diff options
Diffstat (limited to 'bsfs/namespace/namespace.py')
-rw-r--r-- | bsfs/namespace/namespace.py | 102 |
1 files changed, 26 insertions, 76 deletions
diff --git a/bsfs/namespace/namespace.py b/bsfs/namespace/namespace.py index 1d443c1..b388f53 100644 --- a/bsfs/namespace/namespace.py +++ b/bsfs/namespace/namespace.py @@ -1,104 +1,54 @@ -""" -Part of the BlackStar filesystem (bsfs) module. -A copy of the license is provided with the project. -Author: Matthias Baumgartner, 2022 -""" # imports import typing # bsfs imports -from bsfs.utils import URI, typename +from bsfs.utils import URI # exports __all__: typing.Sequence[str] = ( - 'ClosedNamespace', 'Namespace', + 'FinalNamespace', ) ## code ## -class Namespace(): - """A namespace consists of a common prefix that is used in a set of URIs. - Note that the prefix must include the separator between - path and fragment (typically a '#' or a '/'). - """ - - # namespace prefix. - prefix: URI - - # fragment separator. - fsep: str - - # path separator. - psep: str - - def __init__(self, prefix: URI, fsep: str = '#', psep: str = '/'): - # ensure prefix type - prefix = URI(prefix) - # truncate fragment separator - while prefix.endswith(fsep): - prefix = URI(prefix[:-1]) - # truncate path separator - while prefix.endswith(psep): - prefix = URI(prefix[:-1]) - # store members - self.prefix = prefix - self.fsep = fsep - self.psep = psep - - def __eq__(self, other: typing.Any) -> bool: - return isinstance(other, type(self)) \ - and self.prefix == other.prefix \ - and self.fsep == other.fsep \ - and self.psep == other.psep +class Namespace(URI): + """The Namespace allows you to incrementally append path segments to an URI. - def __hash__(self) -> int: - return hash((type(self), self.prefix, self.fsep, self.psep)) + Segments are separated by `Namespace.sep` ('/'). + The `__call__` method signals that the URI is complete until the query part. - def __str__(self) -> str: - return str(self.prefix) - - def __repr__(self) -> str: - return f'{typename(self)}({self.prefix}, {self.fsep}, {self.psep})' - - def __getattr__(self, fragment: str) -> URI: - """Return prefix + fragment.""" - return URI(self.prefix + self.fsep + fragment) - - def __getitem__(self, fragment: str) -> URI: - """Alias for getattr(self, fragment).""" - return self.__getattr__(fragment) + """ - def __add__(self, value: typing.Any) -> 'Namespace': - """Concatenate another namespace to this one.""" - if not isinstance(value, str): - return NotImplemented - return Namespace(self.prefix + self.psep + value, self.fsep, self.psep) + # path separator + sep: str = '/' + def __getattr__(self, query: str) -> 'Namespace': + """Append the *query* to the current value and return as Namespace.""" + return Namespace(self + self.sep + query) -class ClosedNamespace(Namespace): - """Namespace that covers a restricted set of URIs.""" + def __call__(self, sep: str = '#') -> 'FinalNamespace': + """Finalize the namespace.""" + return FinalNamespace(self, sep) - # set of permissible fragments. - fragments: typing.Set[str] - def __init__(self, prefix: URI, *args: str, fsep: str = '#', psep: str = '/'): - super().__init__(prefix, fsep, psep) - self.fragments = set(args) +# FIXME: Integrate FinalNamespace into Namespace? Do we need to have both? +class FinalNamespace(URI): + """The FinalNamespace allows you to append a fragment to an URI.""" - def __eq__(self, other: typing.Any) -> bool: - return super().__eq__(other) and self.fragments == other.fragments + # fragment separator + sep: str - def __hash__(self) -> int: - return hash((type(self), self.prefix, tuple(sorted(self.fragments)))) + def __new__(cls, value: str, sep: str = '#'): + inst = URI.__new__(cls, value) + inst.sep = sep + return inst def __getattr__(self, fragment: str) -> URI: - """Return prefix + fragment or raise a KeyError if the fragment is not part of this namespace.""" - if fragment not in self.fragments: - raise KeyError(f'{fragment} is not a valid fragment of namespace {self.prefix}') - return super().__getattr__(fragment) + """Append the *fragment* to the current value and return as URI.""" + return URI(self + self.sep + fragment) ## EOF ## |