Matter Labs/zinc

awesome @hedgar2017 , thanks!

if you dont mind me reporting another (though this might be purely my fault):
in my attempt at re-writing the merkletree example...:

/// Type alias for a Sha256 digest.
type Digest = [bool; 256];
/// Merkle node in the tree - `bool` signifies node's position in the path.
type Node = (Digest, bool);
/// Merkle path of digests and their left or right position.
type Path = [Node; 10];

/// Computes the hash of the leaf.
fn hash_leaf(leaf: field) -> Digest {
    // same as in example
}

///
fn hash_nodes(left: Digest, right: Digest) -> Digest {
    // same as in example
}

/// Computes the root hash given a `leaf` and a `Path`.
fn root_hash(leaf: field, path: Path) -> Digest {
    // hash the leaf to get the first merkle tree node
    let mut current = hash_leaf(leaf);  // field -> Digest

    // for each level, pair the current merkle tree node with one from the path,
    // then hash the two nodes
    for i in 0..10 {
        let node: Node = path[i];
        let left_and_right = if node.1 {
            [current, node.0]
        } else {
            [node.0, current]
        };

        current = hash_nodes(left_and_right[0], left_and_right[1]);
    };

    // return the root hash
    current
}

... the if conditional produces the error (which doesn't make sense given that hash_leaf isn't called on line 45):

[ERROR   zvm] type error: expected u1, got bool
                 at src/merkle.zn:45:30 (at hash_leaf)
[ERROR   zvm] runtime error: type error: expected u1, got bool
[ERROR zargo] virtual machine 'run': failure: exit code: 1