Re: Invoking guile procs from C in an efficient way

[Rob Browning]

Andreas Rottmann <address@hidden> writes:

>> SCM proc = scm_c_lookup("my_proc");
>> scm_apply(proc, argslist, SCM_EOL);
>>  
> I think it's:
>
> scm_apply(SCM_VARIABLE_REF(scm_c_lookup("my-proc")), argslist, SCM_EOL);

In some cases you can also cache the binding if you want to avoid
repeated lookups (using 1.6 interfaces):

  foo()
  {
    static SCM my_proc = SCM_BOOL_F;
    if(SCM_FALSEP(my_proc))
    {
      my_proc = scm_c_lookup("my-proc");  /* or scm_c_module_lookup */
      /* check for failure here */
      scm_permanent_object(my_proc); /* presumes you always need my_proc */
    }

    scm_apply(scm_variable_ref(my_proc), argslist, SCM_EOL);
  }

Caveats apply -- i.e. don't call this before guile is initialized,
consider synchronization issues (if we ever let multiple posix threads
call guile at the same time), etc.

-- 
Rob Browning
rlb @defaultvalue.org and @debian.org; previously @cs.utexas.edu
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