将UTF8字符串转换为Perl中的数值

例如,
my $str = '中國c'; # Chinese language of china
我想打印出数值
20013,22283,99
    
已邀请:
unpack
将比
split
ord
更有效,因为它不需要制作一堆临时的1个字符的字符串:
use utf8;

my $str = '中國c'; # Chinese language of china

my @codepoints = unpack 'U*', $str;

print join(',', @codepoints) . "n"; # prints 20013,22283,99
快速基准测试显示它比ѭ6快3倍:
use utf8;
use Benchmark 'cmpthese';

my $str = '中國中國中國中國中國中國中國中國中國中國中國中國中國中國c';

cmpthese(0, {
  'unpack'     => sub { my @codepoints = unpack 'U*', $str; },
  'split-map'  => sub { my @codepoints = map { ord } split //, $str },
  'split-for'  => sub { my @cp; for my $c (split(//, $str)) { push @cp, ord($c) } },
  'split-for2' => sub { my $cp; for my $c (split(//, $str)) { $cp = ord($c) } },
});
结果:
               Rate  split-map  split-for split-for2     unpack
split-map   85423/s         --        -7%       -32%       -67%
split-for   91950/s         8%         --       -27%       -64%
split-for2 125550/s        47%        37%         --       -51%
unpack     256941/s       201%       179%       105%         --
较短的字符串差异不太明显,但
unpack
仍然是两倍多。 (
split-for2
比其他分割快一点,因为它不构建代码点列表。)     
见perldoc -f ord:
foreach my $c (split(//, $str))
{
    print ord($c), "n";
}
或压缩成一行:
my @chars = map { ord } split //, $str;
Data :: Dumpered,这会产生:
$VAR1 = [
          20013,
          22283,
          99
        ];
    
要在您的源代码中识别utf8,您必须事先
use utf8;
$ perl
use utf8;
my $str = '中國c'; # Chinese language of china
foreach my $c (split(//, $str))
{
    print ord($c), "n";
}
__END__
20013
22283
99
或更简洁,
print join ',', map ord, split //, $str;
    
http://www.perl.com/pub/2012/04/perlunicook-standard-preamble.html
#!/usr/bin/env perl


 use utf8;      # so literals and identifiers can be in UTF-8
 use v5.12;     # or later to get "unicode_strings" feature
 use strict;    # quote strings, declare variables
 use warnings;  # on by default
 use warnings  qw(FATAL utf8);    # fatalize encoding glitches
 use open      qw(:std :utf8);    # undeclared streams in UTF-8
 # use charnames qw(:full :short);  # unneeded in v5.16

# http://perldoc.perl.org/functions/sprintf.html
# vector flag
# This flag tells Perl to interpret the supplied string as a vector of integers, one for each character in the string. 

my $str = '中國c';

printf "%*vdn", ",", $str;
    

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