Added Fredrik Lundh's sre module and its supporting cast.

NOTE: THIS IS VERY ROUGH ALPHA CODE!

1 files changed, 187 insertions, 0 deletions

diff --git a/Lib/sre_compile.py b/Lib/sre_compile.py
new file mode 100644
index 0000000..3e9700b
--- /dev/null
+++ b/Lib/sre_compile.py
@@ -0,0 +1,187 @@
+#
+# 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) is type(""):
+	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)