[NCI] callback sub parameter definition isn't unified with callback definition in the C lib.

[zhuomingliang]

Hello,
see https://github.com/parrot/parrot/blob/master/src/nci_test.c#-115 , there are two define here.

typedef void (*cb_C1_func)(const char*, void*);
PARROT_DYNEXT_EXPORT void nci_cb_C1(cb_C1_func, void*);

the callback is created by:

     cb_wrapped = new_callback cb, user_data, "vtU"

which means it's first parameter is external_data, and the two is user_data. that is, the callback function should be defined as this one:

.sub _call_back
  .param string external_data
  .param pmc user_data
  print "user data: "
  print u
  print "\n"
  print "external data: "
  print s
  print "\n"
.end

but actually in t/pmc/nci.t, it's defined as:

.sub _call_back
  .param pmc user_data
  .param string external_data
  print "user data: "
  print u
  print "\n"
  print "external data: "
  print s
  print "\n"
.end

according to t/pmc/nci.t it seems that no matter user_data is the first parameter or two, the callback sub must be defined as:

.sub _call_back
  .param pmc user_data
  .param string external_data
.end

then I took a look at PDD16, and it's said user_data should be defined in the second parameter:

.sub _call_back
  .param string external_data
  .param pmc user_data
.end

which is right.

Originally http://trac.parrot.org/parrot/ticket/1992

[plobsing]

It is true that the callback parameters are inconsistent between C and PIR. However, it does mean that all callbacks defined from within parrot are consistent, regardless of dissagreements between C libraries.