#5529: Newtypes with hidden constructors cannot be passed as FFI arguments
-----------------------------------+----------------------------------------
Reporter: mikhail.vorozhtsov | Owner:
Type: bug | Status: new
Priority: normal | Milestone:
Component: Compiler | Version: 7.3
Keywords: | Testcase:
Blockedby: | Difficulty:
Os: Unknown/Multiple | Blocking:
Architecture: Unknown/Multiple | Failure: None/Unknown
-----------------------------------+----------------------------------------
Comment(by mikhail.vorozhtsov):
Once again, I, as a programmer, am completely fine if the module
documentation says that MyType mirrors time_t, exported constructor
doesn't help me a bit (one way to ensure that would be by writing
something like {{{let unused = MyType (undefined :: CTime)}}}, but what
about {{{newtype MyType = MyType Int64}}} (assuming time_t ~ int64_t), how
would you check all possibilities?). GHC doesn't ensure that FFI import's
types are right (with respect to the C types), programmer does. Well,
exporting guts may be seen as a sort of documentation, but I'd rather not
encourage/require that practice.
--
Ticket URL: <http://hackage.haskell.org/trac/ghc/ticket/5529#comment:8>
GHC <http://www.haskell.org/ghc/>
The Glasgow Haskell Compiler
_______________________________________________
Glasgow-haskell-bugs mailing list
[email protected]
http://www.haskell.org/mailman/listinfo/glasgow-haskell-bugs
