Henning Thielemann wrote:
[...]
- So you have to declare them near the test cases and they're orphan instances
The entire project doesn't issue a single warning when compiling with -Wall *except* two orphan instances when building the test cases...
However, I had sometimes the case, where a type from another library was part of my tests and thus I needed its Arbitrary instance. I could have defined instances for the foreign types, but they would have been orphan and I risk that the library author decides to add the instances later.
Hmm... maybe it is a good idea to aktivate the instance declaration with a cabal flag? I've already got: Flag Test Description: Build a binary running test cases Default: False and I could easily add something like if flag( Test ) CPP-Options: -D__TEST__ Build-Depends: QuickCheck >= 2 && < 3 and data MyType = ... #ifdef __TEST__ instance Arbitrary MyType where ... #endif A usage of cabal flags that strongly reminds me of Gentoo's useflags :) However, this will result in a total mess with more than one such flag... //Stephan -- Früher hieß es ja: Ich denke, also bin ich. Heute weiß man: Es geht auch so. - Dieter Nuhr