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authorGuido van Rossum <guido@python.org>1997-07-18 04:26:03 (GMT)
committerGuido van Rossum <guido@python.org>1997-07-18 04:26:03 (GMT)
commit71fa97c60d0299689255dd49031464c719f8b545 (patch)
tree20976c8d68d7d4c2f94a35bc342929a630c6909f /Lib
parentc12da6980fc886664ef0989c68eaf8d2ac8d1cf2 (diff)
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Jeffrey's latest -- reorder my chages somewhat,
removed some of his own cruft. Added \g<...> references in replacement text.
Diffstat (limited to 'Lib')
-rw-r--r--Lib/re.py166
1 files changed, 71 insertions, 95 deletions
diff --git a/Lib/re.py b/Lib/re.py
index abc31c8..3594e36 100644
--- a/Lib/re.py
+++ b/Lib/re.py
@@ -77,14 +77,37 @@ def split(pattern, string, maxsplit=0):
#
#
+def _expand(m, repl):
+ results = []
+ index = 0
+ size = len(repl)
+ while index < size:
+ found = string.find(repl, '\\', index)
+ if found < 0:
+ results.append(repl[index:])
+ break
+ if found > index:
+ results.append(repl[index:found])
+ escape_type, value, index = expand_escape(repl, found+1, REPLACEMENT)
+ if escape_type == CHAR:
+ results.append(value)
+ elif escape_type == MEMORY_REFERENCE:
+ r = m.group(value)
+ if r is None:
+ raise error, ('group "' + str(value) + '" did not contribute '
+ 'to the match')
+ results.append(m.group(value))
+ else:
+ raise error, "bad escape in replacement"
+ return string.join(results, '')
+
class RegexObject:
- def __init__(self, pattern, flags, code, num_regs, groupindex, callouts):
+ def __init__(self, pattern, flags, code, num_regs, groupindex):
self.code = code
self.num_regs = num_regs
self.flags = flags
self.pattern = pattern
self.groupindex = groupindex
- self.callouts = callouts
self.fastmap = build_fastmap(code)
if code[0].name == 'bol':
@@ -132,44 +155,52 @@ class RegexObject:
regs)
def sub(self, repl, string, count=0):
- return self.subn(repl, string, count)[0]
+ return self.subn(repl, string, count)[0]
def subn(self, repl, source, count=0):
- if count < 0: raise error, "negative substibution count"
- if count == 0: import sys; count = sys.maxint
+ if count < 0:
+ raise ValueError, "negative substibution count"
+ if count == 0:
+ import sys
+ count = sys.maxint
if type(repl) == type(''):
if '\\' in repl:
repl = lambda m, r=repl: _expand(m, r)
else:
repl = lambda m, r=repl: r
- n = 0 # Number of matches
- pos = 0 # Where to start searching
- lastmatch = -1 # End of last match
- results = [] # Substrings making up the result
+ n = 0 # Number of matches
+ pos = 0 # Where to start searching
+ lastmatch = -1 # End of last match
+ results = [] # Substrings making up the result
end = len(source)
while n < count and pos <= end:
m = self.search(source, pos)
- if not m: break
+ if not m:
+ break
i, j = m.span(0)
if i == j == lastmatch:
# Empty match adjacent to previous match
- pos = pos+1
+ pos = pos + 1
results.append(source[lastmatch:pos])
continue
- if pos < i: results.append(source[pos:i])
+ if pos < i:
+ results.append(source[pos:i])
results.append(repl(m))
pos = lastmatch = j
if i == j:
# Last match was empty; don't try here again
- pos = pos+1
+ pos = pos + 1
results.append(source[lastmatch:pos])
- n = n+1
+ n = n + 1
results.append(source[pos:])
return (string.join(results, ''), n)
-
+
def split(self, source, maxsplit=0):
- if maxsplit < 0: raise error, "negative split count"
- if maxsplit == 0: import sys; maxsplit = sys.maxint
+ if maxsplit < 0:
+ raise error, "negative split count"
+ if maxsplit == 0:
+ import sys
+ maxsplit = sys.maxint
n = 0
pos = 0
lastmatch = 0
@@ -177,11 +208,13 @@ class RegexObject:
end = len(source)
while n < maxsplit:
m = self.search(source, pos)
- if not m: break
+ if not m:
+ break
i, j = m.span(0)
if i == j:
# Empty match
- if pos >= end: break
+ if pos >= end:
+ break
pos = pos+1
continue
results.append(source[lastmatch:i])
@@ -192,26 +225,6 @@ class RegexObject:
results.append(source[lastmatch:])
return results
-def _expand(m, repl):
- results = []
- index = 0
- size = len(repl)
- while index < size:
- found = string.find(repl, '\\', index)
- if found < 0:
- results.append(repl[index:])
- break
- if found > index:
- results.append(repl[index:found])
- escape_type, value, index = expand_escape(repl, found+1, REPLACEMENT)
- if escape_type == CHAR:
- results.append(value)
- elif escape_type == MEMORY_REFERENCE:
- results.append(m.group(value))
- else:
- raise error, "bad escape in replacement"
- return string.join(results, '')
-
class MatchObject:
def __init__(self, re, string, pos, regs):
self.re = re
@@ -280,16 +293,6 @@ class Instruction:
def __repr__(self):
return '%-15s' % (self.name)
-class FunctionCallout(Instruction):
- name = 'function'
- def __init__(self, function):
- self.function = function
- Instruction.__init__(self, chr(22), 2 + len(self.function))
- def assemble(self, position, labels):
- return self.opcode + chr(len(self.function)) + self.function
- def __repr__(self):
- return '%-15s %-10s' % (self.name, self.function)
-
class End(Instruction):
name = 'end'
def __init__(self):
@@ -608,11 +611,6 @@ def build_fastmap_aux(code, pos, visited, fastmap):
find_label(code, instruction.label),
visited,
fastmap)
- elif instruction.name == 'function':
- for char in map(chr, range(256)):
- fastmap.add(char)
- fastmap.can_be_null = 1
- return
def build_fastmap(code, pos=0):
visited = [0] * len(code)
@@ -825,10 +823,25 @@ def expand_escape(pattern, index, context=NORMAL):
value = string.atoi(pattern[index])
return MEMORY_REFERENCE, value, index + 1
- while (end < len(pattern)) and (pattern[end] in string.digits):
- end = end + 1
- value = pattern[index:end]
+ elif pattern[index] == 'g':
+ if context != REPLACEMENT:
+ return CHAR, 'g', index + 1
+ index = index + 1
+ if index >= len(pattern):
+ raise error, 'unfinished symbolic reference'
+ if pattern[index] != '<':
+ raise error, 'missing < in symbolic reference'
+
+ index = index + 1
+ end = string.find(pattern, '>', index)
+ if end == -1:
+ raise error, 'unfinished symbolic reference'
+ value = pattern[index:end]
+ if not valid_identifier(value):
+ raise error, 'illegal symbolic reference'
+ return MEMORY_REFERENCE, value, end + 1
+
else:
return CHAR, pattern[index], index + 1
@@ -837,7 +850,6 @@ def compile(pattern, flags=0):
label = 0
register = 1
groupindex = {}
- callouts = []
lastop = ''
# look for embedded pattern modifiers at the beginning of the pattern
@@ -989,21 +1001,6 @@ def compile(pattern, flags=0):
index = end + 1
lastop = '(?P=)'
- elif pattern[index] == '!':
- # function callout
- if index >= len(pattern):
- raise error, 'no function callout name'
- start = index + 1
- end = string.find(pattern, ')', start)
- if end == -1:
- raise error, 'no ) to end function callout name'
- name = pattern[start:end]
- if name not in callouts:
- raise error, ('function callout name not listed '
- 'in callouts dict')
- stack.append([FunctionCallout(name)])
- lastop = '(?P!)'
-
else:
raise error, ('unknown Python extension: ' + \
pattern[index])
@@ -1490,25 +1487,4 @@ def compile(pattern, flags=0):
code.append(Label(label))
label = label + 1
code.append(End())
- return RegexObject(pattern, flags, code, register, groupindex, callouts)
-
-if __name__ == '__main__':
- print compile('a(b)*')
- print compile('a{3}')
- print compile('(a){2}')
- print compile('a{2,4}')
- print compile('a|b')
- print compile('a(b|c)')
- print compile('a*')
- print compile('a+')
- print compile('a|b|c')
- print compile('a(b|c)*')
- print compile('\\n')
- print compile('a(?# huh huh)b')
- print compile('[a-c\\w]')
- print compile('[[]')
- print compile('[]]')
- print compile('(<hello>a)')
- print compile('\Q*\e')
- print compile('a{0,}')
-
+ return RegexObject(pattern, flags, code, register, groupindex)