diff --git a/c/mapping/mlr_dsl_cst_assignment_statements.c b/c/mapping/mlr_dsl_cst_assignment_statements.c
index a677bfa2a..cf12917b7 100644
--- a/c/mapping/mlr_dsl_cst_assignment_statements.c
+++ b/c/mapping/mlr_dsl_cst_assignment_statements.c
@@ -301,14 +301,6 @@ mlr_dsl_cst_statement_t* alloc_nonindexed_local_variable_assignment(mlr_dsl_cst_
 	MLR_INTERNAL_CODING_ERROR_IF(pleft->type != MD_AST_NODE_TYPE_NONINDEXED_LOCAL_VARIABLE);
 	MLR_INTERNAL_CODING_ERROR_IF(pleft->pchildren != NULL);
 
-	// xxx XXX mapvar case: rhs is MAP_LITERAL
-	// xxx XXX mapvar case: rhs is FULL_SREC
-	// xxx XXX mapvar case: rhs is OOSVAR_KEYLIST
-	// xxx XXX mapvar case: rhs is FULL_OOSVAR
-	// xxx XXX mapvar case: rhs is NONINDEXED_LOCAL_VARIABLE
-	// xxx XXX mapvar case: rhs is INDEXED_LOCAL_VARIABLE
-	// xxx XXX mapvar case: rhs is FUNCTION_CALLSITE
-
 	pstate->lhs_variable_name = pleft->text;
 	MLR_INTERNAL_CODING_ERROR_IF(pleft->vardef_frame_relative_index == MD_UNUSED_INDEX);
 	pstate->lhs_frame_relative_index = pleft->vardef_frame_relative_index;
diff --git a/c/mapping/rval_evaluators.h b/c/mapping/rval_evaluators.h
index 24b7a28fb..2386b83cf 100644
--- a/c/mapping/rval_evaluators.h
+++ b/c/mapping/rval_evaluators.h
@@ -167,6 +167,9 @@ rxval_evaluator_t* rxval_evaluator_alloc_from_nonindexed_local_variable(
 rxval_evaluator_t* rxval_evaluator_alloc_from_indexed_local_variable(
 	mlr_dsl_ast_node_t* past, fmgr_t* pfmgr, int type_inferencing, int context_flags);
 
+rxval_evaluator_t* rxval_evaluator_alloc_from_oosvar_keylist(
+	mlr_dsl_ast_node_t* past, fmgr_t* pfmgr, int type_inferencing, int context_flags);
+
 rxval_evaluator_t* rxval_evaluator_alloc_wrapping_rval(
 	mlr_dsl_ast_node_t* past, fmgr_t* pfmgr, int type_inferencing, int context_flags);
 
diff --git a/c/mapping/rxval_expr_evaluators.c b/c/mapping/rxval_expr_evaluators.c
index 7068aa1d1..83d35a2e5 100644
--- a/c/mapping/rxval_expr_evaluators.c
+++ b/c/mapping/rxval_expr_evaluators.c
@@ -45,7 +45,8 @@ rxval_evaluator_t* rxval_evaluator_alloc_from_ast(mlr_dsl_ast_node_t* pnode, fmg
 		break;
 
 	case MD_AST_NODE_TYPE_OOSVAR_KEYLIST:
-		return NULL; // xxx XXX mapvar stub
+		return rxval_evaluator_alloc_from_oosvar_keylist(
+			pnode, pfmgr, type_inferencing, context_flags);
 		break;
 
 	case MD_AST_NODE_TYPE_FULL_OOSVAR:
@@ -156,6 +157,57 @@ rxval_evaluator_t* rxval_evaluator_alloc_from_indexed_local_variable(
 	return prxval_evaluator;
 }
 
+// ================================================================
+typedef struct _rxval_evaluator_from_oosvar_keylist_state_t {
+	sllv_t* pkeylist_evaluators;
+} rxval_evaluator_from_oosvar_keylist_state_t;
+
+mlhmmv_value_t rxval_evaluator_from_oosvar_keylist_func(void* pvstate, variables_t* pvars) {
+	rxval_evaluator_from_oosvar_keylist_state_t* pstate = pvstate;
+
+	int all_non_null_or_error = TRUE;
+	sllmv_t* pmvkeys = evaluate_list(pstate->pkeylist_evaluators, pvars, &all_non_null_or_error);
+
+	if (all_non_null_or_error) {
+
+		int lookup_error = FALSE;
+		mlhmmv_value_t* pxval = mlhmmv_get_value_from_level(pvars->poosvars->proot_level,
+			pmvkeys, &lookup_error);
+		sllmv_free(pmvkeys);
+		return mlhmmv_copy_aux(pxval);
+	} else {
+		sllmv_free(pmvkeys);
+		return mlhmmv_value_transfer_terminal(mv_absent());
+	}
+}
+
+static void rxval_evaluator_from_oosvar_keylist_free(rxval_evaluator_t* prxval_evaluator) {
+	rxval_evaluator_from_oosvar_keylist_state_t* pstate = prxval_evaluator->pvstate;
+	for (sllve_t* pe = pstate->pkeylist_evaluators->phead; pe != NULL; pe = pe->pnext) {
+		rval_evaluator_t* prval_evaluator = pe->pvvalue;
+		prval_evaluator->pfree_func(prval_evaluator);
+	}
+	sllv_free(pstate->pkeylist_evaluators);
+	free(pstate);
+	free(prxval_evaluator);
+}
+
+rxval_evaluator_t* rxval_evaluator_alloc_from_oosvar_keylist(
+	mlr_dsl_ast_node_t* pnode, fmgr_t* pfmgr, int type_inferencing, int context_flags)
+{
+	rxval_evaluator_from_oosvar_keylist_state_t* pstate = mlr_malloc_or_die(
+		sizeof(rxval_evaluator_from_oosvar_keylist_state_t));
+	pstate->pkeylist_evaluators = allocate_keylist_evaluators_from_ast_node(
+		pnode, pfmgr, type_inferencing, context_flags);
+
+	rxval_evaluator_t* prxval_evaluator = mlr_malloc_or_die(sizeof(rxval_evaluator_t));
+	prxval_evaluator->pvstate       = pstate;
+	prxval_evaluator->pprocess_func = rxval_evaluator_from_oosvar_keylist_func;
+	prxval_evaluator->pfree_func    = rxval_evaluator_from_oosvar_keylist_free;
+
+	return prxval_evaluator;
+}
+
 // ================================================================
 typedef struct _rxval_evaluator_wrapping_rval_state_t {
 	rval_evaluator_t* prval_evaluator;