The document discusses using Erlang ports to interface with Perl scripts for handling Unicode strings and regular expressions. It provides code for an Erlang module that starts a Perl port and allows sending strings to be printed. The Perl script uses Erlang ports to receive the strings, check them, and print them to standard error. This allows Erlang to leverage Perl for Unicode support and regular expressions on strings containing Unicode characters.

1. [LT] Regexp, Perl, and Port
id:kdaiba

2. whoami
id:kdaiba
Erlang newbie
Perl Monger
Yokohama.pm
Shibuya.pm
Tokyo.pm
Now, setting up quot;Japan Perl Associationquot;
http://trac.endeworks.jp/trac/tpfj/wiki
Infrastructure Engineer

3. Erlang supports unicode in R12B-5

4. Try to print utf-8
perl -e 'map{printf quot;%d,quot;,$_}(unpack quot;C*quot;,quot;寿quot;);print quot;nquot;;'
229,175,191,
1> UniString = [229,175,191].
quot;寿quot;
2> io:format(quot;~p~nquot;,[UniString]).
quot;寿quot;
ok
3>
It's looks OK on mac's terminal. But ...

5. When you run this script...
#!/usr/local/bin/escript
main(_) ->
Item0 = quot;寿quot;,
Item1 = quot;寿限quot;,
Item2 = quot;寿限無quot;,
Item3 = [[229,175,191],[233,153,144],[231,132,161]],
io:format(quot;~p~nquot;, [Item0]),
io:format(quot;~p~nquot;, [Item1]),
io:format(quot;~p~nquot;, [Item2]),
[io:format(quot;~p~nquot;, [X]) || X <- Item3].

6. You'll get returns, like below
quot;寿quot;
[229,175,191,233,153,144]
[229,175,191,233,153,144,231,132,161]
quot;寿quot;
[233,153,144]
[231,132,161]

7. Do google
There is a page,
quot;Representing Unicode characters in Erlangquot;
http://www.erlang.org/eeps/eep-0010.html
It's a quot;Erlang Enhancement Proposals (EEPs)quot;, #10
This proposal's STATUS
http://www.erlang.org/eeps/
Standards Track EEP
Accepted proposal
NOT quot;Proposal is implemented in OTP release R12B-5quot;

8. Can't I use utf-8 now ?
use Erlang::Port to see Unicode

9. I made a perl script to printout utf-8
#!/usr/local/bin/escript
main(_) ->
perlsay:start(quot;./perlsay.plquot;),
perlsay:say(quot;寿限無、寿限無、五劫の擦り切れ、海砂利水魚、水
行末、雲来末、風来末、食う寝る所に住む所、薮ら柑子のぶら柑子、
パイポ、パイポ、パイポのシューリンガン、シューリンガンのグーリンダ
イ、グーリンダイのポンポコピーのポンポコナーの長久命の長助quot;),
perlsay:stop().

10. You'll get returns on STDERR
寿限無、寿限無、五劫の擦り切れ、海砂利水魚、水行末、雲来末、
風来末、食う寝る所に住む所、薮ら柑子のぶら柑子、パイポ、パイ
ポ、パイポのシューリンガン、シューリンガンのグーリンダイ、グーリン
ダイのポンポコピーのポンポコナーの長久命の長助

11. Easy erlang code and
-module(perlsay).
-export([say/1]).
-export([start/1, stop/0]).
-import(perlport, [call/2, stop/1]).
say(String) ->
call([say, String], perlsay).
start(Script) ->
perlport:start(Script, perlsay).
stop() ->
perlport:stop(perlsay).

12. Spaghetti perl script (1/4)
#!/usr/local/bin/perl
package Erlang::Port::Say;
use strict;
use warnings;
use Erlang::Port;
caller or __PACKAGE__->main(@ARGV);
1;

13. Spaghetti perl code (2/4)
sub main {
my $pkg = shift;
Erlang::Port->new(
sub {
my $obj = shift;
my $port = shift;
my $ret = eval { _my_proc( $obj, $port ) };
$ret = $port->_newTuple( [ $port->_newAtom('error') => $@, ] )
if ($@);
$ret;
}
)->loop();
}

14. Spagetti perl Script (3/4)
sub _my_proc {
my $obj = shift;
my $port = shift;
if ( !UNIVERSAL::isa( $obj, 'ARRAY' ) ) {
return $port->_newTuple( [ $port->_newAtom('badarg'), $obj ] );
}
my $key = _to_s( $obj->[0] );
if ( !defined($key) || $key ne 'say' ) {
return $port->_newTuple( [ $port->_newAtom('badarg'), $obj ] );
}
my $str = _to_s( $obj->[1] );
if ( !defined($str) ) {
return $port->_newTuple( [ $port->_newAtom('badarg'), $obj ] );
}
print STDERR $str, quot;nquot;;
$str;
}

15. Spagetti Perl Script (4/4)
sub _to_s {
my $obj = shift;
if ( defined($obj) && !ref($obj) ) {
$obj;
}
elsif ( $obj && ref($obj) eq 'ARRAY' && @$obj == 0 ) {
quot;quot;;
}
elsif ( ref($obj) && UNIVERSAL::isa( $obj, 'Erlang::Atom' ) ) {
$$obj;
}
elsif ( ref($obj) && UNIVERSAL::isa( $obj, 'Erlang::Binary' ) ) {
$$obj;
}
else { undef; }
}

16. quot;song and dancequot; too long ?
I'm sorry to be boring

17. You can use this code like this
#!/usr/local/bin/escript
main(_) ->
perlre:start(quot;./perlre.plquot;),
perlsay:start(quot;./perlsay.plquot;),
F = perlre:match(quot;赤とんぼquot;,quot;(p{Hiragana}+)quot;),
[perlsay:say(X) || X <- F],
perlre:stop(),
perlsay:stop().
# perlre.pl is a sample code of Erlang::Port

18. Finally, you get ...
とんぼ

19. Twist ending
I need to check B12-R5
Today I have bad feelings. So I download B12-R5. It shows,
Eshell V5.6.5 (abort with ^G)
But, when I check my mac's erl, it shows
Eshell V5.6.4 (abort with ^G)
I made a mumbo jumbo ....