diff --git a/c/containers/local_stack.c b/c/containers/local_stack.c
index c0b1edd0e..bfd11032a 100644
--- a/c/containers/local_stack.c
+++ b/c/containers/local_stack.c
@@ -106,6 +106,10 @@ mv_t local_stack_frame_ref_terminal_from_indexed(local_stack_frame_t* pframe,
 	local_stack_frame_entry_t* pentry = &pframe->pvars[vardef_frame_relative_index];
 	mlhmmv_xvalue_t* pbase_xval = &pentry->xvalue;
 
+	if (!(TYPE_MASK_MAP & pentry->type_mask)) {
+		local_stack_frame_throw_type_mismatch_for_read(pentry);
+	}
+
 #ifdef LOCAL_STACK_TRACE_ENABLE
 	// xxx needs an mlhmmv_xvalue_print
 	if (pbase_xval == NULL) {
@@ -146,8 +150,8 @@ mv_t local_stack_frame_ref_terminal_from_indexed(local_stack_frame_t* pframe,
 }
 
 // ----------------------------------------------------------------
-mlhmmv_xvalue_t* local_stack_frame_ref_extended_from_indexed(local_stack_frame_t* pframe,
-	int vardef_frame_relative_index, sllmv_t* pmvkeys)
+mlhmmv_xvalue_t* local_stack_frame_ref_extended_from_nonindexed(local_stack_frame_t* pframe,
+	int vardef_frame_relative_index)
 {
 	LOCAL_STACK_TRACE(printf("LOCAL STACK FRAME %p GET %d\n", pframe, vardef_frame_relative_index));
 	LOCAL_STACK_BOUNDS_CHECK(pframe, "GET", FALSE, vardef_frame_relative_index);
@@ -172,14 +176,43 @@ mlhmmv_xvalue_t* local_stack_frame_ref_extended_from_indexed(local_stack_frame_t
 	}
 #endif
 
-	int error = 0;
-	// Maybe null
-	if (pmvkeys == NULL || pmvkeys->length == 0) {
-		return pmvalue;
-	} else {
-		return mlhmmv_level_look_up_and_ref_xvalue(pmvalue->pnext_level, pmvkeys, &error);
+	return pmvalue;
+}
+
+// ----------------------------------------------------------------
+mlhmmv_xvalue_t* local_stack_frame_ref_extended_from_indexed(local_stack_frame_t* pframe,
+	int vardef_frame_relative_index, sllmv_t* pmvkeys)
+{
+	LOCAL_STACK_TRACE(printf("LOCAL STACK FRAME %p GET %d\n", pframe, vardef_frame_relative_index));
+	LOCAL_STACK_BOUNDS_CHECK(pframe, "GET", FALSE, vardef_frame_relative_index);
+
+	local_stack_frame_entry_t* pentry = &pframe->pvars[vardef_frame_relative_index];
+	mlhmmv_xvalue_t* pmvalue = &pentry->xvalue;
+
+	if (!(TYPE_MASK_MAP & pentry->type_mask)) {
+		local_stack_frame_throw_type_mismatch_for_read(pentry);
 	}
 
+#ifdef LOCAL_STACK_TRACE_ENABLE
+	// xxx needs an mlhmmv_xvalue_print
+	if (pmvalue == NULL) {
+		printf("VALUE IS NULL\n");
+	} else if (pmvalue->is_terminal) {
+		char* s = mv_alloc_format_val(&pmvalue->terminal_mlrval);
+		printf("VALUE IS %s\n", s);
+		free(s);
+	} else if (pmvalue->pnext_level == NULL) {
+		LOCAL_STACK_TRACE(printf("VALUE IS EMPTY\n"));
+	} else {
+		printf("VALUE IS:\n");
+		printf("PTR IS %p\n", pmvalue->pnext_level);
+		mlhmmv_level_print_stacked(pmvalue->pnext_level, 0, TRUE, TRUE, "", stdout);
+	}
+#endif
+
+	int error = 0;
+	// Maybe null
+	return mlhmmv_level_look_up_and_ref_xvalue(pmvalue->pnext_level, pmvkeys, &error);
 }
 
 // ----------------------------------------------------------------
@@ -194,7 +227,7 @@ void local_stack_frame_define_terminal(local_stack_frame_t* pframe, char* variab
 	pentry->type_mask = type_mask;
 
 	if (!(type_mask_from_mv(&val) & pentry->type_mask)) {
-		local_stack_frame_throw_type_mismatch(pentry, &val);
+		local_stack_frame_throw_type_mismatch_for_write(pentry, &val);
 	}
 
 	mlhmmv_xvalue_free(&pentry->xvalue);
@@ -219,11 +252,11 @@ void local_stack_frame_define_extended(local_stack_frame_t* pframe, char* variab
 
 	if (xval.is_terminal) {
 		if (!(type_mask_from_mv(&xval.terminal_mlrval) & pentry->type_mask)) {
-			local_stack_frame_throw_type_mismatch(pentry, &xval.terminal_mlrval);
+			local_stack_frame_throw_type_mismatch_for_write(pentry, &xval.terminal_mlrval);
 		}
 	} else {
 		if (!(TYPE_MASK_MAP & pentry->type_mask)) {
-			local_stack_frame_throw_type_mismatch(pentry, &xval.terminal_mlrval);
+			local_stack_frame_throw_type_mismatch_for_write(pentry, &xval.terminal_mlrval);
 		}
 	}
 
@@ -243,7 +276,7 @@ void local_stack_frame_assign_terminal_indexed(local_stack_frame_t* pframe,
 	local_stack_frame_entry_t* pentry = &pframe->pvars[vardef_frame_relative_index];
 
 	if (!(TYPE_MASK_MAP & pentry->type_mask)) {
-		local_stack_frame_throw_type_mismatch(pentry, &terminal_value);
+		local_stack_frame_throw_type_mismatch_for_write(pentry, &terminal_value);
 	}
 
 	mlhmmv_xvalue_t* pmvalue = &pentry->xvalue;
@@ -268,11 +301,11 @@ void local_stack_frame_assign_extended_nonindexed(local_stack_frame_t* pframe,
 
 	if (xval.is_terminal) {
 		if (!(type_mask_from_mv(&xval.terminal_mlrval) & pentry->type_mask)) {
-			local_stack_frame_throw_type_mismatch(pentry, &xval.terminal_mlrval);
+			local_stack_frame_throw_type_mismatch_for_write(pentry, &xval.terminal_mlrval);
 		}
 	} else {
 		if (!(TYPE_MASK_MAP & pentry->type_mask)) {
-			local_stack_frame_throw_type_mismatch(pentry, &xval.terminal_mlrval);
+			local_stack_frame_throw_type_mismatch_for_write(pentry, &xval.terminal_mlrval);
 		}
 	}
 
@@ -290,7 +323,7 @@ void local_stack_frame_assign_extended_indexed(local_stack_frame_t* pframe,
 	local_stack_frame_entry_t* pentry = &pframe->pvars[vardef_frame_relative_index];
 
 	if (!(TYPE_MASK_MAP & pentry->type_mask)) {
-		local_stack_frame_throw_type_xmismatch(pentry, &new_value);
+		local_stack_frame_throw_type_xmismatch_for_write(pentry, &new_value);
 	}
 
 	mlhmmv_xvalue_t* pmvalue = &pentry->xvalue;
@@ -331,7 +364,7 @@ void local_stack_bounds_check(local_stack_frame_t* pframe, char* op, int set, in
 }
 
 // ----------------------------------------------------------------
-void local_stack_frame_throw_type_mismatch(local_stack_frame_entry_t* pentry, mv_t* pval) {
+void local_stack_frame_throw_type_mismatch_for_write(local_stack_frame_entry_t* pentry, mv_t* pval) {
 	MLR_INTERNAL_CODING_ERROR_IF(pentry->name == NULL);
 	char* sval = mv_alloc_format_val_quoting_strings(pval);
 	fprintf(stderr, "%s: %s type assertion for variable %s unmet by value %s with type %s.\n",
@@ -341,7 +374,7 @@ void local_stack_frame_throw_type_mismatch(local_stack_frame_entry_t* pentry, mv
 	exit(1);
 }
 
-void local_stack_frame_throw_type_xmismatch(local_stack_frame_entry_t* pentry, mlhmmv_xvalue_t* pxval) {
+void local_stack_frame_throw_type_xmismatch_for_write(local_stack_frame_entry_t* pentry, mlhmmv_xvalue_t* pxval) {
 	MLR_INTERNAL_CODING_ERROR_IF(pentry->name == NULL);
 	char* sval = mv_alloc_format_val_quoting_strings(&pxval->terminal_mlrval); // xxx temp
 	fprintf(stderr, "%s: %s type assertion for variable %s unmet by value %s with type %s.\n",
@@ -350,3 +383,18 @@ void local_stack_frame_throw_type_xmismatch(local_stack_frame_entry_t* pentry, m
 	free(sval);
 	exit(1);
 }
+
+// ----------------------------------------------------------------
+void local_stack_frame_throw_type_mismatch_for_read(local_stack_frame_entry_t* pentry) {
+	MLR_INTERNAL_CODING_ERROR_IF(pentry->name == NULL);
+	fprintf(stderr, "%s: %s type assertion for variable %s unmet on read.\n",
+		MLR_GLOBALS.bargv0, type_mask_to_desc(pentry->type_mask), pentry->name);
+	exit(1);
+}
+
+void local_stack_frame_throw_type_xmismatch_for_read(local_stack_frame_entry_t* pentry) {
+	MLR_INTERNAL_CODING_ERROR_IF(pentry->name == NULL);
+	fprintf(stderr, "%s: %s type assertion for variable %s unmet on read.\n",
+		MLR_GLOBALS.bargv0, type_mask_to_desc(pentry->type_mask), pentry->name);
+	exit(1);
+}
diff --git a/c/containers/local_stack.h b/c/containers/local_stack.h
index e35949ad6..14219307d 100644
--- a/c/containers/local_stack.h
+++ b/c/containers/local_stack.h
@@ -82,8 +82,10 @@ void local_stack_bounds_check(local_stack_frame_t* pframe, char* op, int set, in
 
 local_stack_frame_t* local_stack_frame_enter(local_stack_frame_t* pframe);
 void local_stack_frame_exit(local_stack_frame_t* pframe);
-void local_stack_frame_throw_type_mismatch(local_stack_frame_entry_t* pentry, mv_t* pval);
-void local_stack_frame_throw_type_xmismatch(local_stack_frame_entry_t* pentry, mlhmmv_xvalue_t* pxval);
+void local_stack_frame_throw_type_mismatch_for_write(local_stack_frame_entry_t* pentry, mv_t* pval);
+void local_stack_frame_throw_type_xmismatch_for_write(local_stack_frame_entry_t* pentry, mlhmmv_xvalue_t* pxval);
+void local_stack_frame_throw_type_mismatch_for_read(local_stack_frame_entry_t* pentry);
+void local_stack_frame_throw_type_xmismatch_for_read(local_stack_frame_entry_t* pentry);
 
 // ----------------------------------------------------------------
 static inline mv_t local_stack_frame_get_terminal_from_nonindexed(local_stack_frame_t* pframe, // move to reference semantics
@@ -109,7 +111,7 @@ static inline void local_stack_frame_assign_terminal_nonindexed(local_stack_fram
 	local_stack_frame_entry_t* pentry = &pframe->pvars[vardef_frame_relative_index];
 
 	if (!(type_mask_from_mv(&val) & pentry->type_mask)) { // xxx temp
-		local_stack_frame_throw_type_mismatch(pentry, &val);
+		local_stack_frame_throw_type_mismatch_for_write(pentry, &val);
 	}
 
 	mlhmmv_xvalue_free(&pentry->xvalue);
@@ -120,6 +122,9 @@ static inline void local_stack_frame_assign_terminal_nonindexed(local_stack_fram
 mv_t local_stack_frame_ref_terminal_from_indexed(local_stack_frame_t* pframe,
 	int vardef_frame_relative_index, sllmv_t* pmvkeys);
 
+mlhmmv_xvalue_t* local_stack_frame_ref_extended_from_nonindexed(local_stack_frame_t* pframe,
+	int vardef_frame_relative_index);
+
 mlhmmv_xvalue_t* local_stack_frame_ref_extended_from_indexed(local_stack_frame_t* pframe,
 	int vardef_frame_relative_index, sllmv_t* pmvkeys);
 
diff --git a/c/dsl/mlr_dsl_cst_func_subr.c b/c/dsl/mlr_dsl_cst_func_subr.c
index 964c57bfd..a7e11138d 100644
--- a/c/dsl/mlr_dsl_cst_func_subr.c
+++ b/c/dsl/mlr_dsl_cst_func_subr.c
@@ -240,27 +240,6 @@ static void cst_udf_type_check_return_value(cst_udf_state_t* pstate, mlhmmv_xval
 	}
 }
 
-// xxx incorp
-//void local_stack_frame_throw_type_mismatch(local_stack_frame_entry_t* pentry, mv_t* pval) {
-//	MLR_INTERNAL_CODING_ERROR_IF(pentry->name == NULL);
-//	char* sval = mv_alloc_format_val_quoting_strings(pval);
-//	fprintf(stderr, "%s: %s type assertion for variable %s unmet by value %s with type %s.\n",
-//		MLR_GLOBALS.bargv0, type_mask_to_desc(pentry->type_mask), pentry->name,
-//		sval, mt_describe_type_simple(pval->type));
-//	free(sval);
-//	exit(1);
-//}
-//
-//void local_stack_frame_throw_type_xmismatch(local_stack_frame_entry_t* pentry, mlhmmv_xvalue_t* pxval) {
-//	MLR_INTERNAL_CODING_ERROR_IF(pentry->name == NULL);
-//	char* sval = mv_alloc_format_val_quoting_strings(&pxval->terminal_mlrval); // xxx temp
-//	fprintf(stderr, "%s: %s type assertion for variable %s unmet by value %s with type %s.\n",
-//		MLR_GLOBALS.bargv0, type_mask_to_desc(pentry->type_mask), pentry->name,
-//		sval, mlhmmv_xvalue_describe_type_simple(pxval));
-//	free(sval);
-//	exit(1);
-//}
-
 // ----------------------------------------------------------------
 // Callback function for the function manager to invoke into here
 
diff --git a/c/dsl/rxval_expr_evaluators.c b/c/dsl/rxval_expr_evaluators.c
index 89066eb6c..1f92ca1b9 100644
--- a/c/dsl/rxval_expr_evaluators.c
+++ b/c/dsl/rxval_expr_evaluators.c
@@ -265,8 +265,8 @@ typedef struct _rxval_evaluator_from_nonindexed_local_variable_state_t {
 static boxed_xval_t rxval_evaluator_from_nonindexed_local_variable_func(void* pvstate, variables_t* pvars) {
 	rxval_evaluator_from_nonindexed_local_variable_state_t* pstate = pvstate;
 	local_stack_frame_t* pframe = local_stack_get_top_frame(pvars->plocal_stack);
-	mlhmmv_xvalue_t* pxval = local_stack_frame_ref_extended_from_indexed(
-		pframe, pstate->vardef_frame_relative_index, NULL);
+	mlhmmv_xvalue_t* pxval = local_stack_frame_ref_extended_from_nonindexed(
+		pframe, pstate->vardef_frame_relative_index);
 	if (pxval == NULL) {
 		return (boxed_xval_t) {
 			.xval = mlhmmv_xvalue_wrap_terminal(mv_absent()),
diff --git a/c/todo.txt b/c/todo.txt
index 477c64d78..8f5d456a0 100644
--- a/c/todo.txt
+++ b/c/todo.txt
@@ -36,7 +36,8 @@ MAPVAR CHECKLIST:
 
 ! assert_map/assert_scalar/etc.
 
-! this should throw an error: mlr --from s put 'int a=1;var b=a[2]'
+! this should throw an error:
+  mlr --from ../c/s put 'int a=1;var b=a[2]'
 
 ! 'Local variables' 'Notes:' split into surprising and unsurprising
 
@@ -171,6 +172,11 @@ k assign LHS full-srec          from RHS func-retval        alloc ephem & move
 ----------------------------------------------------------------
 EXECUTION TRACE:
 
+! missing operators
+  $ mlr --from ../c/s put -T 'int a=1;var b=a[2]'
+  TRACE (int a 1)
+  TRACE (var b (a 2))
+
 ! trace *assignments* (mutations of pvars state)
 
 * work through the grammar & neaten up pnode->text instances, now that these names are user-visible.