</itemizedlist>
</sect2>
-<!--
<sect2>
<title>Language changes</title>
<itemizedlist>
+ <listitem>
+ <para>
+ GHC now understands the <literal>Haskell98</literal> and
+ <literal>Haskell2010</literal> languages.
+ </para>
+
+ <para>
+ These get processed before the language extension pragmas,
+ and define the default sets of extensions that are enabled.
+ If neither is specified, then the default is
+ <literal>Haskell2010</literal> plus the
+ <literal>MonoPatBinds</literal> extension.
+ </para>
+ </listitem>
+
+ <listitem>
+ <para>
+ GHC now supports the <literal>DoAndIfThenElse</literal>
+ extension, which is part of the Haskell 2010 standard.
+ </para>
+ </listitem>
+
+ <listitem>
+ <para>
+ Datatype contexts, such as the <literal>Eq a</literal> in
+ </para>
+<programlisting>
+data Eq a => Set a = NilSet | ConsSet a (Set a)
+</programlisting>
+ <para>
+ are now treated as an extension
+ <literal>DatatypeContexts</literal> (on by default) by GHC.
+ </para>
+ </listitem>
+
+ <listitem>
+ <para>
+ GHC's support for unicode source has been improved, including
+ removing support for U+22EF for the <literal>..</literal>
+ symbol. See <xref linkend="unicode-syntax" /> for more details.
+ </para>
+ </listitem>
+
+ <listitem>
+ <para>
+ Pragmas are now reread after preprocessing. In particular,
+ this means that if a pragma is used to turn CPP on, then other
+ pragmas can be put in CPP conditionals.
+ </para>
+ </listitem>
+
+ <listitem>
+ <para>
+ The <literal>TypeOperators</literal> extension now allows
+ instance heads to use infix syntax.
+ </para>
+ </listitem>
+
+ <listitem>
+ <para>
+ The <literal>PackageImports</literal> extension now understands
+ <literal>this</literal> to mean the current package.
+ </para>
+ </listitem>
+
+ <listitem>
+ <para>
+ The <literal>INLINE</literal> and <literal>NOINLINE</literal>
+ pragmas can now take a <literal>CONLIKE</literal> modifier,
+ which indicates that the right hand side is cheap to compute,
+ and can thus be duplicated more freely.
+ See <xref linkend="conlike" /> for more details.
+ </para>
+ </listitem>
+
+ <listitem>
+ <para>
+ A <literal>ForceSpecConstr</literal> annotation on a type, e.g.
+ </para>
+<programlisting>
+import SpecConstr
+{-# ANN type SPEC ForceSpecConstr #-}
+</programlisting>
+ <para>
+ can be used to force GHC to fully specialise argument of that
+ type.
+ </para>
+ </listitem>
+
+ <listitem>
+ <para>
+ A <literal>NoSpecConstr</literal> annotation on a type, e.g.
+ </para>
+<programlisting>
+import SpecConstr
+{-# ANN type T NoSpecConstr #-}
+</programlisting>
+ <para>
+ can be used to prevent SpecConstr from specialising on
+ arguments of that type.
+ </para>
+ </listitem>
+
+ <listitem>
+ <para>
+ There is are two experimental new extensions
+ <literal>AlternativeLayoutRule</literal> and
+ <literal>AlternativeLayoutRuleTransitional</literal>,
+ which are for exploring alternative layout rules in Haskell'.
+ The details are subject to change, so we advise against using
+ them in real code for now.
+ </para>
+ </listitem>
+
+ <listitem>
+ <para>
+ The <literal>NewQualifiedOperators</literal> extension has
+ been deprecated, as it was rejected by the Haskell' committee.
+ </para>
+ </listitem>
</itemizedlist>
</sect2>
<sect2>
<title>Warnings</title>
<itemizedlist>
+ <listitem>
+ <para>
+ There is now a warning for missing import lists, controlled
+ by the new <literal>-fwarn-missing-import-lists</literal> flag.
+ </para>
+ </listitem>
+
+ <listitem>
+ <para>
+ GHC will now warn about <literal>SPECIALISE</literal> and
+ <literal>UNPACK</literal> pragmas that have no effect.
+ </para>
+ </listitem>
</itemizedlist>
</sect2>
<sect2>
- <title>Runtime system</title>
-
+ <title>DLLs</title>
<itemizedlist>
+ <listitem>
+ <para>
+ Shared libraries are once again supported on Windows.
+ </para>
+ </listitem>
+
+ <listitem>
+ <para>
+ Shared libraries are now supported on OS X, both on x86 and on
+ PowerPC. The new <literal>-dylib-install-name</literal> GHC
+ flag is used to set the location of the dynamic library.
+ See <xref linkend="finding-shared-libs" /> for more details.
+ </para>
+ </listitem>
</itemizedlist>
</sect2>
<sect2>
- <title>Build system</title>
+ <title>Runtime system</title>
+
<itemizedlist>
+ <listitem>
+ <para>
+ For security reasons, by default, the only RTS flag that
+ programs accept is <literal>+RTS --info</literal>. If you want
+ the full range of RTS flags then you need to link with the new
+ <literal>-rtsopts</literal> flag. See
+ <xref linkend="options-linker" /> for more details.
+ </para>
+ </listitem>
+
+ <listitem>
+ <para>
+ The RTS now exports a function <literal>setKeepCAFs</literal>
+ which is important when loading Haskell DLLs dynamically, as
+ a DLL may refer to CAFs that hae already been GCed.
+ </para>
+ </listitem>
+
+ <listitem>
+ <para>
+ The garbage collector no longer allows you to specify a number
+ of steps; there are now always 2. The <literal>-T</literal>
+ RTS flag has thus been removed.
+ </para>
+ </listitem>
+
+ <listitem>
+ <para>
+ A new RTS flag <literal>-H</literal> causes the RTS to use a
+ larger nursery, but without exceeding the amount of memory
+ that the application is already using. It makes some programs
+ go slower, but others go faster.
+ </para>
+ </listitem>
+
+ <listitem>
+ <para>
+ GHC now returns memory to the OS, if memory usage peaks and
+ then drops again. This is mainly useful for long running
+ processes which normally use very little memory, but
+ occasionally need a lot of memory for a short period of time.
+ </para>
+ </listitem>
+
+ <listitem>
+ <para>
+ On OS X, eventLog events are now available as DTrace probes.
+ </para>
+ </listitem>
+
+ <listitem>
+ <para>
+ The PAPI support has been improved. The new RTS flag
+ <literal>-a#0x40000000</literal> can be used to tell the RTS
+ to collect the native PAPI event <literal>0x40000000</literal>.
+ </para>
+ </listitem>
</itemizedlist>
</sect2>
<sect2>
<title>Compiler</title>
<itemizedlist>
+ <listitem>
+ <para>
+ GHC now defaults to <literal>--make</literal> mode, i.e. GHC
+ will chase dependencies for you automatically by default.
+ </para>
+ </listitem>
+
+ <listitem>
+ <para>
+ GHC now includes an LLVM code generator.
+ </para>
+ <para>
+ This includes a number of new flags:
+ a flag to tell GHC to use LLVM, <literal>-fllvm</literal>;
+ a flag to dump the LLVM input ,<literal>-ddump-llvm</literal>;
+ flags to keep the LLVM intermediate files,
+ <literal>-keep-llvm-file</literal> and
+ <literal>-keep-llvm-files</literal>;
+ flags to set the location and options for the LLVM assembler,
+ optimiser and compiler,
+ <literal>-pgmla</literal>,
+ <literal>-pgmlo</literal>,
+ <literal>-pgmlc</literal>,
+ <literal>-optla</literal>,
+ <literal>-optlo</literal> and
+ <literal>-optlc</literal>.
+ </para>
+ </listitem>
+
+ <listitem>
+ <para>
+ It is now possible to use <literal>-fno-code</literal> with
+ <literal>--make</literal>.
+ </para>
+ </listitem>
+
+ <listitem>
+ <para>
+ The new flag <literal>-dsuppress-coercions</literal> controls
+ whether GHC prints coercions in core dumps.
+ </para>
+ </listitem>
+
+ <listitem>
+ <para>
+ The inliner has been overhauled. The most significant
+ user-visible change is that only saturated functions are
+ inlined, e.g.
+ </para>
+<programlisting>
+(.) f g x = f (g x)
+</programlisting>
+ <para>
+ would only be inlined if <literal>(.)</literal> is applied to 3
+ arguments, while
+ </para>
+<programlisting>
+(.) f g = \x -> f (g x)
+</programlisting>
+ <para>
+ will be inlined if only aplpied to 2 arguments.
+ </para>
+ </listitem>
+
+ <listitem>
+ <para>
+ The <literal>-finline-if-enough-args</literal> flag is no
+ longer supported.
+ </para>
+ </listitem>
+
+ <listitem>
+ <para>
+ Column numbers in warnings and error messages now start at 1,
+ as is more standard, rather than 0.
+ </para>
+ </listitem>
+
+ <listitem>
+ <para>
+ GHCi now understands most linker scripts. In particular, this
+ means that GHCi is able to load the C pthread library.
+ </para>
+ </listitem>
+
+ <listitem>
+ <para>
+ The <literal>ghc --info</literal> output has been updated:
+ </para>
+ <para>
+ It now includes the
+ location of the global package database, in the
+ <literal>Global Package DB</literal> field.
+ </para>
+ <para>
+ It now includes the build, host and target platforms, in the
+ <literal>Build platform</literal>,
+ <literal>Host platform</literal> and
+ <literal>Target platform</literal> fields.
+ </para>
+ <para>
+ It now includes a <literal>Have llvm code generator</literal>
+ field.
+ </para>
+ <para>
+ The <literal>Win32 DLLs</literal> field has been removed.
+ </para>
+ </listitem>
+
+ <listitem>
+ <para>
+ The registerised via-C backend, and the
+ <literal>-fvia-C</literal>, have been deprecated. The poor
+ floating-point performance in the x86 native code generator
+ has now been fixed, so we don't believe there is still any
+ reason to use the via-C backend.
+ </para>
+ </listitem>
+
+ <listitem>
+ <para>
+ There is now a new flag <literal>--supported-extensions</literal>,
+ which currently behaves the same as
+ <literal>--supported-languages</literal>.
+ </para>
+ </listitem>
+
+ <listitem>
+ <para>
+ GHC progress output such as
+ </para>
+<programlisting>
+[ 1 of 5] Compiling Foo ( Foo.hs, Foo.o )
+</programlisting>
+ <para>
+ is now sent to stdout rather than stderr.
+ </para>
+ </listitem>
+
+ <listitem>
+ <para>
+ The new flag <literal>-fexpose-all-unfoldings</literal>
+ makes GHC put unfoldings for <emphasis>everything</emphasis>
+ in the interface file.
+ </para>
+ </listitem>
+
+ <listitem>
+ <para>
+ There are two new flags, <literal>-fno-specialise</literal>
+ and <literal>-fno-float-in</literal>, for disabling the
+ specialise and float-in passes.
+ </para>
+ </listitem>
+
+ <listitem>
+ <para>
+ The new flag <literal>-fstrictness-before=<replaceable>n</replaceable></literal> tells
+ GHC to run an additional strictness analysis pass
+ before simplifier phase <replaceable>n</replaceable>.
+ </para>
+ </listitem>
+
+ <listitem>
+ <para>
+ There is a new flag
+ <literal>-funfolding-dict-discount</literal>
+ for tweaking the optimiser's behaviour.
+ </para>
+ </listitem>
+
+ <listitem>
+ <para>
+ The <literal>-fspec-inline-join-points</literal> flag has been
+ removed.
+ </para>
+ </listitem>
</itemizedlist>
</sect2>
<sect2>
<title>GHCi</title>
<itemizedlist>
+ <listitem>
+ <para>
+ GHCi now supports full import syntax, e.g.
+ </para>
+<programlisting>
+Prelude> import Data.List as L
+Prelude Data.List> L.length "foo"
+3
+</programlisting>
+ </listitem>
+
+ <listitem>
+ <para>
+ GHCi now understands the layout of multiline-commands, so
+ this now works:
+ </para>
+<programlisting>
+Prelude> :{
+Prelude| let x = 1
+Prelude| y = 2 in x + y
+Prelude| :}
+3
+</programlisting>
+ </listitem>
</itemizedlist>
</sect2>
<sect2>
- <title>Template Haskell</title>
+ <title>Template Haskell and Quasi-Quoters</title>
<itemizedlist>
+ <listitem>
+ <para>
+ It is now possible to quasi-quote patterns with
+ <literal>[p| ... |]</literal>.
+ </para>
+ </listitem>
+
+ <listitem>
+ <para>
+ It is no longer to use a <literal>$</literal> before the
+ name of a quasi-quoter, e.g. one can now say
+ <literal>[expr| ... |]</literal> rather than
+ <literal>[$expr| ... |]</literal>.
+ </para>
+ </listitem>
+
+ <listitem>
+ <para>
+ It is now possible to use a quasi-quoter for types, e.g.
+ <literal>f :: [$qq| ... |]</literal>
+ </para>
+ </listitem>
+
+ <listitem>
+ <para>
+ It is now possible to quasi-quote existentials and GADTs.
+ </para>
+ </listitem>
</itemizedlist>
</sect2>
<sect2>
- <title>Package Handling</title>
+ <title>GHC API</title>
<itemizedlist>
+ <listitem>
+ <para>
+ There are now <literal>Data</literal> and
+ <literal>Typeable</literal> instances for the
+ HsSyn typed.
+ </para>
+ </listitem>
+
+ <listitem>
+ <para>
+ As language extensions are not applied until after the base
+ language (Haskell98, Haskell2010 or the default) has been
+ selected, it is now necessary to tell the GHC API the point
+ at which the extension flags should be processed. Normally
+ this is done by calling
+ <literal>DynFlags.flattenExtensionFlags</literal> once all
+ the flags and pragmas have been read.
+ </para>
+ </listitem>
</itemizedlist>
</sect2>
+<!--
<sect2>
<title>Libraries</title>
+
+ <itemizedlist>
+ </itemizedlist>
</sect2>
-->
</sect1>
projects / ghc-hetmet.git / commitdiff