+++ /dev/null
-<sect1>Release notes for version~4.00---10/98
-<label id="release-4-00">
-<p>
-
-<sect2>Language matters
-<p>
-
-<itemize>
-
-<item> Universal and existential quantification: see Section <ref
-name="Explicit universal quantification"
-id="universal-quantification"> and Section <ref name="Existentially
-quantified data constructors" id="existential-quantification">
-respectively.
-
-Universal quantification was in in GHC 2.10 and later, but the
-syntax has changed: it's now @forall a. ...@ instead of @All a => ...@.
-
-<item> Multi-paramter type classes. We have relaxed some of the rules
- since GHC 3.00. In particular
-
-<descrip>
- <tag>@-fallow-overlapping-instances@</tag>
- allows overlapping instances
- <tag>@-fallow-undecidable-instances@</tag>
- allows you to write instance contexts that constrain non-type-variables
-</descrip>
-
-Full details in Section <ref name="Multi-parameter type classes"
-id="multi-param-type-classes">.
-</itemize>
-
-<sect2>New Libraries
-<p>
-
-Documentation in <url name="GHC/Hugs Extension Libraries"
-url="libs.html">.
-
-<descrip>
-
-<tag>@Dynamic@</tag>
-
-Dynamic types.
-
-<tag>@Exceptions@</tag>
-
-The library @Exception@ in @-syslib exts@ provide an interface for
-exception handling. Calls to @error@, pattern matching failures and a
-bunch of other exception can be caught.
-
-</descrip>
-
-<sect2>Compiler internals
-<p>
-
-The intermediate language used by GHC has had a radical overhaul.
-The new Core language (coreSyn/CoreSyn.lhs) is much smaller and
-more uniform. The main transformation engine (the "simplifier")
-has been totally rewritten. The compiler is several thousand lines
-shorter as a result. It's also very much easier to understand
-and modify. (It's true. Honest!)
-
-
-<sect2>Run time system
-<p>
-
-There is a completely new runtime system, aimed at integration with
-Hugs. Tons of cruft removed. Some changes to code generation; things
-typically run a bit faster as a result.
-
-An overview of the new RTS is available: <url name="The New GHC/Hugs
-Runtime System" url="http://www.dcs.gla.ac.uk/~simonm/rts.ps">.
-
-<sect2>Storage Manager/Garbage Collector
-<p>
-
-The new storage manager features a dynamically resizing heap, so you
-won't need those pesky @-H@ options anymore. In fact, the @-H@ option
-is now ignored for compatibility with older versions.
-
-Stacks are now also expandable, and the @-K@ option now specifies a
-<em/maximum/ heap size. The default is (a perhaps conservative) @1M@.
-
-The garbage collector now collects CAFs, so there's no more space
-leaks associated with these. If you think you have a CAF-related
-space leak, we'd like to hear about it.
-
-The storage manager current only has a two-space garbage collector,
-which will be slower than 3.02's generational collector when the
-amount of live data is large. A new generational collector is high on
-our priority list.
-
-For the other new tweakables, see Section <ref name="RTS options to
-control the garbage-collector" id="rts-options-gc">.
-
-<sect2>Profiling
-<p>
-
-There is a new profiler based on <em/Cost Centre Stacks/. This is an
-extension of the previous cost centre scheme, whereby the profilier
-stores information about the call-graph of the program and attributes
-costs to nodes of this graph.
-
-For a quick demo, try compiling a program with @-prof -auto-all@, then
-run it with @+RTS -p@ and see what comes out (in the @<prog>.prof@
-file).
-
-The feature is still experimental, and the call graph may not be
-exactly what you were expecting. Also, we only have time/allocation
-profiling at the moment; heap profiling will follow shortly.
-
-<sect2>Miscellaneous
-<p>
-
-<itemize>
-
-<item> Concurrent Haskell is now the default. No need to
-compile/download special libraries. The context switch interval isn't
-tweakable any more; threads just yield after allocating a fixed amount
-of heap (currently 4k). If you want a quicker context switch, that
-won't be possible: this decision was made for efficiency reasons (it
-reduces the penalty for runnning threaded code to almost zero). We
-might allow the context switch interval to be increased in the future;
-but also context switches are pretty fast (faster than before).
-
-<item> @forkIO@ now returns a @ThreadId@, and there's a new operation
-@killThread@ which will terminate an existing thread. See Section
-<ref name="The Concurrent interface" id="concurrent-interface"> for
-more details.
-
-<item> You need @-syslib concurrent@ to get the @Concurrent@ library.
-
-<item> The rewritten IO library from 3.03 has been ported to 4.00.
-
-<item> New constructs: @foriegn import@ and @foreign export@ for
-H/Direct.
-
-<item> Supported architectures: all the development has been done on
-x86(mainly FreeBSD/Linux) so this is the most stable environment.
-Sparc (Solaris) and x86/Win32 (cygwin32) have also been mildly tested, and
-an Alpha port is in the works. Everything else will need a little
-porting effort; we don't have machines here, so any help would be
-greatly appreciated.
-
-<item> Code is faster and smaller, but programs might run slower due
-to the garbage collector (see "Storage Manager" above). Increasing
-the minimum allocation area with the @-A@ RTS option can claw back
-some of this speed.
-
-<item> We now use GMP 2.02, and attempt to use an already-installed
-copy if available. If you have GMP on your system but the configure
-script doesn't detect it, we'd like to know.
-
-<item> @seq@ works better than in 3.xx - you can now @seq@ functions
-without crashing the program.
-
-<item> The @Eval@ class has been removed (i.e. every type is assumed
-to be in class @Eval@). This change has been made in anticipation of
-Haskell 98.
-
-<item> The native code generator has had very little testing (it's not used
-on x86 yet), so Sparcs may have some trouble with it. Try -fvia-C if
-strange errors occur.
-
-<item> The compiler is slightly faster, but sometimes needs more heap.
-If you have an example where this is the case, please let us know.
-
-</itemize>
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