From 9e6e935df0583fa761148a659181813ca532cb56 Mon Sep 17 00:00:00 2001 From: Damien George Date: Wed, 26 Mar 2014 18:37:06 +0000 Subject: [PATCH] py: Add support for user-defined iterators via __iter__, __next__. --- py/obj.h | 2 +- py/objexcept.c | 42 +++++++++++++++++++++++------------------- py/objtype.c | 4 ++-- py/qstrdefs.h | 1 + py/runtime.c | 28 +++++++++++++++++++++------- py/vm.c | 10 ++++++++++ 6 files changed, 58 insertions(+), 29 deletions(-) diff --git a/py/obj.h b/py/obj.h index b52b5a0c7e..dd728c9c2f 100644 --- a/py/obj.h +++ b/py/obj.h @@ -261,7 +261,7 @@ mp_obj_t mp_obj_new_module(qstr module_name); mp_obj_type_t *mp_obj_get_type(mp_obj_t o_in); const char *mp_obj_get_type_str(mp_obj_t o_in); -bool mp_obj_is_subclass_fast(mp_obj_t object, mp_obj_t classinfo); // arguments should be type objects +bool mp_obj_is_subclass_fast(mp_const_obj_t object, mp_const_obj_t classinfo); // arguments should be type objects void mp_obj_print_helper(void (*print)(void *env, const char *fmt, ...), void *env, mp_obj_t o_in, mp_print_kind_t kind); void mp_obj_print(mp_obj_t o, mp_print_kind_t kind); diff --git a/py/objexcept.c b/py/objexcept.c index 0650920e7d..79b85b28b7 100644 --- a/py/objexcept.c +++ b/py/objexcept.c @@ -202,44 +202,48 @@ mp_obj_t mp_obj_new_exception_msg_varg(const mp_obj_type_t *exc_type, const char } // return true if the given object is an exception type -// TODO make this work for user defined exceptions bool mp_obj_is_exception_type(mp_obj_t self_in) { if (MP_OBJ_IS_TYPE(self_in, &mp_type_type)) { + // optimisation when self_in is a builtin exception mp_obj_type_t *self = self_in; - return self->make_new == mp_obj_exception_make_new; - } else { - return false; + if (self->make_new == mp_obj_exception_make_new) { + return true; + } } + return mp_obj_is_subclass_fast(self_in, &mp_type_BaseException); } // return true if the given object is an instance of an exception type -// TODO make this work for user defined exceptions bool mp_obj_is_exception_instance(mp_obj_t self_in) { - return mp_obj_get_type(self_in)->make_new == mp_obj_exception_make_new; + return mp_obj_is_exception_type(mp_obj_get_type(self_in)); } void mp_obj_exception_clear_traceback(mp_obj_t self_in) { // make sure self_in is an exception instance - assert(mp_obj_get_type(self_in)->make_new == mp_obj_exception_make_new); - mp_obj_exception_t *self = self_in; + // TODO add traceback information to user-defined exceptions (need proper builtin subclassing for that) + if (mp_obj_get_type(self_in)->make_new == mp_obj_exception_make_new) { + mp_obj_exception_t *self = self_in; - // just set the traceback to the null object - // we don't want to call any memory management functions here - self->traceback = MP_OBJ_NULL; + // just set the traceback to the null object + // we don't want to call any memory management functions here + self->traceback = MP_OBJ_NULL; + } } void mp_obj_exception_add_traceback(mp_obj_t self_in, qstr file, machine_uint_t line, qstr block) { // make sure self_in is an exception instance - assert(mp_obj_get_type(self_in)->make_new == mp_obj_exception_make_new); - mp_obj_exception_t *self = self_in; + // TODO add traceback information to user-defined exceptions (need proper builtin subclassing for that) + if (mp_obj_get_type(self_in)->make_new == mp_obj_exception_make_new) { + mp_obj_exception_t *self = self_in; - // for traceback, we are just using the list object for convenience, it's not really a list of Python objects - if (self->traceback == MP_OBJ_NULL) { - self->traceback = mp_obj_new_list(0, NULL); + // for traceback, we are just using the list object for convenience, it's not really a list of Python objects + if (self->traceback == MP_OBJ_NULL) { + self->traceback = mp_obj_new_list(0, NULL); + } + mp_obj_list_append(self->traceback, (mp_obj_t)(machine_uint_t)file); + mp_obj_list_append(self->traceback, (mp_obj_t)(machine_uint_t)line); + mp_obj_list_append(self->traceback, (mp_obj_t)(machine_uint_t)block); } - mp_obj_list_append(self->traceback, (mp_obj_t)(machine_uint_t)file); - mp_obj_list_append(self->traceback, (mp_obj_t)(machine_uint_t)line); - mp_obj_list_append(self->traceback, (mp_obj_t)(machine_uint_t)block); } void mp_obj_exception_get_traceback(mp_obj_t self_in, machine_uint_t *n, machine_uint_t **values) { diff --git a/py/objtype.c b/py/objtype.c index 4898c5ccb4..9cb29744c7 100644 --- a/py/objtype.c +++ b/py/objtype.c @@ -469,7 +469,7 @@ mp_obj_t mp_obj_new_super(mp_obj_t type, mp_obj_t obj) { // object and classinfo should be type objects // (but the function will fail gracefully if they are not) -bool mp_obj_is_subclass_fast(mp_obj_t object, mp_obj_t classinfo) { +bool mp_obj_is_subclass_fast(mp_const_obj_t object, mp_const_obj_t classinfo) { for (;;) { if (object == classinfo) { return true; @@ -482,7 +482,7 @@ bool mp_obj_is_subclass_fast(mp_obj_t object, mp_obj_t classinfo) { return false; } - mp_obj_type_t *self = object; + const mp_obj_type_t *self = object; // for a const struct, this entry might be NULL if (self->bases_tuple == MP_OBJ_NULL) { diff --git a/py/qstrdefs.h b/py/qstrdefs.h index 44c61002a6..1c8afe797d 100644 --- a/py/qstrdefs.h +++ b/py/qstrdefs.h @@ -17,6 +17,7 @@ Q(__repl_print__) Q(__bool__) Q(__len__) +Q(__iter__) Q(__getitem__) Q(__setitem__) Q(__add__) diff --git a/py/runtime.c b/py/runtime.c index 0f5d1229f2..3e0ef98d8b 100644 --- a/py/runtime.c +++ b/py/runtime.c @@ -925,15 +925,21 @@ mp_obj_t rt_getiter(mp_obj_t o_in) { if (type->getiter != NULL) { return type->getiter(o_in); } else { - // check for __getitem__ method + // check for __iter__ method mp_obj_t dest[2]; - rt_load_method_maybe(o_in, MP_QSTR___getitem__, dest); + rt_load_method_maybe(o_in, MP_QSTR___iter__, dest); if (dest[0] != MP_OBJ_NULL) { - // __getitem__ exists, create an iterator - return mp_obj_new_getitem_iter(dest); + // __iter__ exists, call it and return its result + return rt_call_method_n_kw(0, 0, dest); } else { - // object not iterable - nlr_jump(mp_obj_new_exception_msg_varg(&mp_type_TypeError, "'%s' object is not iterable", mp_obj_get_type_str(o_in))); + rt_load_method_maybe(o_in, MP_QSTR___getitem__, dest); + if (dest[0] != MP_OBJ_NULL) { + // __getitem__ exists, create an iterator + return mp_obj_new_getitem_iter(dest); + } else { + // object not iterable + nlr_jump(mp_obj_new_exception_msg_varg(&mp_type_TypeError, "'%s' object is not iterable", mp_obj_get_type_str(o_in))); + } } } } @@ -943,7 +949,15 @@ mp_obj_t rt_iternext(mp_obj_t o_in) { if (type->iternext != NULL) { return type->iternext(o_in); } else { - nlr_jump(mp_obj_new_exception_msg_varg(&mp_type_TypeError, "'%s' object is not an iterator", mp_obj_get_type_str(o_in))); + // check for __next__ method + mp_obj_t dest[2]; + rt_load_method_maybe(o_in, MP_QSTR___next__, dest); + if (dest[0] != MP_OBJ_NULL) { + // __next__ exists, call it and return its result + return rt_call_method_n_kw(0, 0, dest); + } else { + nlr_jump(mp_obj_new_exception_msg_varg(&mp_type_TypeError, "'%s' object is not an iterator", mp_obj_get_type_str(o_in))); + } } } diff --git a/py/vm.c b/py/vm.c index 22243c403e..8ae619f9be 100644 --- a/py/vm.c +++ b/py/vm.c @@ -124,6 +124,7 @@ mp_vm_return_kind_t mp_execute_byte_code_2(const byte *code_info, const byte **i // outer exception handling loop for (;;) { +outer_dispatch_loop: if (nlr_push(&nlr) == 0) { // If we have exception to inject, now that we finish setting up // execution context, raise it. This works as if RAISE_VARARGS @@ -642,6 +643,15 @@ unwind_return: } else { // exception occurred + // check if it's a StopIteration within a for block + if (*save_ip == MP_BC_FOR_ITER && mp_obj_is_subclass_fast(mp_obj_get_type(nlr.ret_val), &mp_type_StopIteration)) { + ip = save_ip + 1; + DECODE_ULABEL; // the jump offset if iteration finishes; for labels are always forward + --sp; // pop the exhausted iterator + ip += unum; // jump to after for-block + goto outer_dispatch_loop; // continue with dispatch loop + } + // set file and line number that the exception occurred at // TODO: don't set traceback for exceptions re-raised by END_FINALLY. // But consider how to handle nested exceptions.