Got LLVM structs working

compiler/gen/src/llvm/build.rs

@@ -216,19 +216,18 @@ pub fn build_expr<'a, 'ctx, 'env>(
                 let array_type = get_array_type(&elem_type, 0);
                 let ptr_type = array_type.ptr_type(AddressSpace::Generic);
                 let struct_type = collection_wrapper(ctx, ptr_type);
-                let struct_val = struct_type.const_zero();
 
                 // The first field in the struct should be the pointer.
-                builder
+                let struct_val = builder
                     .build_insert_value(
-                        struct_val,
+                        struct_type.const_zero(),
                         BasicValueEnum::PointerValue(ptr_type.const_null()),
                         0,
                         "insert_ptr",
                     )
                     .unwrap();
 
-                BasicValueEnum::StructValue(struct_val)
+                BasicValueEnum::StructValue(struct_val.into_struct_value())
             } else {
                 let len_u64 = elems.len() as u64;
                 let elem_bytes = elem_layout.stack_size(env.pointer_bytes) as u64;
@@ -257,24 +256,24 @@ pub fn build_expr<'a, 'ctx, 'env>(
                 let len = dbg!(BasicValueEnum::IntValue(
                     ctx.i32_type().const_int(len_u64, false)
                 ));
-                let struct_val = struct_type.const_zero();
+                let mut struct_val;
 
                 // Field 0: pointer
-                builder
+                struct_val = builder
-                    .build_insert_value(struct_val, ptr_val, 0, "insert_ptr")
+                    .build_insert_value(struct_type.const_zero(), ptr_val, 0, "insert_ptr")
                     .unwrap();
 
                 // Field 1: length
-                builder
+                struct_val = builder
                     .build_insert_value(struct_val, len, 1, "insert_len")
                     .unwrap();
 
                 // Field 2: capacity (initially set to length)
-                builder
+                struct_val = builder
                     .build_insert_value(struct_val, len, 2, "insert_capacity")
                     .unwrap();
 
-                BasicValueEnum::StructValue(struct_val)
+                BasicValueEnum::StructValue(struct_val.into_struct_value())
             }
         }
         _ => {

compiler/gen/tests/test_gen.rs

@@ -494,6 +494,42 @@ mod test_gen {
         assert_llvm_evals_to!("List.len [ 12, 9, 6, 3 ]", 4, i64, |x| x);
     }
 
+    #[test]
+    fn loaded_int_list_len() {
+        assert_llvm_evals_to!(
+            indoc!(
+                r#"
+                    nums = [ 2, 4, 6 ]
+
+                    List.len nums
+                "#
+            ),
+            3,
+            i64,
+            |x| x
+        );
+    }
+
+    #[test]
+    fn fn_int_list_len() {
+        assert_llvm_evals_to!(
+            indoc!(
+                r#"
+                    # TODO remove this annotation once monomorphization works!
+                    getLen : List Int -> Int
+                    getLen = \list -> List.len list
+
+                    nums = [ 2, 4, 6 ]
+
+                    getLen nums
+                "#
+            ),
+            3,
+            i64,
+            |x| x
+        );
+    }
+
     //     #[test]
     //     fn int_list_is_empty() {
     //         assert_evals_to!("List.is_empty [ 12, 9, 6, 3 ]", 0, i32, |x| x);
@@ -510,7 +546,7 @@ mod test_gen {
     }
 
     #[test]
-    fn set_shared_int_list() {
+    fn get_shared_int_list() {
         assert_evals_to!(
             indoc!(
                 r#"