apply created closure immediately

compiler/gen/src/llvm/build.rs

@@ -692,7 +692,9 @@ pub fn build_exp_call<'a, 'ctx, 'env>(
             )
         }
 
-        CallType::ByPointer { name, .. } => {
+        CallType::ByPointer {
+            name, full_layout, ..
+        } => {
             let sub_expr = load_symbol(scope, name);
 
             let mut arg_vals: Vec<BasicValueEnum> =
@@ -702,10 +704,25 @@ pub fn build_exp_call<'a, 'ctx, 'env>(
                 arg_vals.push(load_symbol(scope, arg));
             }
 
-            let call = match sub_expr {
+            let call = match (full_layout, sub_expr) {
-                BasicValueEnum::PointerValue(ptr) => {
+                (_, BasicValueEnum::PointerValue(ptr)) => {
                     env.builder.build_call(ptr, arg_vals.as_slice(), "tmp")
                 }
+                (Layout::Closure(_, _, _), BasicValueEnum::StructValue(closure_struct)) => {
+                    let fpointer = env
+                        .builder
+                        .build_extract_value(closure_struct, 0, "fpointer")
+                        .unwrap()
+                        .into_pointer_value();
+
+                    let closure_data = env
+                        .builder
+                        .build_extract_value(closure_struct, 1, "closure_data")
+                        .unwrap();
+
+                    arg_vals.push(closure_data);
+                    env.builder.build_call(fpointer, arg_vals.as_slice(), "tmp")
+                }
                 non_ptr => {
                     panic!(
                         "Tried to call by pointer, but encountered a non-pointer: {:?}",

compiler/gen/tests/gen_primitives.rs

@@ -2215,4 +2215,23 @@ mod gen_primitives {
             i64
         );
     }
+
+    #[test]
+    fn build_then_apply_closure() {
+        assert_evals_to!(
+            indoc!(
+                r#"
+                app "test" provides [ main ] to "./platform"
+
+                main : Str
+                main =
+                    x = "long string that is malloced"
+
+                    (\_ -> x) {}
+                "#
+            ),
+            "long string that is malloced",
+            &'static str
+        );
+    }
 }