6 use VerboseWarnings qw( pedantic_p error_normal warn_normal warn_pedantic );
9 use vars qw($VERSION @ISA @EXPORT @EXPORT_OK %EXPORT_TAGS);
11 ###############################################################################
15 TmplTokenizer.pm - Simple-minded tokenizer class for HTML::Template .tmpl files
19 Because .tmpl files contains HTML::Template directives
20 that tend to confuse real parsers (e.g., HTML::Parse),
21 it might be better to create a customized scanner
22 to scan the template files for tokens.
23 This module is a simple-minded attempt at such a scanner.
27 ###############################################################################
34 use vars qw( $pedantic_attribute_error_in_nonpedantic_mode_p );
35 use vars qw( $pedantic_tmpl_var_use_in_nonpedantic_mode_p );
37 ###############################################################################
40 use vars qw( $re_directive $re_tmpl_var $re_tmpl_var_escaped $re_tmpl_include );
41 use vars qw( $re_directive_control $re_tmpl_endif_endloop );
43 # $re_directive must not do any backreferences
44 $re_directive = q{<(?:(?i)(?:!--\s*)?\/?TMPL_(?:VAR|LOOP|INCLUDE|IF|ELSE|UNLESS)(?:\s+(?:[a-zA-Z][-a-zA-Z0-9]*=)?(?:'[^']*'|"[^"]*"|[^\s<>]+))*\s*(?:--)?)>};
45 # TMPL_VAR or TMPL_INCLUDE
46 $re_tmpl_var = q{<(?:(?i)(?:!--\s*)?TMPL_(?:VAR)(?:\s+(?:[a-zA-Z][-a-zA-Z0-9]*=)?(?:'[^']*'|"[^"]*"|[^\s<>]+))*\s*(?:--)?)>};
47 $re_tmpl_include = q{<(?:(?i)(?:!--\s*)?TMPL_(?:INCLUDE)(?:\s+(?:[a-zA-Z][-a-zA-Z0-9]*=)?(?:'[^']*'|"[^"]*"|[^\s<>]+))*\s*(?:--)?)>};
48 # TMPL_VAR ESCAPE=1/HTML/URL
49 $re_tmpl_var_escaped = q{<(?:(?i)(?:!--\s*)?TMPL_(?:VAR|INCLUDE)(?:\s+(?:[a-zA-Z][-a-zA-Z0-9]*=)?(?:'[^']*'|"[^"]*"|[^\s<>]+))\s+ESCAPE=(?:1|HTML|URL)(?:\s+(?:[a-zA-Z][-a-zA-Z0-9]*=)?(?:'[^']*'|"[^"]*"|[^\s<>]+))*\s*(?:--)?)>};
50 # Any control flow directive
51 $re_directive_control = q{<(?:(?i)(?:!--\s*)?\/?TMPL_(?:LOOP|IF|ELSE|UNLESS)(?:\s+(?:[a-zA-Z][-a-zA-Z0-9]*=)?(?:'[^']*'|"[^"]*"|[^\s<>]+))*\s*(?:--)?)>};
52 # /LOOP or /IF or /UNLESS
53 $re_tmpl_endif_endloop = q{<(?:(?i)(?:!--\s*)?\/TMPL_(?:LOOP|IF|UNLESS)(?:\s+(?:[a-zA-Z][-a-zA-Z0-9]*=)?(?:'[^']*'|"[^"]*"|[^\s<>]+))*\s*(?:--)?)>};
56 # Hideous stuff from subst.pl, slightly modified to use the above hideous stuff
57 # Note: The $re_tag's set $1 (<tag), $2 (>), and $3 (rest of string)
58 use vars qw( $re_comment $re_entity_name $re_end_entity $re_etag );
59 use vars qw( $re_tag_strict $re_tag_compat @re_tag );
62 my $etag = $compat? '>': '<>\/';
63 # This is no longer similar to the original regexp in subst.pl :-(
64 # Note that we don't want <> in compat mode; Mozilla knows about <
65 q{(<\/?(?:|(?:"(?:} . $re_directive . q{|[^"])*"|'(?:} . $re_directive . q{|[^'])*'|--(?:[^-]|-[^-])*--|(?:}
67 . q{|(?!--)[^"'<>} . $etag . q{]))+))([} . $etag . q{]|(?=<))(.*)};
70 $re_comment = '(?:--(?:[^-]|-[^-])*--)';
71 $re_entity_name = '(?:[^&%#;<>\s]+)'; # NOTE: not really correct SGML
72 $re_end_entity = '(?:;|$|(?=\s))'; # semicolon or before-whitespace
73 $re_etag = q{(?:<\/?(?:"[^"]*"|'[^']*'|[^"'>\/])*[>\/])}; # end-tag
74 @re_tag = ($re_tag_strict, $re_tag_compat) = (re_tag(0), re_tag(1));
77 # End of the hideous stuff
79 use vars qw( $serial );
81 ###############################################################################
83 sub FATAL_P () {'fatal-p'}
84 sub SYNTAXERROR_P () {'syntaxerror-p'}
86 sub FILENAME () {'input'}
87 sub HANDLE () {'handle'}
89 sub READAHEAD () {'readahead'}
90 sub LINENUM_START () {'lc_0'}
92 sub CDATA_MODE_P () {'cdata-mode-p'}
93 sub CDATA_CLOSE () {'cdata-close'}
95 sub ALLOW_CFORMAT_P () {'allow-cformat-p'}
100 my $class = ref($this) || $this;
104 my $handle = sprintf('TMPLTOKENIZER%d', $serial);
108 open($handle, "<$input") || die "$input: $!\n";
110 $self->{+FILENAME} = $input;
111 $self->{+HANDLE} = $handle;
112 $self->{+READAHEAD} = [];
116 ###############################################################################
122 return $this->{+FILENAME};
127 return $this->{+HANDLE};
132 return $this->{+FATAL_P};
137 return $this->{+SYNTAXERROR_P};
140 sub has_readahead_p {
142 return @{$this->{+READAHEAD}};
145 sub _peek_readahead {
147 return $this->{+READAHEAD}->[$#{$this->{+READAHEAD}}];
150 sub line_number_start {
152 return $this->{+LINENUM_START};
157 return $this->{+LINENUM};
162 return $this->{+CDATA_MODE_P};
167 return $this->{+CDATA_CLOSE};
170 sub allow_cformat_p {
172 return $this->{+ALLOW_CFORMAT_P};
179 $this->{+FATAL_P} = $_[0];
183 sub _set_syntaxerror {
185 $this->{+SYNTAXERROR_P} = $_[0];
189 sub _push_readahead {
191 push @{$this->{+READAHEAD}}, $_[0];
197 return pop @{$this->{+READAHEAD}};
200 sub _append_readahead {
202 $this->{+READAHEAD}->[$#{$this->{+READAHEAD}}] .= $_[0];
208 $this->{+READAHEAD}->[$#{$this->{+READAHEAD}}] = $_[0];
212 sub _increment_line_number {
214 $this->{+LINENUM} += 1;
218 sub _set_line_number_start {
220 $this->{+LINENUM_START} = $_[0];
224 sub _set_cdata_mode {
226 $this->{+CDATA_MODE_P} = $_[0];
230 sub _set_cdata_close {
232 $this->{+CDATA_CLOSE} = $_[0];
236 sub set_allow_cformat {
238 $this->{+ALLOW_CFORMAT_P} = $_[0];
242 ###############################################################################
244 sub _extract_attributes ($;$) {
248 $s = $1 if $s =~ /^<\S+(.*)\/\S$/s # XML-style self-closing tags
249 || $s =~ /^<\S+(.*)\S$/s; # SGML-style tags
251 for (my $i = 0; $s =~ /^(?:$re_directive_control)?\s+(?:$re_directive_control)?(?:([a-zA-Z][-a-zA-Z0-9]*)\s*=\s*)?('((?:$re_directive|[^'])*)'|"((?:$re_directive|[^"])*)"|((?:$re_directive|[^\s<>])+))/os;) {
252 my($key, $val, $val_orig, $rest)
253 = ($1, (defined $3? $3: defined $4? $4: $5), $2, $');
255 $attr{+lc($key)} = [$key, $val, $val_orig, $i];
257 if ($val =~ /$re_tmpl_include/os) {
258 warn_normal "TMPL_INCLUDE in attribute: $val_orig\n", $lc;
259 } elsif ($val =~ /$re_tmpl_var/os && $val !~ /$re_tmpl_var_escaped/os) {
260 # XXX: we probably should not warn if key is "onclick" etc
261 # XXX: there's just no reasonable thing to suggest
262 my $suggest = ($key =~ /^(?:action|archive|background|cite|classid|codebase|data|datasrc|for|href|longdesc|profile|src|usemap)$/i? 'URL': 'HTML');
263 undef $suggest if $key =~ /^(?:onblur|onchange|onclick|ondblclick|onfocus|onkeydown|onkeypress|onkeyup|onload|onmousedown|onmousemove|onmouseout|onmouseover|onmouseup|onreset|onselect|onsubmit|onunload)$/i;
265 "Suggest ESCAPE=$suggest for TMPL_VAR in attribute \"$key\""
267 $lc, \$pedantic_tmpl_var_use_in_nonpedantic_mode_p
268 if defined $suggest && (pedantic_p || !$pedantic_tmpl_var_use_in_nonpedantic_mode_p);
269 } elsif ($val_orig !~ /^['"]/) {
270 my $t = $val; $t =~ s/$re_directive_control//os;
272 "Unquoted attribute contains character(s) that should be quoted"
274 $lc, \$pedantic_attribute_error_in_nonpedantic_mode_p
275 if $t =~ /[^-\.A-Za-z0-9]/s;
278 my $s2 = $s; $s2 =~ s/$re_tmpl_endif_endloop//g; # for the next check
279 if ($s2 =~ /\S/s) { # should never happen
280 if ($s =~ /^([^\n]*)\n/s) { # this is even worse
281 error_normal("Completely confused while extracting attributes: $1", $lc);
282 error_normal((scalar(split(/\n/, $s)) - 1) . " more line(s) not shown.", undef);
283 $this->_set_fatal( 1 );
285 warn_normal "Strange attribute syntax: $s\n", $lc;
291 sub _next_token_internal {
296 $this->_pop_readahead if $this->has_readahead_p
297 && !ref $this->_peek_readahead
298 && !length $this->_peek_readahead;
299 if (!$this->has_readahead_p) {
300 my $next = scalar <$h>;
301 $eof_p = !defined $next;
303 $this->_increment_line_number;
304 $this->_push_readahead( $next );
307 $this->_set_line_number_start( $this->line_number ); # remember 1st line num
308 if ($this->has_readahead_p && ref $this->_peek_readahead) { # TmplToken obj.
309 ($it, $kind) = ($this->_pop_readahead, undef);
310 } elsif ($eof_p && !$this->has_readahead_p) { # nothing left to do
312 } elsif ($this->_peek_readahead =~ /^\s+/s) { # whitespace
313 ($kind, $it) = (TmplTokenType::TEXT, $&);
314 $this->_set_readahead( $' );
315 # FIXME the following (the [<\s] part) is an unreliable HACK :-(
316 } elsif ($this->_peek_readahead =~ /^(?:[^<]|<[<\s])*(?:[^<\s])/s) { # non-space normal text
317 ($kind, $it) = (TmplTokenType::TEXT, $&);
318 $this->_set_readahead( $' );
319 warn_normal "Unescaped < in $it\n", $this->line_number_start
320 if !$this->cdata_mode_p && $it =~ /</s;
321 } else { # tag/declaration/processing instruction
323 for (my $cdata_close = $this->cdata_close;;) {
324 if ($this->cdata_mode_p) {
325 my $next = $this->_pop_readahead;
326 if ($next =~ /^$cdata_close/) {
327 ($kind, $it) = (TmplTokenType::TAG, $&);
328 $this->_push_readahead( $' );
330 } elsif ($next =~ /^((?:(?!$cdata_close).)+)($cdata_close)/) {
331 ($kind, $it) = (TmplTokenType::TEXT, $1);
332 $this->_push_readahead( "$2$'" );
335 ($kind, $it) = (TmplTokenType::TEXT, $next);
338 } elsif ($this->_peek_readahead =~ /^$re_tag_compat/os) {
339 # If we detect a "closed start tag" but we know that the
340 # following token looks like a TMPL_VAR, don't stop
341 my($head, $tail, $post) = ($1, $2, $3);
342 if ($tail eq '' && $post =~ $re_tmpl_var) {
343 # Don't bother to show the warning if we're too confused
344 warn_normal "Possible SGML \"closed start tag\" notation: $head<\n", $this->line_number
345 if split(/\n/, $head) < 10;
347 ($kind, $it) = (TmplTokenType::TAG, "$head>");
348 $this->_set_readahead( $post );
350 warn_normal "SGML \"closed start tag\" notation: $head<\n", $this->line_number if $tail eq '';
352 } elsif ($this->_peek_readahead =~ /^<!--(?:(?!-->).)*-->/s) {
353 ($kind, $it) = (TmplTokenType::COMMENT, $&);
354 $this->_set_readahead( $' );
356 warn_normal "Syntax error in comment: $&\n", $this->line_number_start;
357 $this->_set_syntaxerror( 1 );
360 my $next = scalar <$h>;
361 $eof_p = !defined $next;
363 $this->_increment_line_number;
364 $this->_append_readahead( $next );
366 if ($kind ne TmplTokenType::TAG) {
368 } elsif ($it =~ /^<!/) {
369 $kind = TmplTokenType::DECL;
370 $kind = TmplTokenType::COMMENT if $it =~ /^<!--(?:(?!-->).)*-->/;
371 if ($kind == TmplTokenType::COMMENT && $it =~ /^<!--\s*#include/s) {
372 warn_normal "Apache #include directive found instead of HTML::Template <TMPL_INCLUDE> directive", $this->line_number_start;
374 } elsif ($it =~ /^<\?/) {
375 $kind = TmplTokenType::PI;
377 if ($it =~ /^$re_directive/ios && !$this->cdata_mode_p) {
378 $kind = TmplTokenType::DIRECTIVE;
380 if (!$ok_p && $eof_p) {
381 ($kind, $it) = (TmplTokenType::UNKNOWN, $this->_peek_readahead);
382 $this->_set_readahead, undef;
383 $this->_set_syntaxerror( 1 );
386 warn_normal "Unrecognizable token found: "
387 . (split(/\n/, $it) < 10? $it: '(too confused to show details)')
388 . "\n", $this->line_number_start
389 if $kind == TmplTokenType::UNKNOWN;
390 return defined $it? (ref $it? $it: TmplToken->new($it, $kind, $this->line_number, $this->filename)): undef;
393 sub _next_token_intermediate {
395 my $h = $this->_handle;
397 if (!$this->cdata_mode_p) {
398 $it = $this->_next_token_internal($h);
399 if (defined $it && $it->type == TmplTokenType::TAG) {
400 if ($it->string =~ /^<(script|style|textarea)\b/i) {
401 $this->_set_cdata_mode( 1 );
402 $this->_set_cdata_close( "</$1\\s*>" );
404 $it->set_attributes( $this->_extract_attributes($it->string, $it->line_number) );
407 for ($it = '', my $cdata_close = $this->cdata_close;;) {
408 my $next = $this->_next_token_internal($h);
409 last if !defined $next;
410 if (defined $next && $next->string =~ /$cdata_close/i) {
411 $this->_push_readahead( $next ); # push entire TmplToken object
412 $this->_set_cdata_mode( 0 );
414 last unless $this->cdata_mode_p;
415 $it .= $next->string;
417 $it = TmplToken->new( $it, TmplTokenType::CDATA, $this->line_number );
418 $this->_set_cdata_close, undef;
423 sub _token_groupable_p ($) { # groupable into a TEXT_PARAMETRIZED token
425 return $t->type == TmplTokenType::TEXT
426 || ($t->type == TmplTokenType::DIRECTIVE
427 && $t->string =~ /^(?:$re_tmpl_var)$/os)
428 || ($t->type == TmplTokenType::TAG
429 && ($t->string =~ /^<\/?(?:b|em|h[123456]|i|u)\b/is
430 || ($t->string =~ /^<input/i
431 && $t->attributes->{'type'} =~ /^(?:text)$/i)))
434 sub _quote_cformat ($) {
442 return $t->type == TmplTokenType::DIRECTIVE? '%s': _quote_cformat($t->string);
447 my $h = $this->_handle;
449 $this->{_queue} = [] unless defined $this->{_queue};
450 if (@{$this->{_queue}}) {
451 $it = pop @{$this->{_queue}};
453 $it = $this->_next_token_intermediate($h);
454 if (!$this->cdata_mode_p && $this->allow_cformat_p && defined $it
455 && ($it->type == TmplTokenType::TEXT?
456 !blank_p( $it->string ): _token_groupable_p( $it ))) {
457 my @structure = ( $it );
458 my($n_trailing_spaces, $next) = (0, undef);
459 my($nonblank_text_p, $parametrized_p, $next) = (0, 0);
460 if ($it->type == TmplTokenType::TEXT) {
461 $nonblank_text_p = 1 if !blank_p( $it->string );
462 } elsif ($it->type == TmplTokenType::DIRECTIVE) {
465 for (my $i = 1, $n_trailing_spaces = 0;; $i += 1) {
466 $next = $this->_next_token_intermediate($h);
467 push @structure, $next; # for consistency (with initialization)
468 last unless defined $next && _token_groupable_p( $next );
469 if ($next->type == TmplTokenType::TEXT) {
470 if (blank_p( $next->string )) {
471 $n_trailing_spaces += 1;
473 ($n_trailing_spaces, $nonblank_text_p) = (0, 1);
475 } elsif ($next->type == TmplTokenType::DIRECTIVE) {
476 $n_trailing_spaces = 0;
479 $n_trailing_spaces = 0;
482 # Undo the last token
483 push @{$this->{_queue}}, pop @structure;
484 # Undo trailing blank tokens
485 for (my $i = 0; $i < $n_trailing_spaces; $i += 1) {
486 push @{$this->{_queue}}, pop @structure;
488 # FIXME: If the last token is a close tag but there are no tags
489 # FIXME: before it, drop the close tag back into the queue. This
490 # FIXME: is an ugly hack to get rid of "foo %s</h1>" type mess.
492 && $structure[$#structure]->type == TmplTokenType::TAG
493 && $structure[$#structure]->string =~ /^<\//) {
494 my $has_other_tags_p = 0;
495 for (my $i = 0; $i < $#structure; $i += 1) {
496 $has_other_tags_p = 1
497 if $structure[$i]->type == TmplTokenType::TAG;
498 last if $has_other_tags_p;
500 push @{$this->{_queue}}, pop @structure unless $has_other_tags_p
502 if (@structure < 2) {
505 } elsif ($nonblank_text_p && $parametrized_p) {
506 # Create the corresponding c-format string
507 my $string = join('', map { $_->string } @structure);
508 my $form = join('', map { _formalize $_ } @structure);
509 $it = TmplToken->new($string, TmplTokenType::TEXT_PARAMETRIZED, $it->line_number, $it->pathname);
510 $it->set_form( $form );
511 $it->set_children( @structure );
512 } elsif ($nonblank_text_p && $structure[0]->type == TmplTokenType::TEXT && $structure[$#structure]->type == TmplTokenType::TEXT) {
513 # Combine the strings
514 my $string = join('', map { $_->string } @structure);
515 $it = TmplToken->new($string, TmplTokenType::TEXT, $it->line_number, $it->pathname);;
517 # Requeue the tokens thus seen for re-emitting
519 push @{$this->{_queue}}, pop @structure;
522 $it = pop @{$this->{_queue}};
529 ###############################################################################
531 # Other simple functions (These are not methods)
535 return $s =~ /^(?:\s|\ $re_end_entity|$re_tmpl_var)*$/os;
542 $s =~ s/^(\s|\ $re_end_entity)+//os; my $l1 = $l0 - length $s;
543 $s =~ s/(\s|\ $re_end_entity)+$//os; my $l2 = $l0 - $l1 - length $s;
544 return wantarray? (substr($s0, 0, $l1), $s, substr($s0, $l0 - $l2)): $s;
549 # Locale::PO->quote is buggy, it doesn't quote newlines :-/
550 $s =~ s/([\\"])/\\\1/gs;
552 #$s =~ s/[\177-\377]/ sprintf("\\%03o", ord($&)) /egs;
556 # Some functions that shouldn't be here... should be moved out some time
557 sub parametrize ($@) {
558 my($fmt, @params) = @_;
560 for (my $n = 0; length $fmt;) {
561 if ($fmt =~ /^[^%]+/) {
564 } elsif ($fmt =~ /^%%/) {
567 } elsif ($fmt =~ /^%(?:(\d+)\$)?(?:(\d+)(?:\.(\d+))?)?s/) {
569 my($i, $width, $prec) = ((defined $1? $1: $n), $2, $3);
571 if (!defined $width && !defined $prec) {
573 } elsif (defined $width && defined $prec && !$width && !$prec) {
576 die "Unsupported precision specification in format: $&\n"; #XXX
578 } elsif ($fmt =~ /^%[^%a-zA-Z]*[a-zA-Z]/) {
581 die "Unknown or unsupported format specification: $&\n"; #XXX
583 die "Completely confused parametrizing: $fmt\n";#XXX
589 sub charset_canon ($) {
591 $charset = uc($charset);
592 $charset = "$1-$2" if $charset =~ /^(ISO|UTF)(\d.*)/i;
593 $charset = 'Big5' if $charset eq 'BIG5'; # "Big5" must be in mixed case
597 use vars qw( @latin1_utf8 );
599 "\302\200", "\302\201", "\302\202", "\302\203", "\302\204", "\302\205",
600 "\302\206", "\302\207", "\302\210", "\302\211", "\302\212", "\302\213",
601 "\302\214", "\302\215", undef, undef, "\302\220", "\302\221",
602 "\302\222", "\302\223", "\302\224", "\302\225", "\302\226", "\302\227",
603 "\302\230", "\302\231", "\302\232", "\302\233", "\302\234", "\302\235",
604 "\302\236", "\302\237", "\302\240", "\302\241", "\302\242", "\302\243",
605 "\302\244", "\302\245", "\302\246", "\302\247", "\302\250", "\302\251",
606 "\302\252", "\302\253", "\302\254", "\302\255", "\302\256", "\302\257",
607 "\302\260", "\302\261", "\302\262", "\302\263", "\302\264", "\302\265",
608 "\302\266", "\302\267", "\302\270", "\302\271", "\302\272", "\302\273",
609 "\302\274", "\302\275", "\302\276", "\302\277", "\303\200", "\303\201",
610 "\303\202", "\303\203", "\303\204", "\303\205", "\303\206", "\303\207",
611 "\303\210", "\303\211", "\303\212", "\303\213", "\303\214", "\303\215",
612 "\303\216", "\303\217", "\303\220", "\303\221", "\303\222", "\303\223",
613 "\303\224", "\303\225", "\303\226", "\303\227", "\303\230", "\303\231",
614 "\303\232", "\303\233", "\303\234", "\303\235", "\303\236", "\303\237",
615 "\303\240", "\303\241", "\303\242", "\303\243", "\303\244", "\303\245",
616 "\303\246", "\303\247", "\303\250", "\303\251", "\303\252", "\303\253",
617 "\303\254", "\303\255", "\303\256", "\303\257", "\303\260", "\303\261",
618 "\303\262", "\303\263", "\303\264", "\303\265", "\303\266", "\303\267",
619 "\303\270", "\303\271", "\303\272", "\303\273", "\303\274", "\303\275",
620 "\303\276", "\303\277" );
622 sub charset_convert ($$$) {
623 my($s, $charset_in, $charset_out) = @_;
624 if ($s !~ /[\200-\377]/s) { # FIXME: don't worry about iso2022 for now
626 } elsif ($charset_in eq 'ISO-8859-1' && $charset_out eq 'UTF-8') {
627 $s =~ s/[\200-\377]/ $latin1_utf8[ord($&) - 128] /egs;
628 } elsif ($charset_in ne $charset_out) {
629 VerboseWarnings::warn_normal "conversion from $charset_in to $charset_out is not supported\n", undef;
634 ###############################################################################
638 In addition to the basic scanning, this class will also perform
645 Emulation of c-format strings (see below)
649 Display of warnings for certain things that affects either the
650 ability of this class to yield correct output, or things that
651 are known to cause the original template to cause trouble.
655 Automatic correction of some of the things warned about
656 (e.g., SGML "closed start tag" notation).
660 =head2 c-format strings emulation
662 Because English word order is not universal, a simple extraction
663 of translatable strings may yield some strings like "Accounts for"
664 or ambiguous strings like "in". This makes the resulting strings
665 difficult to translate, but does not affect all languages alike.
666 For example, Chinese (with a somewhat different word order) would
667 be hit harder, but French would be relatively unaffected.
669 To overcome this problem, the scanner can be configured to detect
670 patterns with <TMPL_VAR> directives (as well as certain HTML tags),
671 and try to construct a larger pattern that will appear in the PO
672 file as c-format strings with %s placeholders. This additional
673 step allows the translator to deal with cases where word order
674 is different (replacing %s with %1$s, %2$s, etc.), or when certain
675 words will require certain inflectional suffixes in sentences.
677 Because this is an incompatible change, this mode must be explicitly
678 turned on using the set_cformat(1) method call.
682 This tokenizer is mostly based
683 on Ambrose's hideous Perl script known as subst.pl.