Adding cython v0.20.2 in third-party.

third_party/cython/src/Cython/Compiler/TreePath.py

+"""
+A simple XPath-like language for tree traversal.
+
+This works by creating a filter chain of generator functions.  Each
+function selects a part of the expression, e.g. a child node, a
+specific descendant or a node that holds an attribute.
+"""
+
+import re
+import sys
+
+path_tokenizer = re.compile(
+    "("
+    "'[^']*'|\"[^\"]*\"|"
+    "//?|"
+    "\(\)|"
+    "==?|"
+    "[/.*\[\]\(\)@])|"
+    "([^/\[\]\(\)@=\s]+)|"
+    "\s+"
+    ).findall
+
+def iterchildren(node, attr_name):
+    # returns an iterable of all child nodes of that name
+    child = getattr(node, attr_name)
+    if child is not None:
+        if type(child) is list:
+            return child
+        else:
+            return [child]
+    else:
+        return ()
+
+def _get_first_or_none(it):
+    try:
+        try:
+            _next = it.next
+        except AttributeError:
+            return next(it)
+        else:
+            return _next()
+    except StopIteration:
+        return None
+
+def type_name(node):
+    return node.__class__.__name__.split('.')[-1]
+
+def parse_func(next, token):
+    name = token[1]
+    token = next()
+    if token[0] != '(':
+        raise ValueError("Expected '(' after function name '%s'" % name)
+    predicate = handle_predicate(next, token)
+    return name, predicate
+
+def handle_func_not(next, token):
+    """
+    not(...)
+    """
+    name, predicate = parse_func(next, token)
+
+    def select(result):
+        for node in result:
+            if _get_first_or_none(predicate([node])) is None:
+                yield node
+    return select
+
+def handle_name(next, token):
+    """
+    /NodeName/
+    or
+    func(...)
+    """
+    name = token[1]
+    if name in functions:
+        return functions[name](next, token)
+    def select(result):
+        for node in result:
+            for attr_name in node.child_attrs:
+                for child in iterchildren(node, attr_name):
+                    if type_name(child) == name:
+                        yield child
+    return select
+
+def handle_star(next, token):
+    """
+    /*/
+    """
+    def select(result):
+        for node in result:
+            for name in node.child_attrs:
+                for child in iterchildren(node, name):
+                    yield child
+    return select
+
+def handle_dot(next, token):
+    """
+    /./
+    """
+    def select(result):
+        return result
+    return select
+
+def handle_descendants(next, token):
+    """
+    //...
+    """
+    token = next()
+    if token[0] == "*":
+        def iter_recursive(node):
+            for name in node.child_attrs:
+                for child in iterchildren(node, name):
+                    yield child
+                    for c in iter_recursive(child):
+                        yield c
+    elif not token[0]:
+        node_name = token[1]
+        def iter_recursive(node):
+            for name in node.child_attrs:
+                for child in iterchildren(node, name):
+                    if type_name(child) == node_name:
+                        yield child
+                    for c in iter_recursive(child):
+                        yield c
+    else:
+        raise ValueError("Expected node name after '//'")
+
+    def select(result):
+        for node in result:
+            for child in iter_recursive(node):
+                yield child
+
+    return select
+
+def handle_attribute(next, token):
+    token = next()
+    if token[0]:
+        raise ValueError("Expected attribute name")
+    name = token[1]
+    value = None
+    try:
+        token = next()
+    except StopIteration:
+        pass
+    else:
+        if token[0] == '=':
+            value = parse_path_value(next)
+    if sys.version_info >= (2,6) or (sys.version_info >= (2,4) and '.' not in name):
+        import operator
+        readattr = operator.attrgetter(name)
+    else:
+        name_path = name.split('.')
+        def readattr(node):
+            attr_value = node
+            for attr in name_path:
+                attr_value = getattr(attr_value, attr)
+            return attr_value
+    if value is None:
+        def select(result):
+            for node in result:
+                try:
+                    attr_value = readattr(node)
+                except AttributeError:
+                    continue
+                if attr_value is not None:
+                    yield attr_value
+    else:
+        def select(result):
+            for node in result:
+                try:
+                    attr_value = readattr(node)
+                except AttributeError:
+                    continue
+                if attr_value == value:
+                    yield attr_value
+    return select
+
+def parse_path_value(next):
+    token = next()
+    value = token[0]
+    if value:
+        if value[:1] == "'" or value[:1] == '"':
+            return value[1:-1]
+        try:
+            return int(value)
+        except ValueError:
+            pass
+    else:
+        name = token[1].lower()
+        if name == 'true':
+            return True
+        elif name == 'false':
+            return False
+    raise ValueError("Invalid attribute predicate: '%s'" % value)
+
+def handle_predicate(next, token):
+    token = next()
+    selector = []
+    while token[0] != ']':
+        selector.append( operations[token[0]](next, token) )
+        try:
+            token = next()
+        except StopIteration:
+            break
+        else:
+            if token[0] == "/":
+                token = next()
+
+        if not token[0] and token[1] == 'and':
+            return logical_and(selector, handle_predicate(next, token))
+
+    def select(result):
+        for node in result:
+            subresult = iter((node,))
+            for select in selector:
+                subresult = select(subresult)
+            predicate_result = _get_first_or_none(subresult)
+            if predicate_result is not None:
+                yield node
+    return select
+
+def logical_and(lhs_selects, rhs_select):
+    def select(result):
+        for node in result:
+            subresult = iter((node,))
+            for select in lhs_selects:
+                subresult = select(subresult)
+            predicate_result = _get_first_or_none(subresult)
+            subresult = iter((node,))
+            if predicate_result is not None:
+                for result_node in rhs_select(subresult):
+                    yield node
+    return select
+
+
+operations = {
+    "@":  handle_attribute,
+    "":   handle_name,
+    "*":  handle_star,
+    ".":  handle_dot,
+    "//": handle_descendants,
+    "[":  handle_predicate,
+    }
+
+functions = {
+    'not' : handle_func_not
+    }
+
+def _build_path_iterator(path):
+    # parse pattern
+    stream = iter([ (special,text)
+                    for (special,text) in path_tokenizer(path)
+                    if special or text ])
+    try:
+        _next = stream.next
+    except AttributeError:
+        # Python 3
+        def _next():
+            return next(stream)
+    token = _next()
+    selector = []
+    while 1:
+        try:
+            selector.append(operations[token[0]](_next, token))
+        except StopIteration:
+            raise ValueError("invalid path")
+        try:
+            token = _next()
+            if token[0] == "/":
+                token = _next()
+        except StopIteration:
+            break
+    return selector
+
+# main module API
+
+def iterfind(node, path):
+    selector_chain = _build_path_iterator(path)
+    result = iter((node,))
+    for select in selector_chain:
+        result = select(result)
+    return result
+
+def find_first(node, path):
+    return _get_first_or_none(iterfind(node, path))
+
+def find_all(node, path):
+    return list(iterfind(node, path))