Add support for exception handling

[fpringle]

See discussion here.

Adds the following functions from Control.Exception:

Exception.finally :: forall a b. IO a -> IO b -> IO a
Exception.onException :: forall a b. IO a -> IO b -> IO a
Exception.bracket :: forall a b c. IO a -> (a -> IO b) -> (a -> IO c) -> IO c
SomeException.catch :: forall a. IO a -> (SomeException -> IO a) -> IO a

Note that SomeException.catch is specific to SomeException. In the future a more general Exception.catch :: forall e a. IO a -> (e -> IO a) -> IO a could be added.

Examples are in examples/46-exceptions.hell and docs have been updated.

[chrisdone-artificial]

Nice, thank you! I usually only update docs when I cut a release. But this is fine, I can cut a release anyway. 👌

[chrisdone-artificial]

Pushed a release Release 2026-10-02 · chrisdone/hell