On Friday, 18 January 2019 at 20:29:08 UTC, H. S. Teoh wrote:
That would work, but it would also suffer from all the same
problems as macro-based programming in C. The compiler would
be unable to detect when you accidentally pasted type names
together where you intended to be separate, the strings may not
actually represent real types, and generating code from pasting
/ manipulating strings is very error-prone. And you could write
very unmaintainable code like pasting partial tokens together
as strings, etc., which makes it hard for anyone else
(including yourself after 3 months) to understand just what the
code is trying to do.
Generally, you want some level of syntactic / semantic
enforcement by the compiler when you manipulate lists (or
whatever other structures) of types.
T
Well, it's the approach Andrei laid out in his DConf 2018 talk:
https://youtu.be/-0jcE9B5kjs?t=2641
The advantage is how simple it is, and that it only uses existing
language constructs. But, indeed, the problems you mention are
not insignificant.
