diff options
Diffstat (limited to 'Lib/sre_compile.py')
| -rw-r--r-- | Lib/sre_compile.py | 117 |
1 files changed, 68 insertions, 49 deletions
diff --git a/Lib/sre_compile.py b/Lib/sre_compile.py index 502b0616c6..4edb03fa30 100644 --- a/Lib/sre_compile.py +++ b/Lib/sre_compile.py @@ -409,57 +409,39 @@ def _generate_overlap_table(prefix): table[i] = idx + 1 return table -def _compile_info(code, pattern, flags): - # internal: compile an info block. in the current version, - # this contains min/max pattern width, and an optional literal - # prefix or a character map - lo, hi = pattern.getwidth() - if hi > MAXCODE: - hi = MAXCODE - if lo == 0: - code.extend([INFO, 4, 0, lo, hi]) - return - # look for a literal prefix +def _get_literal_prefix(pattern): + # look for literal prefix prefix = [] prefixappend = prefix.append - prefix_skip = 0 + prefix_skip = None + got_all = True + for op, av in pattern.data: + if op is LITERAL: + prefixappend(av) + elif op is SUBPATTERN: + prefix1, prefix_skip1, got_all = _get_literal_prefix(av[1]) + if prefix_skip is None: + if av[0] is not None: + prefix_skip = len(prefix) + elif prefix_skip1 is not None: + prefix_skip = len(prefix) + prefix_skip1 + prefix.extend(prefix1) + if not got_all: + break + else: + got_all = False + break + return prefix, prefix_skip, got_all + +def _get_charset_prefix(pattern): charset = [] # not used charsetappend = charset.append - if not (flags & SRE_FLAG_IGNORECASE): - # look for literal prefix - for op, av in pattern.data: + if pattern.data: + op, av = pattern.data[0] + if op is SUBPATTERN and av[1]: + op, av = av[1][0] if op is LITERAL: - if len(prefix) == prefix_skip: - prefix_skip = prefix_skip + 1 - prefixappend(av) - elif op is SUBPATTERN and len(av[1]) == 1: - op, av = av[1][0] - if op is LITERAL: - prefixappend(av) - else: - break - else: - break - # if no prefix, look for charset prefix - if not prefix and pattern.data: - op, av = pattern.data[0] - if op is SUBPATTERN and av[1]: - op, av = av[1][0] - if op is LITERAL: - charsetappend((op, av)) - elif op is BRANCH: - c = [] - cappend = c.append - for p in av[1]: - if not p: - break - op, av = p[0] - if op is LITERAL: - cappend((op, av)) - else: - break - else: - charset = c + charsetappend((op, av)) elif op is BRANCH: c = [] cappend = c.append @@ -473,8 +455,43 @@ def _compile_info(code, pattern, flags): break else: charset = c - elif op is IN: - charset = av + elif op is BRANCH: + c = [] + cappend = c.append + for p in av[1]: + if not p: + break + op, av = p[0] + if op is LITERAL: + cappend((op, av)) + else: + break + else: + charset = c + elif op is IN: + charset = av + return charset + +def _compile_info(code, pattern, flags): + # internal: compile an info block. in the current version, + # this contains min/max pattern width, and an optional literal + # prefix or a character map + lo, hi = pattern.getwidth() + if hi > MAXCODE: + hi = MAXCODE + if lo == 0: + code.extend([INFO, 4, 0, lo, hi]) + return + # look for a literal prefix + prefix = [] + prefix_skip = 0 + charset = [] # not used + if not (flags & SRE_FLAG_IGNORECASE): + # look for literal prefix + prefix, prefix_skip, got_all = _get_literal_prefix(pattern) + # if no prefix, look for charset prefix + if not prefix: + charset = _get_charset_prefix(pattern) ## if prefix: ## print("*** PREFIX", prefix, prefix_skip) ## if charset: @@ -487,7 +504,7 @@ def _compile_info(code, pattern, flags): mask = 0 if prefix: mask = SRE_INFO_PREFIX - if len(prefix) == prefix_skip == len(pattern.data): + if prefix_skip is None and got_all: mask = mask | SRE_INFO_LITERAL elif charset: mask = mask | SRE_INFO_CHARSET @@ -502,6 +519,8 @@ def _compile_info(code, pattern, flags): # add literal prefix if prefix: emit(len(prefix)) # length + if prefix_skip is None: + prefix_skip = len(prefix) emit(prefix_skip) # skip code.extend(prefix) # generate overlap table |