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Eliminate unused BACK regnode
[perl5.git] / regcomp.sym
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1# regcomp.sym
2#
3# File has two sections, divided by a line of dashes '-'.
4#
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5# Lines beginning with # are ignored, except for those that start with #*
6# which are included in pod/perldebguts.pod. # within a line may be part
7# of a description.
03363afd 8#
486ec47a 9# First section is for regops, second section is for regmatch-states
03363afd 10#
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11# Note that the order in this file is important.
12#
03363afd 13# Format for first section:
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14# NAME \s+ TYPE, arg-description [num-args] [flags] [longjump-len] ; DESCRIPTION
15# flag <S> means is REGNODE_SIMPLE; flag <V> means is REGNODE_VARIES
03363afd 16#
3dab1dad 17#
c476f425 18# run perl regen.pl after editing this file
3dab1dad 19
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20
21
381b57db 22#* Exit points
1de06328 23
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24END END, no ; End of program.
25SUCCEED END, no ; Return from a subroutine, basically.
d09b2d29 26
d3d47aac 27#* Line Start Anchors:
1645b83c 28#Note flags field for SBOL indicates if it is a /^/ or a /\A/
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29SBOL BOL, no ; Match "" at beginning of line: /^/, /\A/
30MBOL BOL, no ; Same, assuming multiline: /^/m
31
32#* Line End Anchors:
33SEOL EOL, no ; Match "" at end of line: /$/
34MEOL EOL, no ; Same, assuming multiline: /$/m
35EOS EOL, no ; Match "" at end of string: /\z/
36
37#* Match Start Anchors:
38GPOS GPOS, no ; Matches where last m//g left off.
39
40#* Word Boundary Opcodes:
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41# The regops that have varieties that vary depending on the character set regex
42# modifiers have to ordered thusly: /d, /l, /u, /a, /aa. This is because code
43# in regcomp.c uses the enum value of the modifier as an offset from the /d
44# version. The complements must come after the non-complements.
3018b823 45# BOUND, POSIX and their complements are affected, as well as EXACTF.
850b7ec9 46BOUND BOUND, no ; Match "" at any word boundary using native charset rules for non-utf8
f2284805 47BOUNDL BOUND, no ; Match "" at any locale word boundary
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48BOUNDU BOUND, no ; Match "" at any word boundary using Unicode rules
49BOUNDA BOUND, no ; Match "" at any word boundary using ASCII rules
693fefec 50# All NBOUND nodes are required by code in regexec.c to be greater than all BOUND ones
850b7ec9 51NBOUND NBOUND, no ; Match "" at any word non-boundary using native charset rules for non-utf8
f2284805 52NBOUNDL NBOUND, no ; Match "" at any locale word non-boundary
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53NBOUNDU NBOUND, no ; Match "" at any word non-boundary using Unicode rules
54NBOUNDA NBOUND, no ; Match "" at any word non-boundary using ASCII rules
d09b2d29 55
381b57db 56#* [Special] alternatives:
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57REG_ANY REG_ANY, no 0 S ; Match any one character (except newline).
58SANY REG_ANY, no 0 S ; Match any one character.
59CANY REG_ANY, no 0 S ; Match any one byte.
975a06f7 60ANYOF ANYOF, sv 1 S ; Match character in (or not in) this class, single char match only
693fefec 61
d3d47aac 62#* POSIX Character Classes:
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63# Order of the below is important. See ordering comment above.
64POSIXD POSIXD, none 0 S ; Some [[:class:]] under /d; the FLAGS field gives which one
65POSIXL POSIXD, none 0 S ; Some [[:class:]] under /l; the FLAGS field gives which one
66POSIXU POSIXD, none 0 S ; Some [[:class:]] under /u; the FLAGS field gives which one
3615ea58 67POSIXA POSIXD, none 0 S ; Some [[:class:]] under /a; the FLAGS field gives which one
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68NPOSIXD NPOSIXD, none 0 S ; complement of POSIXD, [[:^class:]]
69NPOSIXL NPOSIXD, none 0 S ; complement of POSIXL, [[:^class:]]
70NPOSIXU NPOSIXD, none 0 S ; complement of POSIXU, [[:^class:]]
9e84774b 71NPOSIXA NPOSIXD, none 0 S ; complement of POSIXA, [[:^class:]]
3018b823 72# End of order is important
693fefec 73
2448cf39 74CLUMP CLUMP, no 0 V ; Match any extended grapheme cluster sequence
d09b2d29 75
381b57db 76#* Alternation
1de06328 77
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78#* BRANCH The set of branches constituting a single choice are
79#* hooked together with their "next" pointers, since
80#* precedence prevents anything being concatenated to
81#* any individual branch. The "next" pointer of the last
82#* BRANCH in a choice points to the thing following the
83#* whole choice. This is also where the final "next"
84#* pointer of each individual branch points; each branch
85#* starts with the operand node of a BRANCH node.
86#*
f9ef50a7 87BRANCH BRANCH, node 0 V ; Match this alternative, or the next...
d09b2d29 88
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89#*Literals
90# NOTE: the relative ordering of these types is important do not change it
1de06328 91
f8abb37e 92EXACT EXACT, str ; Match this string (preceded by length).
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93EXACTF EXACT, str ; Match this non-UTF-8 string (not guaranteed to be folded) using /id rules (w/len).
94EXACTFL EXACT, str ; Match this string (not guaranteed to be folded) using /il rules (w/len).
3c760661 95EXACTFU EXACT, str ; Match this string (folded iff in UTF-8, length in folding doesn't change if not in UTF-8) using /iu rules (w/len).
8c1182fd 96EXACTFA EXACT, str ; Match this string (not guaranteed to be folded) using /iaa rules (w/len).
3c760661 97EXACTFU_SS EXACT, str ; Match this string (folded iff in UTF-8, length in folding may change even if not in UTF-8) using /iu rules (w/len).
098b07d5 98EXACTFA_NO_TRIE EXACT, str ; Match this string (which is not trie-able; not guaranteed to be folded) using /iaa rules (w/len).
d09b2d29 99
381b57db 100#*Do nothing types
1de06328 101
f8abb37e 102NOTHING NOTHING, no ; Match empty string.
65aa4ca7 103#*A variant of above which delimits a group, thus stops optimizations
f8abb37e 104TAIL NOTHING, no ; Match empty string. Can jump here from outside.
d09b2d29 105
381b57db 106#*Loops
1de06328 107
65aa4ca7 108#* STAR,PLUS '?', and complex '*' and '+', are implemented as
62e6ef33 109#* circular BRANCH structures. Simple cases
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110#* (one character per match) are implemented with STAR
111#* and PLUS for speed and to minimize recursive plunges.
112#*
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113STAR STAR, node 0 V ; Match this (simple) thing 0 or more times.
114PLUS PLUS, node 0 V ; Match this (simple) thing 1 or more times.
d09b2d29 115
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116CURLY CURLY, sv 2 V ; Match this simple thing {n,m} times.
117CURLYN CURLY, no 2 V ; Capture next-after-this simple thing
118CURLYM CURLY, no 2 V ; Capture this medium-complex thing {n,m} times.
119CURLYX CURLY, sv 2 V ; Match this complex thing {n,m} times.
d09b2d29 120
65aa4ca7 121#*This terminator creates a loop structure for CURLYX
f9ef50a7 122WHILEM WHILEM, no 0 V ; Do curly processing and see if rest matches.
d09b2d29 123
381b57db 124#*Buffer related
1de06328 125
65aa4ca7 126#*OPEN,CLOSE,GROUPP ...are numbered at compile time.
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127OPEN OPEN, num 1 ; Mark this point in input as start of #n.
128CLOSE CLOSE, num 1 ; Analogous to OPEN.
d09b2d29 129
f9ef50a7 130REF REF, num 1 V ; Match some already matched string
850b7ec9 131REFF REF, num 1 V ; Match already matched string, folded using native charset rules for non-utf8
f9ef50a7 132REFFL REF, num 1 V ; Match already matched string, folded in loc.
781aab5c 133# N?REFF[AU] could have been implemented using the FLAGS field of the
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134# regnode, but by having a separate node type, we can use the existing switch
135# statement to avoid some tests
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136REFFU REF, num 1 V ; Match already matched string, folded using unicode rules for non-utf8
137REFFA REF, num 1 V ; Match already matched string, folded using unicode rules for non-utf8, no mixing ASCII, non-ASCII
d09b2d29 138
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139#*Named references. Code in regcomp.c assumes that these all are after
140#*the numbered references
01f98ec2 141NREF REF, no-sv 1 V ; Match some already matched string
850b7ec9 142NREFF REF, no-sv 1 V ; Match already matched string, folded using native charset rules for non-utf8
01f98ec2 143NREFFL REF, no-sv 1 V ; Match already matched string, folded in loc.
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144NREFFU REF, num 1 V ; Match already matched string, folded using unicode rules for non-utf8
145NREFFA REF, num 1 V ; Match already matched string, folded using unicode rules for non-utf8, no mixing ASCII, non-ASCII
1de06328 146
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147#*Support for long RE
148LONGJMP LONGJMP, off 1 . 1 ; Jump far away.
149BRANCHJ BRANCHJ, off 1 V 1 ; BRANCH with long offset.
150
151#*Special Case Regops
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152IFMATCH BRANCHJ, off 1 . 2 ; Succeeds if the following matches.
153UNLESSM BRANCHJ, off 1 . 2 ; Fails if the following matches.
154SUSPEND BRANCHJ, off 1 V 1 ; "Independent" sub-RE.
65aa4ca7 155IFTHEN BRANCHJ, off 1 V 1 ; Switch, should be preceded by switcher.
f8abb37e 156GROUPP GROUPP, num 1 ; Whether the group matched.
d09b2d29 157
d09b2d29 158
381b57db 159#*The heavy worker
1de06328 160
13f27704 161EVAL EVAL, evl/flags 2L ; Execute some Perl code.
d09b2d29 162
381b57db 163#*Modifiers
1de06328 164
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165MINMOD MINMOD, no ; Next operator is not greedy.
166LOGICAL LOGICAL, no ; Next opcode should set the flag only.
d09b2d29 167
65aa4ca7 168#*This is not used yet
f9ef50a7 169RENUM BRANCHJ, off 1 . 1 ; Group with independently numbered parens.
d09b2d29 170
381b57db 171#*Trie Related
1de06328 172
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173#* Behave the same as A|LIST|OF|WORDS would. The '..C' variants
174#* have inline charclass data (ascii only), the 'C' store it in the
175#* structure.
486ec47a 176# NOTE: the relative order of the TRIE-like regops is significant
ce5e9471 177
7986cb47 178TRIE TRIE, trie 1 ; Match many EXACT(F[ALU]?)? at once. flags==type
f8abb37e 179TRIEC TRIE,trie charclass ; Same as TRIE, but with embedded charclass data
3dab1dad 180
1de06328 181# For start classes, contains an added fail table.
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182AHOCORASICK TRIE, trie 1 ; Aho Corasick stclass. flags==type
183AHOCORASICKC TRIE,trie charclass ; Same as AHOCORASICK, but with embedded charclass data
1de06328 184
381b57db 185#*Regex Subroutines
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186GOSUB GOSUB, num/ofs 2L ; recurse to paren arg1 at (signed) ofs arg2
187GOSTART GOSTART, no ; recurse to start of pattern
03363afd 188
381b57db 189#*Special conditionals
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190NGROUPP NGROUPP, no-sv 1 ; Whether the group matched.
191INSUBP INSUBP, num 1 ; Whether we are in a specific recurse.
192DEFINEP DEFINEP, none 1 ; Never execute directly.
0a4db386 193
486ec47a 194#*Backtracking Verbs
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195ENDLIKE ENDLIKE, none ; Used only for the type field of verbs
196OPFAIL ENDLIKE, none ; Same as (?!)
197ACCEPT ENDLIKE, parno 1 ; Accepts the current matched string.
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198
199
200#*Verbs With Arguments
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201VERB VERB, no-sv 1 ; Used only for the type field of verbs
202PRUNE VERB, no-sv 1 ; Pattern fails at this startpoint if no-backtracking through this
203MARKPOINT VERB, no-sv 1 ; Push the current location for rollback by cut.
204SKIP VERB, no-sv 1 ; On failure skip forward (to the mark) before retrying
205COMMIT VERB, no-sv 1 ; Pattern fails outright if backtracking through this
206CUTGROUP VERB, no-sv 1 ; On failure go to the next alternation in the group
e2e6a0f1 207
ee9b8eae 208#*Control what to keep in $&.
f8abb37e 209KEEPS KEEPS, no ; $& begins here.
ee9b8eae 210
e1d1eefb 211#*New charclass like patterns
f8abb37e 212LNBREAK LNBREAK, none ; generic newline pattern
3172e3fd 213
381b57db 214# NEW STUFF SOMEWHERE ABOVE THIS LINE
1de06328 215
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216################################################################################
217
7f69552c 218#*SPECIAL REGOPS
1de06328 219
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220#* This is not really a node, but an optimized away piece of a "long"
221#* node. To simplify debugging output, we mark it as if it were a node
f8abb37e 222OPTIMIZED NOTHING, off ; Placeholder for dump.
1de06328 223
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224#* Special opcode with the property that no opcode in a compiled program
225#* will ever be of this type. Thus it can be used as a flag value that
226#* no other opcode has been seen. END is used similarly, in that an END
227#* node cant be optimized. So END implies "unoptimizable" and PSEUDO
228#* mean "not seen anything to optimize yet".
f8abb37e 229PSEUDO PSEUDO, off ; Pseudo opcode for internal use.
1de06328 230
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231-------------------------------------------------------------------------------
232# Format for second section:
65aa4ca7 233# REGOP \t typelist [ \t typelist]
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234# typelist= namelist
235# = namelist:FAIL
236# = name:count
237
238# Anything below is a state
239#
240#
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241TRIE next:FAIL
242EVAL AB:FAIL
243CURLYX end:FAIL
244WHILEM A_pre,A_min,A_max,B_min,B_max:FAIL
245BRANCH next:FAIL
246CURLYM A,B:FAIL
247IFMATCH A:FAIL
248CURLY B_min_known,B_min,B_max:FAIL
249COMMIT next:FAIL
250MARKPOINT next:FAIL
251SKIP next:FAIL
252CUTGROUP next:FAIL
253KEEPS next:FAIL