ghc/docs/users_guide/6.0-notes.sgml

   1 <sect1 id="release-6-0">
   2   <title>Release notes for version 6.0</title>
   3
   4   <sect2>
   5     <title>User-visible compiler changes</title>
   6     <itemizedlist>
   7       <listitem>
   8         <para>Template Haskell, a new feature for compile-time
   9         metaprogramming has been introduced.  See <xref
  10         linkend="template-haskell">.</para>
  11       </listitem>
  12       <listitem>
  13         <para>INLINE pragmas on methods in class or instance
  14         declarations now work properly.</para>
  15       </listitem>
  16       <listitem>
  17         <para>Recursive do-notation (aka <literal>mdo</literal>) is
  18         now supported.  See <xref linkend="mdo-notation">.</para>
  19       </listitem>
  20       <listitem>
  21         <para>There is now a native code generator for PowerPC
  22         platforms.</para>
  23       </listitem>
  24       <listitem>
  25         <para>Profiling: the <option>-xt</option> RTS option enables
  26         inclusion of thread stacks in a heap profile.  See <xref
  27         linkend="rts-options-heap-prof">.</para>
  28       </listitem>
  29       <listitem>
  30         <para>Non-blocking I/O is now supported on Windows.</para>
  31       </listitem>
  32       <listitem>
  33         <para>The <ulink url="../base/Data.Dynamic.html#Typeable"><literal>Typeable</literal></ulink> class can now be
  34         derived, and the implementation of <literal>Typeable</literal>
  35         is now more efficient.</para>
  36       </listitem>
  37     </itemizedlist>
  38   </sect2>
  39
  40   <sect2>
  41     <title>User-visible interpreter (GHCi) changes</title>
  42     <itemizedlist>
  43       <listitem>
  44         <para>Loading a <literal>Main</literal> module that does not
  45         define <literal>main</literal> is no longer an error, although
  46         GHCi will still emit a warning in this case.</para>
  47       </listitem>
  48     </itemizedlist>
  49   </sect2>
  50
  51   <sect2>
  52     <title>User-visible library changes</title>
  53     <itemizedlist>
  54       <listitem>
  55         <para>Hierarchical libraries are now available without needing
  56         to specify an explicit <option>-package</option> flag.  There
  57         are some exceptions to this rule (see <xref
  58         linkend="using-packages">), but if you stick to GHCi and
  59         <option>--make</option> mode then there will normally be no
  60         need to specify <option>-package</option> options at
  61         all.</para>
  62
  63         <para>Non-hierarchical libraries
  64         (i.e. <literal>hslibs</literal> libraries) still need to be
  65         explicitly requested with <option>-package</option>
  66         options.</para>
  67       </listitem>
  68
  69       <listitem>
  70         <para>The <literal>Posix</literal> library has been rewritten.
  71         It is now a hierarchical library rooted at
  72         <literal>System.Posix</literal>, and has some additions aimed
  73         at supporting the latest revision of the POSIX standard (IEEE
  74         Std 1003.1-2001).  See the <ulink
  75         url="../unix/index.html"><literal>unix</literal>
  76         package</ulink> for details.</para>
  77
  78         <para>The old <literal>posix</literal> package is still
  79         available for backwards compatibility, but is deprecated and
  80         will be removed in a future release.</para>
  81       </listitem>
  82
  83       <listitem>
  84         <para><ulink url="../base/Data.IORef.html"><literal>Data.IORef</literal></ulink>: Added <literal>atomicModifyIORef</literal>.</para>
  85       </listitem>
  86
  87       <listitem>
  88         <para><ulink url="../base/System.Cmd.html"><literal>System.Cmd</literal></ulink>: Added <literal>rawSystem</literal>.</para>
  89       </listitem>
  90
  91       <listitem>
  92         <para><ulink
  93         url="../base/System.Environment.html"><literal>System.Environment</literal></ulink>:
  94         Added <literal>withArgs</literal> and <literal>withProgName</literal>.</para>
  95       </listitem>
  96
  97       <listitem>
  98         <para><ulink
  99         url="../network/Network.Socket.html"><literal>Network.Socket</literal></ulink>:
 100         Added <literal>sendFd</literal> and <literal>recvFd</literal>.</para>
 101       </listitem>
 102
 103       <listitem>
 104         <para>The <literal>Readline</literal> library has moved to
 105         <ulink
 106         url="../readline/System.Console.Readline.html"><literal>System.Console.Readline</literal></ulink>,
 107         and is in a package of its own
 108         (<literal>readline</literal>).</para>
 109       </listitem>
 110
 111       <listitem>
 112         <para>The non-hierarchical versions of the FFI libraries are
 113         now all available without needing to specify <literal>-package
 114         lang</literal> (they are actually now in the
 115         <literal>haskell98</literal> package, which is available by
 116         default).</para>
 117       </listitem>
 118
 119       <listitem>
 120         <para><ulink
 121         url="../network/Network.BSD.html"><literal>Network.BSD</literal></ulink>:
 122         <literal>symlink</literal> and <literal>readline</literal> are
 123         now deprecated; use
 124         <literal>System.Posix.createSymbolicLink</literal> and
 125         <literal>System.Posix.readSymbolicLink</literal>
 126         respectively.</para>
 127       </listitem>
 128
 129       <listitem>
 130         <para><ulink
 131         url="../base/Control.Exception.html"><literal>Control.Exception</literal></ulink>:
 132         Added <literal>mapException</literal>.</para>
 133       </listitem>
 134
 135       <listitem>
 136         <para><ulink
 137         url="../base/Data.Dynamic.html"><literal>Data.Dynamic</literal></ulink>:
 138         various changes to make the implementation of
 139         <literal>Typeable</literal> more efficient.  This entails some
 140         changes to the interface, and affects how instances of
 141         <literal>Typeable</literal> are defined.</para>
 142       </listitem>
 143
 144       <listitem>
 145         <para><ulink
 146         url="../base/Data.Tree.html"><literal>Data.Tree</literal></ulink>
 147         is a new library for trees.</para>
 148       </listitem>
 149
 150       <listitem>
 151         <para><ulink
 152         url="../base/Data.Graph.html"><literal>Data.Graph</literal></ulink>
 153         is a new library for graphs.</para>
 154       </listitem>
 155
 156       <listitem>
 157         <para><ulink
 158         url="../base/System.IO.html"><literal>System.IO</literal></ulink>:
 159         Removed <literal>bracket</literal> and
 160         <literal>bracket_</literal> (use the versions from
 161         <literal>Control.Exception</literal> instead).</para>
 162       </listitem>
 163
 164       <listitem>
 165         <para><ulink
 166         url="../base/System.IO.html"><literal>System.IO</literal></ulink>:
 167         The <literal>IOError</literal> type is now a synonym for
 168         <literal>IOException</literal>, whereas previously it was a
 169         synonym for <literal>Exception</literal>.  This has various
 170         consequences, one of which is that the types of
 171         <literal>System.IO.catch</literal> and
 172         <literal>Control.Exception.catch</literal> are now different
 173         (useful, because they do different things).</para>
 174       </listitem>
 175
 176       <listitem>
 177         <para><ulink
 178         url="../base/System.IO.Error.html"><literal>System.IO.Error</literal></ulink>:
 179         added <literal>annotateIOError</literal>,
 180         <literal>modifyIOError</literal>, and <literal>ioeSet{ErrorType,ErrorString,Handle,FileName}</literal>.</para>
 181       </listitem>
 182
 183       <listitem>
 184         <para><ulink
 185         url="../base/Text.ParserCombinators.ReadP.html"><literal>Text.ParserCombinators.ReadP</literal></ulink>:
 186         lots of updates.</para>
 187       </listitem>
 188
 189       <listitem>
 190         <para><literal>Control.Monad.Monoid</literal> is now <ulink url="../base/Data.Monoid.html"><literal>Data.Monoid</literal></ulink>.</para>
 191       </listitem>
 192
 193       <listitem>
 194         <para><ulink
 195         url="../base/Data.PackedString.html"><literal>Data.PackedString</literal></ulink>:
 196         added <literal>joinPS</literal>, <literal>unwordsPS</literal>
 197         and <literal>unlinesPS</literal>.</para>
 198       </listitem>
 199
 200       <listitem>
 201         <para><ulink
 202         url="../base/Data.HashTable.html"><literal>Data.HashTable</literal></ulink>
 203         is a new dynamic hash-table implementation.</para>
 204       </listitem>
 205
 206       <listitem>
 207         <para>Added <ulink
 208         url="../unix/System.Sendfile.html"><literal>System.Sendfile</literal></ulink>.</para>
 209       </listitem>
 210
 211       <listitem>
 212         <para>Added <ulink
 213         url="../base/Foreign.Marshal.Pool.html"><literal>Foreign.Marshal.Pool</literal></ulink>.</para>
 214       </listitem>
 215
 216       <listitem>
 217         <para><ulink
 218         url="../base/Data.Bits.html"><literal>Data.Bits</literal></ulink>:
 219         <literal>shiftL</literal>, <literal>shiftR</literal>,
 220         <literal>rotateL</literal>, and <literal>rotateR</literal> are
 221         now methods of the <literal>Bite</literal> class.</para>
 222       </listitem>
 223
 224       <listitem>
 225         <para>The FFI libraries now conform to the latest version of
 226         the FFI spec:</para>
 227         <itemizedlist>
 228           <listitem>
 229             <para>Added <ulink
 230             url="../base/Foreign.ForeignPtr.html#mallocForeignPtr"><literal>Foreign.ForeignPtr.mallocForeignPtr</literal></ulink>
 231             and friends.</para>
 232           </listitem>
 233           <listitem>
 234             <para>Finalizers added to a <literal>ForeignPtr</literal>
 235             with <literal>addForeignPtrFinalizer</literal> are now run
 236             in strict order; namely the reverse of the order they were
 237             added.</para>
 238           </listitem>
 239           <listitem>
 240             <para><literal>Foreign.C.TypesISO</literal> has been
 241             merged into <ulink
 242             url="../base/Foreign.C.Types.html"><literal>Foreign.C.Types</literal></ulink>.</para>
 243           </listitem>
 244         </itemizedlist>
 245       </listitem>
 246     </itemizedlist>
 247   </sect2>
 248
 249   <sect2>
 250     <title>Experimental features</title>
 251     <itemizedlist>
 252       <listitem>
 253         <para>The <literal>Data</literal> class provides for generic
 254         data traversals and folds; see <ulink
 255         url="../base/Data.Generics.html"><literal>Data.Generics</literal></ulink>.
 256         <literal>Data</literal> can be derived for arbitrary
 257         datatypes.  The <literal>Data</literal> class is still
 258         experimental, so its contents may change in the future.</para>
 259       </listitem>
 260       <listitem>
 261         <para>Several bugs have been fixed in the threaded RTS, and it
 262         should now be rather more robust (it should still be
 263         considered experimental, however).</para>
 264       </listitem>
 265     </itemizedlist>
 266   </sect2>
 267
 268   <sect2>
 269     <title>Internal changes</title>
 270     <itemizedlist>
 271       <listitem>
 272         <para>Sweeping changes to the compiler and runtime system to
 273         change the evaluation model from <quote>push/enter</quote> to
 274         <quote>eval/apply</quote>.  The bottom line is that the
 275         compiler is now more portable and some of the complexity is
 276         now more centralised, while performance and binary sizes
 277         remain about the same.</para>
 278
 279         <para>A paper describing these changes can be found <ulink
 280         url="http://research.microsoft.com/~simonpj/papers/eval-apply">here</ulink>.</para>
 281       </listitem>
 282       <listitem>
 283         <para>The test suite is now driven by a Python script and is
 284         rather more flexible and robust.  It now supports building
 285         tests several different "ways", and as a result we now run
 286         each test with optimisation, profiling, native code
 287         generation, and GHCi in addition to the vanilla way.</para>
 288       </listitem>
 289       <listitem>
 290         <para>The build system now supports bootstrapping the compiler
 291         in a single build tree.  By default, typing
 292         <literal>make</literal> at the top level will bootstrap the
 293         compiler once to create a stage-2 compiler.  See the Building
 294         Guide for more details.</para>
 295       </listitem>
 296       <listitem>
 297         <para>The RTS debugging flags are no longer represented by a
 298         bitfield and now have single-character names.  For example, to
 299         turn on scheduler debugging output, use <literal>-Ds</literal>
 300         rather than <literal>-D1</literal>.</para>
 301       </listitem>
 302       <listitem>
 303         <para>The compiler no longer requires any packages from
 304         <literal>hslibs</literal> to bootstrap.  It is enough to
 305         compile <literal>fptools/libraries</literal> before building
 306         the stage 2 compiler.</para>
 307       </listitem>
 308     </itemizedlist>
 309   </sect2>
 310
 311 </sect1>
 312
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