Added basic implentation for where

src/core/builtin_concepts.py

@@ -50,6 +50,7 @@ class BuiltinConcepts(Enum):
     CONCEPT_EVAL_REQUESTED = "concept eval requested"
     REDUCE_REQUESTED = "reduce requested"  # remove meaningless error when possible
     NOT_A_SET = "not a set"  # the concept has no entry in sets
+    WHERE_CLAUSE_FAILED = "where clause failed"  # failed to validate where clause during evaluation
 
     NODE = "node"
     GENERIC_NODE = "generic node"
@@ -91,6 +92,7 @@ BuiltinErrors = [str(e) for e in {
     BuiltinConcepts.CONCEPT_EVAL_ERROR,
     BuiltinConcepts.CONCEPT_ALREADY_IN_SET,
     BuiltinConcepts.NOT_A_SET,
+    BuiltinConcepts.WHERE_CLAUSE_FAILED
 }]
 
 """
@@ -385,3 +387,20 @@ class ConceptAlreadyInSet(Concept):
     @property
     def concept_set(self):
         return self.props["concept_set"].value
+
+
+class WhereClauseFailed(Concept):
+    def __init__(self, concept=None):
+        super().__init__(BuiltinConcepts.WHERE_CLAUSE_FAILED,
+                         True,
+                         False,
+                         BuiltinConcepts.WHERE_CLAUSE_FAILED)
+        self.set_metadata_value(ConceptParts.BODY, concept)
+        self.metadata.is_evaluated = True
+
+    def __repr__(self):
+        return f"WhereClauseFailed(concept={self.concept})"
+
+    @property
+    def concept(self):
+        return self.body