Why is EvTerm limited?

Hi, I had some funky idea where a type checker plugin would have to synthesize code for a custom-solved instances on the fly. But it seems that does not work because EvTerm is less expressive than Core (especially, no lambdas): https://downloads.haskell.org/~ghc/8.2.2/docs/html/libraries/ghc-8.2.2/TcEvi... What would break if we had | EvExpr CoreExpr as an additional constructor there? Cheers, Joachim -- Joachim “nomeata” Breitner mail@joachim-breitner.de https://www.joachim-breitner.de/