Compatibility with GHC-9.0

[recursion-ninja]

Starting with ghc-9.0, there are new whitepspacing rules around "bang patterns" (!) to remove ambiguity in niche situations with infix operators/constructors.

Currently Decimal does not build with the ghc-9.0 release candidate because there is whitespace in the strict data constructor:

Configuring library for Decimal-0.5.1..
Preprocessing library for Decimal-0.5.1..
Building library for Decimal-0.5.1..
[1 of 1] Compiling Data.Decimal     ( src/Data/Decimal.hs, dist/build/Data/Decimal.o, dist/build/Data/Decimal.dyn_o )

src/Data/Decimal.hs:69:24: error:
    Operator applied to too few arguments: !
   |
69 |       decimalPlaces :: ! Word8,
   |                        ^
cabal: Failed to build Decimal-0.5.1

This pull request fixes the compilation error, making Decimal compatible with ghc-9.0.

[simonmichael]

Could we have a hackage release with this ?

[PaulJohnson]

Version 0.5.2 now up on Hackage.

[simonmichael]

Thank you much!