diff --git a/c/mapping/mlr_dsl_cst.h b/c/mapping/mlr_dsl_cst.h
index 69ec3687b..e35a7357b 100644
--- a/c/mapping/mlr_dsl_cst.h
+++ b/c/mapping/mlr_dsl_cst.h
@@ -164,9 +164,6 @@ typedef struct _mlr_dsl_cst_statement_t {
 
 	mlr_dsl_cst_statement_freer_t* pstatement_freer;
 
-	// For mlr filter
-	int negate_final_filter;
-
 	//  - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
 	// Specific to each statement type:
 
@@ -382,6 +379,12 @@ mlr_dsl_cst_statement_allocator_t alloc_if_head;
 mlr_dsl_cst_statement_allocator_t alloc_while;
 mlr_dsl_cst_statement_allocator_t alloc_do_while;
 mlr_dsl_cst_statement_allocator_t alloc_bare_boolean;
+mlr_dsl_cst_statement_t* alloc_final_filter(
+	mlr_dsl_cst_t*      pcst,
+	mlr_dsl_ast_node_t* pnode,
+	int                 negate_final_filter,
+	int                 type_inferencing,
+	int                 context_flags);
 
 //  - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
 // mapping/mlr_dsl_cst_for_srec_statements.c
diff --git a/c/mapping/mlr_dsl_cst_condish_statements.c b/c/mapping/mlr_dsl_cst_condish_statements.c
index 837e955c4..3576569ac 100644
--- a/c/mapping/mlr_dsl_cst_condish_statements.c
+++ b/c/mapping/mlr_dsl_cst_condish_statements.c
@@ -513,3 +513,64 @@ static void handle_bare_boolean(
 	if (mv_is_non_null(&val))
 		mv_set_boolean_strict(&val);
 }
+
+// ================================================================
+typedef struct _final_filter_state_t {
+	rval_evaluator_t* pexpression_evaluator;
+	int               negate_final_filter;
+} final_filter_state_t;
+
+static mlr_dsl_cst_statement_handler_t handle_final_filter;
+static mlr_dsl_cst_statement_freer_t free_final_filter;
+
+// ----------------------------------------------------------------
+mlr_dsl_cst_statement_t* alloc_final_filter(
+	mlr_dsl_cst_t*      pcst,
+	mlr_dsl_ast_node_t* pnode,
+	int                 negate_final_filter,
+	int                 type_inferencing,
+	int                 context_flags)
+{
+	final_filter_state_t* pstate = mlr_malloc_or_die(sizeof(final_filter_state_t));
+
+	pstate->pexpression_evaluator = rval_evaluator_alloc_from_ast(
+		pnode, pcst->pfmgr, type_inferencing, context_flags);
+
+	pstate->negate_final_filter = negate_final_filter;
+
+	return mlr_dsl_cst_statement_valloc(
+		pnode,
+		handle_final_filter,
+		free_final_filter,
+		pstate);
+}
+
+// ----------------------------------------------------------------
+// xxx move all frees between allocs & handles. and header-file order too.
+
+static void free_final_filter(mlr_dsl_cst_statement_t* pstatement) { // final_filter
+	final_filter_state_t* pstate = pstatement->pvstate;
+
+	pstate->pexpression_evaluator->pfree_func(pstate->pexpression_evaluator);
+
+	free(pstate);
+}
+
+// ----------------------------------------------------------------
+static void handle_final_filter(
+	mlr_dsl_cst_statement_t* pstatement,
+	variables_t*             pvars,
+	cst_outputs_t*           pcst_outputs)
+{
+	final_filter_state_t* pstate = pstatement->pvstate;
+	rval_evaluator_t* pexpression_evaluator = pstate->pexpression_evaluator;
+
+	mv_t val = pexpression_evaluator->pprocess_func(pexpression_evaluator->pvstate, pvars);
+
+	if (mv_is_non_null(&val)) {
+		mv_set_boolean_strict(&val);
+		*pcst_outputs->pshould_emit_rec = val.u.boolv ^ pstate->negate_final_filter;
+	} else {
+		*pcst_outputs->pshould_emit_rec = FALSE;
+	}
+}
diff --git a/c/mapping/mlr_dsl_cst_statements.c b/c/mapping/mlr_dsl_cst_statements.c
index cec6e12d1..b17cb30d2 100644
--- a/c/mapping/mlr_dsl_cst_statements.c
+++ b/c/mapping/mlr_dsl_cst_statements.c
@@ -62,14 +62,6 @@ static mlr_dsl_cst_statement_allocator_t alloc_break;
 static mlr_dsl_cst_statement_allocator_t alloc_continue;
 static mlr_dsl_cst_statement_allocator_t alloc_filter;
 
-//  - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
-static mlr_dsl_cst_statement_t* alloc_final_filter(
-	mlr_dsl_cst_t*      pcst,
-	mlr_dsl_ast_node_t* pnode,
-	int                 negate_final_filter,
-	int                 type_inferencing,
-	int                 context_flags);
-
 // ----------------------------------------------------------------
 static mlr_dsl_cst_statement_handler_t handle_return_void;
 static mlr_dsl_cst_statement_handler_t handle_return_value_from_local_non_map_variable;
@@ -96,7 +88,6 @@ static mlr_dsl_cst_statement_handler_t handle_unset;
 static mlr_dsl_cst_statement_handler_t handle_unset_all;
 
 static mlr_dsl_cst_statement_handler_t handle_filter;
-static mlr_dsl_cst_statement_handler_t handle_final_filter;
 
 static mlr_dsl_cst_statement_handler_t handle_for_oosvar;
 static mlr_dsl_cst_statement_handler_t handle_for_oosvar_key_only;
@@ -577,7 +568,6 @@ static mlr_dsl_cst_statement_t* alloc_blank(mlr_dsl_ast_node_t* past_node) {
 	pstatement->pstatement_handler  = NULL;
 	pstatement->pstatement_freer    = NULL;
 	pstatement->pblock_handler      = NULL;
-	pstatement->negate_final_filter = FALSE;
 	pstatement->pvstate             = FALSE;
 
 	// xxx pre-federation
@@ -625,7 +615,6 @@ mlr_dsl_cst_statement_t* mlr_dsl_cst_statement_valloc(
 	pstatement->pblock              = NULL;
 	pstatement->pblock_handler      = NULL;
 	pstatement->pstatement_freer    = pstatement_freer;
-	pstatement->negate_final_filter = FALSE;
 	pstatement->pvstate             = pvstate;
 	return pstatement;
 }
@@ -645,7 +634,6 @@ mlr_dsl_cst_statement_t* mlr_dsl_cst_statement_valloc_with_block(
 	pstatement->pblock              = pblock;
 	pstatement->pblock_handler      = pblock_handler;
 	pstatement->pstatement_freer    = pstatement_freer;
-	pstatement->negate_final_filter = FALSE;
 	pstatement->pvstate             = pvstate;
 	return pstatement;
 }
@@ -1317,18 +1305,6 @@ static mlr_dsl_cst_statement_t* alloc_filter(mlr_dsl_cst_t* pcst, mlr_dsl_ast_no
 	return pstatement;
 }
 
-// ----------------------------------------------------------------
-static mlr_dsl_cst_statement_t* alloc_final_filter(mlr_dsl_cst_t* pcst, mlr_dsl_ast_node_t* pnode,
-	int negate_final_filter, int type_inferencing, int context_flags)
-{
-	mlr_dsl_cst_statement_t* pstatement = alloc_blank(pnode);
-
-	pstatement->pstatement_handler = handle_final_filter;
-	pstatement->negate_final_filter = negate_final_filter;
-	pstatement->prhs_evaluator = rval_evaluator_alloc_from_ast(pnode, pcst->pfmgr, type_inferencing, context_flags);
-	return pstatement;
-}
-
 // ----------------------------------------------------------------
 // Example ASTs, with and without indexing on the left-hand-side oosvar name:
 
@@ -2092,23 +2068,6 @@ static void handle_filter(
 	}
 }
 
-// ----------------------------------------------------------------
-static void handle_final_filter(
-	mlr_dsl_cst_statement_t* pstatement,
-	variables_t*             pvars,
-	cst_outputs_t*           pcst_outputs)
-{
-	rval_evaluator_t* prhs_evaluator = pstatement->prhs_evaluator;
-
-	mv_t val = prhs_evaluator->pprocess_func(prhs_evaluator->pvstate, pvars);
-	if (mv_is_non_null(&val)) {
-		mv_set_boolean_strict(&val);
-		*pcst_outputs->pshould_emit_rec = val.u.boolv ^ pstatement->negate_final_filter;
-	} else {
-		*pcst_outputs->pshould_emit_rec = FALSE;
-	}
-}
-
 // ----------------------------------------------------------------
 static void handle_for_oosvar(
 	mlr_dsl_cst_statement_t* pstatement,