-This is the release notes for GHC-2.03, describing what's new since the
+This is the release notes for GHC-2.04, describing what's new since the
previous release:
-GHC 2.03 is a minor upgrade of GHC 2.02. It differs in the following
-ways:
+GHC 2.04 is a minor upgrade of GHC 2.02 (and the bugfix release,
+2.03), representing work done through May '97. This new release
+adds the following:
-* A slew of small bugs are fixed. You can find the complete list at
+* Data constructors can now have polymorphic fields, and ordinary
+ functions can have polymorphic arguments. Details on
- http://www.cse.ogi.edu/~simonpj/ghc-bugs.html
+ http://www.cse.ogi.edu/~simonpj/quantification.html
- One bug remains un-fixed, namely the crash when there's an empty
- comment at the end of file.It's wierd!
-
-* Last-minute language changes have been implemented (minor changes
- to the libraries, and to module export/hiding scope rules)
-
-* It is only available as a source distribution. If you want to
- use it you'll have to build it from source. Nowadays this is
- a well-documented process (see the build and installation guide, but
- note that this release is still not self-booting, you still need
- to have The Good Old Compiler (0.29) at your disposal).
-
-None of the bugs in GHC 2.02 are show-stoppers, so you'll only want
-to upgrade if you are a build-from-source junkie and the bugs are
-irritating you.
-
-Apart from bug-fixes, which are itemized elsewhere,
-the exact language and standard-library changes are as follows:
-
-* A hiding clause hides the unqualified name, but not the qualified name.
-
-* There's a new @Numeric@ library, containing mostly mildly marginal
- code for showing and reading numbers. Parts of its exports used to be
- exported by @Prelude@, but now you'll have to import them explicitly.
- It also defines some functions that weren't provided before; have a
- look in the Haskell library report for details of complete interface.
-
-* The following extra functions are exported from IO:
-
- try, bracket, bracket_, hGetLine, hWaitForInput
-
-In addition, we've made following changes to GHC libraries/GHC's
-implementation of the Haskell standard prelude:
-
-
-* The function fromRational__, exported from PrelNum, is now called fromRat
- (And it's exported by @Numeric@).
-
-* Documentation for the Glasgow specific interfaces plus the system
- libraries have been re-instated. Posix library documentation
- included also.
-
-* `maybe' is now exported from Prelude, as it should have been in 2.02.
-
-* Equality on IO.Handle is now defined as specified by the library report.
-
-* Ix.rangeSize returns `0' on an empty range;previously it failed.
-
-* The new interface GlaExts which is meant to be the gateway to the
- various Glasgow extensions has now been documented.
-
-* GlaExts now exports the representation of Char
-
-* The mutable variable interface, MutVar, has also been documented,
- together with ByteArray, MutableArray and Foreign.
-
-* Added documentation on how to compile mutually recursive modules with
- 2.03.
+ Existential types coming, but not done yet.
+
+* Pattern guards implemented, see
+
+ http://www.cse.ogi.edu/~simonpj/guards.html
+
+* Compiler can now compile itself.
+
+* INLINE pragmas honoured (caveat: not yet
+ working on instance-decl methods)
+
+* Simplifier improvements and better inlining gives
+ better code; not sure how *much* better.
+
+* -dshow-rn-stats print out amusing statistics about what
+ the renamer does.
+
+* When compiling without -O, the renamer (the pass responsible for
+ slurping in interface file and making sure everything is in scope
+ etc.) is now more careful about what it will bring in (especially
+ data constructors and instance declarations). The upshot of this
+ change is that a lot of the (unnecessary) work this pass did in
+ 2.02/2.03 is now avoided.
+
+ -fno-prune-tydecls and -fno-prune-instdecls switch off these
+ renamer optimisations. You can try the effect with the renamer
+ statistics. War stories welcome.
+
+* The Heroic Efforts of \tr{Andr\'e Santos <alms@di.ufpe.br>} have
+ been included, AIX/RS6000 is now a supported \tr{ghc}
+ platform! Bug reports concerning this port to (as always)
+ glasgow-haskell-bugs@dcs.gla.ac.uk
+
+* A lot of the bugs that were present in versions 2.02/2.03
+ have been fixed (thanks to everyone that reported bugs!).
+ A list of the reported problems with 2.02/2.03 can be found at
+
+ http://www.dcs.gla.ac.uk/fp/software/ghc/ghc-bugs.html
+
+ No doubt entries for 2.04 will be added here as well :-)
+
+* This release is available in source format only. To build it you'll
+ need to have either a copy of GHC~0.29 or GHC~2.02/3 installed.
+ For people either doing porting work or work on a (supported)
+ platform for which there is no GHC binary bundles available, the
+ necessary intermediate files are also available (.hc and .hi files).
+
+ Consult the installation guide for more information on how
+ to build or bootstrap. The guide is included in the distribution
+ (in the fptools/docs directory), and an on-line version of the
+ document can be found at
+
+ http://www.dcs.gla.ac.uk/fp/software/ghc/ghc-doc/install-guide.html
+
+
+In addition to the above, we've made the following minor changes to
+the GHC libraries/our implementation of the Haskell standard prelude:
+
+* `isPrefixOf' and `isSuffixOf' has been added to `List'
+* The empty type `Void' is now exported from the prelude.
+* `GlaExts' exports the `Lift' data type:
+
+ data Lift a = Lift a
+
+ you might need it someday...
+
+* The `Foreign' interface now also exports the representations
+ for `Word' and `Addr'
+
+* The low-level file handle interface in the POSIX system
+ library has been reworked a bit, most notably is the renaming of
+ `Channel' to `Fd' and the introduction of operations for converting
+ to and from `Handle' and `Fd' values. The changes are:
+
+ --Renamed functions (old name in square brackets)
+ openFd :: FilePath
+ -> OpenMode
+ -> Maybe FileMode
+ -> OpenFileFlags
+ -> IO Fd
+ -- [openChannel]
+ fdSeek :: Fd -> SeekMode -> FileOffset -> IO FileOffset
+ --[seekChannel]
+ fdRead :: Fd -> ByteCount -> IO (String, ByteCount)
+ --[readChannel]
+ fdWrite :: Fd -> String -> IO ByteCount
+ --[writeChannel]
+ fdClose :: Fd -> IO ()
+ --[closeChannel]
+ setFdOption :: Fd -> FdOption -> Bool -> IO ()
+ --[setChannelOption]
+ queryFdOption :: Fd -> FdOption -> IO Bool
+ --[queryChannelOption]
+ dup :: Fd -> IO Fd
+ --[dupChannel]
+ dupTo :: Fd -> Fd -> IO ()
+ --[dupChannelTo]
+
+ data FdOption = AppendOnWrite | CloseOnExec | NonBlockingRead
+ --[ChannelOption]
+ getFdStatus :: Fd -> IO FileStatus
+ --[getChannelStatus]
+
+ -- New data structure collecting together misc flags passed to openFd
+ data OpenFileFlags =
+ OpenFileFlags {
+ append :: Bool,
+ exclusive :: Bool,
+ noctty :: Bool,
+ nonBlock :: Bool,
+ trunc :: Bool
+ }
+
+ --New ops for converting between Fd and Handle:
+ fdToHandle :: Fd -> IO Handle
+ handleToFd :: Handle -> IO Fd
+ intToFd :: Int -> Fd -- use with care.