Thank you all for your help! It turns out that I was missing the constraint solving and zonking step by desugaring the result of tcInferSigma directly. I have the implementation of the function here https://github.com/yiyunliu/ghc-elaboration-test/blob/8f362ad92dc6601b4cb7e4.... Not sure if it's 100% correct but at least it works for all the examples I can come up with so far. - Yiyun On 1/22/20 7:09 AM, Andreas Klebinger wrote:
I tried this for fun a while ago and ran into the issue of needing to provide a type environment containing Prelude and so on. I gave up on that when some of the calls failed because I must have missed to set up some implicit state properly. I didn't have an actual use case (only curiosity) so I didn't look further into it. If you do find a way please let me know.
I would also support adding any missing functions to GHC-the-library to make this possible if any turn out to be required.
As an alternative you could also use the GHCi approach of using a fake Module. This would allow you to copy whatever GHCi is doing. But I expect that to be slower if you expect to process many such strings,
Richard Eisenberg schrieb am 22.01.2020 um 10:36:
You'll need to run the expression through the whole pipeline.
1. Parsing 2. Renaming 3. Type-checking 3a. Constraint generation 3b. Constraint solving 3c. Zonking 4. Desugaring