Allow assignment to undefined to reset a variable value

ribrdb · Dec 28, 2023 · 811541a · 811541a
1 parent 5bc1a7e
commit 811541a
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Showing 3 changed files with 23 additions and 0 deletions.
diff --git a/compile.ts b/compile.ts
@@ -536,6 +536,18 @@ class Compiler {
         }
       }
     } else if (ts.isIdentifier(e)) {
+      if (e.text == "undefined") {
+        if (dest) {
+          this.#emit(methods.setReg, "nil", this.ref(dest, 1, "w"));
+        } else {
+          return {
+            refs: [],
+            name: "",
+            reg: "nil",
+          };
+        }
+        return dest;
+      }
       if (e.text == "self" && !this.currentScope.scope.has(e.text)) {
         const v = this.variable(e);
         this.#emit(methods.getSelf, v);

diff --git a/tests/__snapshots__/compile.test.ts.snap b/tests/__snapshots__/compile.test.ts.snap
@@ -88,3 +88,11 @@ l10:
 l11:
   .ret	"
 `;
+
+exports[`assign_to_undefined.ts 1`] = `
+"foo:
+  .name	"foo"
+  .pname	p1, v
+  set_reg	nil, p1
+  .ret	"
+`
diff --git a/tests/assign_to_undefined.ts b/tests/assign_to_undefined.ts
@@ -0,0 +1,3 @@
+export function foo(v:Value) {
+  v = undefined;
+}