April 2005 - Nhc-bugs

RE: [nhc-bugs] Exporting class methods
by Simon Marlow 19 Apr '05

19 Apr '05

On 19 April 2005 12:15, Malcolm Wallace wrote: >>>> Control.Monad.Reader (Reader, runReader, ask, local) >>>> Control.Monad.Error (instance MonadPlus IO) >> >> These have H98 implementations, as far as I'm aware. > > The mtl package requires multi-param classes and functional > dependencies. Where are the H'98 versions? oops, you're right. But instance MonadPlus IO is ok. Cheers, Simon

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RE: [nhc-bugs] Exporting class methods
by Simon Marlow 19 Apr '05

19 Apr '05

On 15 April 2005 17:26, Malcolm Wallace wrote: > Yes, pretty-much all of these rely on significant extensions to > Haskell'98. Nah, many of these are implementable without changing the compiler: > Ian Lynagh <igloo(a)earth.li> writes: > >> Control.Exception (bracket_, catch, block, unblock >> catchJust, Exception(IOException) >> catchDyn, throwDynTo, bracket, ioErrors, finally ) Needs exception support, of course >> Control.Concurrent ( ThreadId, myThreadId ) >> Control.Concurrent.MVar (MVar, modifyMVar_, swapMVar, newMVar) Easy (no forkIO) >> System.Posix.IO (fdToHandle) nhc98 must have something like this already. >> System.Posix.Types ( Fd(Fd) ) >> System.IO ( hPutBuf, hGetBuf, hIsTerminalDevice ) -- claims to be >> portable! System.Posix (getFileStatus, setFileMode, unionFileModes, >> ownerExecuteMode, groupExecuteMode, fileMode >> EpochTime, modificationTime, sleep, FileOffset, >> fileSize, setFileTimes, epochTime) All implementable using the FFI only >> Control.Monad.Reader (Reader, runReader, ask, local) >> Control.Monad.Error (instance MonadPlus IO) These have H98 implementations, as far as I'm aware. >> Also, unboxed arrays of Int32, Bool, Int and STUArrays of Int and >> Bool (plus runST, mutable array functions, unsafeFreeze, etc). Ok, MArray and IArray need MPTC, but you don't actually need unboxed arrays (Hugs provides these). Cheers, Simon

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Exporting class methods
by Ian Lynagh 15 Apr '05

15 Apr '05

Hi, Andother problem with both nhc98 1.16 and 1.18. $ cat Q.hs module Q where import Data.Bits (shiftL) $ nhc98 -c Q.hs ====== Errors when renaming: Identifier shiftL used at 4:19-4:24 is not defined. If I change the second line to import Data.Bits (Bits(shiftL)) then it compiles fine. ghc and hugs are both happy with it either way. My reading of the report suggests the first form should be allowed (and hence this is a bug in nhc98): http://www.haskell.org/onlinereport/modules.html says: --------8<----------------8<----------------8<-------- 5.2 Export Lists Entities in an export list may be named as follows: 1. A value, field name, or class method, whether declared in the module body or imported, may be named by giving the name of the value as a qvarid, which must be in scope. 5.3.1 What is imported Exactly which entities are to be imported can be specified in one of the following three ways: 1. The imported entities can be specified explicitly by listing them in parentheses. Items in the list have the same form as those in export lists, except qualifiers are not permitted and the `module modid' entity is not permitted. --------8<----------------8<----------------8<-------- By the way, these bugs are coming from looking at compiling darcs with nhc98, but there are also a number of modules/functions missing. Are you interested in a list of these? Here is a (probably incomplete) one: Control.Concurrent.MVar System.IO (hPutBuf, hGetBuf) Control.Exception (catch, block, unblock, bracket_) Thanks Ian

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Error importing Control.Monad (liftM2) with newtype
by Ian Lynagh 11 Apr '05

11 Apr '05

This happens with both nhc98 1.16 and 1.18: $ cat Q.hs module Q () where import Control.Monad (liftM2) newtype A a = A a $ nhc98 -c Q.hs nhc98comp: isRealData InfoClass 1 Prelude.Monad IEnone \/ b . (1 b) [38,39,40,41] [] [(5,([],[])),(25,([],[])),(26,([],[]))] Thanks Ian

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