implement axis keyword of transpose

code/ndarray.c

@@ -1874,11 +1874,16 @@ mp_obj_t ndarray_unary_op(mp_unary_op_t op, mp_obj_t self_in) {
 #endif /* NDARRAY_HAS_UNARY_OPS */
 
 #if NDARRAY_HAS_TRANSPOSE
-mp_obj_t ndarray_transpose(mp_obj_t self_in) {
+// We have to implement the T property separately, for the property can't take keyword arguments
+
 #if ULAB_MAX_DIMS == 1
+// isolating the one-dimensional case saves space, because the transpose is sort of meaningless 
+mp_obj_t ndarray_T(mp_obj_t self_in) {
     return self_in;
-    #endif
+}
-    // TODO: check, what happens to the offset here, if we have a view
+#else
+mp_obj_t ndarray_T(mp_obj_t self_in) {
+    // without argument, simply return a view with axes in reverse order
     ndarray_obj_t *self = MP_OBJ_TO_PTR(self_in);
     if(self->ndim == 1) {
         return self_in;
@@ -1889,13 +1894,90 @@ mp_obj_t ndarray_transpose(mp_obj_t self_in) {
         shape[ULAB_MAX_DIMS - 1 - i] = self->shape[ULAB_MAX_DIMS - self->ndim + i];
         strides[ULAB_MAX_DIMS - 1 - i] = self->strides[ULAB_MAX_DIMS - self->ndim + i];
     }
-    // TODO: I am not sure ndarray_new_view is OK here...
+    ndarray_obj_t *ndarray = ndarray_new_view(self, self->ndim, shape, strides, 0);
-    // should be deep copy...
+    return MP_OBJ_FROM_PTR(ndarray);
+}
+#endif /* ULAB_MAX_DIMS == 1 */
+
+MP_DEFINE_CONST_FUN_OBJ_1(ndarray_T_obj, ndarray_T);
+
+# if ULAB_MAX_DIMS == 1
+// again, nothing to do, if there is only one dimension, though, the arguments might still have to be parsed...
+mp_obj_t ndarray_transpose(mp_obj_t self_in) {
+    return self_in;
+}
+
+MP_DEFINE_CONST_FUN_OBJ_1(ndarray_transpose_obj, ndarray_transpose);
+#else
+mp_obj_t ndarray_transpose(size_t n_args, const mp_obj_t *pos_args, mp_map_t *kw_args) {
+    static const mp_arg_t allowed_args[] = {
+        { MP_QSTR_, MP_ARG_REQUIRED | MP_ARG_OBJ, { .u_rom_obj = MP_ROM_NONE } },
+        { MP_QSTR_axis, MP_ARG_OBJ, { .u_rom_obj = MP_ROM_NONE } },
+    };
+
+    mp_arg_val_t args[MP_ARRAY_SIZE(allowed_args)];
+    mp_arg_parse_all(n_args, pos_args, kw_args, MP_ARRAY_SIZE(allowed_args), allowed_args, args);
+
+    ndarray_obj_t *self = MP_OBJ_TO_PTR(args[0].u_obj);
+
+    if(self->ndim == 1) {
+        return args[0].u_obj;
+    }
+
+    size_t *shape = m_new(size_t, self->ndim);
+    int32_t *strides = m_new(int32_t, self->ndim);
+    uint8_t *order = m_new(uint8_t, self->ndim);
+
+    mp_obj_t axis = args[1].u_obj;
+
+    if(axis == mp_const_none) {
+        // simply swap the order of the axes
+        for(uint8_t i = 0; i < self->ndim; i++) {
+            order[i] = self->ndim - 1 - i;
+        }
+    } else {
+        if(!mp_obj_is_type(axis, &mp_type_tuple)) {
+            mp_raise_TypeError(MP_ERROR_TEXT("keyword argument must be tuple of integers"));
+        }
+        // start with the straight array, and then swap only those specified in the argument
+        for(uint8_t i = 0; i < self->ndim; i++) {
+            order[i] = i;
+        }
+
+        mp_obj_tuple_t *axes = MP_OBJ_TO_PTR(axis);
+
+        if(axes->len > self->ndim) {
+            mp_raise_ValueError(MP_ERROR_TEXT("too many axes specified"));
+        }
+
+        for(uint8_t i = 0; i < axes->len; i++) {
+            int32_t ax = mp_obj_get_int(axes->items[i]);
+            if((ax >= self->ndim) || (ax < 0)) {
+                mp_raise_ValueError(MP_ERROR_TEXT("axis index out of bounds"));
+            } else {
+                order[i] = (uint8_t)ax;
+                // TODO: check that no two identical numbers appear in the tuple
+                for(uint8_t j = 0; j < i; j++) {
+                    if(order[i] == order[j]) {
+                        mp_raise_ValueError(MP_ERROR_TEXT("repeated indices"));
+                    }
+                }
+            }
+        }
+    }
+
+    uint8_t axis_offset = ULAB_MAX_DIMS - self->ndim;
+    for(uint8_t i = 0; i < self->ndim; i++) {
+        shape[axis_offset + i] = self->shape[axis_offset + order[i]];
+        strides[axis_offset + i] = self->strides[axis_offset + order[i]];
+    }
+
     ndarray_obj_t *ndarray = ndarray_new_view(self, self->ndim, shape, strides, 0);
     return MP_OBJ_FROM_PTR(ndarray);
 }
 
-MP_DEFINE_CONST_FUN_OBJ_1(ndarray_transpose_obj, ndarray_transpose);
+MP_DEFINE_CONST_FUN_OBJ_KW(ndarray_transpose_obj, 1, ndarray_transpose);
+#endif /* ULAB_MAX_DIMS == 1 */
 #endif /* NDARRAY_HAS_TRANSPOSE */
 
 #if ULAB_MAX_DIMS > 1

code/ndarray.h

@@ -265,9 +265,16 @@ MP_DECLARE_CONST_FUN_OBJ_1(ndarray_tolist_obj);
 #endif
 
 #if NDARRAY_HAS_TRANSPOSE
+mp_obj_t ndarray_T(mp_obj_t );
+MP_DECLARE_CONST_FUN_OBJ_1(ndarray_T_obj);
+#if ULAB_MAX_DIMS == 1
 mp_obj_t ndarray_transpose(mp_obj_t );
 MP_DECLARE_CONST_FUN_OBJ_1(ndarray_transpose_obj);
-#endif
+#else
+mp_obj_t ndarray_transpose(size_t , const mp_obj_t *, mp_map_t *);
+MP_DECLARE_CONST_FUN_OBJ_KW(ndarray_transpose_obj);
+#endif /* ULAB_MAX_DIMS == 1 */
+#endif /* NDARRAY_HAS_TRANSPOSE */
 
 #if ULAB_NUMPY_HAS_NDINFO
 mp_obj_t ndarray_info(mp_obj_t );

code/ndarray_properties.c

@@ -64,7 +64,7 @@ void ndarray_properties_attr(mp_obj_t self_in, qstr attr, mp_obj_t *dest) {
             #endif
             #if NDARRAY_HAS_TRANSPOSE
             case MP_QSTR_T:
-                dest[0] = ndarray_transpose(self_in);
+                dest[0] = ndarray_T(self_in);
                 break;
             #endif
             #if ULAB_SUPPORTS_COMPLEX