| 1 | # EXTRACT VARIOUSLY DELIMITED TEXT SEQUENCES FROM STRINGS.
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| 2 | # FOR FULL DOCUMENTATION SEE Balanced.pod
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| 3 |
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| 4 | use 5.005;
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| 5 | use strict;
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| 6 |
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| 7 | package Text::Balanced;
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| 8 |
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| 9 | use Exporter;
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| 10 | use SelfLoader;
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| 11 | use vars qw { $VERSION @ISA %EXPORT_TAGS };
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| 12 |
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| 13 | $VERSION = '1.95';
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| 14 | @ISA = qw ( Exporter );
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| 15 |
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| 16 | %EXPORT_TAGS = ( ALL => [ qw(
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| 17 | &extract_delimited
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| 18 | &extract_bracketed
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| 19 | &extract_quotelike
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| 20 | &extract_codeblock
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| 21 | &extract_variable
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| 22 | &extract_tagged
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| 23 | &extract_multiple
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| 24 |
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| 25 | &gen_delimited_pat
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| 26 | &gen_extract_tagged
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| 27 |
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| 28 | &delimited_pat
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| 29 | ) ] );
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| 30 |
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| 31 | Exporter::export_ok_tags('ALL');
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| 32 |
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| 33 | # PROTOTYPES
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| 34 |
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| 35 | sub _match_bracketed($$$$$$);
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| 36 | sub _match_variable($$);
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| 37 | sub _match_codeblock($$$$$$$);
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| 38 | sub _match_quotelike($$$$);
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| 39 |
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| 40 | # HANDLE RETURN VALUES IN VARIOUS CONTEXTS
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| 41 |
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| 42 | sub _failmsg {
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| 43 | my ($message, $pos) = @_;
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| 44 | $@ = bless { error=>$message, pos=>$pos }, "Text::Balanced::ErrorMsg";
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| 45 | }
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| 46 |
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| 47 | sub _fail
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| 48 | {
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| 49 | my ($wantarray, $textref, $message, $pos) = @_;
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| 50 | _failmsg $message, $pos if $message;
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| 51 | return ("",$$textref,"") if $wantarray;
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| 52 | return undef;
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| 53 | }
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| 54 |
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| 55 | sub _succeed
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| 56 | {
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| 57 | $@ = undef;
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| 58 | my ($wantarray,$textref) = splice @_, 0, 2;
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| 59 | my ($extrapos, $extralen) = @_>18 ? splice(@_, -2, 2) : (0,0);
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| 60 | my ($startlen) = $_[5];
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| 61 | my $remainderpos = $_[2];
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| 62 | if ($wantarray)
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| 63 | {
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| 64 | my @res;
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| 65 | while (my ($from, $len) = splice @_, 0, 2)
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| 66 | {
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| 67 | push @res, substr($$textref,$from,$len);
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| 68 | }
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| 69 | if ($extralen) { # CORRECT FILLET
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| 70 | my $extra = substr($res[0], $extrapos-$startlen, $extralen, "\n");
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| 71 | $res[1] = "$extra$res[1]";
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| 72 | eval { substr($$textref,$remainderpos,0) = $extra;
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| 73 | substr($$textref,$extrapos,$extralen,"\n")} ;
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| 74 | #REARRANGE HERE DOC AND FILLET IF POSSIBLE
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| 75 | pos($$textref) = $remainderpos-$extralen+1; # RESET \G
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| 76 | }
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| 77 | else {
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| 78 | pos($$textref) = $remainderpos; # RESET \G
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| 79 | }
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| 80 | return @res;
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| 81 | }
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| 82 | else
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| 83 | {
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| 84 | my $match = substr($$textref,$_[0],$_[1]);
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| 85 | substr($match,$extrapos-$_[0]-$startlen,$extralen,"") if $extralen;
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| 86 | my $extra = $extralen
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| 87 | ? substr($$textref, $extrapos, $extralen)."\n" : "";
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| 88 | eval {substr($$textref,$_[4],$_[1]+$_[5])=$extra} ; #CHOP OUT PREFIX & MATCH, IF POSSIBLE
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| 89 | pos($$textref) = $_[4]; # RESET \G
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| 90 | return $match;
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| 91 | }
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| 92 | }
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| 93 |
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| 94 | # BUILD A PATTERN MATCHING A SIMPLE DELIMITED STRING
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| 95 |
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| 96 | sub gen_delimited_pat($;$) # ($delimiters;$escapes)
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| 97 | {
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| 98 | my ($dels, $escs) = @_;
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| 99 | return "" unless $dels =~ /\S/;
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| 100 | $escs = '\\' unless $escs;
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| 101 | $escs .= substr($escs,-1) x (length($dels)-length($escs));
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| 102 | my @pat = ();
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| 103 | my $i;
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| 104 | for ($i=0; $i<length $dels; $i++)
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| 105 | {
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| 106 | my $del = quotemeta substr($dels,$i,1);
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| 107 | my $esc = quotemeta substr($escs,$i,1);
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| 108 | if ($del eq $esc)
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| 109 | {
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| 110 | push @pat, "$del(?:[^$del]*(?:(?:$del$del)[^$del]*)*)$del";
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| 111 | }
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| 112 | else
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| 113 | {
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| 114 | push @pat, "$del(?:[^$esc$del]*(?:$esc.[^$esc$del]*)*)$del";
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| 115 | }
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| 116 | }
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| 117 | my $pat = join '|', @pat;
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| 118 | return "(?:$pat)";
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| 119 | }
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| 120 |
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| 121 | *delimited_pat = \&gen_delimited_pat;
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| 122 |
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| 123 |
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| 124 | # THE EXTRACTION FUNCTIONS
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| 125 |
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| 126 | sub extract_delimited (;$$$$)
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| 127 | {
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| 128 | my $textref = defined $_[0] ? \$_[0] : \$_;
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| 129 | my $wantarray = wantarray;
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| 130 | my $del = defined $_[1] ? $_[1] : qq{\'\"\`};
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| 131 | my $pre = defined $_[2] ? $_[2] : '\s*';
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| 132 | my $esc = defined $_[3] ? $_[3] : qq{\\};
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| 133 | my $pat = gen_delimited_pat($del, $esc);
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| 134 | my $startpos = pos $$textref || 0;
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| 135 | return _fail($wantarray, $textref, "Not a delimited pattern", 0)
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| 136 | unless $$textref =~ m/\G($pre)($pat)/gc;
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| 137 | my $prelen = length($1);
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| 138 | my $matchpos = $startpos+$prelen;
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| 139 | my $endpos = pos $$textref;
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| 140 | return _succeed $wantarray, $textref,
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| 141 | $matchpos, $endpos-$matchpos, # MATCH
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| 142 | $endpos, length($$textref)-$endpos, # REMAINDER
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| 143 | $startpos, $prelen; # PREFIX
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| 144 | }
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| 145 |
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| 146 | sub extract_bracketed (;$$$)
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| 147 | {
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| 148 | my $textref = defined $_[0] ? \$_[0] : \$_;
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| 149 | my $ldel = defined $_[1] ? $_[1] : '{([<';
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| 150 | my $pre = defined $_[2] ? $_[2] : '\s*';
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| 151 | my $wantarray = wantarray;
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| 152 | my $qdel = "";
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| 153 | my $quotelike;
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| 154 | $ldel =~ s/'//g and $qdel .= q{'};
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| 155 | $ldel =~ s/"//g and $qdel .= q{"};
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| 156 | $ldel =~ s/`//g and $qdel .= q{`};
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| 157 | $ldel =~ s/q//g and $quotelike = 1;
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| 158 | $ldel =~ tr/[](){}<>\0-\377/[[(({{<</ds;
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| 159 | my $rdel = $ldel;
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| 160 | unless ($rdel =~ tr/[({</])}>/)
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| 161 | {
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| 162 | return _fail $wantarray, $textref,
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| 163 | "Did not find a suitable bracket in delimiter: \"$_[1]\"",
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| 164 | 0;
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| 165 | }
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| 166 | my $posbug = pos;
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| 167 | $ldel = join('|', map { quotemeta $_ } split('', $ldel));
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| 168 | $rdel = join('|', map { quotemeta $_ } split('', $rdel));
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| 169 | pos = $posbug;
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| 170 |
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| 171 | my $startpos = pos $$textref || 0;
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| 172 | my @match = _match_bracketed($textref,$pre, $ldel, $qdel, $quotelike, $rdel);
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| 173 |
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| 174 | return _fail ($wantarray, $textref) unless @match;
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| 175 |
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| 176 | return _succeed ( $wantarray, $textref,
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| 177 | $match[2], $match[5]+2, # MATCH
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| 178 | @match[8,9], # REMAINDER
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| 179 | @match[0,1], # PREFIX
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| 180 | );
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| 181 | }
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| 182 |
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| 183 | sub _match_bracketed($$$$$$) # $textref, $pre, $ldel, $qdel, $quotelike, $rdel
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| 184 | {
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| 185 | my ($textref, $pre, $ldel, $qdel, $quotelike, $rdel) = @_;
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| 186 | my ($startpos, $ldelpos, $endpos) = (pos $$textref = pos $$textref||0);
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| 187 | unless ($$textref =~ m/\G$pre/gc)
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| 188 | {
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| 189 | _failmsg "Did not find prefix: /$pre/", $startpos;
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| 190 | return;
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| 191 | }
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| 192 |
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| 193 | $ldelpos = pos $$textref;
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| 194 |
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| 195 | unless ($$textref =~ m/\G($ldel)/gc)
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| 196 | {
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| 197 | _failmsg "Did not find opening bracket after prefix: \"$pre\"",
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| 198 | pos $$textref;
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| 199 | pos $$textref = $startpos;
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| 200 | return;
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| 201 | }
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| 202 |
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| 203 | my @nesting = ( $1 );
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| 204 | my $textlen = length $$textref;
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| 205 | while (pos $$textref < $textlen)
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| 206 | {
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| 207 | next if $$textref =~ m/\G\\./gcs;
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| 208 |
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| 209 | if ($$textref =~ m/\G($ldel)/gc)
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| 210 | {
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| 211 | push @nesting, $1;
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| 212 | }
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| 213 | elsif ($$textref =~ m/\G($rdel)/gc)
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| 214 | {
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| 215 | my ($found, $brackettype) = ($1, $1);
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| 216 | if ($#nesting < 0)
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| 217 | {
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| 218 | _failmsg "Unmatched closing bracket: \"$found\"",
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| 219 | pos $$textref;
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| 220 | pos $$textref = $startpos;
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| 221 | return;
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| 222 | }
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| 223 | my $expected = pop(@nesting);
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| 224 | $expected =~ tr/({[</)}]>/;
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| 225 | if ($expected ne $brackettype)
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| 226 | {
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| 227 | _failmsg qq{Mismatched closing bracket: expected "$expected" but found "$found"},
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| 228 | pos $$textref;
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| 229 | pos $$textref = $startpos;
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| 230 | return;
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| 231 | }
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| 232 | last if $#nesting < 0;
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| 233 | }
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| 234 | elsif ($qdel && $$textref =~ m/\G([$qdel])/gc)
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| 235 | {
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| 236 | $$textref =~ m/\G[^\\$1]*(?:\\.[^\\$1]*)*(\Q$1\E)/gsc and next;
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| 237 | _failmsg "Unmatched embedded quote ($1)",
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| 238 | pos $$textref;
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| 239 | pos $$textref = $startpos;
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| 240 | return;
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| 241 | }
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| 242 | elsif ($quotelike && _match_quotelike($textref,"",1,0))
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| 243 | {
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| 244 | next;
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| 245 | }
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| 246 |
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| 247 | else { $$textref =~ m/\G(?:[a-zA-Z0-9]+|.)/gcs }
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| 248 | }
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| 249 | if ($#nesting>=0)
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| 250 | {
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| 251 | _failmsg "Unmatched opening bracket(s): "
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| 252 | . join("..",@nesting)."..",
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| 253 | pos $$textref;
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| 254 | pos $$textref = $startpos;
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| 255 | return;
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| 256 | }
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| 257 |
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| 258 | $endpos = pos $$textref;
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| 259 |
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| 260 | return (
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| 261 | $startpos, $ldelpos-$startpos, # PREFIX
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| 262 | $ldelpos, 1, # OPENING BRACKET
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| 263 | $ldelpos+1, $endpos-$ldelpos-2, # CONTENTS
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| 264 | $endpos-1, 1, # CLOSING BRACKET
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| 265 | $endpos, length($$textref)-$endpos, # REMAINDER
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| 266 | );
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| 267 | }
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| 268 |
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| 269 | sub revbracket($)
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| 270 | {
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| 271 | my $brack = reverse $_[0];
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| 272 | $brack =~ tr/[({</])}>/;
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| 273 | return $brack;
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| 274 | }
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| 275 |
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| 276 | my $XMLNAME = q{[a-zA-Z_:][a-zA-Z0-9_:.-]*};
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| 277 |
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| 278 | sub extract_tagged (;$$$$$) # ($text, $opentag, $closetag, $pre, \%options)
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| 279 | {
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| 280 | my $textref = defined $_[0] ? \$_[0] : \$_;
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| 281 | my $ldel = $_[1];
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| 282 | my $rdel = $_[2];
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| 283 | my $pre = defined $_[3] ? $_[3] : '\s*';
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| 284 | my %options = defined $_[4] ? %{$_[4]} : ();
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| 285 | my $omode = defined $options{fail} ? $options{fail} : '';
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| 286 | my $bad = ref($options{reject}) eq 'ARRAY' ? join('|', @{$options{reject}})
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| 287 | : defined($options{reject}) ? $options{reject}
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| 288 | : ''
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| 289 | ;
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| 290 | my $ignore = ref($options{ignore}) eq 'ARRAY' ? join('|', @{$options{ignore}})
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| 291 | : defined($options{ignore}) ? $options{ignore}
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| 292 | : ''
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| 293 | ;
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| 294 |
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| 295 | if (!defined $ldel) { $ldel = '<\w+(?:' . gen_delimited_pat(q{'"}) . '|[^>])*>'; }
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| 296 | $@ = undef;
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| 297 |
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| 298 | my @match = _match_tagged($textref, $pre, $ldel, $rdel, $omode, $bad, $ignore);
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| 299 |
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| 300 | return _fail(wantarray, $textref) unless @match;
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| 301 | return _succeed wantarray, $textref,
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| 302 | $match[2], $match[3]+$match[5]+$match[7], # MATCH
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| 303 | @match[8..9,0..1,2..7]; # REM, PRE, BITS
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| 304 | }
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| 305 |
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| 306 | sub _match_tagged # ($$$$$$$)
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| 307 | {
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| 308 | my ($textref, $pre, $ldel, $rdel, $omode, $bad, $ignore) = @_;
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| 309 | my $rdelspec;
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| 310 |
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| 311 | my ($startpos, $opentagpos, $textpos, $parapos, $closetagpos, $endpos) = ( pos($$textref) = pos($$textref)||0 );
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| 312 |
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| 313 | unless ($$textref =~ m/\G($pre)/gc)
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| 314 | {
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| 315 | _failmsg "Did not find prefix: /$pre/", pos $$textref;
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| 316 | goto failed;
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| 317 | }
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| 318 |
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| 319 | $opentagpos = pos($$textref);
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| 320 |
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| 321 | unless ($$textref =~ m/\G$ldel/gc)
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| 322 | {
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| 323 | _failmsg "Did not find opening tag: /$ldel/", pos $$textref;
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| 324 | goto failed;
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| 325 | }
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| 326 |
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| 327 | $textpos = pos($$textref);
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| 328 |
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| 329 | if (!defined $rdel)
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| 330 | {
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| 331 | $rdelspec = $&;
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| 332 | unless ($rdelspec =~ s/\A([[(<{]+)($XMLNAME).*/ quotemeta "$1\/$2". revbracket($1) /oes)
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| 333 | {
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| 334 | _failmsg "Unable to construct closing tag to match: $rdel",
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| 335 | pos $$textref;
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| 336 | goto failed;
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| 337 | }
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| 338 | }
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| 339 | else
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| 340 | {
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| 341 | $rdelspec = eval "qq{$rdel}" || do {
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| 342 | my $del;
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| 343 | for (qw,~ ! ^ & * ) _ + - = } ] : " ; ' > . ? / | ',)
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| 344 | { next if $rdel =~ /\Q$_/; $del = $_; last }
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| 345 | unless ($del) {
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| 346 | use Carp;
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| 347 | croak "Can't interpolate right delimiter $rdel"
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| 348 | }
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| 349 | eval "qq$del$rdel$del";
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| 350 | };
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| 351 | }
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| 352 |
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| 353 | while (pos($$textref) < length($$textref))
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| 354 | {
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| 355 | next if $$textref =~ m/\G\\./gc;
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| 356 |
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| 357 | if ($$textref =~ m/\G(\n[ \t]*\n)/gc )
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| 358 | {
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| 359 | $parapos = pos($$textref) - length($1)
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| 360 | unless defined $parapos;
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| 361 | }
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| 362 | elsif ($$textref =~ m/\G($rdelspec)/gc )
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| 363 | {
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| 364 | $closetagpos = pos($$textref)-length($1);
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| 365 | goto matched;
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| 366 | }
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| 367 | elsif ($ignore && $$textref =~ m/\G(?:$ignore)/gc)
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| 368 | {
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| 369 | next;
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| 370 | }
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| 371 | elsif ($bad && $$textref =~ m/\G($bad)/gcs)
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| 372 | {
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| 373 | pos($$textref) -= length($1); # CUT OFF WHATEVER CAUSED THE SHORTNESS
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| 374 | goto short if ($omode eq 'PARA' || $omode eq 'MAX');
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| 375 | _failmsg "Found invalid nested tag: $1", pos $$textref;
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| 376 | goto failed;
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| 377 | }
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| 378 | elsif ($$textref =~ m/\G($ldel)/gc)
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| 379 | {
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| 380 | my $tag = $1;
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| 381 | pos($$textref) -= length($tag); # REWIND TO NESTED TAG
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| 382 | unless (_match_tagged(@_)) # MATCH NESTED TAG
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| 383 | {
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| 384 | goto short if $omode eq 'PARA' || $omode eq 'MAX';
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| 385 | _failmsg "Found unbalanced nested tag: $tag",
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| 386 | pos $$textref;
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| 387 | goto failed;
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| 388 | }
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| 389 | }
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| 390 | else { $$textref =~ m/./gcs }
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| 391 | }
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| 392 |
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| 393 | short:
|
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| 394 | $closetagpos = pos($$textref);
|
|---|
| 395 | goto matched if $omode eq 'MAX';
|
|---|
| 396 | goto failed unless $omode eq 'PARA';
|
|---|
| 397 |
|
|---|
| 398 | if (defined $parapos) { pos($$textref) = $parapos }
|
|---|
| 399 | else { $parapos = pos($$textref) }
|
|---|
| 400 |
|
|---|
| 401 | return (
|
|---|
| 402 | $startpos, $opentagpos-$startpos, # PREFIX
|
|---|
| 403 | $opentagpos, $textpos-$opentagpos, # OPENING TAG
|
|---|
| 404 | $textpos, $parapos-$textpos, # TEXT
|
|---|
| 405 | $parapos, 0, # NO CLOSING TAG
|
|---|
| 406 | $parapos, length($$textref)-$parapos, # REMAINDER
|
|---|
| 407 | );
|
|---|
| 408 |
|
|---|
| 409 | matched:
|
|---|
| 410 | $endpos = pos($$textref);
|
|---|
| 411 | return (
|
|---|
| 412 | $startpos, $opentagpos-$startpos, # PREFIX
|
|---|
| 413 | $opentagpos, $textpos-$opentagpos, # OPENING TAG
|
|---|
| 414 | $textpos, $closetagpos-$textpos, # TEXT
|
|---|
| 415 | $closetagpos, $endpos-$closetagpos, # CLOSING TAG
|
|---|
| 416 | $endpos, length($$textref)-$endpos, # REMAINDER
|
|---|
| 417 | );
|
|---|
| 418 |
|
|---|
| 419 | failed:
|
|---|
| 420 | _failmsg "Did not find closing tag", pos $$textref unless $@;
|
|---|
| 421 | pos($$textref) = $startpos;
|
|---|
| 422 | return;
|
|---|
| 423 | }
|
|---|
| 424 |
|
|---|
| 425 | sub extract_variable (;$$)
|
|---|
| 426 | {
|
|---|
| 427 | my $textref = defined $_[0] ? \$_[0] : \$_;
|
|---|
| 428 | return ("","","") unless defined $$textref;
|
|---|
| 429 | my $pre = defined $_[1] ? $_[1] : '\s*';
|
|---|
| 430 |
|
|---|
| 431 | my @match = _match_variable($textref,$pre);
|
|---|
| 432 |
|
|---|
| 433 | return _fail wantarray, $textref unless @match;
|
|---|
| 434 |
|
|---|
| 435 | return _succeed wantarray, $textref,
|
|---|
| 436 | @match[2..3,4..5,0..1]; # MATCH, REMAINDER, PREFIX
|
|---|
| 437 | }
|
|---|
| 438 |
|
|---|
| 439 | sub _match_variable($$)
|
|---|
| 440 | {
|
|---|
| 441 | # $#
|
|---|
| 442 | # $^
|
|---|
| 443 | # $$
|
|---|
| 444 | my ($textref, $pre) = @_;
|
|---|
| 445 | my $startpos = pos($$textref) = pos($$textref)||0;
|
|---|
| 446 | unless ($$textref =~ m/\G($pre)/gc)
|
|---|
| 447 | {
|
|---|
| 448 | _failmsg "Did not find prefix: /$pre/", pos $$textref;
|
|---|
| 449 | return;
|
|---|
| 450 | }
|
|---|
| 451 | my $varpos = pos($$textref);
|
|---|
| 452 | unless ($$textref =~ m{\G\$\s*(?!::)(\d+|[][&`'+*./|,";%=~:?!\@<>()-]|\^[a-z]?)}gci)
|
|---|
| 453 | {
|
|---|
| 454 | unless ($$textref =~ m/\G((\$#?|[*\@\%]|\\&)+)/gc)
|
|---|
| 455 | {
|
|---|
| 456 | _failmsg "Did not find leading dereferencer", pos $$textref;
|
|---|
| 457 | pos $$textref = $startpos;
|
|---|
| 458 | return;
|
|---|
| 459 | }
|
|---|
| 460 | my $deref = $1;
|
|---|
| 461 |
|
|---|
| 462 | unless ($$textref =~ m/\G\s*(?:::|')?(?:[_a-z]\w*(?:::|'))*[_a-z]\w*/gci
|
|---|
| 463 | or _match_codeblock($textref, "", '\{', '\}', '\{', '\}', 0)
|
|---|
| 464 | or $deref eq '$#' or $deref eq '$$' )
|
|---|
| 465 | {
|
|---|
| 466 | _failmsg "Bad identifier after dereferencer", pos $$textref;
|
|---|
| 467 | pos $$textref = $startpos;
|
|---|
| 468 | return;
|
|---|
| 469 | }
|
|---|
| 470 | }
|
|---|
| 471 |
|
|---|
| 472 | while (1)
|
|---|
| 473 | {
|
|---|
| 474 | next if $$textref =~ m/\G\s*(?:->)?\s*[{]\w+[}]/gc;
|
|---|
| 475 | next if _match_codeblock($textref,
|
|---|
| 476 | qr/\s*->\s*(?:[_a-zA-Z]\w+\s*)?/,
|
|---|
| 477 | qr/[({[]/, qr/[)}\]]/,
|
|---|
| 478 | qr/[({[]/, qr/[)}\]]/, 0);
|
|---|
| 479 | next if _match_codeblock($textref,
|
|---|
| 480 | qr/\s*/, qr/[{[]/, qr/[}\]]/,
|
|---|
| 481 | qr/[{[]/, qr/[}\]]/, 0);
|
|---|
| 482 | next if _match_variable($textref,'\s*->\s*');
|
|---|
| 483 | next if $$textref =~ m/\G\s*->\s*\w+(?![{([])/gc;
|
|---|
| 484 | last;
|
|---|
| 485 | }
|
|---|
| 486 |
|
|---|
| 487 | my $endpos = pos($$textref);
|
|---|
| 488 | return ($startpos, $varpos-$startpos,
|
|---|
| 489 | $varpos, $endpos-$varpos,
|
|---|
| 490 | $endpos, length($$textref)-$endpos
|
|---|
| 491 | );
|
|---|
| 492 | }
|
|---|
| 493 |
|
|---|
| 494 | sub extract_codeblock (;$$$$$)
|
|---|
| 495 | {
|
|---|
| 496 | my $textref = defined $_[0] ? \$_[0] : \$_;
|
|---|
| 497 | my $wantarray = wantarray;
|
|---|
| 498 | my $ldel_inner = defined $_[1] ? $_[1] : '{';
|
|---|
| 499 | my $pre = defined $_[2] ? $_[2] : '\s*';
|
|---|
| 500 | my $ldel_outer = defined $_[3] ? $_[3] : $ldel_inner;
|
|---|
| 501 | my $rd = $_[4];
|
|---|
| 502 | my $rdel_inner = $ldel_inner;
|
|---|
| 503 | my $rdel_outer = $ldel_outer;
|
|---|
| 504 | my $posbug = pos;
|
|---|
| 505 | for ($ldel_inner, $ldel_outer) { tr/[]()<>{}\0-\377/[[((<<{{/ds }
|
|---|
| 506 | for ($rdel_inner, $rdel_outer) { tr/[]()<>{}\0-\377/]]))>>}}/ds }
|
|---|
| 507 | for ($ldel_inner, $ldel_outer, $rdel_inner, $rdel_outer)
|
|---|
| 508 | {
|
|---|
| 509 | $_ = '('.join('|',map { quotemeta $_ } split('',$_)).')'
|
|---|
| 510 | }
|
|---|
| 511 | pos = $posbug;
|
|---|
| 512 |
|
|---|
| 513 | my @match = _match_codeblock($textref, $pre,
|
|---|
| 514 | $ldel_outer, $rdel_outer,
|
|---|
| 515 | $ldel_inner, $rdel_inner,
|
|---|
| 516 | $rd);
|
|---|
| 517 | return _fail($wantarray, $textref) unless @match;
|
|---|
| 518 | return _succeed($wantarray, $textref,
|
|---|
| 519 | @match[2..3,4..5,0..1] # MATCH, REMAINDER, PREFIX
|
|---|
| 520 | );
|
|---|
| 521 |
|
|---|
| 522 | }
|
|---|
| 523 |
|
|---|
| 524 | sub _match_codeblock($$$$$$$)
|
|---|
| 525 | {
|
|---|
| 526 | my ($textref, $pre, $ldel_outer, $rdel_outer, $ldel_inner, $rdel_inner, $rd) = @_;
|
|---|
| 527 | my $startpos = pos($$textref) = pos($$textref) || 0;
|
|---|
| 528 | unless ($$textref =~ m/\G($pre)/gc)
|
|---|
| 529 | {
|
|---|
| 530 | _failmsg qq{Did not match prefix /$pre/ at"} .
|
|---|
| 531 | substr($$textref,pos($$textref),20) .
|
|---|
| 532 | q{..."},
|
|---|
| 533 | pos $$textref;
|
|---|
| 534 | return;
|
|---|
| 535 | }
|
|---|
| 536 | my $codepos = pos($$textref);
|
|---|
| 537 | unless ($$textref =~ m/\G($ldel_outer)/gc) # OUTERMOST DELIMITER
|
|---|
| 538 | {
|
|---|
| 539 | _failmsg qq{Did not find expected opening bracket at "} .
|
|---|
| 540 | substr($$textref,pos($$textref),20) .
|
|---|
| 541 | q{..."},
|
|---|
| 542 | pos $$textref;
|
|---|
| 543 | pos $$textref = $startpos;
|
|---|
| 544 | return;
|
|---|
| 545 | }
|
|---|
| 546 | my $closing = $1;
|
|---|
| 547 | $closing =~ tr/([<{/)]>}/;
|
|---|
| 548 | my $matched;
|
|---|
| 549 | my $patvalid = 1;
|
|---|
| 550 | while (pos($$textref) < length($$textref))
|
|---|
| 551 | {
|
|---|
| 552 | $matched = '';
|
|---|
| 553 | if ($rd && $$textref =~ m#\G(\Q(?)\E|\Q(s?)\E|\Q(s)\E)#gc)
|
|---|
| 554 | {
|
|---|
| 555 | $patvalid = 0;
|
|---|
| 556 | next;
|
|---|
| 557 | }
|
|---|
| 558 |
|
|---|
| 559 | if ($$textref =~ m/\G\s*#.*/gc)
|
|---|
| 560 | {
|
|---|
| 561 | next;
|
|---|
| 562 | }
|
|---|
| 563 |
|
|---|
| 564 | if ($$textref =~ m/\G\s*($rdel_outer)/gc)
|
|---|
| 565 | {
|
|---|
| 566 | unless ($matched = ($closing && $1 eq $closing) )
|
|---|
| 567 | {
|
|---|
| 568 | next if $1 eq '>'; # MIGHT BE A "LESS THAN"
|
|---|
| 569 | _failmsg q{Mismatched closing bracket at "} .
|
|---|
| 570 | substr($$textref,pos($$textref),20) .
|
|---|
| 571 | qq{...". Expected '$closing'},
|
|---|
| 572 | pos $$textref;
|
|---|
| 573 | }
|
|---|
| 574 | last;
|
|---|
| 575 | }
|
|---|
| 576 |
|
|---|
| 577 | if (_match_variable($textref,'\s*') ||
|
|---|
| 578 | _match_quotelike($textref,'\s*',$patvalid,$patvalid) )
|
|---|
| 579 | {
|
|---|
| 580 | $patvalid = 0;
|
|---|
| 581 | next;
|
|---|
| 582 | }
|
|---|
| 583 |
|
|---|
| 584 |
|
|---|
| 585 | # NEED TO COVER MANY MORE CASES HERE!!!
|
|---|
| 586 | if ($$textref =~ m#\G\s*(?!$ldel_inner)
|
|---|
| 587 | ( [-+*x/%^&|.]=?
|
|---|
| 588 | | [!=]~
|
|---|
| 589 | | =(?!>)
|
|---|
| 590 | | (\*\*|&&|\|\||<<|>>)=?
|
|---|
| 591 | | split|grep|map|return
|
|---|
| 592 | | [([]
|
|---|
| 593 | )#gcx)
|
|---|
| 594 | {
|
|---|
| 595 | $patvalid = 1;
|
|---|
| 596 | next;
|
|---|
| 597 | }
|
|---|
| 598 |
|
|---|
| 599 | if ( _match_codeblock($textref, '\s*', $ldel_inner, $rdel_inner, $ldel_inner, $rdel_inner, $rd) )
|
|---|
| 600 | {
|
|---|
| 601 | $patvalid = 1;
|
|---|
| 602 | next;
|
|---|
| 603 | }
|
|---|
| 604 |
|
|---|
| 605 | if ($$textref =~ m/\G\s*$ldel_outer/gc)
|
|---|
| 606 | {
|
|---|
| 607 | _failmsg q{Improperly nested codeblock at "} .
|
|---|
| 608 | substr($$textref,pos($$textref),20) .
|
|---|
| 609 | q{..."},
|
|---|
| 610 | pos $$textref;
|
|---|
| 611 | last;
|
|---|
| 612 | }
|
|---|
| 613 |
|
|---|
| 614 | $patvalid = 0;
|
|---|
| 615 | $$textref =~ m/\G\s*(\w+|[-=>]>|.|\Z)/gc;
|
|---|
| 616 | }
|
|---|
| 617 | continue { $@ = undef }
|
|---|
| 618 |
|
|---|
| 619 | unless ($matched)
|
|---|
| 620 | {
|
|---|
| 621 | _failmsg 'No match found for opening bracket', pos $$textref
|
|---|
| 622 | unless $@;
|
|---|
| 623 | return;
|
|---|
| 624 | }
|
|---|
| 625 |
|
|---|
| 626 | my $endpos = pos($$textref);
|
|---|
| 627 | return ( $startpos, $codepos-$startpos,
|
|---|
| 628 | $codepos, $endpos-$codepos,
|
|---|
| 629 | $endpos, length($$textref)-$endpos,
|
|---|
| 630 | );
|
|---|
| 631 | }
|
|---|
| 632 |
|
|---|
| 633 |
|
|---|
| 634 | my %mods = (
|
|---|
| 635 | 'none' => '[cgimsox]*',
|
|---|
| 636 | 'm' => '[cgimsox]*',
|
|---|
| 637 | 's' => '[cegimsox]*',
|
|---|
| 638 | 'tr' => '[cds]*',
|
|---|
| 639 | 'y' => '[cds]*',
|
|---|
| 640 | 'qq' => '',
|
|---|
| 641 | 'qx' => '',
|
|---|
| 642 | 'qw' => '',
|
|---|
| 643 | 'qr' => '[imsx]*',
|
|---|
| 644 | 'q' => '',
|
|---|
| 645 | );
|
|---|
| 646 |
|
|---|
| 647 | sub extract_quotelike (;$$)
|
|---|
| 648 | {
|
|---|
| 649 | my $textref = $_[0] ? \$_[0] : \$_;
|
|---|
| 650 | my $wantarray = wantarray;
|
|---|
| 651 | my $pre = defined $_[1] ? $_[1] : '\s*';
|
|---|
| 652 |
|
|---|
| 653 | my @match = _match_quotelike($textref,$pre,1,0);
|
|---|
| 654 | return _fail($wantarray, $textref) unless @match;
|
|---|
| 655 | return _succeed($wantarray, $textref,
|
|---|
| 656 | $match[2], $match[18]-$match[2], # MATCH
|
|---|
| 657 | @match[18,19], # REMAINDER
|
|---|
| 658 | @match[0,1], # PREFIX
|
|---|
| 659 | @match[2..17], # THE BITS
|
|---|
| 660 | @match[20,21], # ANY FILLET?
|
|---|
| 661 | );
|
|---|
| 662 | };
|
|---|
| 663 |
|
|---|
| 664 | sub _match_quotelike($$$$) # ($textref, $prepat, $allow_raw_match)
|
|---|
| 665 | {
|
|---|
| 666 | my ($textref, $pre, $rawmatch, $qmark) = @_;
|
|---|
| 667 |
|
|---|
| 668 | my ($textlen,$startpos,
|
|---|
| 669 | $oppos,
|
|---|
| 670 | $preld1pos,$ld1pos,$str1pos,$rd1pos,
|
|---|
| 671 | $preld2pos,$ld2pos,$str2pos,$rd2pos,
|
|---|
| 672 | $modpos) = ( length($$textref), pos($$textref) = pos($$textref) || 0 );
|
|---|
| 673 |
|
|---|
| 674 | unless ($$textref =~ m/\G($pre)/gc)
|
|---|
| 675 | {
|
|---|
| 676 | _failmsg qq{Did not find prefix /$pre/ at "} .
|
|---|
| 677 | substr($$textref, pos($$textref), 20) .
|
|---|
| 678 | q{..."},
|
|---|
| 679 | pos $$textref;
|
|---|
| 680 | return;
|
|---|
| 681 | }
|
|---|
| 682 | $oppos = pos($$textref);
|
|---|
| 683 |
|
|---|
| 684 | my $initial = substr($$textref,$oppos,1);
|
|---|
| 685 |
|
|---|
| 686 | if ($initial && $initial =~ m|^[\"\'\`]|
|
|---|
| 687 | || $rawmatch && $initial =~ m|^/|
|
|---|
| 688 | || $qmark && $initial =~ m|^\?|)
|
|---|
| 689 | {
|
|---|
| 690 | unless ($$textref =~ m/ \Q$initial\E [^\\$initial]* (\\.[^\\$initial]*)* \Q$initial\E /gcsx)
|
|---|
| 691 | {
|
|---|
| 692 | _failmsg qq{Did not find closing delimiter to match '$initial' at "} .
|
|---|
| 693 | substr($$textref, $oppos, 20) .
|
|---|
| 694 | q{..."},
|
|---|
| 695 | pos $$textref;
|
|---|
| 696 | pos $$textref = $startpos;
|
|---|
| 697 | return;
|
|---|
| 698 | }
|
|---|
| 699 | $modpos= pos($$textref);
|
|---|
| 700 | $rd1pos = $modpos-1;
|
|---|
| 701 |
|
|---|
| 702 | if ($initial eq '/' || $initial eq '?')
|
|---|
| 703 | {
|
|---|
| 704 | $$textref =~ m/\G$mods{none}/gc
|
|---|
| 705 | }
|
|---|
| 706 |
|
|---|
| 707 | my $endpos = pos($$textref);
|
|---|
| 708 | return (
|
|---|
| 709 | $startpos, $oppos-$startpos, # PREFIX
|
|---|
| 710 | $oppos, 0, # NO OPERATOR
|
|---|
| 711 | $oppos, 1, # LEFT DEL
|
|---|
| 712 | $oppos+1, $rd1pos-$oppos-1, # STR/PAT
|
|---|
| 713 | $rd1pos, 1, # RIGHT DEL
|
|---|
| 714 | $modpos, 0, # NO 2ND LDEL
|
|---|
| 715 | $modpos, 0, # NO 2ND STR
|
|---|
| 716 | $modpos, 0, # NO 2ND RDEL
|
|---|
| 717 | $modpos, $endpos-$modpos, # MODIFIERS
|
|---|
| 718 | $endpos, $textlen-$endpos, # REMAINDER
|
|---|
| 719 | );
|
|---|
| 720 | }
|
|---|
| 721 |
|
|---|
| 722 | unless ($$textref =~ m{\G(\b(?:m|s|qq|qx|qw|q|qr|tr|y)\b(?=\s*\S)|<<)}gc)
|
|---|
| 723 | {
|
|---|
| 724 | _failmsg q{No quotelike operator found after prefix at "} .
|
|---|
| 725 | substr($$textref, pos($$textref), 20) .
|
|---|
| 726 | q{..."},
|
|---|
| 727 | pos $$textref;
|
|---|
| 728 | pos $$textref = $startpos;
|
|---|
| 729 | return;
|
|---|
| 730 | }
|
|---|
| 731 |
|
|---|
| 732 | my $op = $1;
|
|---|
| 733 | $preld1pos = pos($$textref);
|
|---|
| 734 | if ($op eq '<<') {
|
|---|
| 735 | $ld1pos = pos($$textref);
|
|---|
| 736 | my $label;
|
|---|
| 737 | if ($$textref =~ m{\G([A-Za-z_]\w*)}gc) {
|
|---|
| 738 | $label = $1;
|
|---|
| 739 | }
|
|---|
| 740 | elsif ($$textref =~ m{ \G ' ([^'\\]* (?:\\.[^'\\]*)*) '
|
|---|
| 741 | | \G " ([^"\\]* (?:\\.[^"\\]*)*) "
|
|---|
| 742 | | \G ` ([^`\\]* (?:\\.[^`\\]*)*) `
|
|---|
| 743 | }gcsx) {
|
|---|
| 744 | $label = $+;
|
|---|
| 745 | }
|
|---|
| 746 | else {
|
|---|
| 747 | $label = "";
|
|---|
| 748 | }
|
|---|
| 749 | my $extrapos = pos($$textref);
|
|---|
| 750 | $$textref =~ m{.*\n}gc;
|
|---|
| 751 | $str1pos = pos($$textref);
|
|---|
| 752 | unless ($$textref =~ m{.*?\n(?=$label\n)}gc) {
|
|---|
| 753 | _failmsg qq{Missing here doc terminator ('$label') after "} .
|
|---|
| 754 | substr($$textref, $startpos, 20) .
|
|---|
| 755 | q{..."},
|
|---|
| 756 | pos $$textref;
|
|---|
| 757 | pos $$textref = $startpos;
|
|---|
| 758 | return;
|
|---|
| 759 | }
|
|---|
| 760 | $rd1pos = pos($$textref);
|
|---|
| 761 | $$textref =~ m{$label\n}gc;
|
|---|
| 762 | $ld2pos = pos($$textref);
|
|---|
| 763 | return (
|
|---|
| 764 | $startpos, $oppos-$startpos, # PREFIX
|
|---|
| 765 | $oppos, length($op), # OPERATOR
|
|---|
| 766 | $ld1pos, $extrapos-$ld1pos, # LEFT DEL
|
|---|
| 767 | $str1pos, $rd1pos-$str1pos, # STR/PAT
|
|---|
| 768 | $rd1pos, $ld2pos-$rd1pos, # RIGHT DEL
|
|---|
| 769 | $ld2pos, 0, # NO 2ND LDEL
|
|---|
| 770 | $ld2pos, 0, # NO 2ND STR
|
|---|
| 771 | $ld2pos, 0, # NO 2ND RDEL
|
|---|
| 772 | $ld2pos, 0, # NO MODIFIERS
|
|---|
| 773 | $ld2pos, $textlen-$ld2pos, # REMAINDER
|
|---|
| 774 | $extrapos, $str1pos-$extrapos, # FILLETED BIT
|
|---|
| 775 | );
|
|---|
| 776 | }
|
|---|
| 777 |
|
|---|
| 778 | $$textref =~ m/\G\s*/gc;
|
|---|
| 779 | $ld1pos = pos($$textref);
|
|---|
| 780 | $str1pos = $ld1pos+1;
|
|---|
| 781 |
|
|---|
| 782 | unless ($$textref =~ m/\G(\S)/gc) # SHOULD USE LOOKAHEAD
|
|---|
| 783 | {
|
|---|
| 784 | _failmsg "No block delimiter found after quotelike $op",
|
|---|
| 785 | pos $$textref;
|
|---|
| 786 | pos $$textref = $startpos;
|
|---|
| 787 | return;
|
|---|
| 788 | }
|
|---|
| 789 | pos($$textref) = $ld1pos; # HAVE TO DO THIS BECAUSE LOOKAHEAD BROKEN
|
|---|
| 790 | my ($ldel1, $rdel1) = ("\Q$1","\Q$1");
|
|---|
| 791 | if ($ldel1 =~ /[[(<{]/)
|
|---|
| 792 | {
|
|---|
| 793 | $rdel1 =~ tr/[({</])}>/;
|
|---|
| 794 | _match_bracketed($textref,"",$ldel1,"","",$rdel1)
|
|---|
| 795 | || do { pos $$textref = $startpos; return };
|
|---|
| 796 | }
|
|---|
| 797 | else
|
|---|
| 798 | {
|
|---|
| 799 | $$textref =~ /$ldel1[^\\$ldel1]*(\\.[^\\$ldel1]*)*$ldel1/gcs
|
|---|
| 800 | || do { pos $$textref = $startpos; return };
|
|---|
| 801 | }
|
|---|
| 802 | $ld2pos = $rd1pos = pos($$textref)-1;
|
|---|
| 803 |
|
|---|
| 804 | my $second_arg = $op =~ /s|tr|y/ ? 1 : 0;
|
|---|
| 805 | if ($second_arg)
|
|---|
| 806 | {
|
|---|
| 807 | my ($ldel2, $rdel2);
|
|---|
| 808 | if ($ldel1 =~ /[[(<{]/)
|
|---|
| 809 | {
|
|---|
| 810 | unless ($$textref =~ /\G\s*(\S)/gc) # SHOULD USE LOOKAHEAD
|
|---|
| 811 | {
|
|---|
| 812 | _failmsg "Missing second block for quotelike $op",
|
|---|
| 813 | pos $$textref;
|
|---|
| 814 | pos $$textref = $startpos;
|
|---|
| 815 | return;
|
|---|
| 816 | }
|
|---|
| 817 | $ldel2 = $rdel2 = "\Q$1";
|
|---|
| 818 | $rdel2 =~ tr/[({</])}>/;
|
|---|
| 819 | }
|
|---|
| 820 | else
|
|---|
| 821 | {
|
|---|
| 822 | $ldel2 = $rdel2 = $ldel1;
|
|---|
| 823 | }
|
|---|
| 824 | $str2pos = $ld2pos+1;
|
|---|
| 825 |
|
|---|
| 826 | if ($ldel2 =~ /[[(<{]/)
|
|---|
| 827 | {
|
|---|
| 828 | pos($$textref)--; # OVERCOME BROKEN LOOKAHEAD
|
|---|
| 829 | _match_bracketed($textref,"",$ldel2,"","",$rdel2)
|
|---|
| 830 | || do { pos $$textref = $startpos; return };
|
|---|
| 831 | }
|
|---|
| 832 | else
|
|---|
| 833 | {
|
|---|
| 834 | $$textref =~ /[^\\$ldel2]*(\\.[^\\$ldel2]*)*$ldel2/gcs
|
|---|
| 835 | || do { pos $$textref = $startpos; return };
|
|---|
| 836 | }
|
|---|
| 837 | $rd2pos = pos($$textref)-1;
|
|---|
| 838 | }
|
|---|
| 839 | else
|
|---|
| 840 | {
|
|---|
| 841 | $ld2pos = $str2pos = $rd2pos = $rd1pos;
|
|---|
| 842 | }
|
|---|
| 843 |
|
|---|
| 844 | $modpos = pos $$textref;
|
|---|
| 845 |
|
|---|
| 846 | $$textref =~ m/\G($mods{$op})/gc;
|
|---|
| 847 | my $endpos = pos $$textref;
|
|---|
| 848 |
|
|---|
| 849 | return (
|
|---|
| 850 | $startpos, $oppos-$startpos, # PREFIX
|
|---|
| 851 | $oppos, length($op), # OPERATOR
|
|---|
| 852 | $ld1pos, 1, # LEFT DEL
|
|---|
| 853 | $str1pos, $rd1pos-$str1pos, # STR/PAT
|
|---|
| 854 | $rd1pos, 1, # RIGHT DEL
|
|---|
| 855 | $ld2pos, $second_arg, # 2ND LDEL (MAYBE)
|
|---|
| 856 | $str2pos, $rd2pos-$str2pos, # 2ND STR (MAYBE)
|
|---|
| 857 | $rd2pos, $second_arg, # 2ND RDEL (MAYBE)
|
|---|
| 858 | $modpos, $endpos-$modpos, # MODIFIERS
|
|---|
| 859 | $endpos, $textlen-$endpos, # REMAINDER
|
|---|
| 860 | );
|
|---|
| 861 | }
|
|---|
| 862 |
|
|---|
| 863 | my $def_func =
|
|---|
| 864 | [
|
|---|
| 865 | sub { extract_variable($_[0], '') },
|
|---|
| 866 | sub { extract_quotelike($_[0],'') },
|
|---|
| 867 | sub { extract_codeblock($_[0],'{}','') },
|
|---|
| 868 | ];
|
|---|
| 869 |
|
|---|
| 870 | sub extract_multiple (;$$$$) # ($text, $functions_ref, $max_fields, $ignoreunknown)
|
|---|
| 871 | {
|
|---|
| 872 | my $textref = defined($_[0]) ? \$_[0] : \$_;
|
|---|
| 873 | my $posbug = pos;
|
|---|
| 874 | my ($lastpos, $firstpos);
|
|---|
| 875 | my @fields = ();
|
|---|
| 876 |
|
|---|
| 877 | #for ($$textref)
|
|---|
| 878 | {
|
|---|
| 879 | my @func = defined $_[1] ? @{$_[1]} : @{$def_func};
|
|---|
| 880 | my $max = defined $_[2] && $_[2]>0 ? $_[2] : 1_000_000_000;
|
|---|
| 881 | my $igunk = $_[3];
|
|---|
| 882 |
|
|---|
| 883 | pos $$textref ||= 0;
|
|---|
| 884 |
|
|---|
| 885 | unless (wantarray)
|
|---|
| 886 | {
|
|---|
| 887 | use Carp;
|
|---|
| 888 | carp "extract_multiple reset maximal count to 1 in scalar context"
|
|---|
| 889 | if $^W && defined($_[2]) && $max > 1;
|
|---|
| 890 | $max = 1
|
|---|
| 891 | }
|
|---|
| 892 |
|
|---|
| 893 | my $unkpos;
|
|---|
| 894 | my $func;
|
|---|
| 895 | my $class;
|
|---|
| 896 |
|
|---|
| 897 | my @class;
|
|---|
| 898 | foreach $func ( @func )
|
|---|
| 899 | {
|
|---|
| 900 | if (ref($func) eq 'HASH')
|
|---|
| 901 | {
|
|---|
| 902 | push @class, (keys %$func)[0];
|
|---|
| 903 | $func = (values %$func)[0];
|
|---|
| 904 | }
|
|---|
| 905 | else
|
|---|
| 906 | {
|
|---|
| 907 | push @class, undef;
|
|---|
| 908 | }
|
|---|
| 909 | }
|
|---|
| 910 |
|
|---|
| 911 | FIELD: while (pos($$textref) < length($$textref))
|
|---|
| 912 | {
|
|---|
| 913 | my ($field, $rem);
|
|---|
| 914 | my @bits;
|
|---|
| 915 | foreach my $i ( 0..$#func )
|
|---|
| 916 | {
|
|---|
| 917 | my $pref;
|
|---|
| 918 | $func = $func[$i];
|
|---|
| 919 | $class = $class[$i];
|
|---|
| 920 | $lastpos = pos $$textref;
|
|---|
| 921 | if (ref($func) eq 'CODE')
|
|---|
| 922 | { ($field,$rem,$pref) = @bits = $func->($$textref);
|
|---|
| 923 | # print "[$field|$rem]" if $field;
|
|---|
| 924 | }
|
|---|
| 925 | elsif (ref($func) eq 'Text::Balanced::Extractor')
|
|---|
| 926 | { @bits = $field = $func->extract($$textref) }
|
|---|
| 927 | elsif( $$textref =~ m/\G$func/gc )
|
|---|
| 928 | { @bits = $field = defined($1) ? $1 : $& }
|
|---|
| 929 | $pref ||= "";
|
|---|
| 930 | if (defined($field) && length($field))
|
|---|
| 931 | {
|
|---|
| 932 | if (!$igunk) {
|
|---|
| 933 | $unkpos = pos $$textref
|
|---|
| 934 | if length($pref) && !defined($unkpos);
|
|---|
| 935 | if (defined $unkpos)
|
|---|
| 936 | {
|
|---|
| 937 | push @fields, substr($$textref, $unkpos, $lastpos-$unkpos).$pref;
|
|---|
| 938 | $firstpos = $unkpos unless defined $firstpos;
|
|---|
| 939 | undef $unkpos;
|
|---|
| 940 | last FIELD if @fields == $max;
|
|---|
| 941 | }
|
|---|
| 942 | }
|
|---|
| 943 | push @fields, $class
|
|---|
| 944 | ? bless (\$field, $class)
|
|---|
| 945 | : $field;
|
|---|
| 946 | $firstpos = $lastpos unless defined $firstpos;
|
|---|
| 947 | $lastpos = pos $$textref;
|
|---|
| 948 | last FIELD if @fields == $max;
|
|---|
| 949 | next FIELD;
|
|---|
| 950 | }
|
|---|
| 951 | }
|
|---|
| 952 | if ($$textref =~ /\G(.)/gcs)
|
|---|
| 953 | {
|
|---|
| 954 | $unkpos = pos($$textref)-1
|
|---|
| 955 | unless $igunk || defined $unkpos;
|
|---|
| 956 | }
|
|---|
| 957 | }
|
|---|
| 958 |
|
|---|
| 959 | if (defined $unkpos)
|
|---|
| 960 | {
|
|---|
| 961 | push @fields, substr($$textref, $unkpos);
|
|---|
| 962 | $firstpos = $unkpos unless defined $firstpos;
|
|---|
| 963 | $lastpos = length $$textref;
|
|---|
| 964 | }
|
|---|
| 965 | last;
|
|---|
| 966 | }
|
|---|
| 967 |
|
|---|
| 968 | pos $$textref = $lastpos;
|
|---|
| 969 | return @fields if wantarray;
|
|---|
| 970 |
|
|---|
| 971 | $firstpos ||= 0;
|
|---|
| 972 | eval { substr($$textref,$firstpos,$lastpos-$firstpos)="";
|
|---|
| 973 | pos $$textref = $firstpos };
|
|---|
| 974 | return $fields[0];
|
|---|
| 975 | }
|
|---|
| 976 |
|
|---|
| 977 |
|
|---|
| 978 | sub gen_extract_tagged # ($opentag, $closetag, $pre, \%options)
|
|---|
| 979 | {
|
|---|
| 980 | my $ldel = $_[0];
|
|---|
| 981 | my $rdel = $_[1];
|
|---|
| 982 | my $pre = defined $_[2] ? $_[2] : '\s*';
|
|---|
| 983 | my %options = defined $_[3] ? %{$_[3]} : ();
|
|---|
| 984 | my $omode = defined $options{fail} ? $options{fail} : '';
|
|---|
| 985 | my $bad = ref($options{reject}) eq 'ARRAY' ? join('|', @{$options{reject}})
|
|---|
| 986 | : defined($options{reject}) ? $options{reject}
|
|---|
| 987 | : ''
|
|---|
| 988 | ;
|
|---|
| 989 | my $ignore = ref($options{ignore}) eq 'ARRAY' ? join('|', @{$options{ignore}})
|
|---|
| 990 | : defined($options{ignore}) ? $options{ignore}
|
|---|
| 991 | : ''
|
|---|
| 992 | ;
|
|---|
| 993 |
|
|---|
| 994 | if (!defined $ldel) { $ldel = '<\w+(?:' . gen_delimited_pat(q{'"}) . '|[^>])*>'; }
|
|---|
| 995 |
|
|---|
| 996 | my $posbug = pos;
|
|---|
| 997 | for ($ldel, $pre, $bad, $ignore) { $_ = qr/$_/ if $_ }
|
|---|
| 998 | pos = $posbug;
|
|---|
| 999 |
|
|---|
| 1000 | my $closure = sub
|
|---|
| 1001 | {
|
|---|
| 1002 | my $textref = defined $_[0] ? \$_[0] : \$_;
|
|---|
| 1003 | my @match = Text::Balanced::_match_tagged($textref, $pre, $ldel, $rdel, $omode, $bad, $ignore);
|
|---|
| 1004 |
|
|---|
| 1005 | return _fail(wantarray, $textref) unless @match;
|
|---|
| 1006 | return _succeed wantarray, $textref,
|
|---|
| 1007 | $match[2], $match[3]+$match[5]+$match[7], # MATCH
|
|---|
| 1008 | @match[8..9,0..1,2..7]; # REM, PRE, BITS
|
|---|
| 1009 | };
|
|---|
| 1010 |
|
|---|
| 1011 | bless $closure, 'Text::Balanced::Extractor';
|
|---|
| 1012 | }
|
|---|
| 1013 |
|
|---|
| 1014 | package Text::Balanced::Extractor;
|
|---|
| 1015 |
|
|---|
| 1016 | sub extract($$) # ($self, $text)
|
|---|
| 1017 | {
|
|---|
| 1018 | &{$_[0]}($_[1]);
|
|---|
| 1019 | }
|
|---|
| 1020 |
|
|---|
| 1021 | package Text::Balanced::ErrorMsg;
|
|---|
| 1022 |
|
|---|
| 1023 | use overload '""' => sub { "$_[0]->{error}, detected at offset $_[0]->{pos}" };
|
|---|
| 1024 |
|
|---|
| 1025 | 1;
|
|---|
| 1026 |
|
|---|
| 1027 | __END__
|
|---|
| 1028 |
|
|---|
| 1029 | =head1 NAME
|
|---|
| 1030 |
|
|---|
| 1031 | Text::Balanced - Extract delimited text sequences from strings.
|
|---|
| 1032 |
|
|---|
| 1033 |
|
|---|
| 1034 | =head1 SYNOPSIS
|
|---|
| 1035 |
|
|---|
| 1036 | use Text::Balanced qw (
|
|---|
| 1037 | extract_delimited
|
|---|
| 1038 | extract_bracketed
|
|---|
| 1039 | extract_quotelike
|
|---|
| 1040 | extract_codeblock
|
|---|
| 1041 | extract_variable
|
|---|
| 1042 | extract_tagged
|
|---|
| 1043 | extract_multiple
|
|---|
| 1044 |
|
|---|
| 1045 | gen_delimited_pat
|
|---|
| 1046 | gen_extract_tagged
|
|---|
| 1047 | );
|
|---|
| 1048 |
|
|---|
| 1049 | # Extract the initial substring of $text that is delimited by
|
|---|
| 1050 | # two (unescaped) instances of the first character in $delim.
|
|---|
| 1051 |
|
|---|
| 1052 | ($extracted, $remainder) = extract_delimited($text,$delim);
|
|---|
| 1053 |
|
|---|
| 1054 |
|
|---|
| 1055 | # Extract the initial substring of $text that is bracketed
|
|---|
| 1056 | # with a delimiter(s) specified by $delim (where the string
|
|---|
| 1057 | # in $delim contains one or more of '(){}[]<>').
|
|---|
| 1058 |
|
|---|
| 1059 | ($extracted, $remainder) = extract_bracketed($text,$delim);
|
|---|
| 1060 |
|
|---|
| 1061 |
|
|---|
| 1062 | # Extract the initial substring of $text that is bounded by
|
|---|
| 1063 | # an XML tag.
|
|---|
| 1064 |
|
|---|
| 1065 | ($extracted, $remainder) = extract_tagged($text);
|
|---|
| 1066 |
|
|---|
| 1067 |
|
|---|
| 1068 | # Extract the initial substring of $text that is bounded by
|
|---|
| 1069 | # a C<BEGIN>...C<END> pair. Don't allow nested C<BEGIN> tags
|
|---|
| 1070 |
|
|---|
| 1071 | ($extracted, $remainder) =
|
|---|
| 1072 | extract_tagged($text,"BEGIN","END",undef,{bad=>["BEGIN"]});
|
|---|
| 1073 |
|
|---|
| 1074 |
|
|---|
| 1075 | # Extract the initial substring of $text that represents a
|
|---|
| 1076 | # Perl "quote or quote-like operation"
|
|---|
| 1077 |
|
|---|
| 1078 | ($extracted, $remainder) = extract_quotelike($text);
|
|---|
| 1079 |
|
|---|
| 1080 |
|
|---|
| 1081 | # Extract the initial substring of $text that represents a block
|
|---|
| 1082 | # of Perl code, bracketed by any of character(s) specified by $delim
|
|---|
| 1083 | # (where the string $delim contains one or more of '(){}[]<>').
|
|---|
| 1084 |
|
|---|
| 1085 | ($extracted, $remainder) = extract_codeblock($text,$delim);
|
|---|
| 1086 |
|
|---|
| 1087 |
|
|---|
| 1088 | # Extract the initial substrings of $text that would be extracted by
|
|---|
| 1089 | # one or more sequential applications of the specified functions
|
|---|
| 1090 | # or regular expressions
|
|---|
| 1091 |
|
|---|
| 1092 | @extracted = extract_multiple($text,
|
|---|
| 1093 | [ \&extract_bracketed,
|
|---|
| 1094 | \&extract_quotelike,
|
|---|
| 1095 | \&some_other_extractor_sub,
|
|---|
| 1096 | qr/[xyz]*/,
|
|---|
| 1097 | 'literal',
|
|---|
| 1098 | ]);
|
|---|
| 1099 |
|
|---|
| 1100 | # Create a string representing an optimized pattern (a la Friedl)
|
|---|
| 1101 | # that matches a substring delimited by any of the specified characters
|
|---|
| 1102 | # (in this case: any type of quote or a slash)
|
|---|
| 1103 |
|
|---|
| 1104 | $patstring = gen_delimited_pat(q{'"`/});
|
|---|
| 1105 |
|
|---|
| 1106 |
|
|---|
| 1107 | # Generate a reference to an anonymous sub that is just like extract_tagged
|
|---|
| 1108 | # but pre-compiled and optimized for a specific pair of tags, and consequently
|
|---|
| 1109 | # much faster (i.e. 3 times faster). It uses qr// for better performance on
|
|---|
| 1110 | # repeated calls, so it only works under Perl 5.005 or later.
|
|---|
| 1111 |
|
|---|
| 1112 | $extract_head = gen_extract_tagged('<HEAD>','</HEAD>');
|
|---|
| 1113 |
|
|---|
| 1114 | ($extracted, $remainder) = $extract_head->($text);
|
|---|
| 1115 |
|
|---|
| 1116 |
|
|---|
| 1117 | =head1 DESCRIPTION
|
|---|
| 1118 |
|
|---|
| 1119 | The various C<extract_...> subroutines may be used to
|
|---|
| 1120 | extract a delimited substring, possibly after skipping a
|
|---|
| 1121 | specified prefix string. By default, that prefix is
|
|---|
| 1122 | optional whitespace (C</\s*/>), but you can change it to whatever
|
|---|
| 1123 | you wish (see below).
|
|---|
| 1124 |
|
|---|
| 1125 | The substring to be extracted must appear at the
|
|---|
| 1126 | current C<pos> location of the string's variable
|
|---|
| 1127 | (or at index zero, if no C<pos> position is defined).
|
|---|
| 1128 | In other words, the C<extract_...> subroutines I<don't>
|
|---|
| 1129 | extract the first occurance of a substring anywhere
|
|---|
| 1130 | in a string (like an unanchored regex would). Rather,
|
|---|
| 1131 | they extract an occurance of the substring appearing
|
|---|
| 1132 | immediately at the current matching position in the
|
|---|
| 1133 | string (like a C<\G>-anchored regex would).
|
|---|
| 1134 |
|
|---|
| 1135 |
|
|---|
| 1136 |
|
|---|
| 1137 | =head2 General behaviour in list contexts
|
|---|
| 1138 |
|
|---|
| 1139 | In a list context, all the subroutines return a list, the first three
|
|---|
| 1140 | elements of which are always:
|
|---|
| 1141 |
|
|---|
| 1142 | =over 4
|
|---|
| 1143 |
|
|---|
| 1144 | =item [0]
|
|---|
| 1145 |
|
|---|
| 1146 | The extracted string, including the specified delimiters.
|
|---|
| 1147 | If the extraction fails an empty string is returned.
|
|---|
| 1148 |
|
|---|
| 1149 | =item [1]
|
|---|
| 1150 |
|
|---|
| 1151 | The remainder of the input string (i.e. the characters after the
|
|---|
| 1152 | extracted string). On failure, the entire string is returned.
|
|---|
| 1153 |
|
|---|
| 1154 | =item [2]
|
|---|
| 1155 |
|
|---|
| 1156 | The skipped prefix (i.e. the characters before the extracted string).
|
|---|
| 1157 | On failure, the empty string is returned.
|
|---|
| 1158 |
|
|---|
| 1159 | =back
|
|---|
| 1160 |
|
|---|
| 1161 | Note that in a list context, the contents of the original input text (the first
|
|---|
| 1162 | argument) are not modified in any way.
|
|---|
| 1163 |
|
|---|
| 1164 | However, if the input text was passed in a variable, that variable's
|
|---|
| 1165 | C<pos> value is updated to point at the first character after the
|
|---|
| 1166 | extracted text. That means that in a list context the various
|
|---|
| 1167 | subroutines can be used much like regular expressions. For example:
|
|---|
| 1168 |
|
|---|
| 1169 | while ( $next = (extract_quotelike($text))[0] )
|
|---|
| 1170 | {
|
|---|
| 1171 | # process next quote-like (in $next)
|
|---|
| 1172 | }
|
|---|
| 1173 |
|
|---|
| 1174 |
|
|---|
| 1175 | =head2 General behaviour in scalar and void contexts
|
|---|
| 1176 |
|
|---|
| 1177 | In a scalar context, the extracted string is returned, having first been
|
|---|
| 1178 | removed from the input text. Thus, the following code also processes
|
|---|
| 1179 | each quote-like operation, but actually removes them from $text:
|
|---|
| 1180 |
|
|---|
| 1181 | while ( $next = extract_quotelike($text) )
|
|---|
| 1182 | {
|
|---|
| 1183 | # process next quote-like (in $next)
|
|---|
| 1184 | }
|
|---|
| 1185 |
|
|---|
| 1186 | Note that if the input text is a read-only string (i.e. a literal),
|
|---|
| 1187 | no attempt is made to remove the extracted text.
|
|---|
| 1188 |
|
|---|
| 1189 | In a void context the behaviour of the extraction subroutines is
|
|---|
| 1190 | exactly the same as in a scalar context, except (of course) that the
|
|---|
| 1191 | extracted substring is not returned.
|
|---|
| 1192 |
|
|---|
| 1193 | =head2 A note about prefixes
|
|---|
| 1194 |
|
|---|
| 1195 | Prefix patterns are matched without any trailing modifiers (C</gimsox> etc.)
|
|---|
| 1196 | This can bite you if you're expecting a prefix specification like
|
|---|
| 1197 | '.*?(?=<H1>)' to skip everything up to the first <H1> tag. Such a prefix
|
|---|
| 1198 | pattern will only succeed if the <H1> tag is on the current line, since
|
|---|
| 1199 | . normally doesn't match newlines.
|
|---|
| 1200 |
|
|---|
| 1201 | To overcome this limitation, you need to turn on /s matching within
|
|---|
| 1202 | the prefix pattern, using the C<(?s)> directive: '(?s).*?(?=<H1>)'
|
|---|
| 1203 |
|
|---|
| 1204 |
|
|---|
| 1205 | =head2 C<extract_delimited>
|
|---|
| 1206 |
|
|---|
| 1207 | The C<extract_delimited> function formalizes the common idiom
|
|---|
| 1208 | of extracting a single-character-delimited substring from the start of
|
|---|
| 1209 | a string. For example, to extract a single-quote delimited string, the
|
|---|
| 1210 | following code is typically used:
|
|---|
| 1211 |
|
|---|
| 1212 | ($remainder = $text) =~ s/\A('(\\.|[^'])*')//s;
|
|---|
| 1213 | $extracted = $1;
|
|---|
| 1214 |
|
|---|
| 1215 | but with C<extract_delimited> it can be simplified to:
|
|---|
| 1216 |
|
|---|
| 1217 | ($extracted,$remainder) = extract_delimited($text, "'");
|
|---|
| 1218 |
|
|---|
| 1219 | C<extract_delimited> takes up to four scalars (the input text, the
|
|---|
| 1220 | delimiters, a prefix pattern to be skipped, and any escape characters)
|
|---|
| 1221 | and extracts the initial substring of the text that
|
|---|
| 1222 | is appropriately delimited. If the delimiter string has multiple
|
|---|
| 1223 | characters, the first one encountered in the text is taken to delimit
|
|---|
| 1224 | the substring.
|
|---|
| 1225 | The third argument specifies a prefix pattern that is to be skipped
|
|---|
| 1226 | (but must be present!) before the substring is extracted.
|
|---|
| 1227 | The final argument specifies the escape character to be used for each
|
|---|
| 1228 | delimiter.
|
|---|
| 1229 |
|
|---|
| 1230 | All arguments are optional. If the escape characters are not specified,
|
|---|
| 1231 | every delimiter is escaped with a backslash (C<\>).
|
|---|
| 1232 | If the prefix is not specified, the
|
|---|
| 1233 | pattern C<'\s*'> - optional whitespace - is used. If the delimiter set
|
|---|
| 1234 | is also not specified, the set C</["'`]/> is used. If the text to be processed
|
|---|
| 1235 | is not specified either, C<$_> is used.
|
|---|
| 1236 |
|
|---|
| 1237 | In list context, C<extract_delimited> returns a array of three
|
|---|
| 1238 | elements, the extracted substring (I<including the surrounding
|
|---|
| 1239 | delimiters>), the remainder of the text, and the skipped prefix (if
|
|---|
| 1240 | any). If a suitable delimited substring is not found, the first
|
|---|
| 1241 | element of the array is the empty string, the second is the complete
|
|---|
| 1242 | original text, and the prefix returned in the third element is an
|
|---|
| 1243 | empty string.
|
|---|
| 1244 |
|
|---|
| 1245 | In a scalar context, just the extracted substring is returned. In
|
|---|
| 1246 | a void context, the extracted substring (and any prefix) are simply
|
|---|
| 1247 | removed from the beginning of the first argument.
|
|---|
| 1248 |
|
|---|
| 1249 | Examples:
|
|---|
| 1250 |
|
|---|
| 1251 | # Remove a single-quoted substring from the very beginning of $text:
|
|---|
| 1252 |
|
|---|
| 1253 | $substring = extract_delimited($text, "'", '');
|
|---|
| 1254 |
|
|---|
| 1255 | # Remove a single-quoted Pascalish substring (i.e. one in which
|
|---|
| 1256 | # doubling the quote character escapes it) from the very
|
|---|
| 1257 | # beginning of $text:
|
|---|
| 1258 |
|
|---|
| 1259 | $substring = extract_delimited($text, "'", '', "'");
|
|---|
| 1260 |
|
|---|
| 1261 | # Extract a single- or double- quoted substring from the
|
|---|
| 1262 | # beginning of $text, optionally after some whitespace
|
|---|
| 1263 | # (note the list context to protect $text from modification):
|
|---|
| 1264 |
|
|---|
| 1265 | ($substring) = extract_delimited $text, q{"'};
|
|---|
| 1266 |
|
|---|
| 1267 |
|
|---|
| 1268 | # Delete the substring delimited by the first '/' in $text:
|
|---|
| 1269 |
|
|---|
| 1270 | $text = join '', (extract_delimited($text,'/','[^/]*')[2,1];
|
|---|
| 1271 |
|
|---|
| 1272 | Note that this last example is I<not> the same as deleting the first
|
|---|
| 1273 | quote-like pattern. For instance, if C<$text> contained the string:
|
|---|
| 1274 |
|
|---|
| 1275 | "if ('./cmd' =~ m/$UNIXCMD/s) { $cmd = $1; }"
|
|---|
| 1276 |
|
|---|
| 1277 | then after the deletion it would contain:
|
|---|
| 1278 |
|
|---|
| 1279 | "if ('.$UNIXCMD/s) { $cmd = $1; }"
|
|---|
| 1280 |
|
|---|
| 1281 | not:
|
|---|
| 1282 |
|
|---|
| 1283 | "if ('./cmd' =~ ms) { $cmd = $1; }"
|
|---|
| 1284 |
|
|---|
| 1285 |
|
|---|
| 1286 | See L<"extract_quotelike"> for a (partial) solution to this problem.
|
|---|
| 1287 |
|
|---|
| 1288 |
|
|---|
| 1289 | =head2 C<extract_bracketed>
|
|---|
| 1290 |
|
|---|
| 1291 | Like C<"extract_delimited">, the C<extract_bracketed> function takes
|
|---|
| 1292 | up to three optional scalar arguments: a string to extract from, a delimiter
|
|---|
| 1293 | specifier, and a prefix pattern. As before, a missing prefix defaults to
|
|---|
| 1294 | optional whitespace and a missing text defaults to C<$_>. However, a missing
|
|---|
| 1295 | delimiter specifier defaults to C<'{}()[]E<lt>E<gt>'> (see below).
|
|---|
| 1296 |
|
|---|
| 1297 | C<extract_bracketed> extracts a balanced-bracket-delimited
|
|---|
| 1298 | substring (using any one (or more) of the user-specified delimiter
|
|---|
| 1299 | brackets: '(..)', '{..}', '[..]', or '<..>'). Optionally it will also
|
|---|
| 1300 | respect quoted unbalanced brackets (see below).
|
|---|
| 1301 |
|
|---|
| 1302 | A "delimiter bracket" is a bracket in list of delimiters passed as
|
|---|
| 1303 | C<extract_bracketed>'s second argument. Delimiter brackets are
|
|---|
| 1304 | specified by giving either the left or right (or both!) versions
|
|---|
| 1305 | of the required bracket(s). Note that the order in which
|
|---|
| 1306 | two or more delimiter brackets are specified is not significant.
|
|---|
| 1307 |
|
|---|
| 1308 | A "balanced-bracket-delimited substring" is a substring bounded by
|
|---|
| 1309 | matched brackets, such that any other (left or right) delimiter
|
|---|
| 1310 | bracket I<within> the substring is also matched by an opposite
|
|---|
| 1311 | (right or left) delimiter bracket I<at the same level of nesting>. Any
|
|---|
| 1312 | type of bracket not in the delimiter list is treated as an ordinary
|
|---|
| 1313 | character.
|
|---|
| 1314 |
|
|---|
| 1315 | In other words, each type of bracket specified as a delimiter must be
|
|---|
| 1316 | balanced and correctly nested within the substring, and any other kind of
|
|---|
| 1317 | ("non-delimiter") bracket in the substring is ignored.
|
|---|
| 1318 |
|
|---|
| 1319 | For example, given the string:
|
|---|
| 1320 |
|
|---|
| 1321 | $text = "{ an '[irregularly :-(] {} parenthesized >:-)' string }";
|
|---|
| 1322 |
|
|---|
| 1323 | then a call to C<extract_bracketed> in a list context:
|
|---|
| 1324 |
|
|---|
| 1325 | @result = extract_bracketed( $text, '{}' );
|
|---|
| 1326 |
|
|---|
| 1327 | would return:
|
|---|
| 1328 |
|
|---|
| 1329 | ( "{ an '[irregularly :-(] {} parenthesized >:-)' string }" , "" , "" )
|
|---|
| 1330 |
|
|---|
| 1331 | since both sets of C<'{..}'> brackets are properly nested and evenly balanced.
|
|---|
| 1332 | (In a scalar context just the first element of the array would be returned. In
|
|---|
| 1333 | a void context, C<$text> would be replaced by an empty string.)
|
|---|
| 1334 |
|
|---|
| 1335 | Likewise the call in:
|
|---|
| 1336 |
|
|---|
| 1337 | @result = extract_bracketed( $text, '{[' );
|
|---|
| 1338 |
|
|---|
| 1339 | would return the same result, since all sets of both types of specified
|
|---|
| 1340 | delimiter brackets are correctly nested and balanced.
|
|---|
| 1341 |
|
|---|
| 1342 | However, the call in:
|
|---|
| 1343 |
|
|---|
| 1344 | @result = extract_bracketed( $text, '{([<' );
|
|---|
| 1345 |
|
|---|
| 1346 | would fail, returning:
|
|---|
| 1347 |
|
|---|
| 1348 | ( undef , "{ an '[irregularly :-(] {} parenthesized >:-)' string }" );
|
|---|
| 1349 |
|
|---|
| 1350 | because the embedded pairs of C<'(..)'>s and C<'[..]'>s are "cross-nested" and
|
|---|
| 1351 | the embedded C<'E<gt>'> is unbalanced. (In a scalar context, this call would
|
|---|
| 1352 | return an empty string. In a void context, C<$text> would be unchanged.)
|
|---|
| 1353 |
|
|---|
| 1354 | Note that the embedded single-quotes in the string don't help in this
|
|---|
| 1355 | case, since they have not been specified as acceptable delimiters and are
|
|---|
| 1356 | therefore treated as non-delimiter characters (and ignored).
|
|---|
| 1357 |
|
|---|
| 1358 | However, if a particular species of quote character is included in the
|
|---|
| 1359 | delimiter specification, then that type of quote will be correctly handled.
|
|---|
| 1360 | for example, if C<$text> is:
|
|---|
| 1361 |
|
|---|
| 1362 | $text = '<A HREF=">>>>">link</A>';
|
|---|
| 1363 |
|
|---|
| 1364 | then
|
|---|
| 1365 |
|
|---|
| 1366 | @result = extract_bracketed( $text, '<">' );
|
|---|
| 1367 |
|
|---|
| 1368 | returns:
|
|---|
| 1369 |
|
|---|
| 1370 | ( '<A HREF=">>>>">', 'link</A>', "" )
|
|---|
| 1371 |
|
|---|
| 1372 | as expected. Without the specification of C<"> as an embedded quoter:
|
|---|
| 1373 |
|
|---|
| 1374 | @result = extract_bracketed( $text, '<>' );
|
|---|
| 1375 |
|
|---|
| 1376 | the result would be:
|
|---|
| 1377 |
|
|---|
| 1378 | ( '<A HREF=">', '>>>">link</A>', "" )
|
|---|
| 1379 |
|
|---|
| 1380 | In addition to the quote delimiters C<'>, C<">, and C<`>, full Perl quote-like
|
|---|
| 1381 | quoting (i.e. q{string}, qq{string}, etc) can be specified by including the
|
|---|
| 1382 | letter 'q' as a delimiter. Hence:
|
|---|
| 1383 |
|
|---|
| 1384 | @result = extract_bracketed( $text, '<q>' );
|
|---|
| 1385 |
|
|---|
| 1386 | would correctly match something like this:
|
|---|
| 1387 |
|
|---|
| 1388 | $text = '<leftop: conj /and/ conj>';
|
|---|
| 1389 |
|
|---|
| 1390 | See also: C<"extract_quotelike"> and C<"extract_codeblock">.
|
|---|
| 1391 |
|
|---|
| 1392 |
|
|---|
| 1393 | =head2 C<extract_variable>
|
|---|
| 1394 |
|
|---|
| 1395 | C<extract_variable> extracts any valid Perl variable or
|
|---|
| 1396 | variable-involved expression, including scalars, arrays, hashes, array
|
|---|
| 1397 | accesses, hash look-ups, method calls through objects, subroutine calles
|
|---|
| 1398 | through subroutine references, etc.
|
|---|
| 1399 |
|
|---|
| 1400 | The subroutine takes up to two optional arguments:
|
|---|
| 1401 |
|
|---|
| 1402 | =over 4
|
|---|
| 1403 |
|
|---|
| 1404 | =item 1.
|
|---|
| 1405 |
|
|---|
| 1406 | A string to be processed (C<$_> if the string is omitted or C<undef>)
|
|---|
| 1407 |
|
|---|
| 1408 | =item 2.
|
|---|
| 1409 |
|
|---|
| 1410 | A string specifying a pattern to be matched as a prefix (which is to be
|
|---|
| 1411 | skipped). If omitted, optional whitespace is skipped.
|
|---|
| 1412 |
|
|---|
| 1413 | =back
|
|---|
| 1414 |
|
|---|
| 1415 | On success in a list context, an array of 3 elements is returned. The
|
|---|
| 1416 | elements are:
|
|---|
| 1417 |
|
|---|
| 1418 | =over 4
|
|---|
| 1419 |
|
|---|
| 1420 | =item [0]
|
|---|
| 1421 |
|
|---|
| 1422 | the extracted variable, or variablish expression
|
|---|
| 1423 |
|
|---|
| 1424 | =item [1]
|
|---|
| 1425 |
|
|---|
| 1426 | the remainder of the input text,
|
|---|
| 1427 |
|
|---|
| 1428 | =item [2]
|
|---|
| 1429 |
|
|---|
| 1430 | the prefix substring (if any),
|
|---|
| 1431 |
|
|---|
| 1432 | =back
|
|---|
| 1433 |
|
|---|
| 1434 | On failure, all of these values (except the remaining text) are C<undef>.
|
|---|
| 1435 |
|
|---|
| 1436 | In a scalar context, C<extract_variable> returns just the complete
|
|---|
| 1437 | substring that matched a variablish expression. C<undef> is returned on
|
|---|
| 1438 | failure. In addition, the original input text has the returned substring
|
|---|
| 1439 | (and any prefix) removed from it.
|
|---|
| 1440 |
|
|---|
| 1441 | In a void context, the input text just has the matched substring (and
|
|---|
| 1442 | any specified prefix) removed.
|
|---|
| 1443 |
|
|---|
| 1444 |
|
|---|
| 1445 | =head2 C<extract_tagged>
|
|---|
| 1446 |
|
|---|
| 1447 | C<extract_tagged> extracts and segments text between (balanced)
|
|---|
| 1448 | specified tags.
|
|---|
| 1449 |
|
|---|
| 1450 | The subroutine takes up to five optional arguments:
|
|---|
| 1451 |
|
|---|
| 1452 | =over 4
|
|---|
| 1453 |
|
|---|
| 1454 | =item 1.
|
|---|
| 1455 |
|
|---|
| 1456 | A string to be processed (C<$_> if the string is omitted or C<undef>)
|
|---|
| 1457 |
|
|---|
| 1458 | =item 2.
|
|---|
| 1459 |
|
|---|
| 1460 | A string specifying a pattern to be matched as the opening tag.
|
|---|
| 1461 | If the pattern string is omitted (or C<undef>) then a pattern
|
|---|
| 1462 | that matches any standard XML tag is used.
|
|---|
| 1463 |
|
|---|
| 1464 | =item 3.
|
|---|
| 1465 |
|
|---|
| 1466 | A string specifying a pattern to be matched at the closing tag.
|
|---|
| 1467 | If the pattern string is omitted (or C<undef>) then the closing
|
|---|
| 1468 | tag is constructed by inserting a C</> after any leading bracket
|
|---|
| 1469 | characters in the actual opening tag that was matched (I<not> the pattern
|
|---|
| 1470 | that matched the tag). For example, if the opening tag pattern
|
|---|
| 1471 | is specified as C<'{{\w+}}'> and actually matched the opening tag
|
|---|
| 1472 | C<"{{DATA}}">, then the constructed closing tag would be C<"{{/DATA}}">.
|
|---|
| 1473 |
|
|---|
| 1474 | =item 4.
|
|---|
| 1475 |
|
|---|
| 1476 | A string specifying a pattern to be matched as a prefix (which is to be
|
|---|
| 1477 | skipped). If omitted, optional whitespace is skipped.
|
|---|
| 1478 |
|
|---|
| 1479 | =item 5.
|
|---|
| 1480 |
|
|---|
| 1481 | A hash reference containing various parsing options (see below)
|
|---|
| 1482 |
|
|---|
| 1483 | =back
|
|---|
| 1484 |
|
|---|
| 1485 | The various options that can be specified are:
|
|---|
| 1486 |
|
|---|
| 1487 | =over 4
|
|---|
| 1488 |
|
|---|
| 1489 | =item C<reject =E<gt> $listref>
|
|---|
| 1490 |
|
|---|
| 1491 | The list reference contains one or more strings specifying patterns
|
|---|
| 1492 | that must I<not> appear within the tagged text.
|
|---|
| 1493 |
|
|---|
| 1494 | For example, to extract
|
|---|
| 1495 | an HTML link (which should not contain nested links) use:
|
|---|
| 1496 |
|
|---|
| 1497 | extract_tagged($text, '<A>', '</A>', undef, {reject => ['<A>']} );
|
|---|
| 1498 |
|
|---|
| 1499 | =item C<ignore =E<gt> $listref>
|
|---|
| 1500 |
|
|---|
| 1501 | The list reference contains one or more strings specifying patterns
|
|---|
| 1502 | that are I<not> be be treated as nested tags within the tagged text
|
|---|
| 1503 | (even if they would match the start tag pattern).
|
|---|
| 1504 |
|
|---|
| 1505 | For example, to extract an arbitrary XML tag, but ignore "empty" elements:
|
|---|
| 1506 |
|
|---|
| 1507 | extract_tagged($text, undef, undef, undef, {ignore => ['<[^>]*/>']} );
|
|---|
| 1508 |
|
|---|
| 1509 | (also see L<"gen_delimited_pat"> below).
|
|---|
| 1510 |
|
|---|
| 1511 |
|
|---|
| 1512 | =item C<fail =E<gt> $str>
|
|---|
| 1513 |
|
|---|
| 1514 | The C<fail> option indicates the action to be taken if a matching end
|
|---|
| 1515 | tag is not encountered (i.e. before the end of the string or some
|
|---|
| 1516 | C<reject> pattern matches). By default, a failure to match a closing
|
|---|
| 1517 | tag causes C<extract_tagged> to immediately fail.
|
|---|
| 1518 |
|
|---|
| 1519 | However, if the string value associated with <reject> is "MAX", then
|
|---|
| 1520 | C<extract_tagged> returns the complete text up to the point of failure.
|
|---|
| 1521 | If the string is "PARA", C<extract_tagged> returns only the first paragraph
|
|---|
| 1522 | after the tag (up to the first line that is either empty or contains
|
|---|
| 1523 | only whitespace characters).
|
|---|
| 1524 | If the string is "", the the default behaviour (i.e. failure) is reinstated.
|
|---|
| 1525 |
|
|---|
| 1526 | For example, suppose the start tag "/para" introduces a paragraph, which then
|
|---|
| 1527 | continues until the next "/endpara" tag or until another "/para" tag is
|
|---|
| 1528 | encountered:
|
|---|
| 1529 |
|
|---|
| 1530 | $text = "/para line 1\n\nline 3\n/para line 4";
|
|---|
| 1531 |
|
|---|
| 1532 | extract_tagged($text, '/para', '/endpara', undef,
|
|---|
| 1533 | {reject => '/para', fail => MAX );
|
|---|
| 1534 |
|
|---|
| 1535 | # EXTRACTED: "/para line 1\n\nline 3\n"
|
|---|
| 1536 |
|
|---|
| 1537 | Suppose instead, that if no matching "/endpara" tag is found, the "/para"
|
|---|
| 1538 | tag refers only to the immediately following paragraph:
|
|---|
| 1539 |
|
|---|
| 1540 | $text = "/para line 1\n\nline 3\n/para line 4";
|
|---|
| 1541 |
|
|---|
| 1542 | extract_tagged($text, '/para', '/endpara', undef,
|
|---|
| 1543 | {reject => '/para', fail => MAX );
|
|---|
| 1544 |
|
|---|
| 1545 | # EXTRACTED: "/para line 1\n"
|
|---|
| 1546 |
|
|---|
| 1547 | Note that the specified C<fail> behaviour applies to nested tags as well.
|
|---|
| 1548 |
|
|---|
| 1549 | =back
|
|---|
| 1550 |
|
|---|
| 1551 | On success in a list context, an array of 6 elements is returned. The elements are:
|
|---|
| 1552 |
|
|---|
| 1553 | =over 4
|
|---|
| 1554 |
|
|---|
| 1555 | =item [0]
|
|---|
| 1556 |
|
|---|
| 1557 | the extracted tagged substring (including the outermost tags),
|
|---|
| 1558 |
|
|---|
| 1559 | =item [1]
|
|---|
| 1560 |
|
|---|
| 1561 | the remainder of the input text,
|
|---|
| 1562 |
|
|---|
| 1563 | =item [2]
|
|---|
| 1564 |
|
|---|
| 1565 | the prefix substring (if any),
|
|---|
| 1566 |
|
|---|
| 1567 | =item [3]
|
|---|
| 1568 |
|
|---|
| 1569 | the opening tag
|
|---|
| 1570 |
|
|---|
| 1571 | =item [4]
|
|---|
| 1572 |
|
|---|
| 1573 | the text between the opening and closing tags
|
|---|
| 1574 |
|
|---|
| 1575 | =item [5]
|
|---|
| 1576 |
|
|---|
| 1577 | the closing tag (or "" if no closing tag was found)
|
|---|
| 1578 |
|
|---|
| 1579 | =back
|
|---|
| 1580 |
|
|---|
| 1581 | On failure, all of these values (except the remaining text) are C<undef>.
|
|---|
| 1582 |
|
|---|
| 1583 | In a scalar context, C<extract_tagged> returns just the complete
|
|---|
| 1584 | substring that matched a tagged text (including the start and end
|
|---|
| 1585 | tags). C<undef> is returned on failure. In addition, the original input
|
|---|
| 1586 | text has the returned substring (and any prefix) removed from it.
|
|---|
| 1587 |
|
|---|
| 1588 | In a void context, the input text just has the matched substring (and
|
|---|
| 1589 | any specified prefix) removed.
|
|---|
| 1590 |
|
|---|
| 1591 |
|
|---|
| 1592 | =head2 C<gen_extract_tagged>
|
|---|
| 1593 |
|
|---|
| 1594 | (Note: This subroutine is only available under Perl5.005)
|
|---|
| 1595 |
|
|---|
| 1596 | C<gen_extract_tagged> generates a new anonymous subroutine which
|
|---|
| 1597 | extracts text between (balanced) specified tags. In other words,
|
|---|
| 1598 | it generates a function identical in function to C<extract_tagged>.
|
|---|
| 1599 |
|
|---|
| 1600 | The difference between C<extract_tagged> and the anonymous
|
|---|
| 1601 | subroutines generated by
|
|---|
| 1602 | C<gen_extract_tagged>, is that those generated subroutines:
|
|---|
| 1603 |
|
|---|
| 1604 | =over 4
|
|---|
| 1605 |
|
|---|
| 1606 | =item *
|
|---|
| 1607 |
|
|---|
| 1608 | do not have to reparse tag specification or parsing options every time
|
|---|
| 1609 | they are called (whereas C<extract_tagged> has to effectively rebuild
|
|---|
| 1610 | its tag parser on every call);
|
|---|
| 1611 |
|
|---|
| 1612 | =item *
|
|---|
| 1613 |
|
|---|
| 1614 | make use of the new qr// construct to pre-compile the regexes they use
|
|---|
| 1615 | (whereas C<extract_tagged> uses standard string variable interpolation
|
|---|
| 1616 | to create tag-matching patterns).
|
|---|
| 1617 |
|
|---|
| 1618 | =back
|
|---|
| 1619 |
|
|---|
| 1620 | The subroutine takes up to four optional arguments (the same set as
|
|---|
| 1621 | C<extract_tagged> except for the string to be processed). It returns
|
|---|
| 1622 | a reference to a subroutine which in turn takes a single argument (the text to
|
|---|
| 1623 | be extracted from).
|
|---|
| 1624 |
|
|---|
| 1625 | In other words, the implementation of C<extract_tagged> is exactly
|
|---|
| 1626 | equivalent to:
|
|---|
| 1627 |
|
|---|
| 1628 | sub extract_tagged
|
|---|
| 1629 | {
|
|---|
| 1630 | my $text = shift;
|
|---|
| 1631 | $extractor = gen_extract_tagged(@_);
|
|---|
| 1632 | return $extractor->($text);
|
|---|
| 1633 | }
|
|---|
| 1634 |
|
|---|
| 1635 | (although C<extract_tagged> is not currently implemented that way, in order
|
|---|
| 1636 | to preserve pre-5.005 compatibility).
|
|---|
| 1637 |
|
|---|
| 1638 | Using C<gen_extract_tagged> to create extraction functions for specific tags
|
|---|
| 1639 | is a good idea if those functions are going to be called more than once, since
|
|---|
| 1640 | their performance is typically twice as good as the more general-purpose
|
|---|
| 1641 | C<extract_tagged>.
|
|---|
| 1642 |
|
|---|
| 1643 |
|
|---|
| 1644 | =head2 C<extract_quotelike>
|
|---|
| 1645 |
|
|---|
| 1646 | C<extract_quotelike> attempts to recognize, extract, and segment any
|
|---|
| 1647 | one of the various Perl quotes and quotelike operators (see
|
|---|
| 1648 | L<perlop(3)>) Nested backslashed delimiters, embedded balanced bracket
|
|---|
| 1649 | delimiters (for the quotelike operators), and trailing modifiers are
|
|---|
| 1650 | all caught. For example, in:
|
|---|
| 1651 |
|
|---|
| 1652 | extract_quotelike 'q # an octothorpe: \# (not the end of the q!) #'
|
|---|
| 1653 |
|
|---|
| 1654 | extract_quotelike ' "You said, \"Use sed\"." '
|
|---|
| 1655 |
|
|---|
| 1656 | extract_quotelike ' s{([A-Z]{1,8}\.[A-Z]{3})} /\L$1\E/; '
|
|---|
| 1657 |
|
|---|
| 1658 | extract_quotelike ' tr/\\\/\\\\/\\\//ds; '
|
|---|
| 1659 |
|
|---|
| 1660 | the full Perl quotelike operations are all extracted correctly.
|
|---|
| 1661 |
|
|---|
| 1662 | Note too that, when using the /x modifier on a regex, any comment
|
|---|
| 1663 | containing the current pattern delimiter will cause the regex to be
|
|---|
| 1664 | immediately terminated. In other words:
|
|---|
| 1665 |
|
|---|
| 1666 | 'm /
|
|---|
| 1667 | (?i) # CASE INSENSITIVE
|
|---|
| 1668 | [a-z_] # LEADING ALPHABETIC/UNDERSCORE
|
|---|
| 1669 | [a-z0-9]* # FOLLOWED BY ANY NUMBER OF ALPHANUMERICS
|
|---|
| 1670 | /x'
|
|---|
| 1671 |
|
|---|
| 1672 | will be extracted as if it were:
|
|---|
| 1673 |
|
|---|
| 1674 | 'm /
|
|---|
| 1675 | (?i) # CASE INSENSITIVE
|
|---|
| 1676 | [a-z_] # LEADING ALPHABETIC/'
|
|---|
| 1677 |
|
|---|
| 1678 | This behaviour is identical to that of the actual compiler.
|
|---|
| 1679 |
|
|---|
| 1680 | C<extract_quotelike> takes two arguments: the text to be processed and
|
|---|
| 1681 | a prefix to be matched at the very beginning of the text. If no prefix
|
|---|
| 1682 | is specified, optional whitespace is the default. If no text is given,
|
|---|
| 1683 | C<$_> is used.
|
|---|
| 1684 |
|
|---|
| 1685 | In a list context, an array of 11 elements is returned. The elements are:
|
|---|
| 1686 |
|
|---|
| 1687 | =over 4
|
|---|
| 1688 |
|
|---|
| 1689 | =item [0]
|
|---|
| 1690 |
|
|---|
| 1691 | the extracted quotelike substring (including trailing modifiers),
|
|---|
| 1692 |
|
|---|
| 1693 | =item [1]
|
|---|
| 1694 |
|
|---|
| 1695 | the remainder of the input text,
|
|---|
| 1696 |
|
|---|
| 1697 | =item [2]
|
|---|
| 1698 |
|
|---|
| 1699 | the prefix substring (if any),
|
|---|
| 1700 |
|
|---|
| 1701 | =item [3]
|
|---|
| 1702 |
|
|---|
| 1703 | the name of the quotelike operator (if any),
|
|---|
| 1704 |
|
|---|
| 1705 | =item [4]
|
|---|
| 1706 |
|
|---|
| 1707 | the left delimiter of the first block of the operation,
|
|---|
| 1708 |
|
|---|
| 1709 | =item [5]
|
|---|
| 1710 |
|
|---|
| 1711 | the text of the first block of the operation
|
|---|
| 1712 | (that is, the contents of
|
|---|
| 1713 | a quote, the regex of a match or substitution or the target list of a
|
|---|
| 1714 | translation),
|
|---|
| 1715 |
|
|---|
| 1716 | =item [6]
|
|---|
| 1717 |
|
|---|
| 1718 | the right delimiter of the first block of the operation,
|
|---|
| 1719 |
|
|---|
| 1720 | =item [7]
|
|---|
| 1721 |
|
|---|
| 1722 | the left delimiter of the second block of the operation
|
|---|
| 1723 | (that is, if it is a C<s>, C<tr>, or C<y>),
|
|---|
| 1724 |
|
|---|
| 1725 | =item [8]
|
|---|
| 1726 |
|
|---|
| 1727 | the text of the second block of the operation
|
|---|
| 1728 | (that is, the replacement of a substitution or the translation list
|
|---|
| 1729 | of a translation),
|
|---|
| 1730 |
|
|---|
| 1731 | =item [9]
|
|---|
| 1732 |
|
|---|
| 1733 | the right delimiter of the second block of the operation (if any),
|
|---|
| 1734 |
|
|---|
| 1735 | =item [10]
|
|---|
| 1736 |
|
|---|
| 1737 | the trailing modifiers on the operation (if any).
|
|---|
| 1738 |
|
|---|
| 1739 | =back
|
|---|
| 1740 |
|
|---|
| 1741 | For each of the fields marked "(if any)" the default value on success is
|
|---|
| 1742 | an empty string.
|
|---|
| 1743 | On failure, all of these values (except the remaining text) are C<undef>.
|
|---|
| 1744 |
|
|---|
| 1745 |
|
|---|
| 1746 | In a scalar context, C<extract_quotelike> returns just the complete substring
|
|---|
| 1747 | that matched a quotelike operation (or C<undef> on failure). In a scalar or
|
|---|
| 1748 | void context, the input text has the same substring (and any specified
|
|---|
| 1749 | prefix) removed.
|
|---|
| 1750 |
|
|---|
| 1751 | Examples:
|
|---|
| 1752 |
|
|---|
| 1753 | # Remove the first quotelike literal that appears in text
|
|---|
| 1754 |
|
|---|
| 1755 | $quotelike = extract_quotelike($text,'.*?');
|
|---|
| 1756 |
|
|---|
| 1757 | # Replace one or more leading whitespace-separated quotelike
|
|---|
| 1758 | # literals in $_ with "<QLL>"
|
|---|
| 1759 |
|
|---|
| 1760 | do { $_ = join '<QLL>', (extract_quotelike)[2,1] } until $@;
|
|---|
| 1761 |
|
|---|
| 1762 |
|
|---|
| 1763 | # Isolate the search pattern in a quotelike operation from $text
|
|---|
| 1764 |
|
|---|
| 1765 | ($op,$pat) = (extract_quotelike $text)[3,5];
|
|---|
| 1766 | if ($op =~ /[ms]/)
|
|---|
| 1767 | {
|
|---|
| 1768 | print "search pattern: $pat\n";
|
|---|
| 1769 | }
|
|---|
| 1770 | else
|
|---|
| 1771 | {
|
|---|
| 1772 | print "$op is not a pattern matching operation\n";
|
|---|
| 1773 | }
|
|---|
| 1774 |
|
|---|
| 1775 |
|
|---|
| 1776 | =head2 C<extract_quotelike> and "here documents"
|
|---|
| 1777 |
|
|---|
| 1778 | C<extract_quotelike> can successfully extract "here documents" from an input
|
|---|
| 1779 | string, but with an important caveat in list contexts.
|
|---|
| 1780 |
|
|---|
| 1781 | Unlike other types of quote-like literals, a here document is rarely
|
|---|
| 1782 | a contiguous substring. For example, a typical piece of code using
|
|---|
| 1783 | here document might look like this:
|
|---|
| 1784 |
|
|---|
| 1785 | <<'EOMSG' || die;
|
|---|
| 1786 | This is the message.
|
|---|
| 1787 | EOMSG
|
|---|
| 1788 | exit;
|
|---|
| 1789 |
|
|---|
| 1790 | Given this as an input string in a scalar context, C<extract_quotelike>
|
|---|
| 1791 | would correctly return the string "<<'EOMSG'\nThis is the message.\nEOMSG",
|
|---|
| 1792 | leaving the string " || die;\nexit;" in the original variable. In other words,
|
|---|
| 1793 | the two separate pieces of the here document are successfully extracted and
|
|---|
| 1794 | concatenated.
|
|---|
| 1795 |
|
|---|
| 1796 | In a list context, C<extract_quotelike> would return the list
|
|---|
| 1797 |
|
|---|
| 1798 | =over 4
|
|---|
| 1799 |
|
|---|
| 1800 | =item [0]
|
|---|
| 1801 |
|
|---|
| 1802 | "<<'EOMSG'\nThis is the message.\nEOMSG\n" (i.e. the full extracted here document,
|
|---|
| 1803 | including fore and aft delimiters),
|
|---|
| 1804 |
|
|---|
| 1805 | =item [1]
|
|---|
| 1806 |
|
|---|
| 1807 | " || die;\nexit;" (i.e. the remainder of the input text, concatenated),
|
|---|
| 1808 |
|
|---|
| 1809 | =item [2]
|
|---|
| 1810 |
|
|---|
| 1811 | "" (i.e. the prefix substring -- trivial in this case),
|
|---|
| 1812 |
|
|---|
| 1813 | =item [3]
|
|---|
| 1814 |
|
|---|
| 1815 | "<<" (i.e. the "name" of the quotelike operator)
|
|---|
| 1816 |
|
|---|
| 1817 | =item [4]
|
|---|
| 1818 |
|
|---|
| 1819 | "'EOMSG'" (i.e. the left delimiter of the here document, including any quotes),
|
|---|
| 1820 |
|
|---|
| 1821 | =item [5]
|
|---|
| 1822 |
|
|---|
| 1823 | "This is the message.\n" (i.e. the text of the here document),
|
|---|
| 1824 |
|
|---|
| 1825 | =item [6]
|
|---|
| 1826 |
|
|---|
| 1827 | "EOMSG" (i.e. the right delimiter of the here document),
|
|---|
| 1828 |
|
|---|
| 1829 | =item [7..10]
|
|---|
| 1830 |
|
|---|
| 1831 | "" (a here document has no second left delimiter, second text, second right
|
|---|
| 1832 | delimiter, or trailing modifiers).
|
|---|
| 1833 |
|
|---|
| 1834 | =back
|
|---|
| 1835 |
|
|---|
| 1836 | However, the matching position of the input variable would be set to
|
|---|
| 1837 | "exit;" (i.e. I<after> the closing delimiter of the here document),
|
|---|
| 1838 | which would cause the earlier " || die;\nexit;" to be skipped in any
|
|---|
| 1839 | sequence of code fragment extractions.
|
|---|
| 1840 |
|
|---|
| 1841 | To avoid this problem, when it encounters a here document whilst
|
|---|
| 1842 | extracting from a modifiable string, C<extract_quotelike> silently
|
|---|
| 1843 | rearranges the string to an equivalent piece of Perl:
|
|---|
| 1844 |
|
|---|
| 1845 | <<'EOMSG'
|
|---|
| 1846 | This is the message.
|
|---|
| 1847 | EOMSG
|
|---|
| 1848 | || die;
|
|---|
| 1849 | exit;
|
|---|
| 1850 |
|
|---|
| 1851 | in which the here document I<is> contiguous. It still leaves the
|
|---|
| 1852 | matching position after the here document, but now the rest of the line
|
|---|
| 1853 | on which the here document starts is not skipped.
|
|---|
| 1854 |
|
|---|
| 1855 | To prevent <extract_quotelike> from mucking about with the input in this way
|
|---|
| 1856 | (this is the only case where a list-context C<extract_quotelike> does so),
|
|---|
| 1857 | you can pass the input variable as an interpolated literal:
|
|---|
| 1858 |
|
|---|
| 1859 | $quotelike = extract_quotelike("$var");
|
|---|
| 1860 |
|
|---|
| 1861 |
|
|---|
| 1862 | =head2 C<extract_codeblock>
|
|---|
| 1863 |
|
|---|
| 1864 | C<extract_codeblock> attempts to recognize and extract a balanced
|
|---|
| 1865 | bracket delimited substring that may contain unbalanced brackets
|
|---|
| 1866 | inside Perl quotes or quotelike operations. That is, C<extract_codeblock>
|
|---|
| 1867 | is like a combination of C<"extract_bracketed"> and
|
|---|
| 1868 | C<"extract_quotelike">.
|
|---|
| 1869 |
|
|---|
| 1870 | C<extract_codeblock> takes the same initial three parameters as C<extract_bracketed>:
|
|---|
| 1871 | a text to process, a set of delimiter brackets to look for, and a prefix to
|
|---|
| 1872 | match first. It also takes an optional fourth parameter, which allows the
|
|---|
| 1873 | outermost delimiter brackets to be specified separately (see below).
|
|---|
| 1874 |
|
|---|
| 1875 | Omitting the first argument (input text) means process C<$_> instead.
|
|---|
| 1876 | Omitting the second argument (delimiter brackets) indicates that only C<'{'> is to be used.
|
|---|
| 1877 | Omitting the third argument (prefix argument) implies optional whitespace at the start.
|
|---|
| 1878 | Omitting the fourth argument (outermost delimiter brackets) indicates that the
|
|---|
| 1879 | value of the second argument is to be used for the outermost delimiters.
|
|---|
| 1880 |
|
|---|
| 1881 | Once the prefix an dthe outermost opening delimiter bracket have been
|
|---|
| 1882 | recognized, code blocks are extracted by stepping through the input text and
|
|---|
| 1883 | trying the following alternatives in sequence:
|
|---|
| 1884 |
|
|---|
| 1885 | =over 4
|
|---|
| 1886 |
|
|---|
| 1887 | =item 1.
|
|---|
| 1888 |
|
|---|
| 1889 | Try and match a closing delimiter bracket. If the bracket was the same
|
|---|
| 1890 | species as the last opening bracket, return the substring to that
|
|---|
| 1891 | point. If the bracket was mismatched, return an error.
|
|---|
| 1892 |
|
|---|
| 1893 | =item 2.
|
|---|
| 1894 |
|
|---|
| 1895 | Try to match a quote or quotelike operator. If found, call
|
|---|
| 1896 | C<extract_quotelike> to eat it. If C<extract_quotelike> fails, return
|
|---|
| 1897 | the error it returned. Otherwise go back to step 1.
|
|---|
| 1898 |
|
|---|
| 1899 | =item 3.
|
|---|
| 1900 |
|
|---|
| 1901 | Try to match an opening delimiter bracket. If found, call
|
|---|
| 1902 | C<extract_codeblock> recursively to eat the embedded block. If the
|
|---|
| 1903 | recursive call fails, return an error. Otherwise, go back to step 1.
|
|---|
| 1904 |
|
|---|
| 1905 | =item 4.
|
|---|
| 1906 |
|
|---|
| 1907 | Unconditionally match a bareword or any other single character, and
|
|---|
| 1908 | then go back to step 1.
|
|---|
| 1909 |
|
|---|
| 1910 | =back
|
|---|
| 1911 |
|
|---|
| 1912 |
|
|---|
| 1913 | Examples:
|
|---|
| 1914 |
|
|---|
| 1915 | # Find a while loop in the text
|
|---|
| 1916 |
|
|---|
| 1917 | if ($text =~ s/.*?while\s*\{/{/)
|
|---|
| 1918 | {
|
|---|
| 1919 | $loop = "while " . extract_codeblock($text);
|
|---|
| 1920 | }
|
|---|
| 1921 |
|
|---|
| 1922 | # Remove the first round-bracketed list (which may include
|
|---|
| 1923 | # round- or curly-bracketed code blocks or quotelike operators)
|
|---|
| 1924 |
|
|---|
| 1925 | extract_codeblock $text, "(){}", '[^(]*';
|
|---|
| 1926 |
|
|---|
| 1927 |
|
|---|
| 1928 | The ability to specify a different outermost delimiter bracket is useful
|
|---|
| 1929 | in some circumstances. For example, in the Parse::RecDescent module,
|
|---|
| 1930 | parser actions which are to be performed only on a successful parse
|
|---|
| 1931 | are specified using a C<E<lt>defer:...E<gt>> directive. For example:
|
|---|
| 1932 |
|
|---|
| 1933 | sentence: subject verb object
|
|---|
| 1934 | <defer: {$::theVerb = $item{verb}} >
|
|---|
| 1935 |
|
|---|
| 1936 | Parse::RecDescent uses C<extract_codeblock($text, '{}E<lt>E<gt>')> to extract the code
|
|---|
| 1937 | within the C<E<lt>defer:...E<gt>> directive, but there's a problem.
|
|---|
| 1938 |
|
|---|
| 1939 | A deferred action like this:
|
|---|
| 1940 |
|
|---|
| 1941 | <defer: {if ($count>10) {$count--}} >
|
|---|
| 1942 |
|
|---|
| 1943 | will be incorrectly parsed as:
|
|---|
| 1944 |
|
|---|
| 1945 | <defer: {if ($count>
|
|---|
| 1946 |
|
|---|
| 1947 | because the "less than" operator is interpreted as a closing delimiter.
|
|---|
| 1948 |
|
|---|
| 1949 | But, by extracting the directive using
|
|---|
| 1950 | S<C<extract_codeblock($text, '{}', undef, 'E<lt>E<gt>')>>
|
|---|
| 1951 | the '>' character is only treated as a delimited at the outermost
|
|---|
| 1952 | level of the code block, so the directive is parsed correctly.
|
|---|
| 1953 |
|
|---|
| 1954 | =head2 C<extract_multiple>
|
|---|
| 1955 |
|
|---|
| 1956 | The C<extract_multiple> subroutine takes a string to be processed and a
|
|---|
| 1957 | list of extractors (subroutines or regular expressions) to apply to that string.
|
|---|
| 1958 |
|
|---|
| 1959 | In an array context C<extract_multiple> returns an array of substrings
|
|---|
| 1960 | of the original string, as extracted by the specified extractors.
|
|---|
| 1961 | In a scalar context, C<extract_multiple> returns the first
|
|---|
| 1962 | substring successfully extracted from the original string. In both
|
|---|
| 1963 | scalar and void contexts the original string has the first successfully
|
|---|
| 1964 | extracted substring removed from it. In all contexts
|
|---|
| 1965 | C<extract_multiple> starts at the current C<pos> of the string, and
|
|---|
| 1966 | sets that C<pos> appropriately after it matches.
|
|---|
| 1967 |
|
|---|
| 1968 | Hence, the aim of of a call to C<extract_multiple> in a list context
|
|---|
| 1969 | is to split the processed string into as many non-overlapping fields as
|
|---|
| 1970 | possible, by repeatedly applying each of the specified extractors
|
|---|
| 1971 | to the remainder of the string. Thus C<extract_multiple> is
|
|---|
| 1972 | a generalized form of Perl's C<split> subroutine.
|
|---|
| 1973 |
|
|---|
| 1974 | The subroutine takes up to four optional arguments:
|
|---|
| 1975 |
|
|---|
| 1976 | =over 4
|
|---|
| 1977 |
|
|---|
| 1978 | =item 1.
|
|---|
| 1979 |
|
|---|
| 1980 | A string to be processed (C<$_> if the string is omitted or C<undef>)
|
|---|
| 1981 |
|
|---|
| 1982 | =item 2.
|
|---|
| 1983 |
|
|---|
| 1984 | A reference to a list of subroutine references and/or qr// objects and/or
|
|---|
| 1985 | literal strings and/or hash references, specifying the extractors
|
|---|
| 1986 | to be used to split the string. If this argument is omitted (or
|
|---|
| 1987 | C<undef>) the list:
|
|---|
| 1988 |
|
|---|
| 1989 | [
|
|---|
| 1990 | sub { extract_variable($_[0], '') },
|
|---|
| 1991 | sub { extract_quotelike($_[0],'') },
|
|---|
| 1992 | sub { extract_codeblock($_[0],'{}','') },
|
|---|
| 1993 | ]
|
|---|
| 1994 |
|
|---|
| 1995 | is used.
|
|---|
| 1996 |
|
|---|
| 1997 |
|
|---|
| 1998 | =item 3.
|
|---|
| 1999 |
|
|---|
| 2000 | An number specifying the maximum number of fields to return. If this
|
|---|
| 2001 | argument is omitted (or C<undef>), split continues as long as possible.
|
|---|
| 2002 |
|
|---|
| 2003 | If the third argument is I<N>, then extraction continues until I<N> fields
|
|---|
| 2004 | have been successfully extracted, or until the string has been completely
|
|---|
| 2005 | processed.
|
|---|
| 2006 |
|
|---|
| 2007 | Note that in scalar and void contexts the value of this argument is
|
|---|
| 2008 | automatically reset to 1 (under C<-w>, a warning is issued if the argument
|
|---|
| 2009 | has to be reset).
|
|---|
| 2010 |
|
|---|
| 2011 | =item 4.
|
|---|
| 2012 |
|
|---|
| 2013 | A value indicating whether unmatched substrings (see below) within the
|
|---|
| 2014 | text should be skipped or returned as fields. If the value is true,
|
|---|
| 2015 | such substrings are skipped. Otherwise, they are returned.
|
|---|
| 2016 |
|
|---|
| 2017 | =back
|
|---|
| 2018 |
|
|---|
| 2019 | The extraction process works by applying each extractor in
|
|---|
| 2020 | sequence to the text string.
|
|---|
| 2021 |
|
|---|
| 2022 | If the extractor is a subroutine it is called in a list context and is
|
|---|
| 2023 | expected to return a list of a single element, namely the extracted
|
|---|
| 2024 | text. It may optionally also return two further arguments: a string
|
|---|
| 2025 | representing the text left after extraction (like $' for a pattern
|
|---|
| 2026 | match), and a string representing any prefix skipped before the
|
|---|
| 2027 | extraction (like $` in a pattern match). Note that this is designed
|
|---|
| 2028 | to facilitate the use of other Text::Balanced subroutines with
|
|---|
| 2029 | C<extract_multiple>. Note too that the value returned by an extractor
|
|---|
| 2030 | subroutine need not bear any relationship to the corresponding substring
|
|---|
| 2031 | of the original text (see examples below).
|
|---|
| 2032 |
|
|---|
| 2033 | If the extractor is a precompiled regular expression or a string,
|
|---|
| 2034 | it is matched against the text in a scalar context with a leading
|
|---|
| 2035 | '\G' and the gc modifiers enabled. The extracted value is either
|
|---|
| 2036 | $1 if that variable is defined after the match, or else the
|
|---|
| 2037 | complete match (i.e. $&).
|
|---|
| 2038 |
|
|---|
| 2039 | If the extractor is a hash reference, it must contain exactly one element.
|
|---|
| 2040 | The value of that element is one of the
|
|---|
| 2041 | above extractor types (subroutine reference, regular expression, or string).
|
|---|
| 2042 | The key of that element is the name of a class into which the successful
|
|---|
| 2043 | return value of the extractor will be blessed.
|
|---|
| 2044 |
|
|---|
| 2045 | If an extractor returns a defined value, that value is immediately
|
|---|
| 2046 | treated as the next extracted field and pushed onto the list of fields.
|
|---|
| 2047 | If the extractor was specified in a hash reference, the field is also
|
|---|
| 2048 | blessed into the appropriate class,
|
|---|
| 2049 |
|
|---|
| 2050 | If the extractor fails to match (in the case of a regex extractor), or returns an empty list or an undefined value (in the case of a subroutine extractor), it is
|
|---|
| 2051 | assumed to have failed to extract.
|
|---|
| 2052 | If none of the extractor subroutines succeeds, then one
|
|---|
| 2053 | character is extracted from the start of the text and the extraction
|
|---|
| 2054 | subroutines reapplied. Characters which are thus removed are accumulated and
|
|---|
| 2055 | eventually become the next field (unless the fourth argument is true, in which
|
|---|
| 2056 | case they are disgarded).
|
|---|
| 2057 |
|
|---|
| 2058 | For example, the following extracts substrings that are valid Perl variables:
|
|---|
| 2059 |
|
|---|
| 2060 | @fields = extract_multiple($text,
|
|---|
| 2061 | [ sub { extract_variable($_[0]) } ],
|
|---|
| 2062 | undef, 1);
|
|---|
| 2063 |
|
|---|
| 2064 | This example separates a text into fields which are quote delimited,
|
|---|
| 2065 | curly bracketed, and anything else. The delimited and bracketed
|
|---|
| 2066 | parts are also blessed to identify them (the "anything else" is unblessed):
|
|---|
| 2067 |
|
|---|
| 2068 | @fields = extract_multiple($text,
|
|---|
| 2069 | [
|
|---|
| 2070 | { Delim => sub { extract_delimited($_[0],q{'"}) } },
|
|---|
| 2071 | { Brack => sub { extract_bracketed($_[0],'{}') } },
|
|---|
| 2072 | ]);
|
|---|
| 2073 |
|
|---|
| 2074 | This call extracts the next single substring that is a valid Perl quotelike
|
|---|
| 2075 | operator (and removes it from $text):
|
|---|
| 2076 |
|
|---|
| 2077 | $quotelike = extract_multiple($text,
|
|---|
| 2078 | [
|
|---|
| 2079 | sub { extract_quotelike($_[0]) },
|
|---|
| 2080 | ], undef, 1);
|
|---|
| 2081 |
|
|---|
| 2082 | Finally, here is yet another way to do comma-separated value parsing:
|
|---|
| 2083 |
|
|---|
| 2084 | @fields = extract_multiple($csv_text,
|
|---|
| 2085 | [
|
|---|
| 2086 | sub { extract_delimited($_[0],q{'"}) },
|
|---|
| 2087 | qr/([^,]+)(.*)/,
|
|---|
| 2088 | ],
|
|---|
| 2089 | undef,1);
|
|---|
| 2090 |
|
|---|
| 2091 | The list in the second argument means:
|
|---|
| 2092 | I<"Try and extract a ' or " delimited string, otherwise extract anything up to a comma...">.
|
|---|
| 2093 | The undef third argument means:
|
|---|
| 2094 | I<"...as many times as possible...">,
|
|---|
| 2095 | and the true value in the fourth argument means
|
|---|
| 2096 | I<"...discarding anything else that appears (i.e. the commas)">.
|
|---|
| 2097 |
|
|---|
| 2098 | If you wanted the commas preserved as separate fields (i.e. like split
|
|---|
| 2099 | does if your split pattern has capturing parentheses), you would
|
|---|
| 2100 | just make the last parameter undefined (or remove it).
|
|---|
| 2101 |
|
|---|
| 2102 |
|
|---|
| 2103 | =head2 C<gen_delimited_pat>
|
|---|
| 2104 |
|
|---|
| 2105 | The C<gen_delimited_pat> subroutine takes a single (string) argument and
|
|---|
| 2106 | > builds a Friedl-style optimized regex that matches a string delimited
|
|---|
| 2107 | by any one of the characters in the single argument. For example:
|
|---|
| 2108 |
|
|---|
| 2109 | gen_delimited_pat(q{'"})
|
|---|
| 2110 |
|
|---|
| 2111 | returns the regex:
|
|---|
| 2112 |
|
|---|
| 2113 | (?:\"(?:\\\"|(?!\").)*\"|\'(?:\\\'|(?!\').)*\')
|
|---|
| 2114 |
|
|---|
| 2115 | Note that the specified delimiters are automatically quotemeta'd.
|
|---|
| 2116 |
|
|---|
| 2117 | A typical use of C<gen_delimited_pat> would be to build special purpose tags
|
|---|
| 2118 | for C<extract_tagged>. For example, to properly ignore "empty" XML elements
|
|---|
| 2119 | (which might contain quoted strings):
|
|---|
| 2120 |
|
|---|
| 2121 | my $empty_tag = '<(' . gen_delimited_pat(q{'"}) . '|.)+/>';
|
|---|
| 2122 |
|
|---|
| 2123 | extract_tagged($text, undef, undef, undef, {ignore => [$empty_tag]} );
|
|---|
| 2124 |
|
|---|
| 2125 |
|
|---|
| 2126 | C<gen_delimited_pat> may also be called with an optional second argument,
|
|---|
| 2127 | which specifies the "escape" character(s) to be used for each delimiter.
|
|---|
| 2128 | For example to match a Pascal-style string (where ' is the delimiter
|
|---|
| 2129 | and '' is a literal ' within the string):
|
|---|
| 2130 |
|
|---|
| 2131 | gen_delimited_pat(q{'},q{'});
|
|---|
| 2132 |
|
|---|
| 2133 | Different escape characters can be specified for different delimiters.
|
|---|
| 2134 | For example, to specify that '/' is the escape for single quotes
|
|---|
| 2135 | and '%' is the escape for double quotes:
|
|---|
| 2136 |
|
|---|
| 2137 | gen_delimited_pat(q{'"},q{/%});
|
|---|
| 2138 |
|
|---|
| 2139 | If more delimiters than escape chars are specified, the last escape char
|
|---|
| 2140 | is used for the remaining delimiters.
|
|---|
| 2141 | If no escape char is specified for a given specified delimiter, '\' is used.
|
|---|
| 2142 |
|
|---|
| 2143 | Note that
|
|---|
| 2144 | C<gen_delimited_pat> was previously called
|
|---|
| 2145 | C<delimited_pat>. That name may still be used, but is now deprecated.
|
|---|
| 2146 |
|
|---|
| 2147 |
|
|---|
| 2148 | =head1 DIAGNOSTICS
|
|---|
| 2149 |
|
|---|
| 2150 | In a list context, all the functions return C<(undef,$original_text)>
|
|---|
| 2151 | on failure. In a scalar context, failure is indicated by returning C<undef>
|
|---|
| 2152 | (in this case the input text is not modified in any way).
|
|---|
| 2153 |
|
|---|
| 2154 | In addition, on failure in I<any> context, the C<$@> variable is set.
|
|---|
| 2155 | Accessing C<$@-E<gt>{error}> returns one of the error diagnostics listed
|
|---|
| 2156 | below.
|
|---|
| 2157 | Accessing C<$@-E<gt>{pos}> returns the offset into the original string at
|
|---|
| 2158 | which the error was detected (although not necessarily where it occurred!)
|
|---|
| 2159 | Printing C<$@> directly produces the error message, with the offset appended.
|
|---|
| 2160 | On success, the C<$@> variable is guaranteed to be C<undef>.
|
|---|
| 2161 |
|
|---|
| 2162 | The available diagnostics are:
|
|---|
| 2163 |
|
|---|
| 2164 | =over 4
|
|---|
| 2165 |
|
|---|
| 2166 | =item C<Did not find a suitable bracket: "%s">
|
|---|
| 2167 |
|
|---|
| 2168 | The delimiter provided to C<extract_bracketed> was not one of
|
|---|
| 2169 | C<'()[]E<lt>E<gt>{}'>.
|
|---|
| 2170 |
|
|---|
| 2171 | =item C<Did not find prefix: /%s/>
|
|---|
| 2172 |
|
|---|
| 2173 | A non-optional prefix was specified but wasn't found at the start of the text.
|
|---|
| 2174 |
|
|---|
| 2175 | =item C<Did not find opening bracket after prefix: "%s">
|
|---|
| 2176 |
|
|---|
| 2177 | C<extract_bracketed> or C<extract_codeblock> was expecting a
|
|---|
| 2178 | particular kind of bracket at the start of the text, and didn't find it.
|
|---|
| 2179 |
|
|---|
| 2180 | =item C<No quotelike operator found after prefix: "%s">
|
|---|
| 2181 |
|
|---|
| 2182 | C<extract_quotelike> didn't find one of the quotelike operators C<q>,
|
|---|
| 2183 | C<qq>, C<qw>, C<qx>, C<s>, C<tr> or C<y> at the start of the substring
|
|---|
| 2184 | it was extracting.
|
|---|
| 2185 |
|
|---|
| 2186 | =item C<Unmatched closing bracket: "%c">
|
|---|
| 2187 |
|
|---|
| 2188 | C<extract_bracketed>, C<extract_quotelike> or C<extract_codeblock> encountered
|
|---|
| 2189 | a closing bracket where none was expected.
|
|---|
| 2190 |
|
|---|
| 2191 | =item C<Unmatched opening bracket(s): "%s">
|
|---|
| 2192 |
|
|---|
| 2193 | C<extract_bracketed>, C<extract_quotelike> or C<extract_codeblock> ran
|
|---|
| 2194 | out of characters in the text before closing one or more levels of nested
|
|---|
| 2195 | brackets.
|
|---|
| 2196 |
|
|---|
| 2197 | =item C<Unmatched embedded quote (%s)>
|
|---|
| 2198 |
|
|---|
| 2199 | C<extract_bracketed> attempted to match an embedded quoted substring, but
|
|---|
| 2200 | failed to find a closing quote to match it.
|
|---|
| 2201 |
|
|---|
| 2202 | =item C<Did not find closing delimiter to match '%s'>
|
|---|
| 2203 |
|
|---|
| 2204 | C<extract_quotelike> was unable to find a closing delimiter to match the
|
|---|
| 2205 | one that opened the quote-like operation.
|
|---|
| 2206 |
|
|---|
| 2207 | =item C<Mismatched closing bracket: expected "%c" but found "%s">
|
|---|
| 2208 |
|
|---|
| 2209 | C<extract_bracketed>, C<extract_quotelike> or C<extract_codeblock> found
|
|---|
| 2210 | a valid bracket delimiter, but it was the wrong species. This usually
|
|---|
| 2211 | indicates a nesting error, but may indicate incorrect quoting or escaping.
|
|---|
| 2212 |
|
|---|
| 2213 | =item C<No block delimiter found after quotelike "%s">
|
|---|
| 2214 |
|
|---|
| 2215 | C<extract_quotelike> or C<extract_codeblock> found one of the
|
|---|
| 2216 | quotelike operators C<q>, C<qq>, C<qw>, C<qx>, C<s>, C<tr> or C<y>
|
|---|
| 2217 | without a suitable block after it.
|
|---|
| 2218 |
|
|---|
| 2219 | =item C<Did not find leading dereferencer>
|
|---|
| 2220 |
|
|---|
| 2221 | C<extract_variable> was expecting one of '$', '@', or '%' at the start of
|
|---|
| 2222 | a variable, but didn't find any of them.
|
|---|
| 2223 |
|
|---|
| 2224 | =item C<Bad identifier after dereferencer>
|
|---|
| 2225 |
|
|---|
| 2226 | C<extract_variable> found a '$', '@', or '%' indicating a variable, but that
|
|---|
| 2227 | character was not followed by a legal Perl identifier.
|
|---|
| 2228 |
|
|---|
| 2229 | =item C<Did not find expected opening bracket at %s>
|
|---|
| 2230 |
|
|---|
| 2231 | C<extract_codeblock> failed to find any of the outermost opening brackets
|
|---|
| 2232 | that were specified.
|
|---|
| 2233 |
|
|---|
| 2234 | =item C<Improperly nested codeblock at %s>
|
|---|
| 2235 |
|
|---|
| 2236 | A nested code block was found that started with a delimiter that was specified
|
|---|
| 2237 | as being only to be used as an outermost bracket.
|
|---|
| 2238 |
|
|---|
| 2239 | =item C<Missing second block for quotelike "%s">
|
|---|
| 2240 |
|
|---|
| 2241 | C<extract_codeblock> or C<extract_quotelike> found one of the
|
|---|
| 2242 | quotelike operators C<s>, C<tr> or C<y> followed by only one block.
|
|---|
| 2243 |
|
|---|
| 2244 | =item C<No match found for opening bracket>
|
|---|
| 2245 |
|
|---|
| 2246 | C<extract_codeblock> failed to find a closing bracket to match the outermost
|
|---|
| 2247 | opening bracket.
|
|---|
| 2248 |
|
|---|
| 2249 | =item C<Did not find opening tag: /%s/>
|
|---|
| 2250 |
|
|---|
| 2251 | C<extract_tagged> did not find a suitable opening tag (after any specified
|
|---|
| 2252 | prefix was removed).
|
|---|
| 2253 |
|
|---|
| 2254 | =item C<Unable to construct closing tag to match: /%s/>
|
|---|
| 2255 |
|
|---|
| 2256 | C<extract_tagged> matched the specified opening tag and tried to
|
|---|
| 2257 | modify the matched text to produce a matching closing tag (because
|
|---|
| 2258 | none was specified). It failed to generate the closing tag, almost
|
|---|
| 2259 | certainly because the opening tag did not start with a
|
|---|
| 2260 | bracket of some kind.
|
|---|
| 2261 |
|
|---|
| 2262 | =item C<Found invalid nested tag: %s>
|
|---|
| 2263 |
|
|---|
| 2264 | C<extract_tagged> found a nested tag that appeared in the "reject" list
|
|---|
| 2265 | (and the failure mode was not "MAX" or "PARA").
|
|---|
| 2266 |
|
|---|
| 2267 | =item C<Found unbalanced nested tag: %s>
|
|---|
| 2268 |
|
|---|
| 2269 | C<extract_tagged> found a nested opening tag that was not matched by a
|
|---|
| 2270 | corresponding nested closing tag (and the failure mode was not "MAX" or "PARA").
|
|---|
| 2271 |
|
|---|
| 2272 | =item C<Did not find closing tag>
|
|---|
| 2273 |
|
|---|
| 2274 | C<extract_tagged> reached the end of the text without finding a closing tag
|
|---|
| 2275 | to match the original opening tag (and the failure mode was not
|
|---|
| 2276 | "MAX" or "PARA").
|
|---|
| 2277 |
|
|---|
| 2278 |
|
|---|
| 2279 |
|
|---|
| 2280 |
|
|---|
| 2281 | =back
|
|---|
| 2282 |
|
|---|
| 2283 |
|
|---|
| 2284 | =head1 AUTHOR
|
|---|
| 2285 |
|
|---|
| 2286 | Damian Conway ([email protected])
|
|---|
| 2287 |
|
|---|
| 2288 |
|
|---|
| 2289 | =head1 BUGS AND IRRITATIONS
|
|---|
| 2290 |
|
|---|
| 2291 | There are undoubtedly serious bugs lurking somewhere in this code, if
|
|---|
| 2292 | only because parts of it give the impression of understanding a great deal
|
|---|
| 2293 | more about Perl than they really do.
|
|---|
| 2294 |
|
|---|
| 2295 | Bug reports and other feedback are most welcome.
|
|---|
| 2296 |
|
|---|
| 2297 |
|
|---|
| 2298 | =head1 COPYRIGHT
|
|---|
| 2299 |
|
|---|
| 2300 | Copyright (c) 1997-2001, Damian Conway. All Rights Reserved.
|
|---|
| 2301 | This module is free software. It may be used, redistributed
|
|---|
| 2302 | and/or modified under the same terms as Perl itself.
|
|---|
