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authorFred Drake <fdrake@acm.org>2001-03-16 20:04:57 (GMT)
committerFred Drake <fdrake@acm.org>2001-03-16 20:04:57 (GMT)
commit669573726bb31d8862e98b3843549e5fe0b54d37 (patch)
tree5969d357eebd6a8f790fb13d54a86d8e9a0a9f0a
parent83e01bf6c84719f8977d1ffd721d75d8eda2ddf8 (diff)
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Change RuntimeError to SGMLParseError, which subclasses RuntimeError
for backward compatibility. Add support for SGML declaration syntax (<!....>) to some reasonable degree. This does not support everything allowed in SGML, but should work with "real" HTML (internal subset in a DOCTYPE is not handled). The content of the declaration is passed to the .handle_decl() method, which can be overridden by subclasses.
-rw-r--r--Lib/sgmllib.py58
1 files changed, 53 insertions, 5 deletions
diff --git a/Lib/sgmllib.py b/Lib/sgmllib.py
index 19580e2..2ebe698 100644
--- a/Lib/sgmllib.py
+++ b/Lib/sgmllib.py
@@ -39,6 +39,14 @@ attrfind = re.compile(
r'\s*([a-zA-Z_][-.a-zA-Z_0-9]*)(\s*=\s*'
r'(\'[^\']*\'|"[^"]*"|[-a-zA-Z0-9./:;+*%?!&$\(\)_#=~]*))?')
+declname = re.compile(r'[a-zA-Z][-_.a-zA-Z0-9]*\s*')
+declstringlit = re.compile(r'(\'[^\']*\'|"[^"]*")\s*')
+
+
+class SGMLParseError(RuntimeError):
+ """Exception raised for all parse errors."""
+ pass
+
# SGML parser base class -- find tags and call handler functions.
# Usage: p = SGMLParser(); p.feed(data); ...; p.close().
@@ -144,7 +152,12 @@ class SGMLParser:
self.handle_data(rawdata[i])
i = i+1
continue
- i = match.end(0)
+ # This is some sort of declaration; in "HTML as
+ # deployed," this should only be the document type
+ # declaration ("<!DOCTYPE html...>").
+ k = self.parse_declaration(i)
+ if k < 0: break
+ i = k
continue
elif rawdata[i] == '&':
match = charref.match(rawdata, i)
@@ -162,7 +175,7 @@ class SGMLParser:
if rawdata[i-1] != ';': i = i-1
continue
else:
- raise RuntimeError, 'neither < nor & ??'
+ raise SGMLParserError('neither < nor & ??')
# We get here only if incomplete matches but
# nothing else
match = incomplete.match(rawdata, i)
@@ -186,7 +199,7 @@ class SGMLParser:
def parse_comment(self, i):
rawdata = self.rawdata
if rawdata[i:i+4] != '<!--':
- raise RuntimeError, 'unexpected call to handle_comment'
+ raise SGMLParseError('unexpected call to parse_comment()')
match = commentclose.search(rawdata, i+4)
if not match:
return -1
@@ -195,11 +208,42 @@ class SGMLParser:
j = match.end(0)
return j-i
+ # Internal -- parse declaration.
+ def parse_declaration(self, i):
+ rawdata = self.rawdata
+ j = i + 2
+ # in practice, this should look like: ((name|stringlit) S*)+ '>'
+ while 1:
+ c = rawdata[j:j+1]
+ if c == ">":
+ # end of declaration syntax
+ self.handle_decl(rawdata[i+2:j])
+ return j + 1
+ if c in "\"'":
+ m = declstringlit.match(rawdata, j)
+ if not m:
+ # incomplete or an error?
+ return -1
+ j = m.end()
+ elif c in "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ":
+ m = declname.match(rawdata, j)
+ if not m:
+ # incomplete or an error?
+ return -1
+ j = m.end()
+ elif i == len(rawdata):
+ # end of buffer between tokens
+ return -1
+ else:
+ raise SGMLParseError(
+ "unexpected char in declaration: %s" % `rawdata[i]`)
+ assert 0, "can't get here!"
+
# Internal -- parse processing instr, return length or -1 if not terminated
def parse_pi(self, i):
rawdata = self.rawdata
if rawdata[i:i+2] != '<?':
- raise RuntimeError, 'unexpected call to handle_pi'
+ raise SGMLParseError('unexpected call to parse_pi()')
match = piclose.search(rawdata, i+2)
if not match:
return -1
@@ -246,7 +290,7 @@ class SGMLParser:
else:
match = tagfind.match(rawdata, i+1)
if not match:
- raise RuntimeError, 'unexpected call to parse_starttag'
+ raise SGMLParseError('unexpected call to parse_starttag')
k = match.end(0)
tag = rawdata[i+1:k].lower()
self.lasttag = tag
@@ -383,6 +427,10 @@ class SGMLParser:
def handle_comment(self, data):
pass
+ # Example -- handle declaration, could be overridden
+ def handle_decl(self, decl):
+ pass
+
# Example -- handle processing instruction, could be overridden
def handle_pi(self, data):
pass