Method _read_partial_featlist

nltk/featstruct.py:2272–2316

(self, s, position, match, reentrances, fstruct)

            return self._read_partial_featlist(s, position, match, reentrances, fstruct)

    def _read_partial_featlist(self, s, position, match, reentrances, fstruct):
        # Prefix features are not allowed:
        if match.group(2):
            raise ValueError("open bracket")
        # Bare prefixes are not allowed:
        if not match.group(3):
            raise ValueError("open bracket")

        # Build a list of the features defined by the structure.
        while position < len(s):
            # Check for the close bracket.
            match = self._END_FSTRUCT_RE.match(s, position)
            if match is not None:
                return fstruct, match.end()

            # Reentances have the form "-> (target)"
            match = self._REENTRANCE_RE.match(s, position)
            if match:
                position = match.end()
                match = self._TARGET_RE.match(s, position)
                if not match:
                    raise ValueError("identifier", position)
                target = match.group(1)
                if target not in reentrances:
                    raise ValueError("bound identifier", position)
                position = match.end()
                fstruct.append(reentrances[target])

            # Anything else is a value.
            else:
                value, position = self._read_value(0, s, position, reentrances)
                fstruct.append(value)

            # If there's a close bracket, handle it at the top of the loop.
            if self._END_FSTRUCT_RE.match(s, position):
                continue

            # Otherwise, there should be a comma
            match = self._COMMA_RE.match(s, position)
            if match is None:
                raise ValueError("comma", position)
            position = match.end()

        # We never saw a close bracket.
        raise ValueError("close bracket", position)

    def _read_partial_featdict(self, s, position, match, reentrances, fstruct):
        # If there was a prefix feature, record it.