py/objarray.c - lite/micropython - Linaro Git Browser

 /*
  * This file is part of the Micro Python project, http://micropython.org/
  *
  * The MIT License (MIT)
  *
  * Copyright (c) 2013, 2014 Damien P. George
  * Copyright (c) 2014 Paul Sokolovsky
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
  * in the Software without restriction, including without limitation the rights
  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  * copies of the Software, and to permit persons to whom the Software is
  * furnished to do so, subject to the following conditions:
  *
  * The above copyright notice and this permission notice shall be included in
  * all copies or substantial portions of the Software.
  *
  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
  * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  * THE SOFTWARE.
  */

 #include <string.h>
 #include <assert.h>
 #include <stdint.h>

 #include "mpconfig.h"
 #include "nlr.h"
 #include "misc.h"
 #include "qstr.h"
 #include "obj.h"
 #include "runtime0.h"
 #include "runtime.h"
 #include "binary.h"

 #if MICROPY_PY_ARRAY || MICROPY_PY_BUILTINS_BYTEARRAY || MICROPY_PY_BUILTINS_MEMORYVIEW

 // About memoryview object: We want to reuse as much code as possible from
 // array, and keep the memoryview object 4 words in size so it fits in 1 GC
 // block.  Also, memoryview must keep a pointer to the base of the buffer so
 // that the buffer is not GC'd if the original parent object is no longer
 // around (we are assuming that all memoryview'able objects return a pointer
 // which points to the start of a GC chunk).  Given the above constraints we
 // do the following:
 //  - typecode high bit is set if the buffer is read-write (else read-only)
 //  - free is the offset in elements to the first item in the memoryview
 //  - len is the length in elements
 //  - items points to the start of the original buffer
 // Note that we don't handle the case where the original buffer might change
 // size due to a resize of the original parent object.

 // make (& TYPECODE_MASK) a null operation if memorview not enabled
 #if MICROPY_PY_BUILTINS_MEMORYVIEW
 #define TYPECODE_MASK (0x7f)
 #else
 #define TYPECODE_MASK (~(mp_uint_t)1)
 #endif

 typedef struct _mp_obj_array_t {
     mp_obj_base_t base;
     mp_uint_t typecode : 8;
     // free is number of unused elements after len used elements
     // alloc size = len + free
     mp_uint_t free : (8 * sizeof(mp_uint_t) - 8);
     mp_uint_t len; // in elements
     void *items;
 } mp_obj_array_t;

 STATIC mp_obj_t array_iterator_new(mp_obj_t array_in);
 STATIC mp_obj_t array_append(mp_obj_t self_in, mp_obj_t arg);
 STATIC mp_int_t array_get_buffer(mp_obj_t o_in, mp_buffer_info_t *bufinfo, mp_uint_t flags);

 /******************************************************************************/
 // array

 #if MICROPY_PY_BUILTINS_BYTEARRAY || MICROPY_PY_ARRAY
 STATIC void array_print(void (*print)(void *env, const char *fmt, ...), void *env, mp_obj_t o_in, mp_print_kind_t kind) {
     mp_obj_array_t *o = o_in;
     if (o->typecode == BYTEARRAY_TYPECODE) {
         print(env, "bytearray(b");
         mp_str_print_quoted(print, env, o->items, o->len, true);
     } else {
         print(env, "array('%c'", o->typecode);
         if (o->len > 0) {
             print(env, ", [");
             for (mp_uint_t i = 0; i < o->len; i++) {
                 if (i > 0) {
                     print(env, ", ");
                 }
                 mp_obj_print_helper(print, env, mp_binary_get_val_array(o->typecode, o->items, i), PRINT_REPR);
             }
             print(env, "]");
         }
     }
     print(env, ")");
 }
 #endif

 #if MICROPY_PY_BUILTINS_BYTEARRAY || MICROPY_PY_ARRAY
 STATIC mp_obj_array_t *array_new(char typecode, mp_uint_t n) {
     int typecode_size = mp_binary_get_size('@', typecode, NULL);
     if (typecode_size <= 0) {
         nlr_raise(mp_obj_new_exception_msg(&mp_type_ValueError, "bad typecode"));
     }
     mp_obj_array_t *o = m_new_obj(mp_obj_array_t);
     #if MICROPY_PY_BUILTINS_BYTEARRAY && MICROPY_PY_ARRAY
     o->base.type = (typecode == BYTEARRAY_TYPECODE) ? &mp_type_bytearray : &mp_type_array;
     #elif MICROPY_PY_BUILTINS_BYTEARRAY
     o->base.type = &mp_type_bytearray;
     #else
     o->base.type = &mp_type_array;
     #endif
     o->typecode = typecode;
     o->free = 0;
     o->len = n;
     o->items = m_malloc(typecode_size * o->len);
     return o;
 }
 #endif

 #if MICROPY_PY_BUILTINS_BYTEARRAY || MICROPY_PY_ARRAY
 STATIC mp_obj_t array_construct(char typecode, mp_obj_t initializer) {
     uint len;
     // Try to create array of exact len if initializer len is known
     mp_obj_t len_in = mp_obj_len_maybe(initializer);
     if (len_in == MP_OBJ_NULL) {
         len = 0;
     } else {
         len = MP_OBJ_SMALL_INT_VALUE(len_in);
     }

     mp_obj_array_t *array = array_new(typecode, len);

     mp_obj_t iterable = mp_getiter(initializer);
     mp_obj_t item;
     mp_uint_t i = 0;
     while ((item = mp_iternext(iterable)) != MP_OBJ_STOP_ITERATION) {
         if (len == 0) {
             array_append(array, item);
         } else {
             mp_binary_set_val_array(typecode, array->items, i++, item);
         }
     }

     return array;
 }
 #endif

 #if MICROPY_PY_ARRAY
 STATIC mp_obj_t array_make_new(mp_obj_t type_in, mp_uint_t n_args, mp_uint_t n_kw, const mp_obj_t *args) {
     mp_arg_check_num(n_args, n_kw, 1, 2, false);

     // get typecode
     mp_uint_t l;
     const char *typecode = mp_obj_str_get_data(args[0], &l);

     if (n_args == 1) {
         // 1 arg: make an empty array
         return array_new(*typecode, 0);
     } else {
         // 2 args: construct the array from the given iterator
         return array_construct(*typecode, args[1]);
     }
 }
 #endif

 #if MICROPY_PY_BUILTINS_BYTEARRAY
 STATIC mp_obj_t bytearray_make_new(mp_obj_t type_in, mp_uint_t n_args, mp_uint_t n_kw, const mp_obj_t *args) {
     mp_arg_check_num(n_args, n_kw, 0, 1, false);

     if (n_args == 0) {
         // no args: construct an empty bytearray
         return array_new(BYTEARRAY_TYPECODE, 0);
     } else if (MP_OBJ_IS_SMALL_INT(args[0])) {
         // 1 arg, an integer: construct a blank bytearray of that length
         uint len = MP_OBJ_SMALL_INT_VALUE(args[0]);
         mp_obj_array_t *o = array_new(BYTEARRAY_TYPECODE, len);
         memset(o->items, 0, len);
         return o;
     } else {
         // 1 arg, an iterator: construct the bytearray from that
         return array_construct(BYTEARRAY_TYPECODE, args[0]);
     }
 }
 #endif

 #if MICROPY_PY_BUILTINS_MEMORYVIEW
 STATIC mp_obj_t memoryview_make_new(mp_obj_t type_in, mp_uint_t n_args, mp_uint_t n_kw, const mp_obj_t *args) {
     // TODO possibly allow memoryview constructor to take start/stop so that one
     // can do memoryview(b, 4, 8) instead of memoryview(b)[4:8] (uses less RAM)

     mp_arg_check_num(n_args, n_kw, 1, 1, false);

     mp_buffer_info_t bufinfo;
     mp_get_buffer_raise(args[0], &bufinfo, MP_BUFFER_READ);

     mp_obj_array_t *self = m_new_obj(mp_obj_array_t);
     self->base.type = type_in;
     self->typecode = bufinfo.typecode;
     self->free = 0;
     self->len = bufinfo.len / mp_binary_get_size('@', bufinfo.typecode, NULL); // element len
     self->items = bufinfo.buf;

     // test if the object can be written to
     if (mp_get_buffer(args[0], &bufinfo, MP_BUFFER_RW)) {
         self->typecode |= 0x80; // used to indicate writable buffer
     }

     return self;
 }
 #endif

 STATIC mp_obj_t array_unary_op(mp_uint_t op, mp_obj_t o_in) {
     mp_obj_array_t *o = o_in;
     switch (op) {
         case MP_UNARY_OP_BOOL: return MP_BOOL(o->len != 0);
         case MP_UNARY_OP_LEN: return MP_OBJ_NEW_SMALL_INT(o->len);
         default: return MP_OBJ_NULL; // op not supported
     }
 }

 STATIC mp_obj_t array_binary_op(mp_uint_t op, mp_obj_t lhs_in, mp_obj_t rhs_in) {
     switch (op) {
         case MP_BINARY_OP_EQUAL: {
             mp_buffer_info_t lhs_bufinfo;
             mp_buffer_info_t rhs_bufinfo;
             array_get_buffer(lhs_in, &lhs_bufinfo, MP_BUFFER_READ);
             if (!mp_get_buffer(rhs_in, &rhs_bufinfo, MP_BUFFER_READ)) {
                 return mp_const_false;
             }
             return MP_BOOL(mp_seq_cmp_bytes(op, lhs_bufinfo.buf, lhs_bufinfo.len, rhs_bufinfo.buf, rhs_bufinfo.len));
         }
         default:
             return MP_OBJ_NULL; // op not supported
     }
 }

 STATIC mp_obj_t array_append(mp_obj_t self_in, mp_obj_t arg) {
     assert(MP_OBJ_IS_TYPE(self_in, &mp_type_array) || MP_OBJ_IS_TYPE(self_in, &mp_type_bytearray));
     mp_obj_array_t *self = self_in;
     if (self->free == 0) {
         int item_sz = mp_binary_get_size('@', self->typecode, NULL);
         // TODO: alloc policy
         self->free = 8;
         self->items = m_realloc(self->items,  item_sz * self->len, item_sz * (self->len + self->free));
         mp_seq_clear(self->items, self->len + 1, self->len + self->free, item_sz);
     }
     mp_binary_set_val_array(self->typecode, self->items, self->len++, arg);
     self->free--;
     return mp_const_none; // return None, as per CPython
 }
 STATIC MP_DEFINE_CONST_FUN_OBJ_2(array_append_obj, array_append);

 STATIC mp_obj_t array_subscr(mp_obj_t self_in, mp_obj_t index_in, mp_obj_t value) {
     if (value == MP_OBJ_NULL) {
         // delete item
         // TODO implement
         // TODO: confirmed that both bytearray and array.array support
         // slice deletion
         return MP_OBJ_NULL; // op not supported
     } else {
         mp_obj_array_t *o = self_in;
         if (0) {
 #if MICROPY_PY_BUILTINS_SLICE
         } else if (MP_OBJ_IS_TYPE(index_in, &mp_type_slice)) {
             if (value != MP_OBJ_SENTINEL) {
                 // Only getting a slice is suported so far, not assignment
                 // TODO: confirmed that both bytearray and array.array support
                 // slice assignment (incl. of different size)
                 return MP_OBJ_NULL; // op not supported
             }
             mp_bound_slice_t slice;
             if (!mp_seq_get_fast_slice_indexes(o->len, index_in, &slice)) {
                 nlr_raise(mp_obj_new_exception_msg(&mp_type_NotImplementedError,
                     "only slices with step=1 (aka None) are supported"));
             }
             mp_obj_array_t *res;
             int sz = mp_binary_get_size('@', o->typecode & TYPECODE_MASK, NULL);
             assert(sz > 0);
             if (0) {
                 // dummy
             #if MICROPY_PY_BUILTINS_MEMORYVIEW
             } else if (o->base.type == &mp_type_memoryview) {
                 res = m_new_obj(mp_obj_array_t);
                 *res = *o;
                 res->free += slice.start;
                 res->len = slice.stop - slice.start;
             #endif
             } else {
                 res = array_new(o->typecode, slice.stop - slice.start);
                 memcpy(res->items, (uint8_t*)o->items + slice.start * sz, (slice.stop - slice.start) * sz);
             }
             return res;
 #endif
         } else {
             mp_uint_t index = mp_get_index(o->base.type, o->len, index_in, false);
             #if MICROPY_PY_BUILTINS_MEMORYVIEW
             if (o->base.type == &mp_type_memoryview) {
                 index += o->free;
                 if (value != MP_OBJ_SENTINEL && (o->typecode & 0x80) == 0) {
                     // store to read-only memoryview
                     return MP_OBJ_NULL;
                 }
             }
             #endif
             if (value == MP_OBJ_SENTINEL) {
                 // load
                 return mp_binary_get_val_array(o->typecode & TYPECODE_MASK, o->items, index);
             } else {
                 // store
                 mp_binary_set_val_array(o->typecode & TYPECODE_MASK, o->items, index, value);
                 return mp_const_none;
             }
         }
     }
 }

 STATIC mp_int_t array_get_buffer(mp_obj_t o_in, mp_buffer_info_t *bufinfo, mp_uint_t flags) {
     mp_obj_array_t *o = o_in;
     int sz = mp_binary_get_size('@', o->typecode & TYPECODE_MASK, NULL);
     bufinfo->buf = o->items;
     bufinfo->len = o->len * sz;
     bufinfo->typecode = o->typecode & TYPECODE_MASK;
     #if MICROPY_PY_BUILTINS_MEMORYVIEW
     if (o->base.type == &mp_type_memoryview) {
         if ((o->typecode & 0x80) == 0 && (flags & MP_BUFFER_WRITE)) {
             // read-only memoryview
             return 1;
         }
         bufinfo->buf = (uint8_t*)bufinfo->buf + (mp_uint_t)o->free * sz;
     }
     #endif
     return 0;
 }

 #if MICROPY_PY_BUILTINS_BYTEARRAY || MICROPY_PY_ARRAY
 STATIC const mp_map_elem_t array_locals_dict_table[] = {
     { MP_OBJ_NEW_QSTR(MP_QSTR_append), (mp_obj_t)&array_append_obj },
 };

 STATIC MP_DEFINE_CONST_DICT(array_locals_dict, array_locals_dict_table);
 #endif

 #if MICROPY_PY_ARRAY
 const mp_obj_type_t mp_type_array = {
     { &mp_type_type },
     .name = MP_QSTR_array,
     .print = array_print,
     .make_new = array_make_new,
     .getiter = array_iterator_new,
     .unary_op = array_unary_op,
     .binary_op = array_binary_op,
     .subscr = array_subscr,
     .buffer_p = { .get_buffer = array_get_buffer },
     .locals_dict = (mp_obj_t)&array_locals_dict,
 };
 #endif

 #if MICROPY_PY_BUILTINS_BYTEARRAY
 const mp_obj_type_t mp_type_bytearray = {
     { &mp_type_type },
     .name = MP_QSTR_bytearray,
     .print = array_print,
     .make_new = bytearray_make_new,
     .getiter = array_iterator_new,
     .unary_op = array_unary_op,
     .binary_op = array_binary_op,
     .subscr = array_subscr,
     .buffer_p = { .get_buffer = array_get_buffer },
     .locals_dict = (mp_obj_t)&array_locals_dict,
 };
 #endif

 #if MICROPY_PY_BUILTINS_MEMORYVIEW
 const mp_obj_type_t mp_type_memoryview = {
     { &mp_type_type },
     .name = MP_QSTR_memoryview,
     .make_new = memoryview_make_new,
     .getiter = array_iterator_new,
     .unary_op = array_unary_op,
     .binary_op = array_binary_op,
     .subscr = array_subscr,
     .buffer_p = { .get_buffer = array_get_buffer },
 };
 #endif

 /* unused
 mp_uint_t mp_obj_array_len(mp_obj_t self_in) {
     return ((mp_obj_array_t *)self_in)->len;
 }
 */

 #if MICROPY_PY_BUILTINS_BYTEARRAY
 mp_obj_t mp_obj_new_bytearray(mp_uint_t n, void *items) {
     mp_obj_array_t *o = array_new(BYTEARRAY_TYPECODE, n);
     memcpy(o->items, items, n);
     return o;
 }

 // Create bytearray which references specified memory area
 mp_obj_t mp_obj_new_bytearray_by_ref(mp_uint_t n, void *items) {
     mp_obj_array_t *o = m_new_obj(mp_obj_array_t);
     o->base.type = &mp_type_bytearray;
     o->typecode = BYTEARRAY_TYPECODE;
     o->free = 0;
     o->len = n;
     o->items = items;
     return o;
 }
 #endif

 /******************************************************************************/
 // array iterator

 typedef struct _mp_obj_array_it_t {
     mp_obj_base_t base;
     mp_obj_array_t *array;
     mp_uint_t offset;
     mp_uint_t cur;
 } mp_obj_array_it_t;

 STATIC mp_obj_t array_it_iternext(mp_obj_t self_in) {
     mp_obj_array_it_t *self = self_in;
     if (self->cur < self->array->len) {
         return mp_binary_get_val_array(self->array->typecode & TYPECODE_MASK, self->array->items, self->offset + self->cur++);
     } else {
         return MP_OBJ_STOP_ITERATION;
     }
 }

 STATIC const mp_obj_type_t array_it_type = {
     { &mp_type_type },
     .name = MP_QSTR_iterator,
     .getiter = mp_identity,
     .iternext = array_it_iternext,
 };

 STATIC mp_obj_t array_iterator_new(mp_obj_t array_in) {
     mp_obj_array_t *array = array_in;
     mp_obj_array_it_t *o = m_new0(mp_obj_array_it_t, 1);
     o->base.type = &array_it_type;
     o->array = array;
     #if MICROPY_PY_BUILTINS_MEMORYVIEW
     if (array->base.type == &mp_type_memoryview) {
         o->offset = array->free;
     }
     #endif
     return o;
 }

 #endif // MICROPY_PY_ARRAY || MICROPY_PY_BUILTINS_BYTEARRAY || MICROPY_PY_BUILTINS_MEMORYVIEW
	/*
	* This file is part of the Micro Python project, http://micropython.org/
	*
	* The MIT License (MIT)
	*
	* Copyright (c) 2013, 2014 Damien P. George
	* Copyright (c) 2014 Paul Sokolovsky
	*
	* Permission is hereby granted, free of charge, to any person obtaining a copy
	* of this software and associated documentation files (the "Software"), to deal
	* in the Software without restriction, including without limitation the rights
	* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
	* copies of the Software, and to permit persons to whom the Software is
	* furnished to do so, subject to the following conditions:
	*
	* The above copyright notice and this permission notice shall be included in
	* all copies or substantial portions of the Software.
	*
	* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
	* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
	* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
	* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
	* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
	* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
	* THE SOFTWARE.
	*/

	#include <string.h>
	#include <assert.h>
	#include <stdint.h>

	#include "mpconfig.h"
	#include "nlr.h"
	#include "misc.h"
	#include "qstr.h"
	#include "obj.h"
	#include "runtime0.h"
	#include "runtime.h"
	#include "binary.h"

	#if MICROPY_PY_ARRAY \|\| MICROPY_PY_BUILTINS_BYTEARRAY \|\| MICROPY_PY_BUILTINS_MEMORYVIEW

	// About memoryview object: We want to reuse as much code as possible from
	// array, and keep the memoryview object 4 words in size so it fits in 1 GC
	// block. Also, memoryview must keep a pointer to the base of the buffer so
	// that the buffer is not GC'd if the original parent object is no longer
	// around (we are assuming that all memoryview'able objects return a pointer
	// which points to the start of a GC chunk). Given the above constraints we
	// do the following:
	// - typecode high bit is set if the buffer is read-write (else read-only)
	// - free is the offset in elements to the first item in the memoryview
	// - len is the length in elements
	// - items points to the start of the original buffer
	// Note that we don't handle the case where the original buffer might change
	// size due to a resize of the original parent object.

	// make (& TYPECODE_MASK) a null operation if memorview not enabled
	#if MICROPY_PY_BUILTINS_MEMORYVIEW
	#define TYPECODE_MASK (0x7f)
	#else
	#define TYPECODE_MASK (~(mp_uint_t)1)
	#endif

	typedef struct _mp_obj_array_t {
	mp_obj_base_t base;
	mp_uint_t typecode : 8;
	// free is number of unused elements after len used elements
	// alloc size = len + free
	mp_uint_t free : (8 * sizeof(mp_uint_t) - 8);
	mp_uint_t len; // in elements
	void *items;
	} mp_obj_array_t;

	STATIC mp_obj_t array_iterator_new(mp_obj_t array_in);
	STATIC mp_obj_t array_append(mp_obj_t self_in, mp_obj_t arg);
	STATIC mp_int_t array_get_buffer(mp_obj_t o_in, mp_buffer_info_t *bufinfo, mp_uint_t flags);

	/******************************************************************************/
	// array

	#if MICROPY_PY_BUILTINS_BYTEARRAY \|\| MICROPY_PY_ARRAY
	STATIC void array_print(void (print)(void env, const char fmt, ...), void env, mp_obj_t o_in, mp_print_kind_t kind) {
	mp_obj_array_t *o = o_in;
	if (o->typecode == BYTEARRAY_TYPECODE) {
	print(env, "bytearray(b");
	mp_str_print_quoted(print, env, o->items, o->len, true);
	} else {
	print(env, "array('%c'", o->typecode);
	if (o->len > 0) {
	print(env, ", [");
	for (mp_uint_t i = 0; i < o->len; i++) {
	if (i > 0) {
	print(env, ", ");
	}
	mp_obj_print_helper(print, env, mp_binary_get_val_array(o->typecode, o->items, i), PRINT_REPR);
	}
	print(env, "]");
	}
	}
	print(env, ")");
	}
	#endif

	#if MICROPY_PY_BUILTINS_BYTEARRAY \|\| MICROPY_PY_ARRAY
	STATIC mp_obj_array_t *array_new(char typecode, mp_uint_t n) {
	int typecode_size = mp_binary_get_size('@', typecode, NULL);
	if (typecode_size <= 0) {
	nlr_raise(mp_obj_new_exception_msg(&mp_type_ValueError, "bad typecode"));
	}
	mp_obj_array_t *o = m_new_obj(mp_obj_array_t);
	#if MICROPY_PY_BUILTINS_BYTEARRAY && MICROPY_PY_ARRAY
	o->base.type = (typecode == BYTEARRAY_TYPECODE) ? &mp_type_bytearray : &mp_type_array;
	#elif MICROPY_PY_BUILTINS_BYTEARRAY
	o->base.type = &mp_type_bytearray;
	#else
	o->base.type = &mp_type_array;
	#endif
	o->typecode = typecode;
	o->free = 0;
	o->len = n;
	o->items = m_malloc(typecode_size * o->len);
	return o;
	}
	#endif

	#if MICROPY_PY_BUILTINS_BYTEARRAY \|\| MICROPY_PY_ARRAY
	STATIC mp_obj_t array_construct(char typecode, mp_obj_t initializer) {
	uint len;
	// Try to create array of exact len if initializer len is known
	mp_obj_t len_in = mp_obj_len_maybe(initializer);
	if (len_in == MP_OBJ_NULL) {
	len = 0;
	} else {
	len = MP_OBJ_SMALL_INT_VALUE(len_in);
	}

	mp_obj_array_t *array = array_new(typecode, len);

	mp_obj_t iterable = mp_getiter(initializer);
	mp_obj_t item;
	mp_uint_t i = 0;
	while ((item = mp_iternext(iterable)) != MP_OBJ_STOP_ITERATION) {
	if (len == 0) {
	array_append(array, item);
	} else {
	mp_binary_set_val_array(typecode, array->items, i++, item);
	}
	}

	return array;
	}
	#endif

	#if MICROPY_PY_ARRAY
	STATIC mp_obj_t array_make_new(mp_obj_t type_in, mp_uint_t n_args, mp_uint_t n_kw, const mp_obj_t *args) {
	mp_arg_check_num(n_args, n_kw, 1, 2, false);

	// get typecode
	mp_uint_t l;
	const char *typecode = mp_obj_str_get_data(args[0], &l);

	if (n_args == 1) {
	// 1 arg: make an empty array
	return array_new(*typecode, 0);
	} else {
	// 2 args: construct the array from the given iterator
	return array_construct(*typecode, args[1]);
	}
	}
	#endif

	#if MICROPY_PY_BUILTINS_BYTEARRAY
	STATIC mp_obj_t bytearray_make_new(mp_obj_t type_in, mp_uint_t n_args, mp_uint_t n_kw, const mp_obj_t *args) {
	mp_arg_check_num(n_args, n_kw, 0, 1, false);

	if (n_args == 0) {
	// no args: construct an empty bytearray
	return array_new(BYTEARRAY_TYPECODE, 0);
	} else if (MP_OBJ_IS_SMALL_INT(args[0])) {
	// 1 arg, an integer: construct a blank bytearray of that length
	uint len = MP_OBJ_SMALL_INT_VALUE(args[0]);
	mp_obj_array_t *o = array_new(BYTEARRAY_TYPECODE, len);
	memset(o->items, 0, len);
	return o;
	} else {
	// 1 arg, an iterator: construct the bytearray from that
	return array_construct(BYTEARRAY_TYPECODE, args[0]);
	}
	}
	#endif

	#if MICROPY_PY_BUILTINS_MEMORYVIEW
	STATIC mp_obj_t memoryview_make_new(mp_obj_t type_in, mp_uint_t n_args, mp_uint_t n_kw, const mp_obj_t *args) {
	// TODO possibly allow memoryview constructor to take start/stop so that one
	// can do memoryview(b, 4, 8) instead of memoryview(b)[4:8] (uses less RAM)

	mp_arg_check_num(n_args, n_kw, 1, 1, false);

	mp_buffer_info_t bufinfo;
	mp_get_buffer_raise(args[0], &bufinfo, MP_BUFFER_READ);

	mp_obj_array_t *self = m_new_obj(mp_obj_array_t);
	self->base.type = type_in;
	self->typecode = bufinfo.typecode;
	self->free = 0;
	self->len = bufinfo.len / mp_binary_get_size('@', bufinfo.typecode, NULL); // element len
	self->items = bufinfo.buf;

	// test if the object can be written to
	if (mp_get_buffer(args[0], &bufinfo, MP_BUFFER_RW)) {
	self->typecode \|= 0x80; // used to indicate writable buffer
	}

	return self;
	}
	#endif

	STATIC mp_obj_t array_unary_op(mp_uint_t op, mp_obj_t o_in) {
	mp_obj_array_t *o = o_in;
	switch (op) {
	case MP_UNARY_OP_BOOL: return MP_BOOL(o->len != 0);
	case MP_UNARY_OP_LEN: return MP_OBJ_NEW_SMALL_INT(o->len);
	default: return MP_OBJ_NULL; // op not supported
	}
	}

	STATIC mp_obj_t array_binary_op(mp_uint_t op, mp_obj_t lhs_in, mp_obj_t rhs_in) {
	switch (op) {
	case MP_BINARY_OP_EQUAL: {
	mp_buffer_info_t lhs_bufinfo;
	mp_buffer_info_t rhs_bufinfo;
	array_get_buffer(lhs_in, &lhs_bufinfo, MP_BUFFER_READ);
	if (!mp_get_buffer(rhs_in, &rhs_bufinfo, MP_BUFFER_READ)) {
	return mp_const_false;
	}
	return MP_BOOL(mp_seq_cmp_bytes(op, lhs_bufinfo.buf, lhs_bufinfo.len, rhs_bufinfo.buf, rhs_bufinfo.len));
	}
	default:
	return MP_OBJ_NULL; // op not supported
	}
	}

	STATIC mp_obj_t array_append(mp_obj_t self_in, mp_obj_t arg) {
	assert(MP_OBJ_IS_TYPE(self_in, &mp_type_array) \|\| MP_OBJ_IS_TYPE(self_in, &mp_type_bytearray));
	mp_obj_array_t *self = self_in;
	if (self->free == 0) {
	int item_sz = mp_binary_get_size('@', self->typecode, NULL);
	// TODO: alloc policy
	self->free = 8;
	self->items = m_realloc(self->items, item_sz * self->len, item_sz * (self->len + self->free));
	mp_seq_clear(self->items, self->len + 1, self->len + self->free, item_sz);
	}
	mp_binary_set_val_array(self->typecode, self->items, self->len++, arg);
	self->free--;
	return mp_const_none; // return None, as per CPython
	}
	STATIC MP_DEFINE_CONST_FUN_OBJ_2(array_append_obj, array_append);

	STATIC mp_obj_t array_subscr(mp_obj_t self_in, mp_obj_t index_in, mp_obj_t value) {
	if (value == MP_OBJ_NULL) {
	// delete item
	// TODO implement
	// TODO: confirmed that both bytearray and array.array support
	// slice deletion
	return MP_OBJ_NULL; // op not supported
	} else {
	mp_obj_array_t *o = self_in;
	if (0) {
	#if MICROPY_PY_BUILTINS_SLICE
	} else if (MP_OBJ_IS_TYPE(index_in, &mp_type_slice)) {
	if (value != MP_OBJ_SENTINEL) {
	// Only getting a slice is suported so far, not assignment
	// TODO: confirmed that both bytearray and array.array support
	// slice assignment (incl. of different size)
	return MP_OBJ_NULL; // op not supported
	}
	mp_bound_slice_t slice;
	if (!mp_seq_get_fast_slice_indexes(o->len, index_in, &slice)) {
	nlr_raise(mp_obj_new_exception_msg(&mp_type_NotImplementedError,
	"only slices with step=1 (aka None) are supported"));
	}
	mp_obj_array_t *res;
	int sz = mp_binary_get_size('@', o->typecode & TYPECODE_MASK, NULL);
	assert(sz > 0);
	if (0) {
	// dummy
	#if MICROPY_PY_BUILTINS_MEMORYVIEW
	} else if (o->base.type == &mp_type_memoryview) {
	res = m_new_obj(mp_obj_array_t);
	res = o;
	res->free += slice.start;
	res->len = slice.stop - slice.start;
	#endif
	} else {
	res = array_new(o->typecode, slice.stop - slice.start);
	memcpy(res->items, (uint8_t)o->items + slice.start sz, (slice.stop - slice.start) * sz);
	}
	return res;
	#endif
	} else {
	mp_uint_t index = mp_get_index(o->base.type, o->len, index_in, false);
	#if MICROPY_PY_BUILTINS_MEMORYVIEW
	if (o->base.type == &mp_type_memoryview) {
	index += o->free;
	if (value != MP_OBJ_SENTINEL && (o->typecode & 0x80) == 0) {
	// store to read-only memoryview
	return MP_OBJ_NULL;
	}
	}
	#endif
	if (value == MP_OBJ_SENTINEL) {
	// load
	return mp_binary_get_val_array(o->typecode & TYPECODE_MASK, o->items, index);
	} else {
	// store
	mp_binary_set_val_array(o->typecode & TYPECODE_MASK, o->items, index, value);
	return mp_const_none;
	}
	}
	}
	}

	STATIC mp_int_t array_get_buffer(mp_obj_t o_in, mp_buffer_info_t *bufinfo, mp_uint_t flags) {
	mp_obj_array_t *o = o_in;
	int sz = mp_binary_get_size('@', o->typecode & TYPECODE_MASK, NULL);
	bufinfo->buf = o->items;
	bufinfo->len = o->len * sz;
	bufinfo->typecode = o->typecode & TYPECODE_MASK;
	#if MICROPY_PY_BUILTINS_MEMORYVIEW
	if (o->base.type == &mp_type_memoryview) {
	if ((o->typecode & 0x80) == 0 && (flags & MP_BUFFER_WRITE)) {
	// read-only memoryview
	return 1;
	}
	bufinfo->buf = (uint8_t)bufinfo->buf + (mp_uint_t)o->free sz;
	}
	#endif
	return 0;
	}

	#if MICROPY_PY_BUILTINS_BYTEARRAY \|\| MICROPY_PY_ARRAY
	STATIC const mp_map_elem_t array_locals_dict_table[] = {
	{ MP_OBJ_NEW_QSTR(MP_QSTR_append), (mp_obj_t)&array_append_obj },
	};

	STATIC MP_DEFINE_CONST_DICT(array_locals_dict, array_locals_dict_table);
	#endif

	#if MICROPY_PY_ARRAY
	const mp_obj_type_t mp_type_array = {
	{ &mp_type_type },
	.name = MP_QSTR_array,
	.print = array_print,
	.make_new = array_make_new,
	.getiter = array_iterator_new,
	.unary_op = array_unary_op,
	.binary_op = array_binary_op,
	.subscr = array_subscr,
	.buffer_p = { .get_buffer = array_get_buffer },
	.locals_dict = (mp_obj_t)&array_locals_dict,
	};
	#endif

	#if MICROPY_PY_BUILTINS_BYTEARRAY
	const mp_obj_type_t mp_type_bytearray = {
	{ &mp_type_type },
	.name = MP_QSTR_bytearray,
	.print = array_print,
	.make_new = bytearray_make_new,
	.getiter = array_iterator_new,
	.unary_op = array_unary_op,
	.binary_op = array_binary_op,
	.subscr = array_subscr,
	.buffer_p = { .get_buffer = array_get_buffer },
	.locals_dict = (mp_obj_t)&array_locals_dict,
	};
	#endif

	#if MICROPY_PY_BUILTINS_MEMORYVIEW
	const mp_obj_type_t mp_type_memoryview = {
	{ &mp_type_type },
	.name = MP_QSTR_memoryview,
	.make_new = memoryview_make_new,
	.getiter = array_iterator_new,
	.unary_op = array_unary_op,
	.binary_op = array_binary_op,
	.subscr = array_subscr,
	.buffer_p = { .get_buffer = array_get_buffer },
	};
	#endif

	/* unused
	mp_uint_t mp_obj_array_len(mp_obj_t self_in) {
	return ((mp_obj_array_t *)self_in)->len;
	}
	*/

	#if MICROPY_PY_BUILTINS_BYTEARRAY
	mp_obj_t mp_obj_new_bytearray(mp_uint_t n, void *items) {
	mp_obj_array_t *o = array_new(BYTEARRAY_TYPECODE, n);
	memcpy(o->items, items, n);
	return o;
	}

	// Create bytearray which references specified memory area
	mp_obj_t mp_obj_new_bytearray_by_ref(mp_uint_t n, void *items) {
	mp_obj_array_t *o = m_new_obj(mp_obj_array_t);
	o->base.type = &mp_type_bytearray;
	o->typecode = BYTEARRAY_TYPECODE;
	o->free = 0;
	o->len = n;
	o->items = items;
	return o;
	}
	#endif

	/******************************************************************************/
	// array iterator

	typedef struct _mp_obj_array_it_t {
	mp_obj_base_t base;
	mp_obj_array_t *array;
	mp_uint_t offset;
	mp_uint_t cur;
	} mp_obj_array_it_t;

	STATIC mp_obj_t array_it_iternext(mp_obj_t self_in) {
	mp_obj_array_it_t *self = self_in;
	if (self->cur < self->array->len) {
	return mp_binary_get_val_array(self->array->typecode & TYPECODE_MASK, self->array->items, self->offset + self->cur++);
	} else {
	return MP_OBJ_STOP_ITERATION;
	}
	}

	STATIC const mp_obj_type_t array_it_type = {
	{ &mp_type_type },
	.name = MP_QSTR_iterator,
	.getiter = mp_identity,
	.iternext = array_it_iternext,
	};

	STATIC mp_obj_t array_iterator_new(mp_obj_t array_in) {
	mp_obj_array_t *array = array_in;
	mp_obj_array_it_t *o = m_new0(mp_obj_array_it_t, 1);
	o->base.type = &array_it_type;
	o->array = array;
	#if MICROPY_PY_BUILTINS_MEMORYVIEW
	if (array->base.type == &mp_type_memoryview) {
	o->offset = array->free;
	}
	#endif
	return o;
	}

	#endif // MICROPY_PY_ARRAY \|\| MICROPY_PY_BUILTINS_BYTEARRAY \|\| MICROPY_PY_BUILTINS_MEMORYVIEW