Nested generic syntax broken?

[iAmMichaelConnor]

Aim

Here's a minimal example. I want to write A<B<C>> for some concrete type C, but the compiler complains with error: Unexpected <, expected one of >, ,, ::, binary operator; I.e. it didn't expect to see < twice.

I conjured this example just as a way of being able to justify writing A<B<Field>>.

    struct A<T> {
        b: T,
    }

    impl<T> A<T> {
        fn new(b: T) -> Self {
            A { b }
        }
    }

    struct B<T> {
        c: T,
    }

    impl<T> B<T> {
        fn new(c: T) -> Self {
            B { c }
        }
    }


    fn main (c: Field, d: Field) -> pub A<B<Field>> {
        let mut b = B::new(c);
        let mut a = A::new(b);
        
        let mut ab = a.b;
        ab.c *= d;
        ab
    }

error: Unexpected <, expected one of >, ,, ::, binary operator
   ┌─ /mnt/user-data/mike/packages/yarn-project/noir-contracts/src/contracts/zk_nft_contract/src/main.nr:50:44
   │
50 │     fn main (c: Field, d: Field) -> pub A<B<Field>> {
   │                                            -

Installation method

noirup

Nargo version

nargo 0.4.1 (git version hash: 3d2233d, is dirty: false)

[jfecher]

Ah, this is caused by the >> being tokenized as a right shift. So the parser sees A lessthan B lessthan Field rightshift rather than two separate greater-than tokens to terminate each generics list.