package re;

# pragma for controlling the regexp engine
use strict;
use warnings;

our $VERSION = "0.23";
our @ISA = qw(Exporter);
our @EXPORT_OK = ('regmust',
qw(is_regexp regexp_pattern
regname regnames regnames_count));
our %EXPORT_OK = map { $_ => 1 } @EXPORT_OK;

my %bitmask = (
taint => 0x00100000, # HINT_RE_TAINT
eval => 0x00200000, # HINT_RE_EVAL
);

my $flags_hint = 0x02000000; # HINT_RE_FLAGS
my $PMMOD_SHIFT = 0;
my %reflags = (
m => 1 << ($PMMOD_SHIFT + 0),
s => 1 << ($PMMOD_SHIFT + 1),
i => 1 << ($PMMOD_SHIFT + 2),
x => 1 << ($PMMOD_SHIFT + 3),
p => 1 << ($PMMOD_SHIFT + 4),
# special cases:
d => 0,
l => 1,
u => 2,
a => 3,
aa => 4,
);

sub setcolor {
eval { # Ignore errors
require Term::Cap;

my $terminal = Tgetent Term::Cap ({OSPEED => 9600}); # Avoid warning.
my $props = $ENV{PERL_RE_TC} || 'md,me,so,se,us,ue';
my @props = split /,/, $props;
my $colors = join "\t", map {$terminal->Tputs($_,1)} @props;

$colors =~ s/\0//g;
$ENV{PERL_RE_COLORS} = $colors;
};
if ($@) {
$ENV{PERL_RE_COLORS} ||= qq'\t\t> <\t> <\t\t';
}

}

my %flags = (
COMPILE => 0x0000FF,
PARSE => 0x000001,
OPTIMISE => 0x000002,
TRIEC => 0x000004,
DUMP => 0x000008,
FLAGS => 0x000010,

EXECUTE => 0x00FF00,
INTUIT => 0x000100,
MATCH => 0x000200,
TRIEE => 0x000400,

EXTRA => 0xFF0000,
TRIEM => 0x010000,
OFFSETS => 0x020000,
OFFSETSDBG => 0x040000,
STATE => 0x080000,
OPTIMISEM => 0x100000,
STACK => 0x280000,
BUFFERS => 0x400000,
GPOS => 0x800000,
);
$flags{ALL} = -1 & ~($flags{OFFSETS}|$flags{OFFSETSDBG}|$flags{BUFFERS});
$flags{All} = $flags{all} = $flags{DUMP} | $flags{EXECUTE};
$flags{Extra} = $flags{EXECUTE} | $flags{COMPILE} | $flags{GPOS};
$flags{More} = $flags{MORE} = $flags{All} | $flags{TRIEC} | $flags{TRIEM} | $flags{STATE};
$flags{State} = $flags{DUMP} | $flags{EXECUTE} | $flags{STATE};
$flags{TRIE} = $flags{DUMP} | $flags{EXECUTE} | $flags{TRIEC};

if (defined &DynaLoader::boot_DynaLoader) {
require XSLoader;
XSLoader::load();
}
# else we're miniperl
# We need to work for miniperl, because the XS toolchain uses Text::Wrap, which
# uses re 'taint'.

sub _load_unload {
my ($on)= @_;
if ($on) {
# We call install() every time, as if we didn't, we wouldn't
# "see" any changes to the color environment var since
# the last time it was called.

# install() returns an integer, which if casted properly
# in C resolves to a structure containing the regexp
# hooks. Setting it to a random integer will guarantee
# segfaults.
$^H{regcomp} = install();
} else {
delete $^H{regcomp};
}
}

sub bits {
my $on = shift;
my $bits = 0;
ARG:
foreach my $idx (0..$#_){
my $s=$_[$idx];
if ($s eq 'Debug' or $s eq 'Debugcolor') {
setcolor() if $s =~/color/i;
${^RE_DEBUG_FLAGS} = 0 unless defined ${^RE_DEBUG_FLAGS};
for my $idx ($idx+1..$#_) {
if ($flags{$_[$idx]}) {
if ($on) {
${^RE_DEBUG_FLAGS} |= $flags{$_[$idx]};
} else {
${^RE_DEBUG_FLAGS} &= ~ $flags{$_[$idx]};
}
} else {
require Carp;
Carp::carp("Unknown \"re\" Debug flag '$_[$idx]', possible flags: ",
join(", ",sort keys %flags ) );
}
}
_load_unload($on ? 1 : ${^RE_DEBUG_FLAGS});
last;
} elsif ($s eq 'debug' or $s eq 'debugcolor') {
setcolor() if $s =~/color/i;
_load_unload($on);
last;
} elsif (exists $bitmask{$s}) {
$bits |= $bitmask{$s};
} elsif ($EXPORT_OK{$s}) {
require Exporter;
re->export_to_level(2, 're', $s);
} elsif ($s =~ s/^\///) {
my $reflags = $^H{reflags} || 0;
my $seen_charset;
while ($s =~ m/( . )/gx) {
local $_ = $1;
if (/[adul]/) {
# The 'a' may be repeated; hide this from the rest of the
# code by counting and getting rid of all of them, then
# changing to 'aa' if there is a repeat.
if ($_ eq 'a') {
my $sav_pos = pos $s;
my $a_count = $s =~ s/a//g;
pos $s = $sav_pos - 1; # -1 because got rid of the 'a'
if ($a_count > 2) {
require Carp;
Carp::carp(
qq 'The "a" flag may only appear a maximum of twice'
);
}
elsif ($a_count == 2) {
$_ = 'aa';
}
}
if ($on) {
if ($seen_charset) {
require Carp;
if ($seen_charset ne $_) {
Carp::carp(
qq 'The "$seen_charset" and "$_" flags '
.qq 'are exclusive'
);
}
else {
Carp::carp(
qq 'The "$seen_charset" flag may not appear '
.qq 'twice'
);
}
}
$^H{reflags_charset} = $reflags{$_};
$seen_charset = $_;
}
else {
delete $^H{reflags_charset}
if defined $^H{reflags_charset}
&& $^H{reflags_charset} == $reflags{$_};
}
} elsif (exists $reflags{$_}) {
$on
? $reflags |= $reflags{$_}
: ($reflags &= ~$reflags{$_});
} else {
require Carp;
Carp::carp(
qq'Unknown regular expression flag "$_"'
);
next ARG;
}
}
($^H{reflags} = $reflags or defined $^H{reflags_charset})
? $^H |= $flags_hint
: ($^H &= ~$flags_hint);
} else {
require Carp;
Carp::carp("Unknown \"re\" subpragma '$s' (known ones are: ",
join(', ', map {qq('$_')} 'debug', 'debugcolor', sort keys %bitmask),
")");
}
}
$bits;
}

sub import {
shift;
$^H |= bits(1, @_);
}

sub unimport {
shift;
$^H &= ~ bits(0, @_);
}

1;

__END__