# Regular expressions used for parsing
-incomplete = regex.compile(
- '<!-?\|</[a-zA-Z][a-zA-Z0-9]*[ \t\n]*\|</?\|' +
- '&#[a-zA-Z0-9]*\|&[a-zA-Z][a-zA-Z0-9]*\|&')
-entityref = regex.compile('&[a-zA-Z][a-zA-Z0-9]*[;.]')
-charref = regex.compile('&#[a-zA-Z0-9]+;')
-starttagopen = regex.compile('<[a-zA-Z]')
-endtag = regex.compile('</[a-zA-Z][a-zA-Z0-9]*[ \t\n]*>')
+interesting = regex.compile('[&<]')
+incomplete = regex.compile('&\([a-zA-Z][a-zA-Z0-9]*\|#[0-9]*\)?\|'
+ '<\([a-zA-Z][^<>]*\|'
+ '/\([a-zA-Z][^<>]*\)?\|'
+ '![^<>]*\)?')
+
+entityref = regex.compile('&\([a-zA-Z][a-zA-Z0-9]*\)[^a-zA-Z0-9]')
+charref = regex.compile('&#\([0-9]+\)[^0-9]')
+
+starttagopen = regex.compile('<[>a-zA-Z]')
+shorttagopen = regex.compile('<[a-zA-Z][a-zA-Z0-9]*/')
+shorttag = regex.compile('<\([a-zA-Z][a-zA-Z0-9]*\)/\([^/]*\)/')
+endtagopen = regex.compile('</[<>a-zA-Z]')
+endbracket = regex.compile('[<>]')
special = regex.compile('<![^<>]*>')
commentopen = regex.compile('<!--')
commentclose = regex.compile('--[ \t\n]*>')
+tagfind = regex.compile('[a-zA-Z][a-zA-Z0-9]*')
+attrfind = regex.compile(
+ '[ \t\n]+\([a-zA-Z_][a-zA-Z_0-9]*\)'
+ '\([ \t\n]*=[ \t\n]*'
+ '\(\'[^\']*\'\|"[^"]*"\|[-a-zA-Z0-9./:+*%?!()_#=~]*\)\)?')
# SGML parser base class -- find tags and call handler functions.
class SGMLParser:
- # Interface -- initialize and reset this instance
- def __init__(self, verbose=0):
- self.verbose = verbose
- self.reset()
-
- # Interface -- reset this instance. Loses all unprocessed data
- def reset(self):
- self.rawdata = ''
- self.stack = []
- self.nomoretags = 0
- self.literal = 0
-
- # For derived classes only -- enter literal mode (CDATA) till EOF
- def setnomoretags(self):
- self.nomoretags = self.literal = 1
-
- # For derived classes only -- enter literal mode (CDATA)
- def setliteral(self, *args):
- self.literal = 1
-
- # Interface -- feed some data to the parser. Call this as
- # often as you want, with as little or as much text as you
- # want (may include '\n'). (This just saves the text, all the
- # processing is done by goahead().)
- def feed(self, data):
- self.rawdata = self.rawdata + data
- self.goahead(0)
-
- # Interface -- handle the remaining data
- def close(self):
- self.goahead(1)
-
- # Internal -- handle data as far as reasonable. May leave state
- # and data to be processed by a subsequent call. If 'end' is
- # true, force handling all data as if followed by EOF marker.
- def goahead(self, end):
- rawdata = self.rawdata
- i = 0
- n = len(rawdata)
- while i < n:
- if self.nomoretags:
- self.handle_data(rawdata[i:n])
- i = n
- break
- j = incomplete.search(rawdata, i)
- if j < 0: j = n
- if i < j: self.handle_data(rawdata[i:j])
- i = j
- if i == n: break
- if rawdata[i] == '<':
- if starttagopen.match(rawdata, i) >= 0:
- if self.literal:
- self.handle_data(rawdata[i])
- i = i+1
- continue
- k = self.parse_starttag(i)
- if k < 0: break
- i = i + k
- continue
- k = endtag.match(rawdata, i)
- if k >= 0:
- j = i+k
- self.parse_endtag(rawdata[i:j])
- i = j
- self.literal = 0
- continue
- if commentopen.match(rawdata, i) >= 0:
- if self.literal:
- self.handle_data(rawdata[i])
- i = i+1
- continue
- k = self.parse_comment(i)
- if k < 0: break
- i = i+k
- continue
- k = special.match(rawdata, i)
- if k >= 0:
- if self.literal:
- self.handle_data(rawdata[i])
- i = i+1
- continue
- i = i+k
- continue
- elif rawdata[i] == '&':
- k = charref.match(rawdata, i)
- if k >= 0:
- j = i+k
- self.handle_charref(rawdata[i+2:j-1])
- i = j
- continue
- k = entityref.match(rawdata, i)
- if k >= 0:
- j = i+k
- self.handle_entityref(rawdata[i+1:j-1])
- i = j
- continue
- else:
- raise RuntimeError, 'neither < nor & ??'
- # We get here only if incomplete matches but
- # nothing else
- k = incomplete.match(rawdata, i)
- if k < 0: raise RuntimeError, 'no incomplete match ??'
- j = i+k
- if j == n or rawdata[i:i+2] == '<!':
- break # Really incomplete
- self.handle_data(rawdata[i:j])
- i = j
- # end while
- if end and i < n:
- self.handle_data(rawdata[i:n])
- i = n
- self.rawdata = rawdata[i:]
- # XXX if end: check for empty stack
-
- # Internal -- parse comment, return length or -1 if not terminated
- def parse_comment(self, i):
- rawdata = self.rawdata
- if rawdata[i:i+4] <> '<!--':
- raise RuntimeError, 'unexpected call to handle_comment'
- j = commentclose.search(rawdata, i+4)
- if j < 0:
- return -1
- self.handle_comment(rawdata[i+4: j])
- j = j+commentclose.match(rawdata, j)
- return j-i
-
- # Internal -- handle starttag, return length or -1 if not terminated
- def parse_starttag(self, i):
- rawdata = self.rawdata
+ # Interface -- initialize and reset this instance
+ def __init__(self, verbose=0):
+ self.verbose = verbose
+ self.reset()
+
+ # Interface -- reset this instance. Loses all unprocessed data
+ def reset(self):
+ self.rawdata = ''
+ self.stack = []
+ self.lasttag = '???'
+ self.nomoretags = 0
+ self.literal = 0
+
+ # For derived classes only -- enter literal mode (CDATA) till EOF
+ def setnomoretags(self):
+ self.nomoretags = self.literal = 1
+
+ # For derived classes only -- enter literal mode (CDATA)
+ def setliteral(self, *args):
+ self.literal = 1
+
+ # Interface -- feed some data to the parser. Call this as
+ # often as you want, with as little or as much text as you
+ # want (may include '\n'). (This just saves the text, all the
+ # processing is done by goahead().)
+ def feed(self, data):
+ self.rawdata = self.rawdata + data
+ self.goahead(0)
+
+ # Interface -- handle the remaining data
+ def close(self):
+ self.goahead(1)
+
+ # Internal -- handle data as far as reasonable. May leave state
+ # and data to be processed by a subsequent call. If 'end' is
+ # true, force handling all data as if followed by EOF marker.
+ def goahead(self, end):
+ rawdata = self.rawdata
+ i = 0
+ n = len(rawdata)
+ while i < n:
+ if self.nomoretags:
+ self.handle_data(rawdata[i:n])
+ i = n
+ break
+ j = interesting.search(rawdata, i)
+ if j < 0: j = n
+ if i < j: self.handle_data(rawdata[i:j])
+ i = j
+ if i == n: break
+ if rawdata[i] == '<':
+ if starttagopen.match(rawdata, i) >= 0:
+ if self.literal:
+ self.handle_data(rawdata[i])
+ i = i+1
+ continue
+ k = self.parse_starttag(i)
+ if k < 0: break
+ i = k
+ continue
+ if endtagopen.match(rawdata, i) >= 0:
+ k = self.parse_endtag(i)
+ if k < 0: break
+ i = k
+ self.literal = 0
+ continue
+ if commentopen.match(rawdata, i) >= 0:
+ if self.literal:
+ self.handle_data(rawdata[i])
+ i = i+1
+ continue
+ k = self.parse_comment(i)
+ if k < 0: break
+ i = i+k
+ continue
+ k = special.match(rawdata, i)
+ if k >= 0:
+ if self.literal:
+ self.handle_data(rawdata[i])
+ i = i+1
+ continue
+ i = i+k
+ continue
+ elif rawdata[i] == '&':
+ k = charref.match(rawdata, i)
+ if k >= 0:
+ k = i+k
+ if rawdata[k-1] != ';': k = k-1
+ name = charref.group(1)
+ self.handle_charref(name)
+ i = k
+ continue
+ k = entityref.match(rawdata, i)
+ if k >= 0:
+ k = i+k
+ if rawdata[k-1] != ';': k = k-1
+ name = entityref.group(1)
+ self.handle_entityref(name)
+ i = k
+ continue
+ else:
+ raise RuntimeError, 'neither < nor & ??'
+ # We get here only if incomplete matches but
+ # nothing else
+ k = incomplete.match(rawdata, i)
+ if k < 0:
+ self.handle_data(rawdata[i])
+ i = i+1
+ continue
+ j = i+k
+ if j == n:
+ break # Really incomplete
+ self.handle_data(rawdata[i:j])
+ i = j
+ # end while
+ if end and i < n:
+ self.handle_data(rawdata[i:n])
+ i = n
+ self.rawdata = rawdata[i:]
+ # XXX if end: check for empty stack
+
+ # Internal -- parse comment, return length or -1 if not terminated
+ def parse_comment(self, i):
+ rawdata = self.rawdata
+ if rawdata[i:i+4] <> '<!--':
+ raise RuntimeError, 'unexpected call to handle_comment'
+ j = commentclose.search(rawdata, i+4)
+ if j < 0:
+ return -1
+ self.handle_comment(rawdata[i+4: j])
+ j = j+commentclose.match(rawdata, j)
+ return j-i
+
+ # Internal -- handle starttag, return length or -1 if not terminated
+ def parse_starttag(self, i):
+ rawdata = self.rawdata
+ if shorttagopen.match(rawdata, i) >= 0:
+ # SGML shorthand: <tag/data/ == <tag>data</tag>
+ # XXX Can data contain &... (entity or char refs)?
+ # XXX Can data contain < or > (tag characters)?
+ # XXX Can there be whitespace before the first /?
+ j = shorttag.match(rawdata, i)
+ if j < 0:
+ return -1
+ tag, data = shorttag.group(1, 2)
+ tag = string.lower(tag)
+ self.finish_shorttag(tag, data)
+ k = i+j
+ if rawdata[k-1] == '<':
+ k = k-1
+ return k
+ # XXX The following should skip matching quotes (' or ")
+ j = endbracket.search(rawdata, i+1)
+ if j < 0:
+ return -1
+ # Now parse the data between i+1 and j into a tag and attrs
+ attrs = []
+ if rawdata[i:i+2] == '<>':
+ # SGML shorthand: <> == <last open tag seen>
+ k = j
+ tag = self.lasttag
+ else:
+ k = tagfind.match(rawdata, i+1)
+ if k < 0:
+ raise RuntimeError, 'unexpected call to parse_starttag'
+ k = i+1+k
+ tag = string.lower(rawdata[i+1:k])
+ self.lasttag = tag
+ while k < j:
+ l = attrfind.match(rawdata, k)
+ if l < 0: break
+ attrname, rest, attrvalue = attrfind.group(1, 2, 3)
+ if not rest:
+ attrvalue = attrname
+ elif attrvalue[:1] == '\'' == attrvalue[-1:] or \
+ attrvalue[:1] == '"' == attrvalue[-1:]:
+ attrvalue = attrvalue[1:-1]
+ attrs.append((string.lower(attrname), attrvalue))
+ k = k + l
+ if rawdata[j] == '>':
+ j = j+1
+ self.finish_starttag(tag, attrs)
+ return j
+
+ # Internal -- parse endtag
+ def parse_endtag(self, i):
+ rawdata = self.rawdata
+ j = endbracket.search(rawdata, i+1)
+ if j < 0:
+ return -1
+ tag = string.lower(string.strip(rawdata[i+2:j]))
+ if rawdata[j] == '>':
+ j = j+1
+ self.finish_endtag(tag)
+ return j
+
+ # Internal -- finish parsing of <tag/data/ (same as <tag>data</tag>)
+ def finish_shorttag(self, tag, data):
+ self.finish_starttag(tag, [])
+ self.handle_data(data)
+ self.finish_endtag(tag)
+
+ # Internal -- finish processing of start tag
+ # Return -1 for unknown tag, 0 for open-only tag, 1 for balanced tag
+ def finish_starttag(self, tag, attrs):
+ try:
+ method = getattr(self, 'start_' + tag)
+ except AttributeError:
+ try:
+ method = getattr(self, 'do_' + tag)
+ except AttributeError:
+ self.unknown_starttag(tag, attrs)
+ return -1
+ else:
+ self.handle_starttag(tag, method, attrs)
+ return 0
+ else:
+ self.stack.append(tag)
+ self.handle_starttag(tag, method, attrs)
+ return 1
+
+ # Internal -- finish processing of end tag
+ def finish_endtag(self, tag):
+ if not tag:
+ found = len(self.stack) - 1
+ if found < 0:
+ self.unknown_endtag(tag)
+ return
+ else:
+ if tag not in self.stack:
try:
- j = string.index(rawdata, '>', i)
- except string.index_error:
- return -1
- # Now parse the data between i+1 and j into a tag and attrs
- attrs = []
- tagfind = regex.compile('[a-zA-Z][a-zA-Z0-9]*')
- attrfind = regex.compile(
- '[ \t\n]+\([a-zA-Z_][a-zA-Z_0-9]*\)' +
- '\([ \t\n]*=[ \t\n]*' +
- '\(\'[^\']*\'\|"[^"]*"\|[-a-zA-Z0-9./:+*%?!()_#]*\)\)?')
- k = tagfind.match(rawdata, i+1)
- if k < 0:
- raise RuntimeError, 'unexpected call to parse_starttag'
- k = i+1+k
- tag = string.lower(rawdata[i+1:k])
- while k < j:
- l = attrfind.match(rawdata, k)
- if l < 0: break
- attrname, rest, attrvalue = attrfind.group(1, 2, 3)
- if not rest:
- attrvalue = attrname
- elif attrvalue[:1] == '\'' == attrvalue[-1:] or \
- attrvalue[:1] == '"' == attrvalue[-1:]:
- attrvalue = attrvalue[1:-1]
- attrs.append((string.lower(attrname), attrvalue))
- k = k + l
- j = j+1
- try:
- method = getattr(self, 'start_' + tag)
- except AttributeError:
- try:
- method = getattr(self, 'do_' + tag)
- except AttributeError:
- self.unknown_starttag(tag, attrs)
- return j-i
- method(attrs)
- return j-i
- self.stack.append(tag)
- method(attrs)
- return j-i
-
- # Internal -- parse endtag
- def parse_endtag(self, data):
- if data[:2] <> '</' or data[-1:] <> '>':
- raise RuntimeError, 'unexpected call to parse_endtag'
- tag = string.lower(string.strip(data[2:-1]))
- try:
- method = getattr(self, 'end_' + tag)
+ method = getattr(self, 'end_' + tag)
except AttributeError:
- self.unknown_endtag(tag)
- return
- # XXX Should invoke end methods when popping their
- # XXX stack entry, not when encountering the tag!
- if self.stack and self.stack[-1] == tag:
- del self.stack[-1]
- else:
- self.report_unbalanced(tag)
- # Now repair it
- found = None
- for i in range(len(self.stack)):
- if self.stack[i] == tag: found = i
- if found <> None:
- del self.stack[found:]
- method()
-
- # Example -- report an unbalanced </...> tag.
- def report_unbalanced(self, tag):
- if self.verbose:
- print '*** Unbalanced </' + tag + '>'
- print '*** Stack:', self.stack
-
- # Example -- handle character reference, no need to override
- def handle_charref(self, name):
- try:
- n = string.atoi(name)
- except string.atoi_error:
- self.unknown_charref(name)
- return
- if not 0 <= n <= 255:
- self.unknown_charref(name)
- return
- self.handle_data(chr(n))
-
- # Definition of entities -- derived classes may override
- entitydefs = \
- {'lt': '<', 'gt': '>', 'amp': '&', 'quot': '"', 'apos': '\''}
-
- # Example -- handle entity reference, no need to override
- def handle_entityref(self, name):
- table = self.entitydefs
- if table.has_key(name):
- self.handle_data(table[name])
- else:
- self.unknown_entityref(name)
- return
-
- # Example -- handle data, should be overridden
- def handle_data(self, data):
- pass
-
- # Example -- handle comment, could be overridden
- def handle_comment(self, data):
- pass
-
- # To be overridden -- handlers for unknown objects
- def unknown_starttag(self, tag, attrs): pass
- def unknown_endtag(self, tag): pass
- def unknown_charref(self, ref): pass
- def unknown_entityref(self, ref): pass
-
-
-class TestSGML(SGMLParser):
-
- def handle_data(self, data):
- r = repr(data)
- if len(r) > 72:
- r = r[:35] + '...' + r[-35:]
- print 'data:', r
-
- def handle_comment(self, data):
- r = repr(data)
- if len(r) > 68:
- r = r[:32] + '...' + r[-32:]
- print 'comment:', r
-
- def unknown_starttag(self, tag, attrs):
- print 'start tag: <' + tag,
- for name, value in attrs:
- print name + '=' + '"' + value + '"',
- print '>'
-
- def unknown_endtag(self, tag):
- print 'end tag: </' + tag + '>'
-
- def unknown_entityref(self, ref):
- print '*** unknown entity ref: &' + ref + ';'
-
- def unknown_charref(self, ref):
- print '*** unknown char ref: &#' + ref + ';'
-
-
-def test():
+ self.unknown_endtag(tag)
+ return
+ found = len(self.stack)
+ for i in range(found):
+ if self.stack[i] == tag: found = i
+ while len(self.stack) > found:
+ tag = self.stack[-1]
+ try:
+ method = getattr(self, 'end_' + tag)
+ except AttributeError:
+ method = None
+ if method:
+ self.handle_endtag(tag, method)
+ else:
+ self.unknown_endtag(tag)
+ del self.stack[-1]
+
+ # Overridable -- handle start tag
+ def handle_starttag(self, tag, method, attrs):
+ method(attrs)
+
+ # Overridable -- handle end tag
+ def handle_endtag(self, tag, method):
+ method()
+
+ # Example -- report an unbalanced </...> tag.
+ def report_unbalanced(self, tag):
+ if self.verbose:
+ print '*** Unbalanced </' + tag + '>'
+ print '*** Stack:', self.stack
+
+ # Example -- handle character reference, no need to override
+ def handle_charref(self, name):
+ try:
+ n = string.atoi(name)
+ except string.atoi_error:
+ self.unknown_charref(name)
+ return
+ if not 0 <= n <= 255:
+ self.unknown_charref(name)
+ return
+ self.handle_data(chr(n))
+
+ # Definition of entities -- derived classes may override
+ entitydefs = \
+ {'lt': '<', 'gt': '>', 'amp': '&', 'quot': '"', 'apos': '\''}
+
+ # Example -- handle entity reference, no need to override
+ def handle_entityref(self, name):
+ table = self.entitydefs
+ if table.has_key(name):
+ self.handle_data(table[name])
+ else:
+ self.unknown_entityref(name)
+ return
+
+ # Example -- handle data, should be overridden
+ def handle_data(self, data):
+ pass
+
+ # Example -- handle comment, could be overridden
+ def handle_comment(self, data):
+ pass
+
+ # To be overridden -- handlers for unknown objects
+ def unknown_starttag(self, tag, attrs): pass
+ def unknown_endtag(self, tag): pass
+ def unknown_charref(self, ref): pass
+ def unknown_entityref(self, ref): pass
+
+
+class TestSGMLParser(SGMLParser):
+
+ def __init__(self, verbose=0):
+ self.testdata = ""
+ SGMLParser.__init__(self, verbose)
+
+ def handle_data(self, data):
+ self.testdata = self.testdata + data
+ if len(`self.testdata`) >= 70:
+ self.flush()
+
+ def flush(self):
+ data = self.testdata
+ if data:
+ self.testdata = ""
+ print 'data:', `data`
+
+ def handle_comment(self, data):
+ self.flush()
+ r = `data`
+ if len(r) > 68:
+ r = r[:32] + '...' + r[-32:]
+ print 'comment:', r
+
+ def unknown_starttag(self, tag, attrs):
+ self.flush()
+ if not attrs:
+ print 'start tag: <' + tag + '>'
+ else:
+ print 'start tag: <' + tag,
+ for name, value in attrs:
+ print name + '=' + '"' + value + '"',
+ print '>'
+
+ def unknown_endtag(self, tag):
+ self.flush()
+ print 'end tag: </' + tag + '>'
+
+ def unknown_entityref(self, ref):
+ self.flush()
+ print '*** unknown entity ref: &' + ref + ';'
+
+ def unknown_charref(self, ref):
+ self.flush()
+ print '*** unknown char ref: &#' + ref + ';'
+
+ def close(self):
+ SGMLParser.close(self)
+ self.flush()
+
+
+def test(args = None):
+ import sys
+
+ if not args:
+ args = sys.argv[1:]
+
+ if args and args[0] == '-s':
+ args = args[1:]
+ klass = SGMLParser
+ else:
+ klass = TestSGMLParser
+
+ if args:
+ file = args[0]
+ else:
file = 'test.html'
- f = open(file, 'r')
- x = TestSGML()
- while 1:
- line = f.readline()
- if not line:
- x.close()
- break
- x.feed(line)
+
+ if file == '-':
+ f = sys.stdin
+ else:
+ try:
+ f = open(file, 'r')
+ except IOError, msg:
+ print file, ":", msg
+ sys.exit(1)
+
+ data = f.read()
+ if f is not sys.stdin:
+ f.close()
+
+ x = klass()
+ for c in data:
+ x.feed(c)
+ x.close()
if __name__ == '__main__':
- test()
+ test()
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