[BUG] "Non-exhaustive patterns" when using TypeApplications

[dcastro]

Description

When interpolating an expression that uses TypeApplications, TH fails with a "Non-exhaustive patterns" error.

To Reproduce

Steps to reproduce the behavior:

$ import Text.Interpolation.Nyan
$ varMonomorphic = 0 :: Int
$ varPolymorphic = 0 :: Num a => a

$ [int||Testing #{varMonomorphic}|]
Testing 0

$ [int||Testing #{varPolymorphic :: Int}|]
Testing 0

$[int||Testing #{varPolymorphic @Int}|]

<interactive>:13:1: error:
    • Exception when trying to run compile-time code:
        src/Language/Haskell/Meta/Extensions.hs:(179,19)-(348,49): Non-exhaustive patterns in case

      Code: template-haskell-2.18.0.0:Language.Haskell.TH.Quote.quoteExp
              int "|Testing #{varPolymorphic @Int}"
    • In the quasi-quotation: [int||Testing #{varPolymorphic @Int}|]

Expected behavior

Expected the interpolation of varPolymorphic @Int to work.

Environment

• master 5e15805
• ghc-9.2.5, LTS-20.05

[dcastro]

cc @Martoon-00

[Martoon-00]

Yeah, unfortunatelly it does not work with the recent LTS, #24 is related.

I'll try handle this once having time. Thanks for posting this issue.

[Martoon-00]

The 0.9.1 versions on hackage should contain the fix, please check!

[dcastro]

Yup, seems to be fixed now, thanks! 😄

λ> let varPolymorphic :: Num a => a; varPolymorphic = 0

λ> [int||Testing #{varPolymorphic @Int}|]
Testing 0