deal with eval errors

src/eval/eval.ts

@@ -49,7 +49,10 @@ export function evalCall(s: CallBlockState, env: DynamicEnvironment): EvalResult
   const fn = evalExpr(s.fn, env);
   const input = evalExpr(s.input, env);
   if (fn !== undefined && input !== undefined) {
-    return fn(input);
+    try {
+      return fn(input);
+    }
+    catch {}
   }
 }