[pypy-svn] r3330 - pypy/trunk/src/pypy/appspace
sanxiyn at codespeak.net
sanxiyn at codespeak.net
Tue Mar 23 15:51:12 CET 2004
Author: sanxiyn
Date: Tue Mar 23 15:51:10 2004
New Revision: 3330
Added:
pypy/trunk/src/pypy/appspace/sre_parse.py
Log:
Import from Python 2.3.3.
Added: pypy/trunk/src/pypy/appspace/sre_parse.py
==============================================================================
--- (empty file)
+++ pypy/trunk/src/pypy/appspace/sre_parse.py Tue Mar 23 15:51:10 2004
@@ -0,0 +1,739 @@
+#
+# Secret Labs' Regular Expression Engine
+#
+# convert re-style regular expression to sre pattern
+#
+# Copyright (c) 1998-2001 by Secret Labs AB. All rights reserved.
+#
+# See the sre.py file for information on usage and redistribution.
+#
+
+"""Internal support module for sre"""
+
+# XXX: show string offset and offending character for all errors
+
+# this module works under 1.5.2 and later. don't use string methods
+import string, sys
+
+from sre_constants import *
+
+SPECIAL_CHARS = ".\\[{()*+?^$|"
+REPEAT_CHARS = "*+?{"
+
+DIGITS = tuple("0123456789")
+
+OCTDIGITS = tuple("01234567")
+HEXDIGITS = tuple("0123456789abcdefABCDEF")
+
+WHITESPACE = tuple(" \t\n\r\v\f")
+
+ESCAPES = {
+ r"\a": (LITERAL, ord("\a")),
+ r"\b": (LITERAL, ord("\b")),
+ r"\f": (LITERAL, ord("\f")),
+ r"\n": (LITERAL, ord("\n")),
+ r"\r": (LITERAL, ord("\r")),
+ r"\t": (LITERAL, ord("\t")),
+ r"\v": (LITERAL, ord("\v")),
+ r"\\": (LITERAL, ord("\\"))
+}
+
+CATEGORIES = {
+ r"\A": (AT, AT_BEGINNING_STRING), # start of string
+ r"\b": (AT, AT_BOUNDARY),
+ r"\B": (AT, AT_NON_BOUNDARY),
+ r"\d": (IN, [(CATEGORY, CATEGORY_DIGIT)]),
+ r"\D": (IN, [(CATEGORY, CATEGORY_NOT_DIGIT)]),
+ r"\s": (IN, [(CATEGORY, CATEGORY_SPACE)]),
+ r"\S": (IN, [(CATEGORY, CATEGORY_NOT_SPACE)]),
+ r"\w": (IN, [(CATEGORY, CATEGORY_WORD)]),
+ r"\W": (IN, [(CATEGORY, CATEGORY_NOT_WORD)]),
+ r"\Z": (AT, AT_END_STRING), # end of string
+}
+
+FLAGS = {
+ # standard flags
+ "i": SRE_FLAG_IGNORECASE,
+ "L": SRE_FLAG_LOCALE,
+ "m": SRE_FLAG_MULTILINE,
+ "s": SRE_FLAG_DOTALL,
+ "x": SRE_FLAG_VERBOSE,
+ # extensions
+ "t": SRE_FLAG_TEMPLATE,
+ "u": SRE_FLAG_UNICODE,
+}
+
+# figure out best way to convert hex/octal numbers to integers
+try:
+ int("10", 8)
+ atoi = int # 2.0 and later
+except TypeError:
+ atoi = string.atoi # 1.5.2
+
+class Pattern:
+ # master pattern object. keeps track of global attributes
+ def __init__(self):
+ self.flags = 0
+ self.open = []
+ self.groups = 1
+ self.groupdict = {}
+ def opengroup(self, name=None):
+ gid = self.groups
+ self.groups = gid + 1
+ if name is not None:
+ ogid = self.groupdict.get(name, None)
+ if ogid is not None:
+ raise error, ("redefinition of group name %s as group %d; "
+ "was group %d" % (repr(name), gid, ogid))
+ self.groupdict[name] = gid
+ self.open.append(gid)
+ return gid
+ def closegroup(self, gid):
+ self.open.remove(gid)
+ def checkgroup(self, gid):
+ return gid < self.groups and gid not in self.open
+
+class SubPattern:
+ # a subpattern, in intermediate form
+ def __init__(self, pattern, data=None):
+ self.pattern = pattern
+ if data is None:
+ data = []
+ self.data = data
+ self.width = None
+ def dump(self, level=0):
+ nl = 1
+ for op, av in self.data:
+ print level*" " + op,; nl = 0
+ if op == "in":
+ # member sublanguage
+ print; nl = 1
+ for op, a in av:
+ print (level+1)*" " + op, a
+ elif op == "branch":
+ print; nl = 1
+ i = 0
+ for a in av[1]:
+ if i > 0:
+ print level*" " + "or"
+ a.dump(level+1); nl = 1
+ i = i + 1
+ elif type(av) in (type(()), type([])):
+ for a in av:
+ if isinstance(a, SubPattern):
+ if not nl: print
+ a.dump(level+1); nl = 1
+ else:
+ print a, ; nl = 0
+ else:
+ print av, ; nl = 0
+ if not nl: print
+ def __repr__(self):
+ return repr(self.data)
+ def __len__(self):
+ return len(self.data)
+ def __delitem__(self, index):
+ del self.data[index]
+ def __getitem__(self, index):
+ return self.data[index]
+ def __setitem__(self, index, code):
+ self.data[index] = code
+ def __getslice__(self, start, stop):
+ return SubPattern(self.pattern, self.data[start:stop])
+ def insert(self, index, code):
+ self.data.insert(index, code)
+ def append(self, code):
+ self.data.append(code)
+ def getwidth(self):
+ # determine the width (min, max) for this subpattern
+ if self.width:
+ return self.width
+ lo = hi = 0L
+ for op, av in self.data:
+ if op is BRANCH:
+ i = sys.maxint
+ j = 0
+ for av in av[1]:
+ l, h = av.getwidth()
+ i = min(i, l)
+ j = max(j, h)
+ lo = lo + i
+ hi = hi + j
+ elif op is CALL:
+ i, j = av.getwidth()
+ lo = lo + i
+ hi = hi + j
+ elif op is SUBPATTERN:
+ i, j = av[1].getwidth()
+ lo = lo + i
+ hi = hi + j
+ elif op in (MIN_REPEAT, MAX_REPEAT):
+ i, j = av[2].getwidth()
+ lo = lo + long(i) * av[0]
+ hi = hi + long(j) * av[1]
+ elif op in (ANY, RANGE, IN, LITERAL, NOT_LITERAL, CATEGORY):
+ lo = lo + 1
+ hi = hi + 1
+ elif op == SUCCESS:
+ break
+ self.width = int(min(lo, sys.maxint)), int(min(hi, sys.maxint))
+ return self.width
+
+class Tokenizer:
+ def __init__(self, string):
+ self.string = string
+ self.index = 0
+ self.__next()
+ def __next(self):
+ if self.index >= len(self.string):
+ self.next = None
+ return
+ char = self.string[self.index]
+ if char[0] == "\\":
+ try:
+ c = self.string[self.index + 1]
+ except IndexError:
+ raise error, "bogus escape (end of line)"
+ char = char + c
+ self.index = self.index + len(char)
+ self.next = char
+ def match(self, char, skip=1):
+ if char == self.next:
+ if skip:
+ self.__next()
+ return 1
+ return 0
+ def get(self):
+ this = self.next
+ self.__next()
+ return this
+ def tell(self):
+ return self.index, self.next
+ def seek(self, index):
+ self.index, self.next = index
+
+def isident(char):
+ return "a" <= char <= "z" or "A" <= char <= "Z" or char == "_"
+
+def isdigit(char):
+ return "0" <= char <= "9"
+
+def isname(name):
+ # check that group name is a valid string
+ if not isident(name[0]):
+ return False
+ for char in name:
+ if not isident(char) and not isdigit(char):
+ return False
+ return True
+
+def _group(escape, groups):
+ # check if the escape string represents a valid group
+ try:
+ gid = atoi(escape[1:])
+ if gid and gid < groups:
+ return gid
+ except ValueError:
+ pass
+ return None # not a valid group
+
+def _class_escape(source, escape):
+ # handle escape code inside character class
+ code = ESCAPES.get(escape)
+ if code:
+ return code
+ code = CATEGORIES.get(escape)
+ if code:
+ return code
+ try:
+ if escape[1:2] == "x":
+ # hexadecimal escape (exactly two digits)
+ while source.next in HEXDIGITS and len(escape) < 4:
+ escape = escape + source.get()
+ escape = escape[2:]
+ if len(escape) != 2:
+ raise error, "bogus escape: %s" % repr("\\" + escape)
+ return LITERAL, atoi(escape, 16) & 0xff
+ elif escape[1:2] in OCTDIGITS:
+ # octal escape (up to three digits)
+ while source.next in OCTDIGITS and len(escape) < 5:
+ escape = escape + source.get()
+ escape = escape[1:]
+ return LITERAL, atoi(escape, 8) & 0xff
+ if len(escape) == 2:
+ return LITERAL, ord(escape[1])
+ except ValueError:
+ pass
+ raise error, "bogus escape: %s" % repr(escape)
+
+def _escape(source, escape, state):
+ # handle escape code in expression
+ code = CATEGORIES.get(escape)
+ if code:
+ return code
+ code = ESCAPES.get(escape)
+ if code:
+ return code
+ try:
+ if escape[1:2] == "x":
+ # hexadecimal escape
+ while source.next in HEXDIGITS and len(escape) < 4:
+ escape = escape + source.get()
+ if len(escape) != 4:
+ raise ValueError
+ return LITERAL, atoi(escape[2:], 16) & 0xff
+ elif escape[1:2] == "0":
+ # octal escape
+ while source.next in OCTDIGITS and len(escape) < 4:
+ escape = escape + source.get()
+ return LITERAL, atoi(escape[1:], 8) & 0xff
+ elif escape[1:2] in DIGITS:
+ # octal escape *or* decimal group reference (sigh)
+ if source.next in DIGITS:
+ escape = escape + source.get()
+ if (escape[1] in OCTDIGITS and escape[2] in OCTDIGITS and
+ source.next in OCTDIGITS):
+ # got three octal digits; this is an octal escape
+ escape = escape + source.get()
+ return LITERAL, atoi(escape[1:], 8) & 0xff
+ # got at least one decimal digit; this is a group reference
+ group = _group(escape, state.groups)
+ if group:
+ if not state.checkgroup(group):
+ raise error, "cannot refer to open group"
+ return GROUPREF, group
+ raise ValueError
+ if len(escape) == 2:
+ return LITERAL, ord(escape[1])
+ except ValueError:
+ pass
+ raise error, "bogus escape: %s" % repr(escape)
+
+def _parse_sub(source, state, nested=1):
+ # parse an alternation: a|b|c
+
+ items = []
+ while 1:
+ items.append(_parse(source, state))
+ if source.match("|"):
+ continue
+ if not nested:
+ break
+ if not source.next or source.match(")", 0):
+ break
+ else:
+ raise error, "pattern not properly closed"
+
+ if len(items) == 1:
+ return items[0]
+
+ subpattern = SubPattern(state)
+
+ # check if all items share a common prefix
+ while 1:
+ prefix = None
+ for item in items:
+ if not item:
+ break
+ if prefix is None:
+ prefix = item[0]
+ elif item[0] != prefix:
+ break
+ else:
+ # all subitems start with a common "prefix".
+ # move it out of the branch
+ for item in items:
+ del item[0]
+ subpattern.append(prefix)
+ continue # check next one
+ break
+
+ # check if the branch can be replaced by a character set
+ for item in items:
+ if len(item) != 1 or item[0][0] != LITERAL:
+ break
+ else:
+ # we can store this as a character set instead of a
+ # branch (the compiler may optimize this even more)
+ set = []
+ for item in items:
+ set.append(item[0])
+ subpattern.append((IN, set))
+ return subpattern
+
+ subpattern.append((BRANCH, (None, items)))
+ return subpattern
+
+def _parse(source, state):
+ # parse a simple pattern
+
+ subpattern = SubPattern(state)
+
+ while 1:
+
+ if source.next in ("|", ")"):
+ break # end of subpattern
+ this = source.get()
+ if this is None:
+ break # end of pattern
+
+ if state.flags & SRE_FLAG_VERBOSE:
+ # skip whitespace and comments
+ if this in WHITESPACE:
+ continue
+ if this == "#":
+ while 1:
+ this = source.get()
+ if this in (None, "\n"):
+ break
+ continue
+
+ if this and this[0] not in SPECIAL_CHARS:
+ subpattern.append((LITERAL, ord(this)))
+
+ elif this == "[":
+ # character set
+ set = []
+## if source.match(":"):
+## pass # handle character classes
+ if source.match("^"):
+ set.append((NEGATE, None))
+ # check remaining characters
+ start = set[:]
+ while 1:
+ this = source.get()
+ if this == "]" and set != start:
+ break
+ elif this and this[0] == "\\":
+ code1 = _class_escape(source, this)
+ elif this:
+ code1 = LITERAL, ord(this)
+ else:
+ raise error, "unexpected end of regular expression"
+ if source.match("-"):
+ # potential range
+ this = source.get()
+ if this == "]":
+ if code1[0] is IN:
+ code1 = code1[1][0]
+ set.append(code1)
+ set.append((LITERAL, ord("-")))
+ break
+ elif this:
+ if this[0] == "\\":
+ code2 = _class_escape(source, this)
+ else:
+ code2 = LITERAL, ord(this)
+ if code1[0] != LITERAL or code2[0] != LITERAL:
+ raise error, "bad character range"
+ lo = code1[1]
+ hi = code2[1]
+ if hi < lo:
+ raise error, "bad character range"
+ set.append((RANGE, (lo, hi)))
+ else:
+ raise error, "unexpected end of regular expression"
+ else:
+ if code1[0] is IN:
+ code1 = code1[1][0]
+ set.append(code1)
+
+ # XXX: <fl> should move set optimization to compiler!
+ if len(set)==1 and set[0][0] is LITERAL:
+ subpattern.append(set[0]) # optimization
+ elif len(set)==2 and set[0][0] is NEGATE and set[1][0] is LITERAL:
+ subpattern.append((NOT_LITERAL, set[1][1])) # optimization
+ else:
+ # XXX: <fl> should add charmap optimization here
+ subpattern.append((IN, set))
+
+ elif this and this[0] in REPEAT_CHARS:
+ # repeat previous item
+ if this == "?":
+ min, max = 0, 1
+ elif this == "*":
+ min, max = 0, MAXREPEAT
+
+ elif this == "+":
+ min, max = 1, MAXREPEAT
+ elif this == "{":
+ here = source.tell()
+ min, max = 0, MAXREPEAT
+ lo = hi = ""
+ while source.next in DIGITS:
+ lo = lo + source.get()
+ if source.match(","):
+ while source.next in DIGITS:
+ hi = hi + source.get()
+ else:
+ hi = lo
+ if not source.match("}"):
+ subpattern.append((LITERAL, ord(this)))
+ source.seek(here)
+ continue
+ if lo:
+ min = atoi(lo)
+ if hi:
+ max = atoi(hi)
+ if max < min:
+ raise error, "bad repeat interval"
+ else:
+ raise error, "not supported"
+ # figure out which item to repeat
+ if subpattern:
+ item = subpattern[-1:]
+ else:
+ item = None
+ if not item or (len(item) == 1 and item[0][0] == AT):
+ raise error, "nothing to repeat"
+ if item[0][0] in (MIN_REPEAT, MAX_REPEAT):
+ raise error, "multiple repeat"
+ if source.match("?"):
+ subpattern[-1] = (MIN_REPEAT, (min, max, item))
+ else:
+ subpattern[-1] = (MAX_REPEAT, (min, max, item))
+
+ elif this == ".":
+ subpattern.append((ANY, None))
+
+ elif this == "(":
+ group = 1
+ name = None
+ if source.match("?"):
+ group = 0
+ # options
+ if source.match("P"):
+ # python extensions
+ if source.match("<"):
+ # named group: skip forward to end of name
+ name = ""
+ while 1:
+ char = source.get()
+ if char is None:
+ raise error, "unterminated name"
+ if char == ">":
+ break
+ name = name + char
+ group = 1
+ if not isname(name):
+ raise error, "bad character in group name"
+ elif source.match("="):
+ # named backreference
+ name = ""
+ while 1:
+ char = source.get()
+ if char is None:
+ raise error, "unterminated name"
+ if char == ")":
+ break
+ name = name + char
+ if not isname(name):
+ raise error, "bad character in group name"
+ gid = state.groupdict.get(name)
+ if gid is None:
+ raise error, "unknown group name"
+ subpattern.append((GROUPREF, gid))
+ continue
+ else:
+ char = source.get()
+ if char is None:
+ raise error, "unexpected end of pattern"
+ raise error, "unknown specifier: ?P%s" % char
+ elif source.match(":"):
+ # non-capturing group
+ group = 2
+ elif source.match("#"):
+ # comment
+ while 1:
+ if source.next is None or source.next == ")":
+ break
+ source.get()
+ if not source.match(")"):
+ raise error, "unbalanced parenthesis"
+ continue
+ elif source.next in ("=", "!", "<"):
+ # lookahead assertions
+ char = source.get()
+ dir = 1
+ if char == "<":
+ if source.next not in ("=", "!"):
+ raise error, "syntax error"
+ dir = -1 # lookbehind
+ char = source.get()
+ p = _parse_sub(source, state)
+ if not source.match(")"):
+ raise error, "unbalanced parenthesis"
+ if char == "=":
+ subpattern.append((ASSERT, (dir, p)))
+ else:
+ subpattern.append((ASSERT_NOT, (dir, p)))
+ continue
+ else:
+ # flags
+ if not source.next in FLAGS:
+ raise error, "unexpected end of pattern"
+ while source.next in FLAGS:
+ state.flags = state.flags | FLAGS[source.get()]
+ if group:
+ # parse group contents
+ if group == 2:
+ # anonymous group
+ group = None
+ else:
+ group = state.opengroup(name)
+ p = _parse_sub(source, state)
+ if not source.match(")"):
+ raise error, "unbalanced parenthesis"
+ if group is not None:
+ state.closegroup(group)
+ subpattern.append((SUBPATTERN, (group, p)))
+ else:
+ while 1:
+ char = source.get()
+ if char is None:
+ raise error, "unexpected end of pattern"
+ if char == ")":
+ break
+ raise error, "unknown extension"
+
+ elif this == "^":
+ subpattern.append((AT, AT_BEGINNING))
+
+ elif this == "$":
+ subpattern.append((AT, AT_END))
+
+ elif this and this[0] == "\\":
+ code = _escape(source, this, state)
+ subpattern.append(code)
+
+ else:
+ raise error, "parser error"
+
+ return subpattern
+
+def parse(str, flags=0, pattern=None):
+ # parse 're' pattern into list of (opcode, argument) tuples
+
+ source = Tokenizer(str)
+
+ if pattern is None:
+ pattern = Pattern()
+ pattern.flags = flags
+ pattern.str = str
+
+ p = _parse_sub(source, pattern, 0)
+
+ tail = source.get()
+ if tail == ")":
+ raise error, "unbalanced parenthesis"
+ elif tail:
+ raise error, "bogus characters at end of regular expression"
+
+ if flags & SRE_FLAG_DEBUG:
+ p.dump()
+
+ if not (flags & SRE_FLAG_VERBOSE) and p.pattern.flags & SRE_FLAG_VERBOSE:
+ # the VERBOSE flag was switched on inside the pattern. to be
+ # on the safe side, we'll parse the whole thing again...
+ return parse(str, p.pattern.flags)
+
+ return p
+
+def parse_template(source, pattern):
+ # parse 're' replacement string into list of literals and
+ # group references
+ s = Tokenizer(source)
+ p = []
+ a = p.append
+ def literal(literal, p=p):
+ if p and p[-1][0] is LITERAL:
+ p[-1] = LITERAL, p[-1][1] + literal
+ else:
+ p.append((LITERAL, literal))
+ sep = source[:0]
+ if type(sep) is type(""):
+ makechar = chr
+ else:
+ makechar = unichr
+ while 1:
+ this = s.get()
+ if this is None:
+ break # end of replacement string
+ if this and this[0] == "\\":
+ # group
+ if this == "\\g":
+ name = ""
+ if s.match("<"):
+ while 1:
+ char = s.get()
+ if char is None:
+ raise error, "unterminated group name"
+ if char == ">":
+ break
+ name = name + char
+ if not name:
+ raise error, "bad group name"
+ try:
+ index = atoi(name)
+ except ValueError:
+ if not isname(name):
+ raise error, "bad character in group name"
+ try:
+ index = pattern.groupindex[name]
+ except KeyError:
+ raise IndexError, "unknown group name"
+ a((MARK, index))
+ elif len(this) > 1 and this[1] in DIGITS:
+ code = None
+ while 1:
+ group = _group(this, pattern.groups+1)
+ if group:
+ if (s.next not in DIGITS or
+ not _group(this + s.next, pattern.groups+1)):
+ code = MARK, group
+ break
+ elif s.next in OCTDIGITS:
+ this = this + s.get()
+ else:
+ break
+ if not code:
+ this = this[1:]
+ code = LITERAL, makechar(atoi(this[-6:], 8) & 0xff)
+ if code[0] is LITERAL:
+ literal(code[1])
+ else:
+ a(code)
+ else:
+ try:
+ this = makechar(ESCAPES[this][1])
+ except KeyError:
+ pass
+ literal(this)
+ else:
+ literal(this)
+ # convert template to groups and literals lists
+ i = 0
+ groups = []
+ literals = []
+ for c, s in p:
+ if c is MARK:
+ groups.append((i, s))
+ literals.append(None)
+ else:
+ literals.append(s)
+ i = i + 1
+ return groups, literals
+
+def expand_template(template, match):
+ g = match.group
+ sep = match.string[:0]
+ groups, literals = template
+ literals = literals[:]
+ try:
+ for index, group in groups:
+ literals[index] = s = g(group)
+ if s is None:
+ raise IndexError
+ except IndexError:
+ raise error, "empty group"
+ return string.join(literals, sep)
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