Unicode/gen-case

   1 #! /usr/bin/perl
   2 use strict;
   3 use warnings;
   4
   5 my @trans;
   6
   7 print "\t/* -*- c -*- source code generated by ", join(" ", $0, @ARGV), " */\n";
   8 while (<>) {
   9     s/#.*$//;
  10     next if /^\s*$/;
  11     my($code, $status, $mapping) = /^([[:xdigit:]]+);\s*([CFST]);\s*([[:xdigit:]]+(?:\s+[[:xdigit:]]+)*);\s*$/
  12         or warn("$ARGV:$.: weird line\n"), next;
  13     next unless $status eq "C" or $status eq "S";
  14     warn("$ARGV:$.: multi-char simple mapping\n"), next
  15         if $mapping =~ /\s/;
  16     $code = hex($code);
  17     $mapping = hex($mapping);
  18     $trans[$code] = $mapping;
  19 } continue {
  20     close ARGV if eof;
  21 }
  22
  23 sub gobble {
  24     my($begin, $step) = @_;
  25     my $diff = $trans[$begin] - $begin;
  26     my @codes;
  27     my @holes;
  28     my $probe = $begin;
  29     my $hole;
  30     while (1) {
  31         my @beyond;
  32         while (defined($trans[$probe]) && $trans[$probe] == $probe + $diff) {
  33             push @beyond, $probe;
  34             $probe += $step;
  35         }
  36         last unless @beyond >= 2;
  37         push @holes, $hole if defined $hole;
  38         push @codes, @beyond;
  39         $hole = $probe;
  40         $probe += $step;
  41     }
  42     return 0 unless @codes;
  43
  44     # The following formula was tuned for i486-linux-gnu-gcc-4.0 -O1.
  45     if (@codes <= 2 + @holes) {
  46         print "if (", join(" || ", map { sprintf("c == 0x%X", $_) } @codes), ")\n";
  47     } else {
  48         printf "if (c >= 0x%X && c <= 0x%X", $codes[0], $codes[-1];
  49         printf " && c != 0x%X", $_ foreach @holes;
  50         if ($step == 2) { printf " && (c & 1) == %d", $begin & 1 }
  51         elsif ($step != 1) { printf " && c %% %d == %d", $step, $begin % $step }
  52         print ")\n";
  53     }
  54     if ($diff != 0) {
  55         if ($diff < 0) { printf "\t\tc -= "; $diff = -$diff }
  56         else { printf "\t\tc += " }
  57         if ($diff < 10) { printf "%d", $diff }
  58         else { printf "0x%X", $diff }
  59     }
  60     print ";\n";
  61
  62     undef $trans[$_] foreach @codes;
  63     return 1;
  64 }
  65
  66 my $first = 1;
  67 for (my $code = 0; $code <= $#trans; ++$code) {
  68     next unless defined $trans[$code];
  69
  70     print $first ? "\t" : "\telse ";
  71     gobble($code, 1) or gobble($code, 2) or gobble($code, 3) or gobble($code, 4)
  72         or printf "if (c == 0x%X)\n\t\tc = 0x%X;\n", $code, $trans[$code];
  73     $first = 0;
  74 }
  75 close STDOUT or die "$0: -: $!\n";
  76
  77 __END__
  78
  79 =head1 NAME
  80
  81 gen-case - Generate C source code for folding the case of a Unicode character.
  82
  83 =head1 SYNOPSIS
  84
  85 B<gen-case> CaseFolding.txt > ../src/intl/casefold.inc
  86
  87 =head1 DESCRIPTION
  88
  89 B<gen-case> reads F<CaseFolding.txt> of the Unicode Character Database
  90 and generates C source code that implements the I<simple case folding>
  91 as defined in that file.
  92
  93 The generated source code can then be used like this:
  94
  95   unicode_val_T
  96   unicode_simple_case_fold(unicode_val_T c)
  97   {
  98   #include "casefold.inc"
  99           return c;
 100   }
 101
 102 =head1 BUGS
 103
 104 Does not support B<--help> nor B<--version>.
 105
 106 =head1 AUTHOR
 107
 108 Kalle Olavi Niemitalo <kon@iki.fi>
 109
 110 =head1 COPYRIGHT AND LICENSE
 111
 112 Copyright (c) 2006 Kalle Olavi Niemitalo.
 113
 114 Permission to use, copy, modify, and distribute this software for any
 115 purpose with or without fee is hereby granted, provided that the above
 116 copyright notice and this permission notice appear in all copies.
 117
 118 THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 119 WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 120 MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 121 ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 122 WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 123 ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 124 OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.