/usr/share/perl5/PPIx/Regexp/Tokenizer.pm is in libppix-regexp-perl 0.023-1.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739 740 741 742 743 744 745 746 747 748 749 750 751 752 753 754 755 756 757 758 759 760 761 762 763 764 765 766 767 768 769 770 771 772 773 774 775 776 777 778 779 780 781 782 783 784 785 786 787 788 789 790 791 792 793 794 795 796 797 798 799 800 801 802 803 804 805 806 807 808 809 810 811 812 813 814 815 816 817 818 819 820 821 822 823 824 825 826 827 828 829 830 831 832 833 834 835 836 837 838 839 840 841 842 843 844 845 846 847 848 849 850 851 852 853 854 855 856 857 858 859 860 861 862 863 864 865 866 867 868 869 870 871 872 873 874 875 876 877 878 879 880 881 882 883 884 885 886 887 888 889 890 891 892 893 894 895 896 897 898 899 900 901 902 903 904 905 906 907 908 909 910 911 912 913 914 915 916 917 918 919 920 921 922 923 924 925 926 927 928 929 930 931 932 933 934 935 936 937 938 939 940 941 942 943 944 945 946 947 948 949 950 951 952 953 954 955 956 957 958 959 960 961 962 963 964 965 966 967 968 969 970 971 972 973 974 975 976 977 978 979 980 981 982 983 984 985 986 987 988 989 990 991 992 993 994 995 996 997 998 999 1000 1001 1002 1003 1004 1005 1006 1007 1008 1009 1010 1011 1012 1013 1014 1015 1016 1017 1018 1019 1020 1021 1022 1023 1024 1025 1026 1027 1028 1029 1030 1031 1032 1033 1034 1035 1036 1037 1038 1039 1040 1041 1042 1043 1044 1045 1046 1047 1048 1049 1050 1051 1052 1053 1054 1055 1056 1057 1058 1059 1060 1061 1062 1063 1064 1065 1066 1067 1068 1069 1070 1071 1072 1073 1074 1075 1076 1077 1078 1079 1080 1081 1082 1083 1084 1085 1086 1087 1088 1089 1090 1091 1092 1093 1094 1095 1096 1097 1098 1099 1100 1101 1102 1103 1104 1105 1106 1107 1108 1109 1110 1111 1112 1113 1114 1115 1116 1117 1118 | package PPIx::Regexp::Tokenizer;
use strict;
use warnings;
use base qw{ PPIx::Regexp::Support };
use Carp qw{ confess };
use PPIx::Regexp::Constant qw{
MINIMUM_PERL
TOKEN_LITERAL
TOKEN_UNKNOWN
};
use PPIx::Regexp::Token::Assertion ();
use PPIx::Regexp::Token::Backreference ();
use PPIx::Regexp::Token::Backtrack ();
use PPIx::Regexp::Token::CharClass::POSIX ();
use PPIx::Regexp::Token::CharClass::POSIX::Unknown ();
use PPIx::Regexp::Token::CharClass::Simple ();
use PPIx::Regexp::Token::Code ();
use PPIx::Regexp::Token::Comment ();
use PPIx::Regexp::Token::Condition ();
use PPIx::Regexp::Token::Control ();
use PPIx::Regexp::Token::Delimiter ();
use PPIx::Regexp::Token::Greediness ();
use PPIx::Regexp::Token::GroupType::Assertion ();
use PPIx::Regexp::Token::GroupType::BranchReset ();
use PPIx::Regexp::Token::GroupType::Code ();
use PPIx::Regexp::Token::GroupType::Modifier ();
use PPIx::Regexp::Token::GroupType::NamedCapture ();
use PPIx::Regexp::Token::GroupType::Subexpression ();
use PPIx::Regexp::Token::GroupType::Switch ();
use PPIx::Regexp::Token::Interpolation ();
use PPIx::Regexp::Token::Literal ();
use PPIx::Regexp::Token::Modifier ();
use PPIx::Regexp::Token::Operator ();
use PPIx::Regexp::Token::Quantifier ();
use PPIx::Regexp::Token::Recursion ();
use PPIx::Regexp::Token::Structure ();
use PPIx::Regexp::Token::Unknown ();
use PPIx::Regexp::Token::Whitespace ();
use PPIx::Regexp::Util qw{ __instance };
use Scalar::Util qw{ looks_like_number };
our $VERSION = '0.023';
{
# Names of classes containing tokenization machinery. There are few
# known ordering requirements, since each class recognizes its own,
# and I have tried to prevent overlap. Absent such constraints, the
# order is in percieved frequency of acceptance, to keep the search
# as short as possible. If I were conscientious I would gather
# statistics on this.
my @classes = ( # TODO make readonly when acceptable way appears
'PPIx::Regexp::Token::Literal',
'PPIx::Regexp::Token::Interpolation',
'PPIx::Regexp::Token::Control', # Note 1
'PPIx::Regexp::Token::CharClass::Simple', # Note 2
'PPIx::Regexp::Token::Quantifier',
'PPIx::Regexp::Token::Greediness',
'PPIx::Regexp::Token::CharClass::POSIX', # Note 3
'PPIx::Regexp::Token::Structure',
'PPIx::Regexp::Token::Assertion',
'PPIx::Regexp::Token::Backreference',
'PPIx::Regexp::Token::Operator', # Note 4
);
# Note 1: If we are in quote mode ( \Q ... \E ), Control makes a
# literal out of anything it sees other than \E. So it
# needs to come before almost all other tokenizers. Not
# Literal, which already makes literals, and not
# Interpolation, which is legal in quote mode, but
# everything else.
# Note 2: CharClass::Simple must come after Literal, because it
# relies on Literal to recognize a Unicode named character
# ( \N{something} ), so any \N that comes through to it
# must be the \N simple character class (which represents
# anything but a newline, and was introduced in Perl
# 5.11.0.
# Note 3: CharClass::POSIX has to come before Structure, since both
# look for square brackets, and CharClass::POSIX is the
# more particular.
# Note 4: Operator relies on Literal making the characters literal
# if they appear in a context where they can not be
# operators, and Control making them literals if quoting,
# so it must come after both.
sub _known_tokenizers {
my ( $self ) = @_;
my $mode = $self->{mode};
my @expect;
if ( $self->{expect_next} ) {
$self->{expect} = $self->{expect_next};
$self->{expect_next} = undef;
}
if ( $self->{expect} ) {
@expect = $self->_known_tokenizer_check(
@{ $self->{expect} } );
}
exists $self->{known}{$mode} and return (
@expect, @{ $self->{known}{$mode} } );
my @found = $self->_known_tokenizer_check( @classes );
$self->{known}{$mode} = \@found;
return (@expect, @found);
}
sub _known_tokenizer_check {
my ( $self, @args ) = @_;
my $mode = $self->{mode};
my $handler = '__PPIX_TOKENIZER__' . $mode;
my @found;
foreach my $class ( @args ) {
$class->can( $handler ) or next;
push @found, $class;
}
return @found;
}
}
{
my $errstr;
sub new {
my ( $class, $re, %args ) = @_;
ref $class and $class = ref $class;
$errstr = undef;
exists $args{default_modifiers}
and 'ARRAY' ne ref $args{default_modifiers}
and do {
$errstr = 'default_modifiers must be an array reference';
return;
};
my $self = {
capture => undef, # Captures from find_regexp.
content => undef, # The string we are tokenizing.
cookie => {}, # Cookies
cursor_curr => 0, # The current position in the string.
cursor_limit => undef, # The end of the portion of the
# string being tokenized.
cursor_orig => undef, # Position of cursor when tokenizer
# called. Used by get_token to prevent
# recursion.
cursor_modifiers => undef, # Position of modifiers.
default_modifiers => $args{default_modifiers} || [],
delimiter_finish => undef, # Finishing delimiter of regexp.
delimiter_re => undef, # Recognize finishing delimiter.
delimiter_start => undef, # Starting delimiter of regexp.
encoding => $args{encoding}, # Character encoding.
expect => undef, # Extra classes to expect.
expect_next => undef, # Extra classes as of next parse cycle
failures => 0, # Number of parse failures.
find => undef, # String for find_regexp
known => {}, # Known tokenizers, by mode.
match => undef, # Match from find_regexp.
mode => 'init', # Initialize
modifiers => [{}], # Modifier hash.
pending => [], # Tokens made but not returned.
prior => TOKEN_UNKNOWN, # Prior significant token.
source => $re, # The object we were initialized with.
trace => __PACKAGE__->_defined_or(
$args{trace}, $ENV{PPIX_REGEXP_TOKENIZER_TRACE}, 0 ),
};
if ( __instance( $re, 'PPI::Element' ) ) {
$self->{content} = $re->content();
} elsif ( ref $re ) {
$errstr = ref( $re ) . ' not supported';
return;
} else {
$self->{content} = $re;
}
bless $self, $class;
$self->{content} = $self->decode( $self->{content} );
$self->{cursor_limit} = length $self->{content};
$self->{trace}
and warn "\ntokenizing '$self->{content}'\n";
return $self;
}
sub errstr {
return $errstr;
}
}
sub capture {
my ( $self ) = @_;
$self->{capture} or return;
defined wantarray or return;
return wantarray ? @{ $self->{capture} } : $self->{capture};
}
sub content {
my ( $self ) = @_;
return $self->{content};
}
sub cookie {
my ( $self, $name, @args ) = @_;
defined $name
or confess "Programming error - undefined cookie name";
@args or return $self->{cookie}{$name};
my $cookie = shift @args;
if ( ref $cookie eq 'CODE' ) {
return ( $self->{cookie}{$name} = $cookie );
} elsif ( defined $cookie ) {
confess "Programming error - cookie must be CODE ref or undef";
} else {
return delete $self->{cookie}{$name};
}
}
sub default_modifiers {
my ( $self ) = @_;
return [ @{ $self->{default_modifiers} } ];
}
sub __effective_modifiers {
my ( $self ) = @_;
'HASH' eq ref $self->{effective_modifiers}
or return {};
return { %{ $self->{effective_modifiers} } };
}
sub encoding {
my ( $self ) = @_;
return $self->{encoding};
}
sub expect {
my ( $self, @args ) = @_;
$self->{expect_next} = [
map { m/ \A PPIx::Regexp:: /smx ? $_ : 'PPIx::Regexp::' . $_ }
@args
];
$self->{expect} = undef;
return;
}
sub failures {
my ( $self ) = @_;
return $self->{failures};
}
sub find_matching_delimiter {
my ( $self ) = @_;
$self->{cursor_curr} ||= 0;
my $start = substr
$self->{content},
$self->{cursor_curr},
1;
my $inx = $self->{cursor_curr};
my $finish = (
my $bracketed = $self->close_bracket( $start ) ) || $start;
my $nest = 0;
while ( ++$inx < $self->{cursor_limit} ) {
my $char = substr $self->{content}, $inx, 1;
if ( $char eq '\\' && $finish ne '\\' ) {
++$inx;
} elsif ( $bracketed && $char eq $start ) {
++$nest;
} elsif ( $char eq $finish ) {
--$nest < 0
and return $inx - $self->{cursor_curr};
}
}
return;
}
sub find_regexp {
my ( $self, $regexp ) = @_;
ref $regexp eq 'Regexp'
or confess
'Argument is a ', ( ref $regexp || 'scalar' ), ' not a Regexp';
defined $self->{find} or $self->_remainder();
$self->{find} =~ $regexp
or return;
my @capture;
foreach my $inx ( 0 .. $#+ ) {
if ( defined $-[$inx] && defined $+[$inx] ) {
push @capture, $self->{capture} = substr
$self->{find},
$-[$inx],
$+[$inx] - $-[$inx];
} else {
push @capture, undef;
}
}
$self->{match} = shift @capture;
$self->{capture} = \@capture;
# The following circumlocution seems to be needed under Perl 5.13.0
# for reasons I do not fathom -- at least in the case where
# wantarray is false. RT 56864 details the symptoms, which I was
# never able to reproduce outside Perl::Critic. But returning $+[0]
# directly, the value could transmogrify between here and the
# calling module.
## my @data = ( $-[0], $+[0] );
## return wantarray ? @data : $data[1];
return wantarray ? ( $-[0] + 0, $+[0] + 0 ) : $+[0] + 0;
}
sub get_token {
my ( $self ) = @_;
caller eq __PACKAGE__ or $self->{cursor_curr} > $self->{cursor_orig}
or confess 'Programming error - get_token() called without ',
'first calling make_token()';
my $handler = '__PPIX_TOKENIZER__' . $self->{mode};
my $character = substr(
$self->{content},
$self->{cursor_curr},
1
);
return ( __PACKAGE__->$handler( $self, $character ) );
}
sub interpolates {
my ( $self ) = @_;
return $self->{delimiter_start} ne q{'};
}
sub make_token {
my ( $self, $length, $class, $arg ) = @_;
defined $class or $class = caller;
if ( $length + $self->{cursor_curr} > $self->{cursor_limit} ) {
$length = $self->{cursor_limit} - $self->{cursor_curr}
or return;
}
$class =~ m/ \A PPIx::Regexp:: /smx
or $class = 'PPIx::Regexp::' . $class;
my $content = substr
$self->{content},
$self->{cursor_curr},
$length;
$self->{trace}
and warn "make_token( $length, '$class' ) => '$content'\n";
$self->{trace} > 1
and warn " make_token: cursor_curr = $self->{cursor_curr}; ",
"cursor_limit = $self->{cursor_limit}\n";
my $token = $class->_new( $content ) or return;
$token->significant() and $self->{expect} = undef;
$token->__PPIX_TOKEN__post_make( $self, $arg );
$token->isa( TOKEN_UNKNOWN ) and $self->{failures}++;
$self->{cursor_curr} += $length;
$self->{find} = undef;
$self->{match} = undef;
$self->{capture} = undef;
foreach my $name ( keys %{ $self->{cookie} } ) {
my $cookie = $self->{cookie}{$name};
$cookie->( $self, $token )
or delete $self->{cookie}{$name};
}
# Record this token as the prior token if it is significant. We must
# do this after processing cookies, so that the cookies have access
# to the old token if they want.
$token->significant()
and $self->{prior} = $token;
return $token;
}
sub match {
my ( $self ) = @_;
return $self->{match};
}
sub modifier {
my ( $self, $modifier ) = @_;
return $self->{modifiers}[-1]{$modifier};
}
sub modifier_duplicate {
my ( $self ) = @_;
push @{ $self->{modifiers} },
{ %{ $self->{modifiers}[-1] } };
return;
}
sub modifier_modify {
my ( $self, %args ) = @_;
# Modifier code is centralized in PPIx::Regexp::Token::Modifier
$self->{modifiers}[-1] =
PPIx::Regexp::Token::Modifier::__PPIX_TOKENIZER__modifier_modify(
$self->{modifiers}[-1], \%args );
return;
}
sub modifier_pop {
my ( $self ) = @_;
@{ $self->{modifiers} } > 1
and pop @{ $self->{modifiers} };
return;
}
sub next_token {
my ( $self ) = @_;
{
if ( @{ $self->{pending} } ) {
return shift @{ $self->{pending} };
}
if ( $self->{cursor_curr} >= $self->{cursor_limit} ) {
$self->{cursor_limit} >= length $self->{content}
and return;
$self->{mode} eq 'finish' and return;
$self->{mode} = 'finish';
$self->{cursor_limit}++;
}
if ( my @tokens = $self->get_token() ) {
push @{ $self->{pending} }, @tokens;
redo;
}
}
return;
}
sub peek {
my ( $self, $offset ) = @_;
defined $offset or $offset = 0;
$offset < 0 and return;
$offset += $self->{cursor_curr};
$offset >= $self->{cursor_limit} and return;
return substr $self->{content}, $offset, 1;
}
sub ppi_document {
my ( $self ) = @_;
defined $self->{find} or $self->_remainder();
return PPI::Document->new( \"$self->{find}" );
}
sub prior {
my ( $self, $method, @args ) = @_;
defined $method or return $self->{prior};
$self->{prior}->can( $method )
or confess 'Programming error - ',
( ref $self->{prior} || $self->{prior} ),
' does not support method ', $method;
return $self->{prior}->$method( @args );
}
sub significant {
return 1;
}
sub tokens {
my ( $self ) = @_;
my @rslt;
while ( my $token = $self->next_token() ) {
push @rslt, $token;
}
return @rslt;
}
sub _remainder {
my ( $self ) = @_;
$self->{cursor_curr} > $self->{cursor_limit}
and confess "Programming error - Trying to find past end of string";
$self->{find} = substr(
$self->{content},
$self->{cursor_curr},
$self->{cursor_limit} - $self->{cursor_curr}
);
return;
}
sub __PPIX_TOKENIZER__init {
my ( $class, $tokenizer, $character ) = @_;
$tokenizer->{mode} = 'kaput';
$tokenizer->{content} =~ m/ \A ( qr | m | s )? ( \s* ) ( [^\w\s] ) /smx
or return $tokenizer->make_token(
length( $tokenizer->{content} ), TOKEN_UNKNOWN );
# my ( $type, $white, $delim ) = ( $1, $2, $3 );
my ( $type, $white ) = ( $1, $2 );
defined $type or $type = '';
$tokenizer->{type} = $type;
my @tokens;
push @tokens, $tokenizer->make_token( length $type,
'PPIx::Regexp::Token::Structure' );
length $white > 0
and push @tokens, $tokenizer->make_token( length $white,
'PPIx::Regexp::Token::Whitespace' );
{
my @mods = @{ $tokenizer->{default_modifiers} };
if ( $tokenizer->{content} =~ m/ ( [[:lower:]]* ) \s* \z /smx ) {
my $mod = $1;
$tokenizer->{cursor_limit} -= length $mod;
push @mods, $mod;
}
$tokenizer->{effective_modifiers} =
PPIx::Regexp::Token::Modifier::__aggregate_modifiers (
@mods );
$tokenizer->{modifiers} = [
{ %{ $tokenizer->{effective_modifiers} } },
];
$tokenizer->{cursor_modifiers} = $tokenizer->{cursor_limit};
}
$tokenizer->{delimiter_start} = substr
$tokenizer->{content},
$tokenizer->{cursor_curr},
1;
if ( $type eq 's' and my $offset = $tokenizer->find_matching_delimiter() ) {
$tokenizer->{cursor_limit} = $tokenizer->{cursor_curr} + $offset;
} else {
$tokenizer->{cursor_limit} = $tokenizer->{cursor_modifiers} - 1;
}
$tokenizer->{delimiter_finish} = substr
$tokenizer->{content},
$tokenizer->{cursor_limit},
1;
$tokenizer->{delimiter_re} = undef;
push @tokens, $tokenizer->make_token( 1,
'PPIx::Regexp::Token::Delimiter' );
$tokenizer->{mode} = 'regexp';
return @tokens;
}
sub __PPIX_TOKENIZER__regexp {
my ( $class, $tokenizer, $character ) = @_;
my $mode = $tokenizer->{mode};
my $handler = '__PPIX_TOKENIZER__' . $mode;
$tokenizer->{cursor_orig} = $tokenizer->{cursor_curr};
foreach my $class( $tokenizer->_known_tokenizers() ) {
my @tokens = grep { $_ } $class->$handler( $tokenizer, $character );
$tokenizer->{trace}
and warn $class, "->$handler( \$tokenizer, '$character' )",
" => (@tokens)\n";
@tokens
and return ( map {
ref $_ ? $_ : $tokenizer->make_token( $_,
$class ) } @tokens );
}
# Find a fallback processor for the character.
my $fallback = __PACKAGE__->can( '__PPIX_TOKEN_FALLBACK__' . $mode )
|| __PACKAGE__->can( '__PPIX_TOKEN_FALLBACK__regexp' )
|| confess "Programming error - unable to find fallback for $mode";
return $fallback->( $class, $tokenizer, $character );
}
*__PPIX_TOKENIZER__repl = \&__PPIX_TOKENIZER__regexp;
sub __PPIX_TOKEN_FALLBACK__regexp {
my ( $class, $tokenizer, $character ) = @_;
# As a fallback in regexp mode, any escaped character is a literal.
if ( $character eq '\\'
&& $tokenizer->{cursor_limit} - $tokenizer->{cursor_curr} > 1
) {
return $tokenizer->make_token( 2, TOKEN_LITERAL );
}
# Any normal character is unknown.
return $tokenizer->make_token( 1, TOKEN_UNKNOWN );
}
sub __PPIX_TOKEN_FALLBACK__repl {
my ( $class, $tokenizer, $character ) = @_;
# As a fallback in replacement mode, any escaped character is a literal.
if ( $character eq '\\'
&& defined ( my $next = $tokenizer->peek( 1 ) ) ) {
if ( $tokenizer->interpolates() || $next eq q<'> || $next eq '\\' ) {
return $tokenizer->make_token( 2, TOKEN_LITERAL );
}
return $tokenizer->make_token( 1, TOKEN_LITERAL );
}
# So is any normal character.
return $tokenizer->make_token( 1, TOKEN_LITERAL );
}
sub __PPIX_TOKENIZER__finish {
my ( $class, $tokenizer, $character ) = @_;
$tokenizer->{cursor_limit} > length $tokenizer->{content}
and confess "Programming error - ran off string";
my @tokens = $tokenizer->make_token( 1,
'PPIx::Regexp::Token::Delimiter' );
if ( $tokenizer->{cursor_curr} eq $tokenizer->{cursor_modifiers} ) {
# We are out of string. Make the modifier token and close up
# shop.
$tokenizer->{cursor_limit} = length $tokenizer->{content};
push @tokens, $tokenizer->make_token(
$tokenizer->{cursor_limit} - $tokenizer->{cursor_curr},
'PPIx::Regexp::Token::Modifier' );
$tokenizer->{mode} = 'kaput';
} else {
# Clear the cookies, because we are going around again.
$tokenizer->{cookie} = {};
# Move the cursor limit to just before the modifiers.
$tokenizer->{cursor_limit} = $tokenizer->{cursor_modifiers} - 1;
# If the preceding regular expression was bracketed, we need to
# consume possible whitespace and find another delimiter.
if ( $tokenizer->close_bracket( $tokenizer->{delimiter_start} ) ) {
my $accept;
$accept = $tokenizer->find_regexp( qr{ \A \s+ }smx )
and push @tokens, $tokenizer->make_token(
$accept, 'PPIx::Regexp::Token::Whitespace' );
my $character = $tokenizer->peek();
$tokenizer->{delimiter_start} = $character;
push @tokens, $tokenizer->make_token(
1, 'PPIx::Regexp::Token::Delimiter' );
$tokenizer->{delimiter_finish} = substr
$tokenizer->{content},
$tokenizer->{cursor_limit} - 1,
1;
$tokenizer->{delimiter_re} = undef;
}
if ( $tokenizer->modifier( 'e' ) ) {
# With /e, the replacement portion is code. We make it all
# into one big PPIx::Regexp::Token::Code, slap on the
# trailing delimiter and modifiers, and return it all.
push @tokens, $tokenizer->make_token(
$tokenizer->{cursor_limit} - $tokenizer->{cursor_curr},
'PPIx::Regexp::Token::Code',
{ perl_version_introduced => MINIMUM_PERL },
);
$tokenizer->{cursor_limit} = length $tokenizer->{content};
push @tokens, $tokenizer->make_token( 1,
'PPIx::Regexp::Token::Delimiter' );
push @tokens, $tokenizer->make_token(
$tokenizer->{cursor_limit} - $tokenizer->{cursor_curr},
'PPIx::Regexp::Token::Modifier' );
$tokenizer->{mode} = 'kaput';
} else {
# Put our mode to replacement.
$tokenizer->{mode} = 'repl';
}
}
return @tokens;
}
1;
__END__
=head1 NAME
PPIx::Regexp::Tokenizer - Tokenize a regular expression
=head1 SYNOPSIS
use PPIx::Regexp::Dumper;
PPIx::Regexp::Dumper->new( 'qr{foo}smx' )
->print();
=head1 INHERITANCE
C<PPIx::Regexp::Tokenizer> is a
L<PPIx::Regexp::Support|PPIx::Regexp::Support>.
C<PPIx::Regexp::Tokenizer> has no descendants.
=head1 DESCRIPTION
This class provides tokenization of the regular expression.
=head1 METHODS
This class provides the following public methods. Methods not documented
here (or documented below under L</EXTERNAL TOKENIZERS>) are private,
and unsupported in the sense that the author reserves the right to
change or remove them without notice.
=head2 new
my $tokenizer = PPIx::Regexp::Tokenizer->new( 'xyzzy' );
This static method instantiates the tokenizer. You must pass it the
regular expression to be parsed, either as a string or as a
L<PPI::Element|PPI::Element> of some sort. You can also pass optional
name/value pairs of arguments. The option names are specified B<without>
a leading dash. Supported options are:
=over
=item default_modifiers array_reference
This argument specifies default statement modifiers. It is optional, but
if specified must be an array reference. See the
L<PPIx::Regexp|PPIx::Regexp> L<new()|PPIx::Regexp/new> documentation for
the details.
=item encoding name
This option specifies the encoding of the string to be tokenized. If
specified, an C<Encode::decode> is done on the string (or the C<content>
of the PPI class) before it is tokenized.
=item trace number
Specifying a positive value for this option causes a trace of the
tokenization. This option is unsupported in the sense that the author
reserves the right to alter it without notice.
If this option is unspecified, the value comes from environment variable
C<PPIX_REGEXP_TOKENIZER_TRACE> (see L</ENVIRONMENT VARIABLES>). If this
environment variable does not exist, the default is 0.
=back
Undocumented options are unsupported.
The returned value is the instantiated tokenizer, or C<undef> if
instantiation failed. In the latter case a call to L</errstr> will
return the reason.
=head2 content
print $tokenizer->content();
This method returns the string being tokenized. This will be the result
of the L<< PPI::Element->content()|PPI::Element/content >> method if the
object was instantiated with a L<PPI::Element|PPI::Element>.
=head2 default_modifiers
print join ', ', @{ $tokenizer->default_modifiers() };
This method returns a reference to a copy of the array passed to the
C<default_modifiers> argument to L<new()|/new>. If this argument was not
used to instantiate the object, the return is a reference to an empty
array.
=head2 encoding
This method returns the encoding of the data being parsed, if one was
set when the class was instantiated; otherwise it simply returns undef.
=head2 errstr
my $tokenizer = PPIx::Regexp::Tokenizer->new( 'xyzzy' )
or die PPIx::Regexp::Tokenizer->errstr();
This static method returns an error description if tokenizer
instantiation failed.
=head2 failures
print $tokenizer->failures(), " tokenization failures\n";
This method returns the number of tokenization failures encountered. A
tokenization failure is represented in the output token stream by a
L<PPIx::Regexp::Token::Unknown|PPIx::Regexp::Token::Unknown>.
=head2 modifier
$tokenizer->modifier( 'x' )
and print "Tokenizing an extended regular expression\n";
This method returns true if the given modifier character was found on
the end of the regular expression, and false otherwise.
=head2 next_token
my $token = $tokenizer->next_token();
This method returns the next token in the token stream, or nothing if
there are no more tokens.
=head2 significant
This method exists simply for the convenience of
L<PPIx::Regexp::Dumper|PPIx::Regexp::Dumper>. It always returns true.
=head2 tokens
my @tokens = $tokenizer->tokens();
This method returns all remaining tokens in the token stream.
=head1 EXTERNAL TOKENIZERS
This class does very little of its own tokenization. Instead the token
classes contain external tokenization routines, whose name is
'__PPIX_TOKENIZER__' concatenated with the current mode of the tokenizer
('regexp' for regular expressions, 'repl' for the replacement string).
These external tokenizers are called as static methods, and passed the
C<PPIx::Regexp::Tokenizer> object and the current character in the
character stream.
If the external tokenizer wants to make one or more tokens, it returns
an array containing either length in characters for tokens of the
tokenizer's own class, or the results of one or more L</make_token>
calls for tokens of an arbitrary class.
If the external tokenizer is not interested in the characters starting
at the current position it simply returns.
The following methods are for the use of external tokenizers, and B<are
not part of the public interface to this class.>
=head2 capture
if ( $tokenizer->find_regexp( qr{ \A ( foo ) }smx ) ) {
foreach ( $tokenizer->capture() ) {
print "$_\n";
}
}
This method returns all the contents of any capture buffers from the
previous call to L</find_regexp>. The first element of the array (i.e.
element 0) corresponds to C<$1>, and so on.
The captures are cleared by L</make_token>, as well as by another call
to L</find_regexp>.
=head2 cookie
$tokenizer->cookie( foo => sub { 1 } );
my $cookie = $tokenizer->cookie( 'foo' );
my $old_hint = $tokenizer->cookie( foo => undef );
This method either creates, deletes, or accesses a cookie.
A cookie is a code reference which is called whenever the tokenizer makes
a token. If it returns a false value, it is deleted. Explicitly setting
the cookie to C<undef> also deletes it.
When you call C<< $tokenizer->cookie( 'foo' ) >>, the current cookie is
returned. If you pass a new value of C<undef> to delete the token, the
deleted cookie (if any) is returned.
When the L</make_token> method calls a cookie, it passes it the tokenizer
and the token just made. If a token calls a cookie, it is recommended that
it merely pass the tokenizer, though of course the token can do whatever
it wants.
The cookie mechanism seems to be a bit of a crock, but it appeared to be
more work to fix things up in the lexer after the tokenizer got
something wrong.
The recommended way to write a cookie is to use a closure to store any
necessary data, and have a call to the cookie return the data; otherwise
the ultimate consumer of the cookie has no way to access the data. Of
course, it may be that the presence of the cookie at a certain point in
the parse is all that is required.
=head2 expect
$tokenizer->expect( 'PPIx::Regexp::Token::Code' );
This method inserts a given class at the head of the token scan, for the
next iteration only. More than one class can be specified. Class names
can be abbreviated by removing the leading 'PPIx::Regexp::'.
The expectation lasts from the next time L</get_token> is called until
the next time L<make_token> makes a significant token, or until the next
C<expect> call if that is done sooner.
=head2 find_regexp
my $end = $tokenizer->find_regexp( qr{ \A \w+ }smx );
my ( $begin, $end ) = $tokenizer->find_regexp(
qr{ \A \w+ }smx );
This method finds the given regular expression in the content, starting
at the current position. If called in scalar context, the offset from
the current position to the end of the matched string is returned. If
called in list context, the offsets to both the beginning and the end of
the matched string are returned.
=head2 find_matching_delimiter
my $offset = $tokenizer->find_matching_delimiter();
This method is used by tokenizers to find the delimiter matching the
character at the current position in the content string. If the
delimiter is an opening bracket of some sort, bracket nesting will be
taken into account.
When searching for the matching delimiter, the back slash character is
considered to escape the following character, so back-slashed delimiters
will be ignored. No other quoting mechanisms are recognized, though, so
delimiters inside quotes still count. This is actually the way Perl
works, as
$ perl -e 'qr<(?{ print "}" })>'
demonstrates.
This method returns the offset from the current position in the content
string to the matching delimiter (which will always be positive), or
undef if no match can be found.
=head2 get_token
my $token = $tokenizer->make_token( 3 );
my @tokens = $tokenizer->get_token();
This method returns the next token that can be made from the input
stream. It is B<not> part of the external interface, but is intended for
the use of an external tokenizer which calls it after making and
retaining its own token to look at the next token ( if any ) in the
input stream.
If any external tokenizer calls get_token without first calling
make_token, a fatal error occurs; this is better than the infinite
recursion which would occur if the condition were not trapped.
An external tokenizer B<must> return anything returned by get_token;
otherwise tokens get lost.
=head2 interpolates
This method returns true if the top-level structure being tokenized
interpolates; that is, if the delimiter is not a single quote.
=head2 make_token
return $tokenizer->make_token( 3, 'PPIx::Regexp::Token::Unknown' );
This method is used by this class (and possibly by individual
tokenizers) to manufacture a token. Its arguments are the number of
characters to include in the token, and optionally the class of the
token. If no class name is given, the caller's class is used. Class
names may be shortened by removing the initial 'PPIx::Regexp::', which
will be restored by this method.
The token will be manufactured from the given number of characters
starting at the current cursor position, which will be adjusted.
If the given length would include characters past the end of the string
being tokenized, the length is reduced appropriately. If this means a
token with no characters, nothing is returned.
=head2 match
if ( $tokenizer->find_regexp( qr{ \A \w+ }smx ) ) {
print $tokenizer->match(), "\n";
}
This method returns the string matched by the previous call to
L</find_regexp>.
The match is set to C<undef> by L</make_token>, as well as by another
call to L</find_regexp>.
=head2 modifier_duplicate
$tokenizer->modifier_duplicate();
This method duplicates the modifiers on the top of the modifier stack,
with the intent of creating a locally-scoped copy of the modifiers. This
should only be called by an external tokenizer that is actually creating
a modifier scope. In other words, only when creating a
L<PPIx::Regexp::Token::Structure|PPIx::Regexp::Token::Structure> token
whose content is '('.
=head2 modifier_modify
$tokenizer->modifier_modify( name => $value ... );
This method sets new values for the modifiers in the local scope. Only
the modifiers whose names are actually passed have their values changed.
This method is intended to be called after manufacturing a
L<PPIx::Regexp::Token::Modifier|PPIx::Regexp::Token::Modifier> token,
and passed the results of its C<modifiers> method.
=head2 modifier_pop
$tokenizer->modifier_pop();
This method removes the modifiers on the top of the modifier stack. This
should only be called by an external tokenizer that is ending a modifier
scope. In other words, only when creating a
L<PPIx::Regexp::Token::Structure|PPIx::Regexp::Token::Structure> token
whose content is ')'.
Note that this method will never pop the last modifier item off the
stack, to guard against unmatched right parentheses.
=head2 peek
my $character = $tokenizer->peek();
my $next_char = $tokenizer->peek( 1 );
This method returns the character at the given non-negative offset from
the current position. If no offset is given, an offset of 0 is used.
If you ask for a negative offset or an offset off the end of the sting,
C<undef> is returned.
=head2 ppi_document
This method makes a PPI document out of the remainder of the string, and
returns it.
=head2 prior
$tokenizer->prior( 'can_be_quantified' )
and print "The prior token can be quantified.\n";
This method calls the named method on the most-recently-instantiated
significant token, and returns the result. Any arguments subsequent to
the method name will be passed to the method.
Because this method is designed to be used within the tokenizing system,
it will die horribly if the named method does not exist.
=head1 ENVIRONMENT VARIABLES
A tokenizer trace can be requested by setting environment variable
PPIX_REGEXP_TOKENIZER_TRACE to a numeric value other than 0. Use of this
environment variable is unsupported in the same sense that the C<trace>
option of L</new> is unsupported. Explicitly specifying the C<trace>
option to L</new> overrides the environment variable.
The real reason this is documented is to give the user a way to
troubleshoot funny output from the tokenizer.
=head1 SUPPORT
Support is by the author. Please file bug reports at
L<http://rt.cpan.org>, or in electronic mail to the author.
=head1 AUTHOR
Thomas R. Wyant, III F<wyant at cpan dot org>
=head1 COPYRIGHT AND LICENSE
Copyright (C) 2009-2011 by Thomas R. Wyant, III
This program is free software; you can redistribute it and/or modify it
under the same terms as Perl 5.10.0. For more details, see the full text
of the licenses in the directory LICENSES.
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
# ex: set textwidth=72 :
|