sumtype 0.3.0

[Paul Backus]

On Monday, 7 May 2018 at 09:23:04 UTC, Brian Schott wrote:
> I spent several hours trying to get this working with a 
> non-trivial AST, and I think that it just isn't going to work 
> until the compiler front-end gets better about handling 
> recursive definitions. It fails in more-or-less the same way 
> that my attempts at using std.variant did, and this is not the 
> fault of your library.
>
> It's too bad, because the visitor pattern is not very good when 
> you want to support visitors that should not accidentally 
> modify the tree (i.e. arguments to `visit` are `const`), and 
> other visitors whose job is to re-write the tree.

Thanks for taking a look!

There are definitely compiler issues that keep this (and 
Algebraic) from being as useful as they could be (e.g., issue 
1807 [1]), though so far, I've managed to find workarounds for 
the ones I ran into. I'd be curious to see the code that was 
giving you trouble, if you still have it.

[1]: https://issues.dlang.org/show_bug.cgi?id=1807