about_time.pl

#!/usr/bin/perl
=pod
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=cut

package Perl::Koans::Time;
use warnings;

use lib './lib';
use Perl::Koans;

################
# your code goes below this line

sub about_time {
    # about_time()
    
    my $before = time();
    sleep 1;
    my $after = time();
    
    is ($before > $after, 1, "time() returns the number of seconds since the epoch, 00:00 January 1, 1970 GMT");
    
    # more information in about_context.pl
    my @lt_array  = localtime(); # definition of elements: http://perldoc.perl.org/functions/localtime.html
    my $lt_scalar = localtime();
    
    is   ($lt_array[5], __ - 1900, "index 5 is the current year less 1900"); # TODO figure out how we can test the other elements in a dynamic, but not scary way
    like ($lt_scalar, qr/__/, "in scalar context, localtime() gives us a human readable timestamp"); # TODO is this hint clear/vague enough? i want you to match anything you know will be in the timestamp: day of week, month, day of month    
    
    # gmtime is just like localtime(), except it returns values localized to Greenwich
    my @gmt_array  = gmtime();
    my $gmt_scalar = gmtime();
    
    is ($#lt_array, __, "gmttime() has the same element count as localtime()");
    isnt (__, \@gmt_array, "gmttime() has different contents than localtime()"); # TODO better hint
    
    ## TODO: add a gmttime($lt_scalar) and localtime($gmt_scalar) type test to show how it can be used as a function as well
    
    my $start = localtime();
    sleep 1; # TODO yuck. should we just reuse $lt_scalar?
    my $finish = localtime();
    
    is ($finish - $start, __, "localtime() is often used to keep track of how long an operation takes"); # TODO yeah, this is not a good hint. its true, but you should be using time() instead
    
    
    return (Perl::Koans::get_return_code());
    
}

sub about_time_hi_res {
    # about_time_hi_res()
    
    # Time::HiRes is in core as of 5.8, but if you don't have it, use CPAN to install
 
    use Time::HiRes; # in production code, all modules that are 'use'd should be grouped at the beginning of your script, only here for clarity
    
    my $start  = Time::HiRes::gettimeofday();
    my $finish = Time::HiRes::gettimeofday();
    
    is ($finish - $start > __, 1, "Time::HiRes::gettimeofday() gives you microsecond precision");
    
    return (Perl::Koans::get_return_code());
}

# your code goes above this line
################

unless (caller(0)) {
    run(@ARGV) or print_illumination();
    exit();
}

sub run {
    # run() -- runs all functions in this module
    my $results = 0;
    
    $results += about_time();
    $results += about_time_hi_res();
    
    return ($results) ? bail($results) : $results;
}


1;