Class Flags

Lib/tomllib/_parser.py:208–263

Flags that map to parsed keys/namespaces.

class Flags:
    """Flags that map to parsed keys/namespaces."""

    # Marks an immutable namespace (inline array or inline table).
    FROZEN: Final = 0
    # Marks a nest that has been explicitly created and can no longer
    # be opened using the "[table]" syntax.
    EXPLICIT_NEST: Final = 1

    def __init__(self) -> None:
        self._flags: dict[str, dict[Any, Any]] = {}
        self._pending_flags: set[tuple[Key, int]] = set()

    def add_pending(self, key: Key, flag: int) -> None:
        self._pending_flags.add((key, flag))

    def finalize_pending(self) -> None:
        for key, flag in self._pending_flags:
            self.set(key, flag, recursive=False)
        self._pending_flags.clear()

    def unset_all(self, key: Key) -> None:
        cont = self._flags
        for k in key[:-1]:
            if k not in cont:
                return
            cont = cont[k]["nested"]
        cont.pop(key[-1], None)

    def set(self, key: Key, flag: int, *, recursive: bool) -> None:  # noqa: A003
        cont = self._flags
        key_parent, key_stem = key[:-1], key[-1]
        for k in key_parent:
            if k not in cont:
                cont[k] = {"flags": set(), "recursive_flags": set(), "nested": {}}
            cont = cont[k]["nested"]
        if key_stem not in cont:
            cont[key_stem] = {"flags": set(), "recursive_flags": set(), "nested": {}}
        cont[key_stem]["recursive_flags" if recursive else "flags"].add(flag)

    def is_(self, key: Key, flag: int) -> bool:
        if not key:
            return False  # document root has no flags
        cont = self._flags
        for k in key[:-1]:
            if k not in cont:
                return False
            inner_cont = cont[k]
            if flag in inner_cont["recursive_flags"]:
                return True
            cont = inner_cont["nested"]
        key_stem = key[-1]
        if key_stem in cont:
            inner_cont = cont[key_stem]
            return flag in inner_cont["flags"] or flag in inner_cont["recursive_flags"]
        return False