Re: help check a piece of code

[Andy Bach]

On Sat, Apr 1, 2017 at 4:24 AM, K. Peng <k.p...@att.net> wrote:

> I don't know why the "ref" and "scalar" functions here can be used to
> validate if it's ASCII or UTF8 encoding.
>
>
> use constant ASCII => ref eval {
>         require Encode;
>         Encode::find_encoding('ascii');
> };
>
> use constant UTF8 => scalar eval {
>         Encode::encode_utf8( chr(182) ) eq pack( 'H*', 'C2B6' );
> };
>

Not entirely clear but the constant ASCII will have a value of "Encode::XS"
if 'ascii' is found as a valid encoding and UTF8 will have the value "1" if
the utf8 encoding of "chr 182" matches the "Hex string (high nibble first)
of "C2B6" - appears to be the paragraph char.

use constant ASCII => ref eval {
        require Encode;
        Encode::find_encoding('ascii');
};
        print "r: ", eval { Encode::find_encoding('ascii');
}, "\n";
        print "r: ", ref eval { Encode::find_encoding('ascii');
}, "\n";
        print "r: ", ref  Encode::find_encoding('ascii') , "\n";
        print "r: ", ref  Encode::find_encoding('himom') , "\n";

use constant UTF8 => scalar eval {
        Encode::encode_utf8( chr(182) ) eq pack( 'H*', 'C2B6' );
};
        print "s: ", eval { Encode::encode_utf8( chr(182) ) eq pack( 'H*',
'C2B6' );
}, "\n";
        print "s: ", scalar eval { Encode::encode_utf8( chr(182) ) eq pack(
'H*', 'C2B6' );
}, "\n";
        print "s: ",  Encode::encode_utf8( chr(182) ) eq pack( 'H*', 'C2B6'
) , "\n";
        printf("c: %c %s\n",  chr(182),  pack( 'H*', 'C2B6' ) );

$ perl /tmp/r.pl
r: Encode::XS=SCALAR(0xb39ff0)
r: Encode::XS
r: Encode::XS
r:
s: 1
s: 1
s: 1
c:  ¶



-- 

a

Andy Bach,
afb...@gmail.com
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608 261-5738 wk