ghc/docs/users_guide/4-07-notes.sgml

   1 <sect1 id="release-4-07">
   2   <title>Release notes for version 4.07 (May 2000)</title>
   3
   4   <sect2>
   5     <title>User-visible compiler changes</title>
   6
   7     <itemizedlist>
   8       <listitem>
   9         <para>New profiling subsystem, based on cost-centre stacks.
  10         See <xref linkend="profiling">.</para>
  11       </listitem>
  12
  13       <listitem>
  14         <para>The x86 native code generator has been reworked
  15         considerably, and now works reliably.  Using the NCG rather
  16         than compiling via C reduces compilation times by roughly a
  17         half while having minimal effect on the run-time of the
  18         compiled program (about 2-4% slower, worse for floating-point
  19         intensive programs).</para>
  20
  21         <para>Add the <option>-fasm-x86</option> flag to GHC's command
  22         line to enable it.</para>
  23       </listitem>
  24
  25       <listitem>
  26         <para>Implicit parameters.</para>
  27       </listitem>
  28
  29       <listitem>
  30         <para>Functional dependencies.</para>
  31       </listitem>
  32
  33       <listitem>
  34         <para>New <literal>DEPRECATED</literal> pragma for marking
  35         outdated interfaces as deprecated.</para>
  36       </listitem>
  37
  38       <listitem>
  39         <para>New flag: <option>-fdump-minimal-imports</option>, which
  40         dumps a file <literal>M.imports</literal> that contains the
  41         (allegedly) minimal bunch of imports needed by the current
  42         module.</para>
  43       </listitem>
  44
  45       <listitem>
  46         <para>New &ldquo;package&rdquo; system for libraries.  See
  47         <xref linkend="packages"> for the details.</para>
  48       </listitem>
  49
  50       <listitem>
  51         <para>The long-standing bug that caused some programs which
  52         used <link linkend="trace"><literal>trace</literal></link> to
  53         exit with a deadlock error has been fixed.</para>
  54       </listitem>
  55
  56       <listitem>
  57         <para>Trying to put into a full <link
  58         linkend="sec-MVars"><literal>MVar</literal></link> will now
  59         raise a <link
  60         linkend="PutFullMVar"><literal>PutFullMVar</literal></link>
  61         exception.</para>
  62       </listitem>
  63
  64       <listitem>
  65         <para>If a thread is about to be garbage collected, because it
  66         is waiting on an <literal>MVar</literal> that no other thread
  67         has access to, then it will now be sent the <link
  68         linkend="BlockedOnDeadMVar"><literal>BlockedOnDeadMVar</literal></link>
  69         exception.</para>
  70       </listitem>
  71
  72       <listitem>
  73         <para>A thread that is found to be blocked against itself
  74         (i.e. is black holed) is now sent a
  75         <literal>NonTermination</literal> exception.</para>
  76       </listitem>
  77
  78       <listitem>
  79         <para>Operations which may <emphasis>block</emphasis>, such as
  80         <literal>takeMVar</literal>, <literal>raiseInThread</literal>,
  81         and several I/O operations, may now receive asynchronous
  82         exceptions even in the scope of a
  83         <literal>blockAsyncExceptions</literal>.  These are called
  84         <firstterm>interruptible</firstterm> operations.  See <xref
  85         linkend="interruptible-operations"> for more details.</para>
  86       </listitem>
  87
  88       <listitem>
  89         <para>Result type signatures now work.</para>
  90       </listitem>
  91
  92       <listitem>
  93         <para>A truckload of bugfixes.</para>
  94       </listitem>
  95
  96     </itemizedlist>
  97   </sect2>
  98
  99   <sect2>
 100     <title>User-visible library changes</title>
 101
 102     <itemizedlist>
 103       <listitem>
 104         <para>The FFI has been revised and expanded; see <xref
 105         linkend="sec-Foreign"> and <xref linkend="sec-CTypes">.</para>
 106       </listitem>
 107
 108       <listitem>
 109         <para>HaXml, a library for parsing and generating XML, has
 110         been added to the <literal>text</literal> package (<xref
 111         linkend="sec-haxml">).</para>
 112       </listitem>
 113
 114       <listitem>
 115         <para>The <literal>QuickCheck</literal> library for performing
 116         functional testing has been added to the
 117         <literal>util</literal> package.</para>
 118       </listitem>
 119
 120       <listitem>
 121         <para>Two new experimental interfaces to arrays:
 122         <literal>IArray</literal> for immutable arrays (<xref
 123         linkend="sec-iarray">), and <literal>MArray</literal> for
 124         mutable arrays (<xref linkend="sec-marray">).</para>
 125
 126         <para>Comments on these interfaces are welcome; eventually
 127         we'd like them to replace <literal>ByteArray</literal>,
 128         <literal>STArray</literal> and
 129         <literal>IOArray</literal>.</para>
 130       </listitem>
 131
 132       <listitem>
 133         <para>New function: <link
 134         linkend="tryTakeMVar"><literal>tryTakeMVar</literal></link>.</para>
 135       </listitem>
 136
 137       <listitem>
 138         <para><literal>MutableArray</literal> has gone away, use
 139         <literal>STArray</literal> (see <xref linkend="sec-ST">)
 140         instead.</para>
 141       </listitem>
 142
 143       <listitem>
 144         <para><literal>hPutBuf</literal>,
 145         <literal>hPutBufBA</literal>, <literal>hGetBuf</literal>, and
 146         <literal>hGetBufBA</literal>, have been renamed to
 147         <literal>hPutBufFull</literal>,
 148         <literal>hPutBufBAFull</literal>,
 149         <literal>hGetBufFull</literal>, and
 150         <literal>hGetBufBAFull</literal>.  Functions with the old
 151         names still exist, but have slightly different semantics.  See
 152         <xref linkend="sec-bulk-transfers"> for more details.</para>
 153       </listitem>
 154     </itemizedlist>
 155   </sect2>
 156
 157   <sect2>
 158     <title>Internal changes</title>
 159
 160     <itemizedlist>
 161       <listitem>
 162         <para><literal>Con</literal> is gone; the
 163         <literal>CoreExpr</literal> type is simpler.</para>
 164       </listitem>
 165
 166       <listitem>
 167         <para><literal>NoRepLits</literal> have gone.</para>
 168       </listitem>
 169
 170       <listitem>
 171         <para>Better usage info in interface files, which means less
 172         recompilation.</para>
 173       </listitem>
 174
 175       <listitem>
 176         <para>CCall primop is tidied up.</para>
 177       </listitem>
 178
 179       <listitem>
 180         <para>Constant folding now done by Rules.</para>
 181       </listitem>
 182
 183       <listitem>
 184         <para>Lots of hackery in the simplifier.</para>
 185       </listitem>
 186
 187       <listitem>
 188         <para>Improvements in CPR and strictness analysis.</para>
 189       </listitem>
 190
 191     </itemizedlist>
 192
 193   </sect2>
 194
 195 </sect1>
 196
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