Oleg Grenrus

I'd prefer a code snippet I can insert into an editor and see it fail.

```diff diff --git a/src/Generics/SOP/Constraint.hs b/src/Generics/SOP/Constraint.hs index 321677e..0252cbf 100644 --- a/src/Generics/SOP/Constraint.hs +++ b/src/Generics/SOP/Constraint.hs @@ -77,8 +77,8 @@ type SListI2 = All SListI -- means that 'f' can assume that all elements...

Another variant, which doesn't require changing `generics-sop` is to write double hcollapse as: ```haskell {-# LANGUAGE TypeApplications, RankNTypes, ScopedTypeVariables, DefaultSignatures, FlexibleContexts, AllowAmbiguousTypes, PolyKinds, DataKinds #-} import GHC.Generics as GHC import...

After thinking about this, I'd suggest something like ``` testOption :: Parser String testOption = strEnv ( envvar "PROGNAME_TEST" metavar "VAL" help "For testing purposes only") ``` i.e. introduce `EnvVarFields`...

@HuwCampbell it's not necessary to change `execParserPure` type, it can assume empty enviroment. We could have ``` hs execParserPure = execParserPureWithEnv mempty ```

@HuwCampbell about old GHCs, see https://github.com/quchen/prettyprinter/pull/74 We can try to convince @quchen to allow extending support back to `GHC-7.0`, if it would make you more happy to switch to `prettyprinter`....

@kindaro use `:seti`, don't use `:set`.

Then, I'm afraid, you cannot have your cake and eat it too. Settings set with `:set -XFoo` affect how GHC interprets modules, and `Cabal` has no means to tell GHC...

> For example, it can ask GHC to load a script that resets all language extensions to their default state. How? AFAIK that is not possible. (Please link to GHC...

> cabal already passes a script to ghci when invoking `cabal repl` outside of project context to set the working directory properly because of the fake-package machinery, so that capability...