Proposal for CurieNamespace with embedded catalog.

It is my understanding that we are supposed to use the curies package, but it isn't clear how one
would add maps incrementally (see: tests/test_utils/test_curienamespace.py#113 as an example). Any
solution that passes test_curienamespace.py should do.

Author: hsolbrig

linkml_runtime/utils/curienamespace.py

@@ -1,16 +1,39 @@
-from typing import Optional, Union
+from logging import warning
+from typing import Optional, Union, Dict
 
 from rdflib import Namespace, URIRef
 
 
 class CurieNamespace(Namespace):
-    def __new__(cls, prefix: str, value: Union[str, URIRef]):
-        value = str(value)
-        try:
-            rt = str.__new__(cls, value)
-        except UnicodeDecodeError:
-            rt = str.__new__(cls, value, 'utf-8')
+    # We would prefer to use curies.Converter here, but there doesn't appear to be any way to build it incrementally
+    catalog: Dict[str, "CurieNamespace"] = dict()
+
+    @classmethod
+    def to_curie(cls, uri: Union[str, URIRef]) -> str:
+        uri = str(uri)
+        candidate_ns = ""
+        for prefix, ns in cls.catalog.items():
+            if uri.startswith(ns) and len(ns) > len(candidate_ns):
+                candidate_ns = ns
+        if candidate_ns:
+            return candidate_ns.curie(uri[len(candidate_ns):])
+        return None
+
+    @classmethod
+    def to_uri(cls, curie: str) -> Optional[URIRef]:
+        prefix, localname = curie.split(':', 1)
+        ns = CurieNamespace.catalog.get(prefix, None)
+        return ns[localname] if ns else None
+
+    def __new__(cls, prefix: str, ns: Union[str, bytes, URIRef]) -> "CurieNamespace":
+        rt = Namespace.__new__(cls, str(ns) if not isinstance(ns, bytes) else ns)
         rt.prefix = prefix
+        if prefix in CurieNamespace.catalog:
+            if CurieNamespace.catalog[prefix] != str(rt):
+                # prefix is bound to a different namespace
+                warning(f"Prefix: {prefix} already references {CurieNamespace.catalog[prefix]} - not updated to {rt}")
+        else:
+            CurieNamespace.catalog[prefix] = rt
         return rt
 
     def curie(self, reference: Optional[str] = '') -> str: