def METHOD_NAME(self, text):
    """
    Compute matches when text is a simple name.
    Return a list of all names currently defined in self.namespace
    that match.
    """
    matches = []
    n = len(text)
    for ns in (self.namespace,):
        for word in ns:
            if word[:n] == text:
                matches.append(word)
    return matches