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Diffstat (limited to 'lib/URI/_punycode.pm')
| -rw-r--r-- | lib/URI/_punycode.pm | 203 |
1 files changed, 203 insertions, 0 deletions
diff --git a/lib/URI/_punycode.pm b/lib/URI/_punycode.pm new file mode 100644 index 0000000..f54eee5 --- /dev/null +++ b/lib/URI/_punycode.pm @@ -0,0 +1,203 @@ +package URI::_punycode; + +use strict; +use warnings; + +our $VERSION = "1.69"; + +use Exporter 'import'; +our @EXPORT = qw(encode_punycode decode_punycode); + +use integer; + +our $DEBUG = 0; + +use constant BASE => 36; +use constant TMIN => 1; +use constant TMAX => 26; +use constant SKEW => 38; +use constant DAMP => 700; +use constant INITIAL_BIAS => 72; +use constant INITIAL_N => 128; + +my $Delimiter = chr 0x2D; +my $BasicRE = qr/[\x00-\x7f]/; + +sub _croak { require Carp; Carp::croak(@_); } + +sub digit_value { + my $code = shift; + return ord($code) - ord("A") if $code =~ /[A-Z]/; + return ord($code) - ord("a") if $code =~ /[a-z]/; + return ord($code) - ord("0") + 26 if $code =~ /[0-9]/; + return; +} + +sub code_point { + my $digit = shift; + return $digit + ord('a') if 0 <= $digit && $digit <= 25; + return $digit + ord('0') - 26 if 26 <= $digit && $digit <= 36; + die 'NOT COME HERE'; +} + +sub adapt { + my($delta, $numpoints, $firsttime) = @_; + $delta = $firsttime ? $delta / DAMP : $delta / 2; + $delta += $delta / $numpoints; + my $k = 0; + while ($delta > ((BASE - TMIN) * TMAX) / 2) { + $delta /= BASE - TMIN; + $k += BASE; + } + return $k + (((BASE - TMIN + 1) * $delta) / ($delta + SKEW)); +} + +sub decode_punycode { + my $code = shift; + + my $n = INITIAL_N; + my $i = 0; + my $bias = INITIAL_BIAS; + my @output; + + if ($code =~ s/(.*)$Delimiter//o) { + push @output, map ord, split //, $1; + return _croak('non-basic code point') unless $1 =~ /^$BasicRE*$/o; + } + + while ($code) { + my $oldi = $i; + my $w = 1; + LOOP: + for (my $k = BASE; 1; $k += BASE) { + my $cp = substr($code, 0, 1, ''); + my $digit = digit_value($cp); + defined $digit or return _croak("invalid punycode input"); + $i += $digit * $w; + my $t = ($k <= $bias) ? TMIN + : ($k >= $bias + TMAX) ? TMAX : $k - $bias; + last LOOP if $digit < $t; + $w *= (BASE - $t); + } + $bias = adapt($i - $oldi, @output + 1, $oldi == 0); + warn "bias becomes $bias" if $DEBUG; + $n += $i / (@output + 1); + $i = $i % (@output + 1); + splice(@output, $i, 0, $n); + warn join " ", map sprintf('%04x', $_), @output if $DEBUG; + $i++; + } + return join '', map chr, @output; +} + +sub encode_punycode { + my $input = shift; + my @input = split //, $input; + + my $n = INITIAL_N; + my $delta = 0; + my $bias = INITIAL_BIAS; + + my @output; + my @basic = grep /$BasicRE/, @input; + my $h = my $b = @basic; + push @output, @basic; + push @output, $Delimiter if $b && $h < @input; + warn "basic codepoints: (@output)" if $DEBUG; + + while ($h < @input) { + my $m = min(grep { $_ >= $n } map ord, @input); + warn sprintf "next code point to insert is %04x", $m if $DEBUG; + $delta += ($m - $n) * ($h + 1); + $n = $m; + for my $i (@input) { + my $c = ord($i); + $delta++ if $c < $n; + if ($c == $n) { + my $q = $delta; + LOOP: + for (my $k = BASE; 1; $k += BASE) { + my $t = ($k <= $bias) ? TMIN : + ($k >= $bias + TMAX) ? TMAX : $k - $bias; + last LOOP if $q < $t; + my $cp = code_point($t + (($q - $t) % (BASE - $t))); + push @output, chr($cp); + $q = ($q - $t) / (BASE - $t); + } + push @output, chr(code_point($q)); + $bias = adapt($delta, $h + 1, $h == $b); + warn "bias becomes $bias" if $DEBUG; + $delta = 0; + $h++; + } + } + $delta++; + $n++; + } + return join '', @output; +} + +sub min { + my $min = shift; + for (@_) { $min = $_ if $_ <= $min } + return $min; +} + +1; +__END__ + +=head1 NAME + +URI::_punycode - encodes Unicode string in Punycode + +=head1 SYNOPSIS + + use URI::_punycode; + $punycode = encode_punycode($unicode); + $unicode = decode_punycode($punycode); + +=head1 DESCRIPTION + +URI::_punycode is a module to encode / decode Unicode strings into +Punycode, an efficient encoding of Unicode for use with IDNA. + +This module requires Perl 5.6.0 or over to handle UTF8 flagged Unicode +strings. + +=head1 FUNCTIONS + +This module exports following functions by default. + +=over 4 + +=item encode_punycode + + $punycode = encode_punycode($unicode); + +takes Unicode string (UTF8-flagged variable) and returns Punycode +encoding for it. + +=item decode_punycode + + $unicode = decode_punycode($punycode) + +takes Punycode encoding and returns original Unicode string. + +=back + +These functions throw exceptions on failure. You can catch 'em via +C<eval>. + +=head1 AUTHOR + +Tatsuhiko Miyagawa E<lt>miyagawa@bulknews.netE<gt> is the author of +IDNA::Punycode v0.02 which was the basis for this module. + +This library is free software; you can redistribute it and/or modify +it under the same terms as Perl itself. + +=head1 SEE ALSO + +L<IDNA::Punycode>, RFC 3492 + +=cut |