diff --git a/c/containers/mlr_dsl_ast.c b/c/containers/mlr_dsl_ast.c
index 7b7ce4e76..a3b70a909 100644
--- a/c/containers/mlr_dsl_ast.c
+++ b/c/containers/mlr_dsl_ast.c
@@ -2,6 +2,15 @@
 #include "lib/mlrutil.h"
 #include "containers/mlr_dsl_ast.h"
 
+// ----------------------------------------------------------------
+mlr_dsl_ast_root_t* mlr_dsl_ast_root_alloc() {
+	mlr_dsl_ast_root_t* proot = mlr_malloc_or_die(sizeof(mlr_dsl_ast_root_t));
+	proot->pbegin_statements = sllv_alloc();
+	proot->pmain_statements  = sllv_alloc();
+	proot->pend_statements   = sllv_alloc();
+	return proot;
+}
+
 // ----------------------------------------------------------------
 mlr_dsl_ast_node_t* mlr_dsl_ast_node_alloc(char* text, int type) {
 	mlr_dsl_ast_node_t* pnode = (mlr_dsl_ast_node_t*)mlr_malloc_or_die(
@@ -121,6 +130,20 @@ char* mlr_dsl_ast_node_describe_type(int type) {
 	}
 }
 
+// ----------------------------------------------------------------
+static void mlr_dsl_ast_root_free_statement_list(sllv_t* plist) {
+	for (sllve_t* pe = plist->phead; pe != NULL; pe = pe->pnext)
+		mlr_dsl_ast_node_free(pe->pvvalue);
+	sllv_free(plist);
+}
+
+void mlr_dsl_ast_root_free(mlr_dsl_ast_root_t* proot) {
+	mlr_dsl_ast_root_free_statement_list(proot->pbegin_statements);
+	mlr_dsl_ast_root_free_statement_list(proot->pmain_statements);
+	mlr_dsl_ast_root_free_statement_list(proot->pend_statements);
+	free(proot);
+}
+
 // ----------------------------------------------------------------
 void mlr_dsl_ast_node_free(mlr_dsl_ast_node_t* pnode) {
 	if (pnode->pchildren) {
diff --git a/c/containers/mlr_dsl_ast.h b/c/containers/mlr_dsl_ast.h
index ecaf0f2ee..76e4a74b5 100644
--- a/c/containers/mlr_dsl_ast.h
+++ b/c/containers/mlr_dsl_ast.h
@@ -23,20 +23,25 @@
 #define MLR_DSL_AST_NODE_TYPE_BEGIN             0xff22
 #define MLR_DSL_AST_NODE_TYPE_END               0xff44
 
+typedef struct _mlr_dsl_ast_root_t {
+	sllv_t* pbegin_statements;
+	sllv_t* pmain_statements;
+	sllv_t* pend_statements;
+} mlr_dsl_ast_root_t;
+
 typedef struct _mlr_dsl_ast_node_t {
 	char*   text;
 	int     type;
 	sllv_t* pchildren;
 } mlr_dsl_ast_node_t;
 
-mlr_dsl_ast_node_t* mlr_dsl_ast_node_alloc(char* text, int type);
+mlr_dsl_ast_root_t* mlr_dsl_ast_root_alloc();
 
-mlr_dsl_ast_node_t* mlr_dsl_ast_node_copy(mlr_dsl_ast_node_t* pother);
+mlr_dsl_ast_node_t* mlr_dsl_ast_node_alloc(char* text, int type);
 
 mlr_dsl_ast_node_t* mlr_dsl_ast_node_alloc_zary(char* text, int type);
 
-mlr_dsl_ast_node_t* mlr_dsl_ast_node_alloc_unary(char* text, int type,
-	mlr_dsl_ast_node_t* pa);
+mlr_dsl_ast_node_t* mlr_dsl_ast_node_alloc_unary(char* text, int type, mlr_dsl_ast_node_t* pa);
 
 mlr_dsl_ast_node_t* mlr_dsl_ast_node_alloc_binary(char* text, int type,
 	mlr_dsl_ast_node_t* pa, mlr_dsl_ast_node_t* pb);
@@ -44,6 +49,8 @@ mlr_dsl_ast_node_t* mlr_dsl_ast_node_alloc_binary(char* text, int type,
 mlr_dsl_ast_node_t* mlr_dsl_ast_node_alloc_ternary(char* text, int type,
 	mlr_dsl_ast_node_t* pa, mlr_dsl_ast_node_t* pb, mlr_dsl_ast_node_t* pc);
 
+mlr_dsl_ast_node_t* mlr_dsl_ast_node_copy(mlr_dsl_ast_node_t* pother);
+
 // See comments in mlr_dsl_parse.y for this seemingly awkward syntax wherein
 // we change the function name after having set it up. This is a consequence of
 // bottom-up DSL parsing.
@@ -57,4 +64,6 @@ char* mlr_dsl_ast_node_describe_type(int type);
 
 void mlr_dsl_ast_node_free(mlr_dsl_ast_node_t* pnode);
 
+void mlr_dsl_ast_root_free(mlr_dsl_ast_root_t* proot);
+
 #endif // MLR_DSL_AST_H