On Sunday, 6 April 2014 at 20:17:09 UTC, Walter Bright wrote:
It's seriously wrong to allow such. It makes a larger code base
nearly impossible to reliably reason about, leading one to rely
on conventions like "don't add stuff to namespaces".
Depends on how it is done. For BETA, there was a seperate
"fragment system" that allowed AST specified extension points.
This system was used for both extensions and for
encapsulation/API definition. You basically defined "slots" in
the syntax three where code could be injected (following the
grammar of the slot) and what should be hidden etc. It was
simplistic elegance IMO:
http://www.cs.au.dk/~beta/Manuals/latest/beta/fragment.html
The weakness was that they didn't allow for dynamic dispatch
(required static resolution), but that was an implementation
issue, I think.
