Add google-endpoints to third_party/.

third_party/google-endpoints/future/backports/html/parser.py

Index: third_party/google-endpoints/future/backports/html/parser.py
diff --git a/third_party/google-endpoints/future/backports/html/parser.py b/third_party/google-endpoints/future/backports/html/parser.py
new file mode 100644
index 0000000000000000000000000000000000000000..7b8cdba6138ee0786637940087ad8adf38008937
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+++ b/third_party/google-endpoints/future/backports/html/parser.py
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+"""A parser for HTML and XHTML.
+
+Backported for python-future from Python 3.3.
+"""
+
+# This file is based on sgmllib.py, but the API is slightly different.
+
+# XXX There should be a way to distinguish between PCDATA (parsed
+# character data -- the normal case), RCDATA (replaceable character
+# data -- only char and entity references and end tags are special)
+# and CDATA (character data -- only end tags are special).
+
+from __future__ import (absolute_import, division,
+                        print_function, unicode_literals)
+from future.builtins import *
+from future.backports import _markupbase
+import re
+import warnings
+
+# Regular expressions used for parsing
+
+interesting_normal = re.compile('[&<]')
+incomplete = re.compile('&[a-zA-Z#]')
+
+entityref = re.compile('&([a-zA-Z][-.a-zA-Z0-9]*)[^a-zA-Z0-9]')
+charref = re.compile('&#(?:[0-9]+|[xX][0-9a-fA-F]+)[^0-9a-fA-F]')
+
+starttagopen = re.compile('<[a-zA-Z]')
+piclose = re.compile('>')
+commentclose = re.compile(r'--\s*>')
+tagfind = re.compile('([a-zA-Z][-.a-zA-Z0-9:_]*)(?:\s|/(?!>))*')
+# see http://www.w3.org/TR/html5/tokenization.html#tag-open-state
+# and http://www.w3.org/TR/html5/tokenization.html#tag-name-state
+tagfind_tolerant = re.compile('[a-zA-Z][^\t\n\r\f />\x00]*')
+# Note:
+#  1) the strict attrfind isn't really strict, but we can't make it
+#     correctly strict without breaking backward compatibility;
+#  2) if you change attrfind remember to update locatestarttagend too;
+#  3) if you change attrfind and/or locatestarttagend the parser will
+#     explode, so don't do it.
+attrfind = re.compile(
+    r'\s*([a-zA-Z_][-.:a-zA-Z_0-9]*)(\s*=\s*'
+    r'(\'[^\']*\'|"[^"]*"|[^\s"\'=<>`]*))?')
+attrfind_tolerant = re.compile(
+    r'((?<=[\'"\s/])[^\s/>][^\s/=>]*)(\s*=+\s*'
+    r'(\'[^\']*\'|"[^"]*"|(?![\'"])[^>\s]*))?(?:\s|/(?!>))*')
+locatestarttagend = re.compile(r"""
+  <[a-zA-Z][-.a-zA-Z0-9:_]*          # tag name
+  (?:\s+                             # whitespace before attribute name
+    (?:[a-zA-Z_][-.:a-zA-Z0-9_]*     # attribute name
+      (?:\s*=\s*                     # value indicator
+        (?:'[^']*'                   # LITA-enclosed value
+          |\"[^\"]*\"                # LIT-enclosed value
+          |[^'\">\s]+                # bare value
+         )
+       )?
+     )
+   )*
+  \s*                                # trailing whitespace
+""", re.VERBOSE)
+locatestarttagend_tolerant = re.compile(r"""
+  <[a-zA-Z][-.a-zA-Z0-9:_]*          # tag name
+  (?:[\s/]*                          # optional whitespace before attribute name
+    (?:(?<=['"\s/])[^\s/>][^\s/=>]*  # attribute name
+      (?:\s*=+\s*                    # value indicator
+        (?:'[^']*'                   # LITA-enclosed value
+          |"[^"]*"                   # LIT-enclosed value
+          |(?!['"])[^>\s]*           # bare value
+         )
+         (?:\s*,)*                   # possibly followed by a comma
+       )?(?:\s|/(?!>))*
+     )*
+   )?
+  \s*                                # trailing whitespace
+""", re.VERBOSE)
+endendtag = re.compile('>')
+# the HTML 5 spec, section 8.1.2.2, doesn't allow spaces between
+# </ and the tag name, so maybe this should be fixed
+endtagfind = re.compile('</\s*([a-zA-Z][-.a-zA-Z0-9:_]*)\s*>')
+
+
+class HTMLParseError(Exception):
+    """Exception raised for all parse errors."""
+
+    def __init__(self, msg, position=(None, None)):
+        assert msg
+        self.msg = msg
+        self.lineno = position[0]
+        self.offset = position[1]
+
+    def __str__(self):
+        result = self.msg
+        if self.lineno is not None:
+            result = result + ", at line %d" % self.lineno
+        if self.offset is not None:
+            result = result + ", column %d" % (self.offset + 1)
+        return result
+
+
+class HTMLParser(_markupbase.ParserBase):
+    """Find tags and other markup and call handler functions.
+
+    Usage:
+        p = HTMLParser()
+        p.feed(data)
+        ...
+        p.close()
+
+    Start tags are handled by calling self.handle_starttag() or
+    self.handle_startendtag(); end tags by self.handle_endtag().  The
+    data between tags is passed from the parser to the derived class
+    by calling self.handle_data() with the data as argument (the data
+    may be split up in arbitrary chunks).  Entity references are
+    passed by calling self.handle_entityref() with the entity
+    reference as the argument.  Numeric character references are
+    passed to self.handle_charref() with the string containing the
+    reference as the argument.
+    """
+
+    CDATA_CONTENT_ELEMENTS = ("script", "style")
+
+    def __init__(self, strict=False):
+        """Initialize and reset this instance.
+
+        If strict is set to False (the default) the parser will parse invalid
+        markup, otherwise it will raise an error.  Note that the strict mode
+        is deprecated.
+        """
+        if strict:
+            warnings.warn("The strict mode is deprecated.",
+                          DeprecationWarning, stacklevel=2)
+        self.strict = strict
+        self.reset()
+
+    def reset(self):
+        """Reset this instance.  Loses all unprocessed data."""
+        self.rawdata = ''
+        self.lasttag = '???'
+        self.interesting = interesting_normal
+        self.cdata_elem = None
+        _markupbase.ParserBase.reset(self)
+
+    def feed(self, data):
+        r"""Feed data to the parser.
+
+        Call this as often as you want, with as little or as much text
+        as you want (may include '\n').
+        """
+        self.rawdata = self.rawdata + data
+        self.goahead(0)
+
+    def close(self):
+        """Handle any buffered data."""
+        self.goahead(1)
+
+    def error(self, message):
+        raise HTMLParseError(message, self.getpos())
+
+    __starttag_text = None
+
+    def get_starttag_text(self):
+        """Return full source of start tag: '<...>'."""
+        return self.__starttag_text
+
+    def set_cdata_mode(self, elem):
+        self.cdata_elem = elem.lower()
+        self.interesting = re.compile(r'</\s*%s\s*>' % self.cdata_elem, re.I)
+
+    def clear_cdata_mode(self):
+        self.interesting = interesting_normal
+        self.cdata_elem = None
+
+    # 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:
+            match = self.interesting.search(rawdata, i) # < or &
+            if match:
+                j = match.start()
+            else:
+                if self.cdata_elem:
+                    break
+                j = n
+            if i < j: self.handle_data(rawdata[i:j])
+            i = self.updatepos(i, j)
+            if i == n: break
+            startswith = rawdata.startswith
+            if startswith('<', i):
+                if starttagopen.match(rawdata, i): # < + letter
+                    k = self.parse_starttag(i)
+                elif startswith("</", i):
+                    k = self.parse_endtag(i)
+                elif startswith("<!--", i):
+                    k = self.parse_comment(i)
+                elif startswith("<?", i):
+                    k = self.parse_pi(i)
+                elif startswith("<!", i):
+                    if self.strict:
+                        k = self.parse_declaration(i)
+                    else:
+                        k = self.parse_html_declaration(i)
+                elif (i + 1) < n:
+                    self.handle_data("<")
+                    k = i + 1
+                else:
+                    break
+                if k < 0:
+                    if not end:
+                        break
+                    if self.strict:
+                        self.error("EOF in middle of construct")
+                    k = rawdata.find('>', i + 1)
+                    if k < 0:
+                        k = rawdata.find('<', i + 1)
+                        if k < 0:
+                            k = i + 1
+                    else:
+                        k += 1
+                    self.handle_data(rawdata[i:k])
+                i = self.updatepos(i, k)
+            elif startswith("&#", i):
+                match = charref.match(rawdata, i)
+                if match:
+                    name = match.group()[2:-1]
+                    self.handle_charref(name)
+                    k = match.end()
+                    if not startswith(';', k-1):
+                        k = k - 1
+                    i = self.updatepos(i, k)
+                    continue
+                else:
+                    if ";" in rawdata[i:]: #bail by consuming &#
+                        self.handle_data(rawdata[0:2])
+                        i = self.updatepos(i, 2)
+                    break
+            elif startswith('&', i):
+                match = entityref.match(rawdata, i)
+                if match:
+                    name = match.group(1)
+                    self.handle_entityref(name)
+                    k = match.end()
+                    if not startswith(';', k-1):
+                        k = k - 1
+                    i = self.updatepos(i, k)
+                    continue
+                match = incomplete.match(rawdata, i)
+                if match:
+                    # match.group() will contain at least 2 chars
+                    if end and match.group() == rawdata[i:]:
+                        if self.strict:
+                            self.error("EOF in middle of entity or char ref")
+                        else:
+                            if k <= i:
+                                k = n
+                            i = self.updatepos(i, i + 1)
+                    # incomplete
+                    break
+                elif (i + 1) < n:
+                    # not the end of the buffer, and can't be confused
+                    # with some other construct
+                    self.handle_data("&")
+                    i = self.updatepos(i, i + 1)
+                else:
+                    break
+            else:
+                assert 0, "interesting.search() lied"
+        # end while
+        if end and i < n and not self.cdata_elem:
+            self.handle_data(rawdata[i:n])
+            i = self.updatepos(i, n)
+        self.rawdata = rawdata[i:]
+
+    # Internal -- parse html declarations, return length or -1 if not terminated
+    # See w3.org/TR/html5/tokenization.html#markup-declaration-open-state
+    # See also parse_declaration in _markupbase
+    def parse_html_declaration(self, i):
+        rawdata = self.rawdata
+        assert rawdata[i:i+2] == '<!', ('unexpected call to '
+                                        'parse_html_declaration()')
+        if rawdata[i:i+4] == '<!--':
+            # this case is actually already handled in goahead()
+            return self.parse_comment(i)
+        elif rawdata[i:i+3] == '<![':
+            return self.parse_marked_section(i)
+        elif rawdata[i:i+9].lower() == '<!doctype':
+            # find the closing >
+            gtpos = rawdata.find('>', i+9)
+            if gtpos == -1:
+                return -1
+            self.handle_decl(rawdata[i+2:gtpos])
+            return gtpos+1
+        else:
+            return self.parse_bogus_comment(i)
+
+    # Internal -- parse bogus comment, return length or -1 if not terminated
+    # see http://www.w3.org/TR/html5/tokenization.html#bogus-comment-state
+    def parse_bogus_comment(self, i, report=1):
+        rawdata = self.rawdata
+        assert rawdata[i:i+2] in ('<!', '</'), ('unexpected call to '
+                                                'parse_comment()')
+        pos = rawdata.find('>', i+2)
+        if pos == -1:
+            return -1
+        if report:
+            self.handle_comment(rawdata[i+2:pos])
+        return pos + 1
+
+    # Internal -- parse processing instr, return end or -1 if not terminated
+    def parse_pi(self, i):
+        rawdata = self.rawdata
+        assert rawdata[i:i+2] == '<?', 'unexpected call to parse_pi()'
+        match = piclose.search(rawdata, i+2) # >
+        if not match:
+            return -1
+        j = match.start()
+        self.handle_pi(rawdata[i+2: j])
+        j = match.end()
+        return j
+
+    # Internal -- handle starttag, return end or -1 if not terminated
+    def parse_starttag(self, i):
+        self.__starttag_text = None
+        endpos = self.check_for_whole_start_tag(i)
+        if endpos < 0:
+            return endpos
+        rawdata = self.rawdata
+        self.__starttag_text = rawdata[i:endpos]
+
+        # Now parse the data between i+1 and j into a tag and attrs
+        attrs = []
+        match = tagfind.match(rawdata, i+1)
+        assert match, 'unexpected call to parse_starttag()'
+        k = match.end()
+        self.lasttag = tag = match.group(1).lower()
+        while k < endpos:
+            if self.strict:
+                m = attrfind.match(rawdata, k)
+            else:
+                m = attrfind_tolerant.match(rawdata, k)
+            if not m:
+                break
+            attrname, rest, attrvalue = m.group(1, 2, 3)
+            if not rest:
+                attrvalue = None
+            elif attrvalue[:1] == '\'' == attrvalue[-1:] or \
+                 attrvalue[:1] == '"' == attrvalue[-1:]:
+                attrvalue = attrvalue[1:-1]
+            if attrvalue:
+                attrvalue = self.unescape(attrvalue)
+            attrs.append((attrname.lower(), attrvalue))
+            k = m.end()
+
+        end = rawdata[k:endpos].strip()
+        if end not in (">", "/>"):
+            lineno, offset = self.getpos()
+            if "\n" in self.__starttag_text:
+                lineno = lineno + self.__starttag_text.count("\n")
+                offset = len(self.__starttag_text) \
+                         - self.__starttag_text.rfind("\n")
+            else:
+                offset = offset + len(self.__starttag_text)
+            if self.strict:
+                self.error("junk characters in start tag: %r"
+                           % (rawdata[k:endpos][:20],))
+            self.handle_data(rawdata[i:endpos])
+            return endpos
+        if end.endswith('/>'):
+            # XHTML-style empty tag: <span attr="value" />
+            self.handle_startendtag(tag, attrs)
+        else:
+            self.handle_starttag(tag, attrs)
+            if tag in self.CDATA_CONTENT_ELEMENTS:
+                self.set_cdata_mode(tag)
+        return endpos
+
+    # Internal -- check to see if we have a complete starttag; return end
+    # or -1 if incomplete.
+    def check_for_whole_start_tag(self, i):
+        rawdata = self.rawdata
+        if self.strict:
+            m = locatestarttagend.match(rawdata, i)
+        else:
+            m = locatestarttagend_tolerant.match(rawdata, i)
+        if m:
+            j = m.end()
+            next = rawdata[j:j+1]
+            if next == ">":
+                return j + 1
+            if next == "/":
+                if rawdata.startswith("/>", j):
+                    return j + 2
+                if rawdata.startswith("/", j):
+                    # buffer boundary
+                    return -1
+                # else bogus input
+                if self.strict:
+                    self.updatepos(i, j + 1)
+                    self.error("malformed empty start tag")
+                if j > i:
+                    return j
+                else:
+                    return i + 1
+            if next == "":
+                # end of input
+                return -1
+            if next in ("abcdefghijklmnopqrstuvwxyz=/"
+                        "ABCDEFGHIJKLMNOPQRSTUVWXYZ"):
+                # end of input in or before attribute value, or we have the
+                # '/' from a '/>' ending
+                return -1
+            if self.strict:
+                self.updatepos(i, j)
+                self.error("malformed start tag")
+            if j > i:
+                return j
+            else:
+                return i + 1
+        raise AssertionError("we should not get here!")
+
+    # Internal -- parse endtag, return end or -1 if incomplete
+    def parse_endtag(self, i):
+        rawdata = self.rawdata
+        assert rawdata[i:i+2] == "</", "unexpected call to parse_endtag"
+        match = endendtag.search(rawdata, i+1) # >
+        if not match:
+            return -1
+        gtpos = match.end()
+        match = endtagfind.match(rawdata, i) # </ + tag + >
+        if not match:
+            if self.cdata_elem is not None:
+                self.handle_data(rawdata[i:gtpos])
+                return gtpos
+            if self.strict:
+                self.error("bad end tag: %r" % (rawdata[i:gtpos],))
+            # find the name: w3.org/TR/html5/tokenization.html#tag-name-state
+            namematch = tagfind_tolerant.match(rawdata, i+2)
+            if not namematch:
+                # w3.org/TR/html5/tokenization.html#end-tag-open-state
+                if rawdata[i:i+3] == '</>':
+                    return i+3
+                else:
+                    return self.parse_bogus_comment(i)
+            tagname = namematch.group().lower()
+            # consume and ignore other stuff between the name and the >
+            # Note: this is not 100% correct, since we might have things like
+            # </tag attr=">">, but looking for > after tha name should cover
+            # most of the cases and is much simpler
+            gtpos = rawdata.find('>', namematch.end())
+            self.handle_endtag(tagname)
+            return gtpos+1
+
+        elem = match.group(1).lower() # script or style
+        if self.cdata_elem is not None:
+            if elem != self.cdata_elem:
+                self.handle_data(rawdata[i:gtpos])
+                return gtpos
+
+        self.handle_endtag(elem.lower())
+        self.clear_cdata_mode()
+        return gtpos
+
+    # Overridable -- finish processing of start+end tag: <tag.../>
+    def handle_startendtag(self, tag, attrs):
+        self.handle_starttag(tag, attrs)
+        self.handle_endtag(tag)
+
+    # Overridable -- handle start tag
+    def handle_starttag(self, tag, attrs):
+        pass
+
+    # Overridable -- handle end tag
+    def handle_endtag(self, tag):
+        pass
+
+    # Overridable -- handle character reference
+    def handle_charref(self, name):
+        pass
+
+    # Overridable -- handle entity reference
+    def handle_entityref(self, name):
+        pass
+
+    # Overridable -- handle data
+    def handle_data(self, data):
+        pass
+
+    # Overridable -- handle comment
+    def handle_comment(self, data):
+        pass
+
+    # Overridable -- handle declaration
+    def handle_decl(self, decl):
+        pass
+
+    # Overridable -- handle processing instruction
+    def handle_pi(self, data):
+        pass
+
+    def unknown_decl(self, data):
+        if self.strict:
+            self.error("unknown declaration: %r" % (data,))
+
+    # Internal -- helper to remove special character quoting
+    def unescape(self, s):
+        if '&' not in s:
+            return s
+        def replaceEntities(s):
+            s = s.groups()[0]
+            try:
+                if s[0] == "#":
+                    s = s[1:]
+                    if s[0] in ['x','X']:
+                        c = int(s[1:].rstrip(';'), 16)
+                    else:
+                        c = int(s.rstrip(';'))
+                    return chr(c)
+            except ValueError:
+                return '&#' + s
+            else:
+                from future.backports.html.entities import html5
+                if s in html5:
+                    return html5[s]
+                elif s.endswith(';'):
+                    return '&' + s
+                for x in range(2, len(s)):
+                    if s[:x] in html5:
+                        return html5[s[:x]] + s[x:]
+                else:
+                    return '&' + s
+
+        return re.sub(r"&(#?[xX]?(?:[0-9a-fA-F]+;|\w{1,32};?))",
+                      replaceEntities, s)
+