<itemizedlist>
<listitem>
<para>
+ GHC now supports SMP:
+ when you compile with <option>-threaded</option>, you now get
+ an RTS flag <option>-N</option> that allows you to specify the
+ number of OS threads that GHC should use. Defaults to 1.
+ See <xref linkend="sec-using-smp" /> and <xref
+ linkend="lang-parallel" />.
+ </para>
+ </listitem>
+ <listitem>
+ <para>
+ GHC's modules are now also bundled into a
+ <literal>ghc</literal> package, allowing programs to make use
+ of GHC as a library. The interface has not yet been properly
+ designed, so is subject to change.
+ </para>
+ </listitem>
+ <listitem>
+ <para>
+ GHC now handles impredicative polymorphism and there are
+ changes to the way scoped type variables work; see
+ <ulink url="http://www.haskell.org/pipermail/glasgow-haskell-users/2006-January/009565.html"> Simon's e-mail</ulink>
+ for more details.
+ </para>
+ </listitem>
+ <listitem>
+ <para>
+ GHC now supports bang patterns to require a function is strict
+ in a given argument, e.g.
+ <programlisting>
+ f (!x, y) = [x,y]</programlisting>
+ is equivalent to
+ <programlisting>
+ f (x, y) | x `seq` False = undefined
+ | otherwise = [x,y]</programlisting>
+ </para>
+ </listitem>
+ <listitem>
+ <para>
+ The restriction that you cannot use two packages together if
+ they contain a module with the same name has been removed.
+ In implementation terms, the package name is now included in
+ every exported symbol name in the object file, so that
+ modules with the same name in different packages do not
+ clash. See <xref linkend="package-overlaps" />.
+ </para>
+ </listitem>
+ <listitem>
+ <para>
+ GHC now treats source files as UTF-8 (ASCII is a strict
+ subset of UTF-8, so ASCII source files will continue to
+ work as before). However, invalid UTF-8 sequences are
+ ignored in comments, so ASCII code with comments in, for
+ example, Latin-1 will also work.
+ </para>
+ </listitem>
+ <listitem>
+ <para>
+ GADTs can now use record syntax. Also, if the datatype could
+ have been declared with Haskell 98 syntax then deriving
+ clauses are permitted. For more info see <xref linkend="gadt" />.
+ </para>
+ </listitem>
+ <listitem>
+ <para>
+ There is a new pragma <literal>LANGUAGE</literal> which allows
+ extensions to be specified portably, i.e. without having to
+ resort to the <literal>OPTIONS_GHC</literal> pragma and giving
+ GHC-specific options. The arguments to the pragma are the same
+ extensions that Cabal knows about. More info in
+ <xref linkend="language-pragma" />.
+ </para>
+ </listitem>
+ <listitem>
+ <para>
+ When you use <command>ghc --make</command>, GHC will now take
+ the executable filename from the name of the file containing
+ the <literal>Main</literal> module rather than using
+ <filename>a.out</filename>. The <filename>.exe</filename>
+ extension is appended on Windows, and it can of course be
+ overridden with <option>-o</option>.
+ </para>
+ </listitem>
+ <listitem>
+ <para>
+ GHC's garbage collector now deals more intelligently with
+ mutable data, so you mostly no longer need to worry about GC
+ performance when a lot of memory is taken up by
+ <literal>STArray</literal>s, <literal>IOArray</literal>s,
+ <literal>STRef</literal>s or <literal>IORef</literal>s.
+ </para>
+ </listitem>
+ <listitem>
+ <para>
+ GHC now allows more generalisation when typing mutually
+ recursive bindings, resulting in more programs being accepted.
+ See <xref linkend="typing-binds" /> for more details.
+ </para>
+ </listitem>
+ <listitem>
+ <para>
+ The rules for instance declarations have been further relaxed.
+ You are now permitted to have instances whose heads contain
+ only type variables, e.g.
+ <programlisting>
+ instance C a</programlisting>
+ and instances whose constraints are not only type variables,
+ e.g.
+ <programlisting>
+ instance C2 Int a => C3 [a] b</programlisting>
+ For more details, see <xref linkend="instance-rules" />.
+ </para>
+ </listitem>
+ <listitem>
+ <para>
The following flags (and, where appropriate, their inverses)
used to be static (can only be given on
the command line) but are now dynamic (can also be given in
</listitem>
<listitem>
<para>
- The equality test performed when pattern matching against
- an overloaded numeric literal now uses the
+ When the <option>-fno-implicit-prelude</option> is given,
+ the equality test performed when pattern matching against an
+ overloaded numeric literal now uses the
<literal>(==)</literal> in scope, rather than the one from
<literal>Prelude</literal>. Likewise, the subtraction and
inequality test performed when pattern matching against
</listitem>
<listitem>
<para>
- With the exception of the arrow syntax, the types of functions
- used by sugar (such as do notation, numeric literal patterns)
- need not match the types of the <literal>Prelude</literal>
- functions normally used.
- </para>
- </listitem>
- <listitem>
- <para>
- GADTs can now use record syntax. Also, if the datatype could
- have been declared with Haskell 98 syntax then deriving
- clauses are permitted. For more info see <xref linkend="gadt" />.
- </para>
- </listitem>
- <listitem>
- <para>
- There is a new pragma <literal>LANGUAGE</literal> which allows
- extensions to be specified portably, i.e. without having to
- resort to the <literal>OPTIONS_GHC</literal> pragma and giving
- GHC-specific options. The arguments to the pragma are the same
- extensions that Cabal knows about. More info in
- <xref linkend="language-pragma" />.
- </para>
- </listitem>
- <listitem>
- <para>
- GHC now allows more generalisation when typing mutually
- recursive bindings, resulting in more programs being accepted.
- See <xref linkend="typing-binds" /> for more details.
+ Another change to <option>-fno-implicit-prelude</option>:
+ with the exception of the arrow syntax, the types of
+ functions used by sugar (such as do notation, numeric
+ literal patterns) need not match the types of the
+ <literal>Prelude</literal> functions normally used.
</para>
</listitem>
<listitem>
</listitem>
<listitem>
<para>
- GHC now treats source files as UTF-8 (ASCII is a strict
- subset of UTF-8, so ASCII source files will continue to
- work as before). However, invalid UTF-8 sequences are
- ignored in comments, so ASCII code with comments in, for
- example, Latin-1 will also work.
- </para>
- </listitem>
- <listitem>
- <para>
- When you use <command>ghc --make</command>, GHC will now take
- the executable filename from the name of the file containing
- the <literal>Main</literal> module rather than using
- <filename>a.out</filename>. The <filename>.exe</filename>
- extension is appended on Windows, and it can of course be
- overridden with <option>-o</option>.
- </para>
- </listitem>
- <listitem>
- <para>
If you <literal>newtype</literal> the IO monad, e.g.
<programlisting>
newtype MyIO a = MyIO (IO a)</programlisting>
</listitem>
<listitem>
<para>
- GHC now includes the package name in symbol names; the upshot
- of this is that it is possible to link a program that uses
- multiple packages each containing a module of the same name.
- </para>
- </listitem>
- <listitem>
- <para>
- GHCi now has a <literal>:main</literal> command that allows
- you to call the <literal>main</literal> function with
- command-line arguments.
- See <xref linkend="ghci-commands" /> for more information.
- </para>
- </listitem>
- <listitem>
- <para>
- GHCi now has <literal>:ctags</literal> and
- <literal>:etags</literal> commands to generate tags files for
- vi-style and emacs-style editors respectively.
- See <xref linkend="ghci-commands" /> for more information.
- </para>
- </listitem>
- <listitem>
- <para>
- The rules for instance declarations have been further relaxed.
- You are now permitted to have instances whose heads contain
- only type variables, e.g.
- <programlisting>
- instance C a</programlisting>
- and instances whose constraints are not only type variables,
- e.g.
- <programlisting>
- instance C2 Int a => C3 [a] b</programlisting>
- For more details, see <xref linkend="instance-rules" />.
- </para>
- </listitem>
- <listitem>
- <para>
- GHCi now allows tab completion of in-scope names.
- </para>
- </listitem>
- <listitem>
- <para>
The old syntax for FFI declarations (deprecated since 5.04)
is no longer accepted.
</para>
<option>--make</option>, and hence can be used by cabal.
</para>
</listitem>
+ </itemizedlist>
+ </sect2>
+
+ <sect2>
+ <title>GHCi changes</title>
+
+ <itemizedlist>
<listitem>
<para>
- GHC now supports bang patterns to require a function is strict
- in a given argument, e.g.
- <programlisting>
- f (!x, y) = [x,y]</programlisting>
- is equivalent to
- <programlisting>
- f (x, y) | x `seq` False = undefined
- | otherwise = [x,y]</programlisting>
- </para>
- </listitem>
- <listitem>
- <para>
- GHC now handles impredicative polymorphism; see
- <ulink url="http://www.haskell.org/pipermail/glasgow-haskell-users/2006-January/009565.html"> Simon's e-mail</ulink>
- for more details.
- </para>
- </listitem>
- <listitem>
- <para>
- GHC's modules are now also bundled into a
- <literal>ghc</literal> package, allowing programs to make use
- of GHC as a library. The interface has not yet been properly
- designed, so is subject to change.
+ GHCi now allows tab completion of in-scope names and modules
+ on platforms that use readline (i.e. not Windows).
</para>
</listitem>
<listitem>
<para>
- GHC's garbage collector now deals more intelligently with
- mutable data, so you no longer need to worry about GC
- performance when a lot of memory is taken up by
- <literal>STArray</literal>s, <literal>IOArray</literal>s,
- <literal>STRef</literal>s or <literal>IORef</literal>s.
+ GHCi now has a <literal>:main</literal> command that allows
+ you to call the <literal>main</literal> function with
+ command-line arguments.
+ See <xref linkend="ghci-commands" /> for more information.
</para>
</listitem>
<listitem>
<para>
- GHC now supports SMP:
- when you compile with <option>-threaded</option>, you now get
- an RTS flag <option>-N</option> that allows you to specify the
- number of OS threads that GHC should use. Defaults to 1.
+ GHCi now has <literal>:ctags</literal> and
+ <literal>:etags</literal> commands to generate tags files for
+ vi-style and emacs-style editors respectively.
+ See <xref linkend="ghci-commands" /> for more information.
</para>
</listitem>
</itemizedlist>
projects / ghc-hetmet.git / commitdiff