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#
# Secret Labs' Regular Expression Engine
# $Id$
#
# convert template to internal format
#
# Copyright (c) 1997-2000 by Secret Labs AB. All rights reserved.
#
# This code can only be used for 1.6 alpha testing. All other use
# require explicit permission from Secret Labs AB.
#
# Portions of this engine have been developed in cooperation with
# CNRI. Hewlett-Packard provided funding for 1.6 integration and
# other compatibility work.
#
# FIXME: <fl> formalize (objectify?) and document the compiler code
# format, so that other frontends can use this compiler
import array, string, sys
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"
# FIXME: <fl> should move some optimizations from the parser to here!
class Code:
def __init__(self):
self.data = []
def __len__(self):
return len(self.data)
def __getitem__(self, index):
return self.data[index]
def __setitem__(self, index, code):
self.data[index] = code
def append(self, code):
self.data.append(code)
def todata(self):
# print self.data
return array.array(WORDSIZE, self.data).tostring()
def _lower(literal):
# return _sre._lower(literal) # FIXME
return string.lower(literal)
def _compile(code, pattern, flags):
append = code.append
for op, av in pattern:
if op is ANY:
if "s" in flags:
append(CODES[op]) # any character at all!
else:
append(CODES[NOT_LITERAL])
append(10)
elif op in (SUCCESS, FAILURE):
append(CODES[op])
elif op is AT:
append(CODES[op])
append(POSITIONS[av])
elif op is BRANCH:
append(CODES[op])
tail = []
for av in av[1]:
skip = len(code); append(0)
_compile(code, av, flags)
append(CODES[JUMP])
tail.append(len(code)); append(0)
code[skip] = len(code) - skip
append(0) # end of branch
for tail in tail:
code[tail] = len(code) - tail
elif op is CALL:
append(CODES[op])
skip = len(code); append(0)
_compile(code, av, flags)
append(CODES[SUCCESS])
code[skip] = len(code) - skip
elif op is CATEGORY: # not used by current parser
append(CODES[op])
append(CATEGORIES[av])
elif op is GROUP:
if "i" in flags:
append(CODES[MAP_IGNORE[op]])
else:
append(CODES[op])
append(av)
elif op is IN:
if "i" in flags:
append(CODES[MAP_IGNORE[op]])
def fixup(literal):
return ord(_lower(literal))
else:
append(CODES[op])
fixup = ord
skip = len(code); append(0)
for op, av in av:
append(CODES[op])
if op is NEGATE:
pass
elif op is LITERAL:
append(fixup(av))
elif op is RANGE:
append(fixup(av[0]))
append(fixup(av[1]))
elif op is CATEGORY:
append(CATEGORIES[av])
else:
raise ValueError, "unsupported set operator"
append(CODES[FAILURE])
code[skip] = len(code) - skip
elif op in (LITERAL, NOT_LITERAL):
if "i" in flags:
append(CODES[MAP_IGNORE[op]])
append(ord(_lower(av)))
else:
append(CODES[op])
append(ord(av))
elif op is MARK:
append(CODES[op])
append(av)
elif op in (REPEAT, MIN_REPEAT, MAX_REPEAT):
lo, hi = av[2].getwidth()
if lo == 0:
raise SyntaxError, "cannot repeat zero-width items"
if lo == hi == 1 and op is MAX_REPEAT:
append(CODES[MAX_REPEAT_ONE])
skip = len(code); append(0)
append(av[0])
append(av[1])
_compile(code, av[2], flags)
append(CODES[SUCCESS])
code[skip] = len(code) - skip
else:
append(CODES[op])
skip = len(code); append(0)
append(av[0])
append(av[1])
_compile(code, av[2], flags)
if op is MIN_REPEAT:
append(CODES[MIN_UNTIL])
else:
# FIXME: MAX_REPEAT PROBABLY DOESN'T WORK (?)
append(CODES[MAX_UNTIL])
code[skip] = len(code) - skip
elif op is SUBPATTERN:
## group = av[0]
## if group:
## append(CODES[MARK])
## append((group-1)*2)
_compile(code, av[1], flags)
## if group:
## append(CODES[MARK])
## append((group-1)*2+1)
else:
raise ValueError, ("unsupported operand type", op)
def compile(p, flags=()):
# convert pattern list to internal format
if type(p) in (type(""), type(u"")):
import sre_parse
pattern = p
p = sre_parse.parse(p)
else:
pattern = None
# print p.getwidth()
# print p
code = Code()
_compile(code, p.data, p.pattern.flags)
code.append(CODES[SUCCESS])
# print list(code.data)
data = code.todata()
if 0: # debugging
print
print "-" * 68
import sre_disasm
sre_disasm.disasm(data)
print "-" * 68
# print len(data), p.pattern.groups, len(p.pattern.groupdict)
return _sre.compile(pattern, data, p.pattern.groups-1, p.pattern.groupdict)
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