#include "foo_stub.h"
#endif
-#ifdef __GLASGOW_HASKELL__
-extern void __stginit_Foo ( void );
-#endif
-
int main(int argc, char *argv[])
{
int i;
hs_init(&argc, &argv);
-#ifdef __GLASGOW_HASKELL__
- hs_add_root(__stginit_Foo);
-#endif
for (i = 0; i < 5; i++) {
printf("%d\n", foo(2500));
(i.e. those arguments between
<literal>+RTS...-RTS</literal>).</para>
- <para>Next, we call
- <function>hs_add_root</function><indexterm><primary><function>hs_add_root</function></primary>
- </indexterm>, a GHC-specific interface which is required to
- initialise the Haskell modules in the program. The argument
- to <function>hs_add_root</function> should be the name of the
- initialization function for the "root" module in your program
- - in other words, the module which directly or indirectly
- imports all the other Haskell modules in the program. In a
- standalone Haskell program the root module is normally
- <literal>Main</literal>, but when you are using Haskell code
- from a library it may not be. If your program has multiple
- root modules, then you can call
- <function>hs_add_root</function> multiple times, one for each
- root. The name of the initialization function for module
- <replaceable>M</replaceable> is
- <literal>__stginit_<replaceable>M</replaceable></literal>, and
- it may be declared as an external function symbol as in the
- code above. Note that the symbol name should be transformed
- according to the Z-encoding:</para>
-
<informaltable>
<tgroup cols="2" align="left" colsep="1" rowsep="1">
<thead>
// Initialize Haskell runtime
hs_init(&argc, &argv);
- // Tell Haskell about all root modules
- hs_add_root(__stginit_Foo);
-
// do any other initialization here and
// return false if there was a problem
return HS_BOOL_TRUE;
</programlisting>
<para>The initialisation routine, <literal>mylib_init</literal>, calls
- <literal>hs_init()</literal> and <literal>hs_add_root()</literal> as
+ <literal>hs_init()</literal> as
normal to initialise the Haskell runtime, and the corresponding
deinitialisation function <literal>mylib_end()</literal> calls
<literal>hs_exit()</literal> to shut down the runtime.</para>
invoke <literal>foreign export</literal>ed functions from
multiple OS threads concurrently. The runtime system must
be initialised as usual by
- calling <literal>hs_init()</literal>
- and <literal>hs_add_root</literal>, and these calls must
+ calling <literal>hs_init()</literal>, and this call must
complete before invoking any <literal>foreign
export</literal>ed functions.</para>
</sect3>
<title>Floating point and the FFI</title>
<para>
- On POSIX systems, the <literal>fenv.h</literal> header
+ The standard C99 <literal>fenv.h</literal> header
provides operations for inspecting and modifying the state of
the floating point unit. In particular, the rounding mode
used by floating point operations can be changed, and the