Merge remote-tracking branch 'origin/trunk' into list-get

compiler/builtins/src/std.rs

@@ -371,9 +371,22 @@ pub fn types() -> MutMap<Symbol, (SolvedType, Region)> {
 
     // List module
 
-    // #getUnsafe : List elem, Int -> elem
+    // get : List elem, Int -> Result elem [ IndexOutOfBounds ]*
+    let index_out_of_bounds = SolvedType::TagUnion(
+        vec![(TagName::Global("IndexOutOfBounds".into()), vec![])],
+        Box::new(SolvedType::Wildcard),
+    );
+
     add_type(
-        Symbol::LIST_GET_UNSAFE,
+        Symbol::LIST_GET,
+        SolvedType::Func(
+            vec![list_type(flex(TVAR1)), int_type()],
+            Box::new(result_type(flex(TVAR1), index_out_of_bounds)),
+        ),
+    );
+
+    add_type(
+        Symbol::LIST_GET_UNSAFE, // TODO remove this once we can code gen Result
         SolvedType::Func(
             vec![list_type(flex(TVAR1)), int_type()],
             Box::new(flex(TVAR1)),

compiler/gen/tests/gen_builtins.rs

@@ -301,11 +301,6 @@ mod gen_builtins {
         assert_evals_to!("List.isEmpty []", true, bool);
     }
 
-    // #[test]
-    // fn get_0_int_list() {
-    //     assert_evals_to!("List.get [ 12, 9, 6, 3 ] 0", (1, 12), (u64, i64));
-    // }
-
     #[test]
     fn head_int_list() {
         assert_evals_to!("List.first [ 12, 9, 6, 3 ]", (1, 12), (u64, i64));

compiler/uniq/src/sharing.rs

@@ -495,7 +495,13 @@ impl FieldAccess {
     }
 
     pub fn list_seen() -> Self {
-        Self::default()
+        use Mark::*;
+        use Usage::*;
+
+        let mut result = Self::default();
+        result.fields.insert(LIST_ELEM.into(), Simple(Seen));
+
+        result
     }
 
     pub fn list_update() -> Self {