;
}


sub is_big {
    my ($n) = @_;
    return $n > 10;
}


 
# and later...
 
for (1..$MAX_NUMBER_OF_ATTEMPTS) {
    print '[', sqrt get_big_int(), "]\n";
}