Weld: Accelerating numpy, scikit and pandas as much as 100x with Rust and LLVM(notamonadtutorial.com)

    enum A { Foo{ x: i32, y: f32 }, Bar(B), Baz([u32; 4]), Moo(i32), Mooz(i32) }
    struct B { z: f32, w: (f64, f32) }

    let b = B { z: 42.0, ..}; // create a b with z == 42 and default w
    let B{ w: (first, _), .. } = b; // get B.w.0 field
    let a = A::Foo{ x: 42.0, ..};
    if let A::Bar(Bar { z, ..}) = a {
      // if a is an A::Bar, get b.z field of A::Bar(b)
    }
    if let A::Baz([0, 1, 2, 3]) = a {
      // if a is an A::Baz containing an array 
      // with value [0, 1, 2, 3]
    }
    match a {
        A::Moo(1..3 @ v) => {
           // if a is an A::Moo where x in A::Moo(x) is in range [0, 3) and put the value in the local v variable
        }
        A::Moo(x) | A::Mooz(x) => { 
           // Either A::Moo or A::mooz, gives you the value of x
        }
        // ERROR: I forgot to match some patterns
    }

    foo(b);

    fn foo(B{ z, ..}: B) -> f64 { 
      // get the z field of the first function argument
      z
    }