| # |
| # Secret Labs' Regular Expression Engine |
| # |
| # convert template to internal format |
| # |
| # Copyright (c) 1997-2000 by Secret Labs AB. All rights reserved. |
| # |
| # Portions of this engine have been developed in cooperation with |
| # CNRI. Hewlett-Packard provided funding for 1.6 integration and |
| # other compatibility work. |
| # |
| |
| import array |
| import _sre |
| |
| from sre_constants import * |
| |
| # find an array type code that matches the engine's code size |
| for WORDSIZE in "BHil": |
| if len(array.array(WORDSIZE, [0]).tostring()) == _sre.getcodesize(): |
| break |
| else: |
| raise RuntimeError, "cannot find a useable array type" |
| |
| def _compile(code, pattern, flags): |
| # internal: compile a (sub)pattern |
| emit = code.append |
| for op, av in pattern: |
| if op in (LITERAL, NOT_LITERAL): |
| if flags & SRE_FLAG_IGNORECASE: |
| emit(OPCODES[OP_IGNORE[op]]) |
| else: |
| emit(OPCODES[op]) |
| emit(ord(av)) |
| elif op is IN: |
| if flags & SRE_FLAG_IGNORECASE: |
| emit(OPCODES[OP_IGNORE[op]]) |
| def fixup(literal, flags=flags): |
| return _sre.getlower(ord(literal), flags) |
| else: |
| emit(OPCODES[op]) |
| fixup = ord |
| skip = len(code); emit(0) |
| for op, av in av: |
| emit(OPCODES[op]) |
| if op is NEGATE: |
| pass |
| elif op is LITERAL: |
| emit(fixup(av)) |
| elif op is RANGE: |
| emit(fixup(av[0])) |
| emit(fixup(av[1])) |
| elif op is CATEGORY: |
| if flags & SRE_FLAG_LOCALE: |
| emit(CHCODES[CH_LOCALE[av]]) |
| elif flags & SRE_FLAG_UNICODE: |
| emit(CHCODES[CH_UNICODE[av]]) |
| else: |
| emit(CHCODES[av]) |
| else: |
| raise error, "internal: unsupported set operator" |
| emit(OPCODES[FAILURE]) |
| code[skip] = len(code) - skip |
| elif op is ANY: |
| if flags & SRE_FLAG_DOTALL: |
| emit(OPCODES[op]) |
| else: |
| emit(OPCODES[CATEGORY]) |
| emit(CHCODES[CATEGORY_NOT_LINEBREAK]) |
| elif op in (REPEAT, MIN_REPEAT, MAX_REPEAT): |
| if flags & SRE_FLAG_TEMPLATE: |
| emit(OPCODES[REPEAT]) |
| skip = len(code); emit(0) |
| emit(av[0]) |
| emit(av[1]) |
| _compile(code, av[2], flags) |
| emit(OPCODES[SUCCESS]) |
| code[skip] = len(code) - skip |
| else: |
| lo, hi = av[2].getwidth() |
| if lo == 0: |
| raise error, "nothing to repeat" |
| if 0 and lo == hi == 1 and op is MAX_REPEAT: |
| # FIXME: <fl> need a better way to figure out when |
| # it's safe to use this one (in the parser, probably) |
| emit(OPCODES[MAX_REPEAT_ONE]) |
| skip = len(code); emit(0) |
| emit(av[0]) |
| emit(av[1]) |
| _compile(code, av[2], flags) |
| emit(OPCODES[SUCCESS]) |
| code[skip] = len(code) - skip |
| else: |
| emit(OPCODES[op]) |
| skip = len(code); emit(0) |
| emit(av[0]) |
| emit(av[1]) |
| _compile(code, av[2], flags) |
| emit(OPCODES[SUCCESS]) |
| code[skip] = len(code) - skip |
| elif op is SUBPATTERN: |
| group = av[0] |
| if group: |
| emit(OPCODES[MARK]) |
| emit((group-1)*2) |
| _compile(code, av[1], flags) |
| if group: |
| emit(OPCODES[MARK]) |
| emit((group-1)*2+1) |
| elif op in (SUCCESS, FAILURE): |
| emit(OPCODES[op]) |
| elif op in (ASSERT, ASSERT_NOT, CALL): |
| emit(OPCODES[op]) |
| skip = len(code); emit(0) |
| _compile(code, av, flags) |
| emit(OPCODES[SUCCESS]) |
| code[skip] = len(code) - skip |
| elif op is AT: |
| emit(OPCODES[op]) |
| if flags & SRE_FLAG_MULTILINE: |
| emit(ATCODES[AT_MULTILINE[av]]) |
| else: |
| emit(ATCODES[av]) |
| elif op is BRANCH: |
| emit(OPCODES[op]) |
| tail = [] |
| for av in av[1]: |
| skip = len(code); emit(0) |
| _compile(code, av, flags) |
| emit(OPCODES[JUMP]) |
| tail.append(len(code)); emit(0) |
| code[skip] = len(code) - skip |
| emit(0) # end of branch |
| for tail in tail: |
| code[tail] = len(code) - tail |
| elif op is CATEGORY: |
| emit(OPCODES[op]) |
| if flags & SRE_FLAG_LOCALE: |
| emit(CHCODES[CH_LOCALE[av]]) |
| elif flags & SRE_FLAG_UNICODE: |
| emit(CHCODES[CH_UNICODE[av]]) |
| else: |
| emit(CHCODES[av]) |
| elif op is GROUP: |
| if flags & SRE_FLAG_IGNORECASE: |
| emit(OPCODES[OP_IGNORE[op]]) |
| else: |
| emit(OPCODES[op]) |
| emit(av-1) |
| elif op is MARK: |
| emit(OPCODES[op]) |
| emit(av) |
| else: |
| raise ValueError, ("unsupported operand type", op) |
| |
| def _compile_info(code, pattern, flags): |
| # internal: compile an info block. in the current version, |
| # this contains min/max pattern width and a literal prefix, |
| # if any |
| lo, hi = pattern.getwidth() |
| if lo == 0: |
| return # not worth it |
| # look for a literal prefix |
| prefix = [] |
| if not (flags & SRE_FLAG_IGNORECASE): |
| for op, av in pattern.data: |
| if op is LITERAL: |
| prefix.append(ord(av)) |
| else: |
| break |
| # add an info block |
| emit = code.append |
| emit(OPCODES[INFO]) |
| skip = len(code); emit(0) |
| # literal flag |
| mask = 0 |
| if len(prefix) == len(pattern.data): |
| mask = 1 |
| emit(mask) |
| # pattern length |
| emit(lo) |
| if hi < 32768: |
| emit(hi) |
| else: |
| emit(0) |
| # add literal prefix |
| emit(len(prefix)) |
| if prefix: |
| code.extend(prefix) |
| # generate overlap table |
| table = [-1] + ([0]*len(prefix)) |
| for i in range(len(prefix)): |
| table[i+1] = table[i]+1 |
| while table[i+1] > 0 and prefix[i] != prefix[table[i+1]-1]: |
| table[i+1] = table[table[i+1]-1]+1 |
| code.extend(table[1:]) # don't store first entry |
| code[skip] = len(code) - skip |
| |
| def compile(p, flags=0): |
| # internal: convert pattern list to internal format |
| |
| # compile, as necessary |
| if type(p) in (type(""), type(u"")): |
| import sre_parse |
| pattern = p |
| p = sre_parse.parse(p) |
| else: |
| pattern = None |
| |
| flags = p.pattern.flags | flags |
| code = [] |
| |
| # compile info block |
| _compile_info(code, p, flags) |
| |
| # compile the pattern |
| _compile(code, p.data, flags) |
| |
| code.append(OPCODES[SUCCESS]) |
| |
| # FIXME: <fl> get rid of this limitation! |
| assert p.pattern.groups <= 100,\ |
| "sorry, but this version only supports 100 named groups" |
| |
| return _sre.compile( |
| pattern, flags, |
| array.array(WORDSIZE, code).tostring(), |
| p.pattern.groups-1, p.pattern.groupdict |
| ) |