Changed schema for Value -> Term, majorly breaking change (#622)

* Changed schema for Value -> Term, majorly breaking change

* Following the schema change, Value -> Term into all processing

* Updated Cassandra for g, p, s, o index patterns (7 indexes)

* Reviewed and updated all tests

* Neo4j, Memgraph and FalkorDB remain broken, will look at once settled down

trustgraph-base/trustgraph/schema/core/primitives.py

@@ -1,22 +1,57 @@
-
 from dataclasses import dataclass, field
 
+# Term type constants
+IRI = "i"      # IRI/URI node
+BLANK = "b"    # Blank node
+LITERAL = "l"  # Literal value
+TRIPLE = "t"   # Quoted triple (RDF-star)
+
+
 @dataclass
 class Error:
     type: str = ""
     message: str = ""
 
+
 @dataclass
-class Value:
+class Term:
+    """
+    RDF Term - can represent an IRI, blank node, literal, or quoted triple.
+
+    The 'type' field determines which other fields are relevant:
+    - IRI: use 'iri' field
+    - BLANK: use 'id' field
+    - LITERAL: use 'value', 'datatype', 'language' fields
+    - TRIPLE: use 'triple' field
+    """
+    type: str = ""  # One of: IRI, BLANK, LITERAL, TRIPLE
+
+    # For IRI terms (type == IRI)
+    iri: str = ""
+
+    # For blank nodes (type == BLANK)
+    id: str = ""
+
+    # For literals (type == LITERAL)
     value: str = ""
-    is_uri: bool = False
-    type: str = ""
+    datatype: str = ""   # XSD datatype URI (mutually exclusive with language)
+    language: str = ""   # Language tag (mutually exclusive with datatype)
+
+    # For quoted triples (type == TRIPLE)
+    triple: "Triple | None" = None
+
 
 @dataclass
 class Triple:
-    s: Value | None = None
-    p: Value | None = None
-    o: Value | None = None
+    """
+    RDF Triple / Quad.
+
+    The optional 'g' field specifies the named graph (None = default graph).
+    """
+    s: Term | None = None    # Subject
+    p: Term | None = None    # Predicate
+    o: Term | None = None    # Object
+    g: str | None = None     # Graph name (IRI), None = default graph
 
 @dataclass
 class Field:

trustgraph-base/trustgraph/schema/knowledge/embeddings.py

@@ -1,7 +1,7 @@
 from dataclasses import dataclass, field
 
 from ..core.metadata import Metadata
-from ..core.primitives import Value, RowSchema
+from ..core.primitives import Term, RowSchema
 from ..core.topic import topic
 
 ############################################################################
@@ -10,7 +10,7 @@ from ..core.topic import topic
 
 @dataclass
 class EntityEmbeddings:
-    entity: Value | None = None
+    entity: Term | None = None
     vectors: list[list[float]] = field(default_factory=list)
 
 # This is a 'batching' mechanism for the above data

trustgraph-base/trustgraph/schema/knowledge/graph.py

@@ -1,6 +1,6 @@
 from dataclasses import dataclass, field
 
-from ..core.primitives import Value, Triple
+from ..core.primitives import Term, Triple
 from ..core.metadata import Metadata
 from ..core.topic import topic
 
@@ -10,7 +10,7 @@ from ..core.topic import topic
 
 @dataclass
 class EntityContext:
-    entity: Value | None = None
+    entity: Term | None = None
     context: str = ""
 
 # This is a 'batching' mechanism for the above data

trustgraph-base/trustgraph/schema/services/lookup.py

@@ -1,6 +1,6 @@
 from dataclasses import dataclass
 
-from ..core.primitives import Error, Value, Triple
+from ..core.primitives import Error, Term, Triple
 from ..core.topic import topic
 from ..core.metadata import Metadata
 

trustgraph-base/trustgraph/schema/services/query.py

@@ -1,6 +1,6 @@
 from dataclasses import dataclass, field
 
-from ..core.primitives import Error, Value, Triple
+from ..core.primitives import Error, Term, Triple
 from ..core.topic import topic
 
 ############################################################################
@@ -17,7 +17,7 @@ class GraphEmbeddingsRequest:
 @dataclass
 class GraphEmbeddingsResponse:
     error: Error | None = None
-    entities: list[Value] = field(default_factory=list)
+    entities: list[Term] = field(default_factory=list)
 
 ############################################################################
 
@@ -27,9 +27,10 @@ class GraphEmbeddingsResponse:
 class TriplesQueryRequest:
     user: str = ""
     collection: str = ""
-    s: Value | None = None
-    p: Value | None = None
-    o: Value | None = None
+    s: Term | None = None
+    p: Term | None = None
+    o: Term | None = None
+    g: str | None = None  # Graph IRI. None=default graph, "*"=all graphs
     limit: int = 0
 
 @dataclass

trustgraph-base/trustgraph/schema/services/retrieval.py

@@ -1,6 +1,6 @@
 from dataclasses import dataclass
 from ..core.topic import topic
-from ..core.primitives import Error, Value
+from ..core.primitives import Error, Term
 
 ############################################################################