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|
#!/usr/bin/perl
# module to build
require './recurse2txt';
require './lib/Math/Base/Convert/Bases.pm'; # pointer to all standard bases
# will update the Bitmaps module version below
#
my $VERSION = do { my @r = (q$Revision: 0.02 $ =~ /\d+/g); sprintf "%d."."%02d" x $#r, @r };
my $bases = Math::Base::Convert->_bases;
my %base2;
my %dmaps;
my @xmaps = (\%dmaps);
# make lookup bit maps - there are two kinds
#
# 1) for generic in 'xmaps' of the form "bit pattern" => "decimal value"
#
# 2) for specific in 'dmaps' of the form "bit pattern" => "base character"
#
# i.e.
#
# case 1)
# %bmap4 = ( # base 16 translation table
# '0000' => 0,
# '0001' => 1,
# '0010' => 2,
# '0011' => 3,
# '0100' => 4,
# '0101' => 5,
# '0110' => 6,
# '0111' => 7,
# '1000' => 8,
# '1001' => 9,
# '1010' => 10,
# '1011' => 11,
# '1100' => 12,
# '1101' => 13,
# '1110' => 14,
# '1111' => 15,
#);
#
# case 2)
#%dmap4 = ( # heX - base 16 translation table
# '0000' => 0,
# '0001' => 1,
# '0010' => 2,
# '0011' => 3,
# '0100' => 4,
# '0101' => 5,
# '0110' => 6,
# '0111' => 7,
# '1000' => 8,
# '1001' => 9,
# '1010' => 'a',
# '1011' => 'b',
# '1100' => 'c',
# '1101' => 'd',
# '1110' => 'e',
# '1111' => 'f',
#);
#
my $mapbits = sub {
my($bits,$val) = @_;
my $bp = length($bits);
# 0, binary, hex not mapped
return if $bp == 4 || # hex is direct
$bp == 1; # binary maps directly from value
$xmaps[$bp]->{$bits} = $val; # build generic translation maps
return if $bp == 3; # octal maps from standard lookup, numeric
if (exists $base2{$bp}) { # standard base present with this base power?
foreach(0..$#{$base2{$bp}}) {
my $bnam = $base2{$bp}->[$_];
$dmaps{$bnam}->{$bits} = $bases->{$bnam}->[$val];
}
}
};
# create a hash of all standard power 2 bases where the key
# points to a list of bases associated with each power of 2
#
foreach (sort keys %$bases) {
my $len = @{$bases->{$_}};
unless ($len & $len -1) { # isnotp2
my $bp = int(log($len)/log(2) +0.5);
if (exists $base2{$bp}) {
push @{$base2{$bp}}, $_;
} else {
$base2{$bp} = [$_];
}
}
}
# create an 8 bit wide binary map of the range 0..255
#
foreach (0..255) {
my $p = pack('c',$_);
my $bits = unpack('B*',$p);
my @bits = $bits;
while ($bits =~ s/^0// && length($bits)) {
push @bits, $bits;
}
foreach $bits (@bits) {
$mapbits->($bits,$_);
}
}
my $moduletxt = q|#!/usr/bin/perl -w
package Math::Base::Convert::Bitmaps;
use vars qw($VERSION);
$VERSION = '|. $VERSION .q|';
# created by Makefile.PL |. scalar gmtime($ENV{SOURCE_DATE_EPOCH}). q|
#
# Do not edit this package,
#
# edit the 'bitmaps' file in the source directory instead
#
# Why is this module here? The tables in this module
# load from the disk and order of magnitude faster than
# they can be created by perl at run time.
#
$VAR = |. (Dumper(\@xmaps))[0] .q|
__END__
=head1 NAME
Math::Base::Convert::Bitmaps - pregenerated bit pattern to base power of 2 translation tables
This package contains no documentation
=head1 AUTHOR
Michael Robinton, michael@bizsystems.com
=head1 COPYRIGHT
Copyright 2012-2015, Michael Robinton
This program is free software; you may redistribute it and/or modify it
under the same terms as Perl itself.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
=cut
1;
|;
open (F,'>lib/Math/Base/Convert/Bitmaps.pm') or return 0;
select F;
$| = 1;
print F $moduletxt;
close F;
1;
|
