Commits on Jan 29, 2024

1. Type param constraints now respect default cap of the type. …

   Prior to this change, any type named in a type constraint would
   get an implicit cap of `#any` if no explicit cap was named.
   The exception to this rule is primitives, which will use an implicit
   cap of `val` in a type constraint (though I'm not sure why you'd
   ever use a primitive as a type constraint to begin with).
   In both cases, the default cap declared by the user in the type
   declaration was being ignored, and this is the only context where
   that happens, violating the principle of least surprise.
   I also don't think this deviation is documented anywhere.
   
   As a veteran pony programmer, this still surprises and annoys me
   regularly when I run into it; I commonly make this mistake and
   have to recompile with an explicit cap that matches my declared default cap.
   
   Furthermore, using #any as a type parameter constraint is rarely what
   you actually want (not constraining the cap at all turns out to not
   let you do very much), so it doesn't make much sense to be the
   implicit cap. To illustrate this, there isn't a single example of
   a type constraint having a final cap of `#any` in the standard library.
   The lines that have been affected by this change are all cases of using
   type intersections where only one of the terms was being used to constrain
   the cap.
   
   After this change the default cap declared by the user will be
   universally respected.
   
   This is a breaking change for anyone who is relying on this behaviour.

   

   jemc authored and SeanTAllen committed Jan 29, 2024
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