namespace refactoring and cleanup

1 files changed, 26 insertions, 71 deletions

diff --git a/bsfs/namespace/namespace.py b/bsfs/namespace/namespace.py
index 0a62b78..b388f53 100644
--- a/bsfs/namespace/namespace.py
+++ b/bsfs/namespace/namespace.py
@@ -3,97 +3,52 @@
 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 ##