Match failure when combining Unions and expression types

[rdeits]

It appears that attempting to create an @match that uses unions and expression types results in no matches being found. A few examples:

This works:

julia> @match :(x[1]) begin
           (v_ref) => (v)
       end
:(x[1])

But adding a union gives no match:

julia> @match :(x[1]) begin
           (v_ref |
           (v_ref <= ub_)) => (v)
       end

Removing the _ref tag fixes it:

julia> @match :(x[1]) begin
           (v_ |
           (v_ <= ub_)) => (v)
       end
:(x[1])

Similarly, with a _Symbol tag, this works:

julia> @match :(x) begin
           (v_Symbol) => (v)
       end
:x

and this doesn't:

@match :(x) begin
    (v_Symbol |
    (v_Symbol <= ub_)) => (v)
end

Do unions just not support type restrictions?

[MikeInnes]

There's no intentional reason why this couldn't be supported, but it may just be that we parse the unions before the types and then the types parser can't see inside the union. Not sure, but it should be fixable at any rate.

[rdeits]

Ok, thanks! I think I may have a fix for this...