Perl 学习手札之十六： New features in Perl 5.10
Using Perl 5.10 featuresperl 5.10 includes new language features
incompatible with previous version
use feature ':5.10';
use feature qw(switch say state);
use 5.010 say feature.
#!/usr/bin/perl
#
use strict;
use warnings;
use feature ":5.10";
main(@ARGV);
sub main
{
say "This is the Perl 5.10 new features exercise file.";
say "this is another line";
}
sub error
{
my $e = shift || 'unkown error';
my $me = ( split(/[\\\/]/, $0 ) )[-1];
print("$me: $e\n");
exit 0;
} switch feature:
switch.pl
#!/usr/bin/perl
#
use strict;
use warnings;
use feature ":5.10";
main(@ARGV);
sub main
{
my $s='jimi hendrix';#5
given($s){
when(undef){say'$s is undefined'}
when('jimi'){say'$s is musician'}
when(/jimi/){say'$s maybe a muscian'}
when(){say'$s is odd number'}
default{say '$s is something else!'}
}
}
sub error
{
my $e = shift || 'unkown error';
my $me = ( split(/[\\\/]/, $0 ) )[-1];
print("$me: $e\n");
exit 0;
} state feature;
state.pl
#!/usr/bin/perl
#
use strict;
use warnings;
use feature ":5.10";
main(@ARGV);
sub main
{
my $i = 5;
increment($i);
increment($i);
increment($i);
increment($i);
}
sub increment{
state $n = shift;
say ++$n;
}
sub error
{
my $e = shift || 'unkown error';
my $me = ( split(/[\\\/]/, $0 ) )[-1];
print("$me: $e\n");
exit 0;
} 注意此时的state关键字，如果用my替换，运行结果会不同！
到此为止，Perl学习手札的更新，告一段落。进阶更新待定
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