Rodrigo Mesquita pushed to branch wip/romes/edsko-exceptions-2 at Glasgow Haskell Compiler / GHC

Commits:

• 5affd08b
  by Rodrigo Mesquita at 2026-05-08T14:49:38+01:00

  docs: toException shouldn't insist on empty context
  
  ExceptionWithContext is an example of a type whose instance won't
  fulfill that contract (it would be non-sensical to empty the context of
  ExceptionWithContext...!)
  

• bdb42453
  by Rodrigo Mesquita at 2026-05-08T14:49:38+01:00

  Draft: DONT TOUCH the toException in Exception SomeException!
  

1 changed file:

• libraries/ghc-internal/src/GHC/Internal/Exception/Type.hs

Changes:

 -}

 class (Typeable e, Show e) => Exception e where

-    -- | @toException@ should produce a 'SomeException' with no attached 'ExceptionContext'.

     toException   :: e -> SomeException

     fromException :: SomeException -> Maybe e

-    toException e = SomeException e

-      where ?exceptionContext = emptyExceptionContext

+    toException e = e

     fromException (SomeException e) = cast e

     -- | Render this exception value in a human-friendly manner.