Solving current inference state prior to finding index traits.

crates/cairo-lang-semantic/src/expr/compute.rs

@@ -1866,6 +1866,11 @@ fn compute_expr_indexed_semantic(
 ) -> Maybe<Expr> {
     let syntax_db = ctx.db.upcast();
     let expr = compute_expr_semantic(ctx, &syntax.expr(syntax_db));
+    let index_expr_syntax = &syntax.index_expr(syntax_db);
+    let index_expr = compute_expr_semantic(ctx, index_expr_syntax);
+    // Make sure the maximal amount of types is known when trying to access. Ignoring the returned
+    // value, as any errors will be reported later.
+    ctx.resolver.inference().solve().ok();
     let candidate_traits: Vec<_> = ["Index", "IndexView"]
         .iter()
         .map(|trait_name| get_core_trait(ctx.db, CoreTraitContext::Ops, (*trait_name).into()))
@@ -1881,8 +1886,6 @@ fn compute_expr_indexed_semantic(
         |ty, _, _| Some(MultipleImplementationOfIndexOperator(ty)),
     )?;
 
-    let index_expr_syntax = &syntax.index_expr(syntax_db);
-    let index_expr = compute_expr_semantic(ctx, index_expr_syntax);
     expr_function_call(
         ctx,
         function_id,

crates/cairo-lang-semantic/src/expr/test_data/operators

@@ -128,8 +128,8 @@ impl Struct2Index of Index<Struct2, usize, felt252> {
 
 //! > expected_diagnostics
 error: Type `test::Struct1` could not be indexed.
-Candidate `core::ops::index::Index::index` inference failed with: Trait has no implementation in context: core::ops::index::Index::<test::Struct1, ?2>.
-Candidate `core::ops::index::IndexView::index` inference failed with: Trait has no implementation in context: core::ops::index::IndexView::<test::Struct1, ?2>.
+Candidate `core::ops::index::Index::index` inference failed with: Trait has no implementation in context: core::ops::index::Index::<test::Struct1, ?3>.
+Candidate `core::ops::index::IndexView::index` inference failed with: Trait has no implementation in context: core::ops::index::IndexView::<test::Struct1, ?3>.
  --> lib.cairo:21:15
     let _y1 = x1[0];
               ^***^

crates/cairo-lang-semantic/src/items/tests/early_conform

@@ -981,13 +981,13 @@ impl MyIndexView of IndexView<u64, MyType, ()> {
 
 //! > expected_diagnostics
 error[E0002]: Method `my_into` could not be called on type `core::integer::u16`.
-Candidate `test::MyInto::my_into` inference failed with: Trait has no implementation in context: test::MyInto::<core::integer::u16, ?3>.
+Candidate `test::MyInto::my_into` inference failed with: Trait has no implementation in context: test::MyInto::<core::integer::u16, ?1>.
  --> lib.cairo:15:13
     x[3_u16.my_into()];
             ^*****^
 
 error[E0002]: Method `my_into` could not be called on type `core::integer::u16`.
-Candidate `test::MyInto::my_into` inference failed with: Trait has no implementation in context: test::MyInto::<core::integer::u16, ?5>.
+Candidate `test::MyInto::my_into` inference failed with: Trait has no implementation in context: test::MyInto::<core::integer::u16, ?4>.
  --> lib.cairo:16:17
     3_u64[3_u16.my_into()];
                 ^*****^

crates/cairo-lang-semantic/src/items/tests/trait_type

@@ -904,8 +904,8 @@ impl MyImpl of MyTrait {
 
 //! > expected_diagnostics
 error: Type `core::integer::u32` could not be indexed.
-Candidate `core::ops::index::Index::index` inference failed with: Trait has no implementation in context: core::ops::index::Index::<core::integer::u32, ?1>.
-Candidate `core::ops::index::IndexView::index` inference failed with: Trait has no implementation in context: core::ops::index::IndexView::<core::integer::u32, ?1>.
+Candidate `core::ops::index::Index::index` inference failed with: Trait has no implementation in context: core::ops::index::Index::<core::integer::u32, ?2>.
+Candidate `core::ops::index::IndexView::index` inference failed with: Trait has no implementation in context: core::ops::index::IndexView::<core::integer::u32, ?2>.
  --> lib.cairo:8:9
         x[0];
         ^**^

tests/bug_samples/issue6580.cairo

@@ -0,0 +1,22 @@
+#[derive(Drop, Debug)]
+struct SomeStruct {
+    num: felt252
+}
+
+#[test]
+fn inner_index_access() {
+    let arr_of_bytearrays: Array<ByteArray> = array!["str1", "str2", "str3"];
+    let arr_of_arrays_of_nums: Array<Array<u64>> = array![array![9], array![2], array![19, 20, 21]];
+    let arr_of_arrays_of_structs: Array<Array<SomeStruct>> = array![
+        array![SomeStruct { num: 8 }],
+        array![SomeStruct { num: 2 }],
+        array![SomeStruct { num: 9 }, SomeStruct { num: 10 }, SomeStruct { num: 11 }]
+    ];
+
+    let index_1 = 2_usize;
+    let index_2 = 2_usize;
+
+    let _nested_item = arr_of_arrays_of_nums[index_1][index_2];
+    let _char = arr_of_bytearrays[index_1][index_2];
+    let _some_struct = arr_of_arrays_of_structs[index_1][index_2];
+}

tests/bug_samples/lib.cairo

@@ -48,6 +48,7 @@ mod issue5629;
 mod issue5680;
 mod issue5764;
 mod issue5967;
+mod issue6580;
 mod loop_break_in_match;
 mod loop_only_change;
 mod partial_param_local;