typemap: switch list -> tuple

list being mutable can't be used as dictionary keys

python/apertium_core.i

@@ -9,31 +9,31 @@
 // Wrapper on char ** for char **argv
 // Modified for python 3 from http://www.swig.org/Doc1.3/Python.html#Python_nn59
 
-%typemap(in) char ** {
-  if (PyList_Check($input)) {
-    int size = PyList_Size($input);
+%typemap(in) (int argc, char **argv) {
+  if (PyTuple_Check($input)) {
     int i = 0;
-    $1 = (char **) malloc((size+1)*sizeof(char *));
-    for (i = 0; i < size; i++) {
-      PyObject *py_obj = PyList_GetItem($input, i);
+    $1 = PyTuple_Size($input);
+    $2 = (char **) malloc(($1 + 1)*sizeof(char *));
+    for (i = 0; i < $1; i++) {
+      PyObject *py_obj = PyTuple_GetItem($input, i);
       if (PyUnicode_Check(py_obj)) {
-        $1[i] = strdup(PyUnicode_AsUTF8(py_obj));
+        $2[i] = strdup(PyUnicode_AsUTF8(py_obj));
       }
       else {
-        PyErr_SetString(PyExc_TypeError, "list must contain strings");
-        free($1);
+        PyErr_SetString(PyExc_TypeError, "tuple must contain strings");
+        free($2);
         return NULL;
       }
     }
-    $1[i] = 0;
+    $2[i] = 0;
   } else {
-    PyErr_SetString(PyExc_TypeError, "not a list");
+    PyErr_SetString(PyExc_TypeError, "not a tuple");
     return NULL;
   }
 }
 
-%typemap(freearg) char ** {
-  free((char *) $1);
+%typemap(freearg) (int argc, char **argv) {
+  free((char *) $2);
 }
 
 %inline%{
@@ -98,7 +98,7 @@ class ApertiumTransfer: public Transfer
     read(transferfile, datafile);
   }
 
-  void transfer_text(char argc, char **argv, char *input_path, char *output_path)
+  void transfer_text(int argc, char **argv, char *input_path, char *output_path)
   {
     FILE* input = fopen(input_path, "r");
     FILE* output = fopen(output_path, "w");