--- a/src/expr.c	Wed Aug 21 13:08:16 2019 +0200
+++ b/src/expr.c	Wed Aug 21 13:08:52 2019 +0200
@@ -1,9 +1,25 @@
 #include "expr.h"
 
+#include <src/base/str.h>
+#include <src/base/vec.h>
+
 #include <assert.h>
 #include <stdbool.h>
 #include <stdio.h>
 
+yref_t yref_new_id(yvalue_id_t id) {
+    yref_t ref = { .typ = YREF_ID, .ref.id = id };
+    return ref;
+}
+yref_t yref_new_str(ystr_t* sym) {
+    yref_t ref = { .typ = YREF_SYM, .ref.sym = *sym };
+    return ref;
+}
+yref_t yref_new_c(const char* sym) {
+    yref_t ref = { .typ = YREF_SYM, .ref.sym = ystr_new(sym) };
+    return ref;
+}
+
 void yref_destroy(yref_t* ref) {
     if (ref == NULL) return;
     if (ref->typ == YREF_SYM) ystr_destroy(&ref->ref.sym);

--- a/src/expr.h	Wed Aug 21 13:08:16 2019 +0200
+++ b/src/expr.h	Wed Aug 21 13:08:52 2019 +0200
@@ -36,6 +36,21 @@
 } yref_t;
 
 /**
+ * Create a new reference with the given ID.
+ */
+yref_t yref_new_id(yvalue_id_t id);
+
+/**
+ * Create a new reference to the given symbol. Takes ownership of `sym`, it must not be freed afterwards.
+ */
+yref_t yref_new_str(ystr_t* sym);
+
+/**
+ * Create a new reference to the given symbol.
+ */
+yref_t yref_new_c(const char* sym);
+
+/**
  * @brief Deallocate memory used by the reference itself.
  */
 void yref_destroy(yref_t* ref);