package re;
-our $VERSION = 0.06_02;
+# pragma for controlling the regex engine
+use strict;
+use warnings;
+
+our $VERSION = "0.08";
+our @ISA = qw(Exporter);
+our @EXPORT_OK = qw(is_regexp regexp_pattern regmust
+ regname regnames
+ regnames_count regnames_iterinit regnames_iternext);
+our %EXPORT_OK = map { $_ => 1 } @EXPORT_OK;
+
+# *** WARNING *** WARNING *** WARNING *** WARNING *** WARNING ***
+#
+# If you modify these values see comment below!
+
+my %bitmask = (
+ taint => 0x00100000, # HINT_RE_TAINT
+ eval => 0x00200000, # HINT_RE_EVAL
+);
+
+# - File::Basename contains a literal for 'taint' as a fallback. If
+# taint is changed here, File::Basename must be updated as well.
+#
+# - ExtUtils::ParseXS uses a hardcoded
+# BEGIN { $^H |= 0x00200000 }
+# in it to allow re.xs to be built. So if 'eval' is changed here then
+# ExtUtils::ParseXS must be changed as well.
+#
+# *** WARNING *** WARNING *** WARNING *** WARNING *** WARNING ***
+
+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} = $colors;
+ };
+ if ($@) {
+ $ENV{PERL_RE_COLORS} ||= qq'\t\t> <\t> <\t\t';
+ }
+
+}
+
+my %flags = (
+ COMPILE => 0x0000FF,
+ PARSE => 0x000001,
+ OPTIMISE => 0x000002,
+ TRIEC => 0x000004,
+ DUMP => 0x000008,
+
+ EXECUTE => 0x00FF00,
+ INTUIT => 0x000100,
+ MATCH => 0x000200,
+ TRIEE => 0x000400,
+
+ EXTRA => 0xFF0000,
+ TRIEM => 0x010000,
+ OFFSETS => 0x020000,
+ OFFSETSDBG => 0x040000,
+ STATE => 0x080000,
+ OPTIMISEM => 0x100000,
+ STACK => 0x280000,
+);
+$flags{ALL} = -1;
+$flags{All} = $flags{all} = $flags{DUMP} | $flags{EXECUTE};
+$flags{Extra} = $flags{EXECUTE} | $flags{COMPILE};
+$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};
+
+my $installed;
+my $installed_error;
+
+sub _do_install {
+ if ( ! defined($installed) ) {
+ require XSLoader;
+ $installed = eval { XSLoader::load('re', $VERSION) } || 0;
+ $installed_error = $@;
+ }
+}
+
+sub _load_unload {
+ my ($on)= @_;
+ if ($on) {
+ _do_install();
+ if ( ! $installed ) {
+ die "'re' not installed!? ($installed_error)";
+ } else {
+ # 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 regex
+ # 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;
+ unless (@_) {
+ require Carp;
+ Carp::carp("Useless use of \"re\" pragma");
+ }
+ 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);
+ } elsif (exists $bitmask{$s}) {
+ $bits |= $bitmask{$s};
+ } elsif ($EXPORT_OK{$s}) {
+ _do_install();
+ require Exporter;
+ re->export_to_level(2, 're', $s);
+ } else {
+ require Carp;
+ Carp::carp("Unknown \"re\" subpragma '$s' (known ones are: ",
+ join(', ', map {qq('$_')} 'debug', 'debugcolor', sort keys %bitmask),
+ ")");
+ }
+ }
+ $bits;
+}
+
+sub import {
+ shift;
+ $^H |= bits(1, @_);
+}
+
+sub unimport {
+ shift;
+ $^H &= ~ bits(0, @_);
+}
+
+1;
+
+__END__
=head1 NAME
...
use re qw(Debug All); # Finer tuned debugging options.
- use re qw(Debug More);
+ use re qw(Debug More);
no re qw(Debug ALL); # Turn of all re debugging in this scope
+ use re qw(is_regexp regexp_pattern); # import utility functions
+ my ($pat,$mods)=regexp_pattern(qr/foo/i);
+ if (is_regexp($obj)) {
+ print "Got regexp: ",
+ scalar regexp_pattern($obj); # just as perl would stringify it
+ } # but no hassle with blessed re's.
+
(We use $^X in these examples because it's tainted by default.)
=head1 DESCRIPTION
+=head2 'taint' mode
+
When C<use re 'taint'> is in effect, and a tainted string is the target
of a regex, the regex memories (or values returned by the m// operator
in list context) are tainted. This feature is useful when regex operations
on tainted data aren't meant to extract safe substrings, but to perform
other transformations.
+=head2 'eval' mode
+
When C<use re 'eval'> is in effect, a regex is allowed to contain
C<(?{ ... })> zero-width assertions even if regular expression contains
variable interpolation. That is normally disallowed, since it is a
I<is> allowed if $pat is a precompiled regular expression, even
if $pat contains C<(?{ ... })> assertions.
+=head2 'debug' mode
+
When C<use re 'debug'> is in effect, perl emits debugging messages when
compiling and using regular expressions. The output is the same as that
obtained by running a C<-DDEBUGGING>-enabled perl interpreter with the
strings on/off, pre-point part on/off.
See L<perldebug/"Debugging regular expressions"> for additional info.
+As of 5.9.5 the directive C<use re 'debug'> and its equivalents are
+lexically scoped, as the other directives are. However they have both
+compile-time and run-time effects.
+
+See L<perlmodlib/Pragmatic Modules>.
+
+=head2 'Debug' mode
+
Similarly C<use re 'Debug'> produces debugging output, the difference
being that it allows the fine tuning of what debugging output will be
emitted. Options are divided into three groups, those related to
Dump the final program out after it is compiled and optimised.
-
=back
=item Execute related options
=item STATE
-Enable debugging of states in the engine.
+Enable debugging of states in the engine.
=item STACK
=back
As of 5.9.5 the directive C<use re 'debug'> and its equivalents are
-lexically scoped, as the other directives are. However they have both
+lexically scoped, as the other directives are. However they have both
compile-time and run-time effects.
-See L<perlmodlib/Pragmatic Modules>.
+=head2 Exportable Functions
-=cut
+As of perl 5.9.5 're' debug contains a number of utility functions that
+may be optionally exported into the caller's namespace. They are listed
+below.
-# N.B. File::Basename contains a literal for 'taint' as a fallback. If
-# taint is changed here, File::Basename must be updated as well.
-my %bitmask = (
-taint => 0x00100000, # HINT_RE_TAINT
-eval => 0x00200000, # HINT_RE_EVAL
-);
+=over 4
-sub setcolor {
- eval { # Ignore errors
- require Term::Cap;
+=item is_regexp($ref)
- 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;
+Returns true if the argument is a compiled regular expression as returned
+by C<qr//>, false if it is not.
- $colors =~ s/\0//g;
- $ENV{PERL_RE_COLORS} = $colors;
- };
- if ($@) {
- $ENV{PERL_RE_COLORS}||=qq'\t\t> <\t> <\t\t'
- }
+This function will not be confused by overloading or blessing. In
+internals terms, this extracts the regexp pointer out of the
+PERL_MAGIC_qr structure so it it cannot be fooled.
-}
+=item regexp_pattern($ref)
-my %flags = (
- COMPILE => 0x0000FF,
- PARSE => 0x000001,
- OPTIMISE => 0x000002,
- TRIEC => 0x000004,
- DUMP => 0x000008,
+If the argument is a compiled regular expression as returned by C<qr//>,
+then this function returns the pattern.
- EXECUTE => 0x00FF00,
- INTUIT => 0x000100,
- MATCH => 0x000200,
- TRIEE => 0x000400,
+In list context it returns a two element list, the first element
+containing the pattern and the second containing the modifiers used when
+the pattern was compiled.
- EXTRA => 0xFF0000,
- TRIEM => 0x010000,
- OFFSETS => 0x020000,
- OFFSETSDBG => 0x040000,
- STATE => 0x080000,
- OPTIMISEM => 0x100000,
- STACK => 0x280000,
-);
-$flags{ALL} = -1;
-$flags{All} = $flags{all} = $flags{DUMP} | $flags{EXECUTE};
-$flags{Extra} = $flags{EXECUTE} | $flags{COMPILE};
-$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} | $flags{TRIEC};
+ my ($pat, $mods) = regexp_pattern($ref);
-my $installed;
-my $installed_error;
+In scalar context it returns the same as perl would when strigifying a raw
+C<qr//> with the same pattern inside. If the argument is not a compiled
+reference then this routine returns false but defined in scalar context,
+and the empty list in list context. Thus the following
-sub _load_unload {
- my ($on)= @_;
- if ($on) {
- if ( ! defined($installed) ) {
- require XSLoader;
- $installed = eval { XSLoader::load('re') } || 0;
- $installed_error = $@;
- }
- if ( ! $installed ) {
- die "'re' not installed!? ($installed_error)";
- } else {
- # 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.
+ if (regexp_pattern($ref) eq '(?i-xsm:foo)')
- # install() returns an integer, which if casted properly
- # in C resolves to a structure containing the regex
- # hooks. Setting it to a random integer will guarantee
- # segfaults.
- $^H{regcomp} = install();
- }
- } else {
- delete $^H{regcomp};
- }
-}
+will be warning free regardless of what $ref actually is.
-sub bits {
- my $on = shift;
- my $bits = 0;
- unless (@_) {
- return;
- }
- 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);
- } elsif (exists $bitmask{$s}) {
- $bits |= $bitmask{$s};
- } else {
- require Carp;
- Carp::carp("Unknown \"re\" subpragma '$s' (known ones are: ",
- join(', ', map {qq('$_')} 'debug', 'debugcolor', sort keys %bitmask),
- ")");
- }
- }
- $bits;
-}
+Like C<is_regexp> this function will not be confused by overloading
+or blessing of the object.
-sub import {
- shift;
- $^H |= bits(1, @_);
-}
+=item regmust($ref)
-sub unimport {
- shift;
- $^H &= ~ bits(0, @_);
-}
+If the argument is a compiled regular expression as returned by C<qr//>,
+then this function returns what the optimiser consiers to be the longest
+anchored fixed string and longest floating fixed string in the pattern.
-1;
+A I<fixed string> is defined as being a substring that must appear for the
+pattern to match. An I<anchored fixed string> is a fixed string that must
+appear at a particular offset from the beginning of the match. A I<floating
+fixed string> is defined as a fixed string that can appear at any point in
+a range of positions relative to the start of the match. For example,
+
+ my $qr = qr/here .* there/x;
+ my ($anchored, $floating) = regmust($qr);
+ print "anchored:'$anchored'\nfloating:'$floating'\n";
+
+results in
+
+ anchored:'here'
+ floating:'there'
+
+Because the C<here> is before the C<.*> in the pattern, its position
+can be determined exactly. That's not true, however, for the C<there>;
+it could appear at any point after where the anchored string appeared.
+Perl uses both for its optimisations, prefering the longer, or, if they are
+equal, the floating.
+
+B<NOTE:> This may not necessarily be the definitive longest anchored and
+floating string. This will be what the optimiser of the Perl that you
+are using thinks is the longest. If you believe that the result is wrong
+please report it via the L<perlbug> utility.
+
+=item regname($name,$qr,$all)
+
+Returns the contents of a named buffer. If $qr is missing, or is not the
+result of a qr// then returns the result of the last successful match. If
+$all is true then returns an array ref containing one entry per buffer,
+otherwise returns the first defined buffer.
+
+=item regnames($qr,$all)
+
+Returns a list of all of the named buffers defined in a pattern. If
+$all is true then it returns all names defined, if not returns only
+names which were involved in the last successful match. If $qr is omitted
+or is not the result of a qr// then returns the details for the last
+successful match.
+
+=item regnames_iterinit($qr)
+
+Initializes the internal hash iterator associated to a regexps named capture
+buffers. If $qr is omitted resets the iterator associated with the regexp used
+in the last successful match.
+
+=item regnames_iternext($qr,$all)
+
+Gets the next key from the hash associated with a regexp. If $qr
+is omitted resets the iterator associated with the regexp used in the
+last successful match. If $all is true returns the keys of all of the
+distinct named buffers in the pattern, if not returns only those names
+used in the last successful match.
+
+=item regnames_count($qr)
+
+Returns the number of distinct names defined in the regexp $qr. If
+$qr is omitted or not a regexp returns the count of names in the
+last successful match.
+
+B<Note:> that this result is always the actual number of distinct
+named buffers defined, it may not actually match that which is
+returned by C<regnames()> and related routines when those routines
+have not been called with the $all parameter set..
+
+=back
+
+=head1 SEE ALSO
+
+L<perlmodlib/Pragmatic Modules>.
+
+=cut
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