add circuitpython code

1 files changed, 887 insertions, 0 deletions

diff --git a/circuitpython/py/objarray.c b/circuitpython/py/objarray.c
new file mode 100644
index 0000000..b71687f
--- /dev/null
+++ b/circuitpython/py/objarray.c
@@ -0,0 +1,887 @@
+/*
+ * This file is part of the MicroPython project, http://micropython.org/
+ *
+ * The MIT License (MIT)
+ *
+ * SPDX-FileCopyrightText: 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 "py/runtime.h"
+#include "py/binary.h"
+#include "py/objstr.h"
+#include "py/objarray.h"
+
+#include "supervisor/shared/translate.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.
+
+#if MICROPY_PY_BUILTINS_MEMORYVIEW
+#define TYPECODE_MASK (0x7f)
+#define memview_offset free
+#else
+// make (& TYPECODE_MASK) a null operation if memorview not enabled
+#define TYPECODE_MASK (~(size_t)0)
+// memview_offset should not be accessed if memoryview is not enabled,
+// so not defined to catch errors
+#endif
+
+STATIC mp_obj_t array_iterator_new(mp_obj_t array_in, mp_obj_iter_buf_t *iter_buf);
+STATIC mp_obj_t array_append(mp_obj_t self_in, mp_obj_t arg);
+STATIC mp_obj_t array_extend(mp_obj_t self_in, mp_obj_t arg_in);
+STATIC mp_int_t array_get_buffer(mp_obj_t o_in, mp_buffer_info_t *bufinfo, mp_uint_t flags);
+#if MICROPY_CPYTHON_COMPAT
+STATIC mp_obj_t array_decode(size_t n_args, const mp_obj_t *args);
+#endif
+
+
+/******************************************************************************/
+// array
+
+#if MICROPY_PY_BUILTINS_BYTEARRAY || MICROPY_PY_ARRAY
+STATIC void array_print(const mp_print_t *print, mp_obj_t o_in, mp_print_kind_t kind) {
+    (void)kind;
+    mp_obj_array_t *o = MP_OBJ_TO_PTR(o_in);
+    if (o->typecode == BYTEARRAY_TYPECODE) {
+        mp_print_str(print, "bytearray(b");
+        mp_str_print_quoted(print, o->items, o->len, true);
+    } else {
+        mp_printf(print, "array('%c'", o->typecode);
+        if (o->len > 0) {
+            mp_print_str(print, ", [");
+            for (size_t i = 0; i < o->len; i++) {
+                if (i > 0) {
+                    mp_print_str(print, ", ");
+                }
+                mp_obj_print_helper(print, mp_binary_get_val_array(o->typecode, o->items, i), PRINT_REPR);
+            }
+            mp_print_str(print, "]");
+        }
+    }
+    mp_print_str(print, ")");
+}
+#endif
+
+#if MICROPY_PY_BUILTINS_BYTEARRAY || MICROPY_PY_ARRAY
+STATIC mp_obj_array_t *array_new(char typecode, size_t n) {
+    if (typecode == 'x') {
+        mp_raise_ValueError(MP_ERROR_TEXT("bad typecode"));
+    }
+    int typecode_size = mp_binary_get_size('@', typecode, NULL);
+    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_new(byte, 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) {
+    // bytearrays can be raw-initialised from anything with the buffer protocol
+    // other arrays can only be raw-initialised from bytes and bytearray objects
+    mp_buffer_info_t bufinfo;
+    if (((MICROPY_PY_BUILTINS_BYTEARRAY
+          && typecode == BYTEARRAY_TYPECODE)
+         || (MICROPY_PY_ARRAY
+             && (mp_obj_is_type(initializer, &mp_type_bytes)
+                 || (MICROPY_PY_BUILTINS_BYTEARRAY && mp_obj_is_type(initializer, &mp_type_bytearray)))))
+        && mp_get_buffer(initializer, &bufinfo, MP_BUFFER_READ)) {
+        // construct array from raw bytes
+        size_t sz = mp_binary_get_size('@', typecode, NULL);
+        if (bufinfo.len % sz) {
+            mp_raise_ValueError(MP_ERROR_TEXT("bytes length not a multiple of item size"));
+        }
+        size_t len = bufinfo.len / sz;
+        mp_obj_array_t *o = array_new(typecode, len);
+        memcpy(o->items, bufinfo.buf, len * sz);
+        return MP_OBJ_FROM_PTR(o);
+    }
+
+    size_t 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, NULL);
+    mp_obj_t item;
+    size_t i = 0;
+    while ((item = mp_iternext(iterable)) != MP_OBJ_STOP_ITERATION) {
+        if (len == 0) {
+            array_append(MP_OBJ_FROM_PTR(array), item);
+        } else {
+            mp_binary_set_val_array(typecode, array->items, i++, item);
+        }
+    }
+
+    return MP_OBJ_FROM_PTR(array);
+}
+#endif
+
+#if MICROPY_PY_ARRAY
+STATIC mp_obj_t array_make_new(const mp_obj_type_t *type_in, size_t n_args, size_t n_kw, const mp_obj_t *args) {
+    (void)type_in;
+    mp_arg_check_num(n_args, n_kw, 1, 2, false);
+
+    // get typecode
+    const char *typecode = mp_obj_str_get_str(args[0]);
+
+    if (n_args == 1) {
+        // 1 arg: make an empty array
+        return MP_OBJ_FROM_PTR(array_new(*typecode, 0));
+    } else {
+        // 2 args: construct the array from the given object
+        return array_construct(*typecode, args[1]);
+    }
+}
+#endif
+
+#if MICROPY_PY_BUILTINS_BYTEARRAY
+STATIC mp_obj_t bytearray_make_new(const mp_obj_type_t *type_in, size_t n_args, size_t n_kw, const mp_obj_t *args) {
+    (void)type_in;
+    mp_arg_check_num(n_args, n_kw, 0, 3, false);
+
+    if (n_args == 0) {
+        // no args: construct an empty bytearray
+        return MP_OBJ_FROM_PTR(array_new(BYTEARRAY_TYPECODE, 0));
+    } else if (mp_obj_is_int(args[0])) {
+        if (n_args > 1) {
+            mp_raise_TypeError(MP_ERROR_TEXT("wrong number of arguments"));
+        }
+        // 1 arg, an integer: construct a blank bytearray of that length
+        mp_uint_t len = mp_obj_get_int(args[0]);
+        mp_obj_array_t *o = array_new(BYTEARRAY_TYPECODE, len);
+        memset(o->items, 0, len);
+        return MP_OBJ_FROM_PTR(o);
+    } else {
+        // 1 arg: construct the bytearray from that
+        return array_construct(BYTEARRAY_TYPECODE, args[0]);
+    }
+}
+#endif
+
+#if MICROPY_PY_BUILTINS_MEMORYVIEW
+
+mp_obj_t mp_obj_new_memoryview(byte typecode, size_t nitems, void *items) {
+    mp_obj_array_t *self = m_new_obj(mp_obj_array_t);
+    mp_obj_memoryview_init(self, typecode, 0, nitems, items);
+    return MP_OBJ_FROM_PTR(self);
+}
+
+STATIC mp_obj_t memoryview_make_new(const mp_obj_type_t *type_in, size_t n_args, size_t n_kw, const mp_obj_t *args) {
+    (void)type_in;
+
+    // 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 = MP_OBJ_TO_PTR(mp_obj_new_memoryview(bufinfo.typecode,
+        bufinfo.len / mp_binary_get_size('@', bufinfo.typecode, NULL),
+        bufinfo.buf));
+
+    // If the input object is a memoryview then need to point the items of the
+    // new memoryview to the start of the buffer so the GC can trace it.
+    if (mp_obj_get_type(args[0]) == &mp_type_memoryview) {
+        mp_obj_array_t *other = MP_OBJ_TO_PTR(args[0]);
+        self->memview_offset = other->memview_offset;
+        self->items = other->items;
+    }
+
+    // test if the object can be written to
+    if (mp_get_buffer(args[0], &bufinfo, MP_BUFFER_RW)) {
+        self->typecode |= MP_OBJ_ARRAY_TYPECODE_FLAG_RW; // indicate writable buffer
+    }
+
+    return MP_OBJ_FROM_PTR(self);
+}
+
+#if MICROPY_CPYTHON_COMPAT
+STATIC mp_obj_t memoryview_cast(const mp_obj_t self_in, const mp_obj_t typecode_in) {
+    mp_obj_array_t *self = MP_OBJ_TO_PTR(self_in);
+    const char *typecode = mp_obj_str_get_str(typecode_in);
+    size_t element_size = mp_binary_get_size('@', typecode[0], NULL);
+    size_t bytelen = self->len * mp_binary_get_size('@', self->typecode & ~MP_OBJ_ARRAY_TYPECODE_FLAG_RW, NULL);
+    if (bytelen % element_size != 0) {
+        mp_raise_TypeError(MP_ERROR_TEXT("memoryview: length is not a multiple of itemsize"));
+    }
+    mp_obj_array_t *result = MP_OBJ_TO_PTR(mp_obj_new_memoryview(*typecode, bytelen / element_size, self->items));
+
+    // test if the object can be written to
+    if (self->typecode & MP_OBJ_ARRAY_TYPECODE_FLAG_RW) {
+        result->typecode |= MP_OBJ_ARRAY_TYPECODE_FLAG_RW; // indicate writable buffer
+    }
+    return MP_OBJ_FROM_PTR(result);
+}
+STATIC MP_DEFINE_CONST_FUN_OBJ_2(memoryview_cast_obj, memoryview_cast);
+#endif
+
+#if MICROPY_PY_BUILTINS_MEMORYVIEW_ITEMSIZE
+STATIC void memoryview_attr(mp_obj_t self_in, qstr attr, mp_obj_t *dest) {
+    if (dest[0] != MP_OBJ_NULL) {
+        return;
+    }
+    if (attr == MP_QSTR_itemsize) {
+        mp_obj_array_t *self = MP_OBJ_TO_PTR(self_in);
+        dest[0] = MP_OBJ_NEW_SMALL_INT(mp_binary_get_size('@', self->typecode & TYPECODE_MASK, NULL));
+    }
+}
+#endif
+
+#endif
+
+STATIC mp_obj_t array_unary_op(mp_unary_op_t op, mp_obj_t o_in) {
+    mp_obj_array_t *o = MP_OBJ_TO_PTR(o_in);
+    switch (op) {
+        case MP_UNARY_OP_BOOL:
+            return mp_obj_new_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 int typecode_for_comparison(int typecode, bool *is_unsigned) {
+    if (typecode == BYTEARRAY_TYPECODE) {
+        typecode = 'B';
+    }
+    if (typecode <= 'Z') {
+        typecode += 32; // to lowercase
+        *is_unsigned = true;
+    }
+    return typecode;
+}
+
+STATIC mp_obj_t array_binary_op(mp_binary_op_t op, mp_obj_t lhs_in, mp_obj_t rhs_in) {
+    mp_obj_array_t *lhs = MP_OBJ_TO_PTR(lhs_in);
+    switch (op) {
+        case MP_BINARY_OP_MULTIPLY:
+        case MP_BINARY_OP_INPLACE_MULTIPLY: {
+            if (!mp_obj_is_int(rhs_in)) {
+                return MP_OBJ_NULL; // op not supported
+            }
+            mp_uint_t repeat = mp_obj_get_int(rhs_in);
+            bool inplace = (op == MP_BINARY_OP_INPLACE_MULTIPLY);
+            mp_buffer_info_t lhs_bufinfo;
+            array_get_buffer(lhs_in, &lhs_bufinfo, MP_BUFFER_READ);
+            mp_obj_array_t *res;
+            byte *ptr;
+            size_t orig_lhs_bufinfo_len = lhs_bufinfo.len;
+            if (inplace) {
+                res = lhs;
+                size_t item_sz = mp_binary_get_size('@', lhs->typecode, NULL);
+                lhs->items = m_renew(byte, lhs->items, (lhs->len + lhs->free) * item_sz, lhs->len * repeat * item_sz);
+                lhs->len = lhs->len * repeat;
+                lhs->free = 0;
+                if (!repeat) {
+                    return MP_OBJ_FROM_PTR(res);
+                }
+                repeat--;
+                ptr = (byte *)res->items + orig_lhs_bufinfo_len;
+            } else {
+                res = array_new(lhs_bufinfo.typecode, lhs->len * repeat);
+                ptr = (byte *)res->items;
+            }
+            if (orig_lhs_bufinfo_len) {
+                for (; repeat--; ptr += orig_lhs_bufinfo_len) {
+                    memcpy(ptr, lhs_bufinfo.buf, orig_lhs_bufinfo_len);
+                }
+            }
+            return MP_OBJ_FROM_PTR(res);
+        }
+        case MP_BINARY_OP_ADD: {
+            // allow to add anything that has the buffer protocol (extension to CPython)
+            mp_buffer_info_t lhs_bufinfo;
+            mp_buffer_info_t rhs_bufinfo;
+            array_get_buffer(lhs_in, &lhs_bufinfo, MP_BUFFER_READ);
+            mp_get_buffer_raise(rhs_in, &rhs_bufinfo, MP_BUFFER_READ);
+
+            size_t sz = mp_binary_get_size('@', lhs_bufinfo.typecode, NULL);
+
+            // convert byte count to element count (in case rhs is not multiple of sz)
+            size_t rhs_len = rhs_bufinfo.len / sz;
+
+            // note: lhs->len is element count of lhs, lhs_bufinfo.len is byte count
+            mp_obj_array_t *res = array_new(lhs_bufinfo.typecode, lhs->len + rhs_len);
+            mp_seq_cat((byte *)res->items, lhs_bufinfo.buf, lhs_bufinfo.len, rhs_bufinfo.buf, rhs_len * sz, byte);
+            return MP_OBJ_FROM_PTR(res);
+        }
+
+        case MP_BINARY_OP_INPLACE_ADD: {
+            #if MICROPY_PY_BUILTINS_MEMORYVIEW
+            if (lhs->base.type == &mp_type_memoryview) {
+                return MP_OBJ_NULL; // op not supported
+            }
+            #endif
+            array_extend(lhs_in, rhs_in);
+            return lhs_in;
+        }
+
+        case MP_BINARY_OP_CONTAINS: {
+            #if MICROPY_PY_BUILTINS_BYTEARRAY
+            // Can search string only in bytearray
+            mp_buffer_info_t lhs_bufinfo;
+            mp_buffer_info_t rhs_bufinfo;
+            if (mp_get_buffer(rhs_in, &rhs_bufinfo, MP_BUFFER_READ)) {
+                if (!mp_obj_is_type(lhs_in, &mp_type_bytearray)) {
+                    return mp_const_false;
+                }
+                array_get_buffer(lhs_in, &lhs_bufinfo, MP_BUFFER_READ);
+                return mp_obj_new_bool(
+                    find_subbytes(lhs_bufinfo.buf, lhs_bufinfo.len, rhs_bufinfo.buf, rhs_bufinfo.len, 1) != NULL);
+            }
+            #endif
+
+            // Otherwise, can only look for a scalar numeric value in an array
+            if (mp_obj_is_int(rhs_in) || mp_obj_is_float(rhs_in)) {
+                mp_raise_NotImplementedError(NULL);
+            }
+
+            return mp_const_false;
+        }
+
+        case MP_BINARY_OP_EQUAL:
+        case MP_BINARY_OP_LESS:
+        case MP_BINARY_OP_LESS_EQUAL:
+        case MP_BINARY_OP_MORE:
+        case MP_BINARY_OP_MORE_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;
+            }
+            // mp_seq_cmp_bytes is used so only compatible representations can be correctly compared.
+            // The type doesn't matter: array/bytearray/str/bytes all have the same buffer layout, so
+            // just check if the typecodes are compatible; for testing equality the types should have the
+            // same code except for signedness, and not be floating point because nan never equals nan.
+            // For > and < the types should be the same and unsigned.
+            // Note that typecode_for_comparison always returns lowercase letters to save code size.
+            // No need for (& TYPECODE_MASK) here: xxx_get_buffer already takes care of that.
+            bool is_unsigned = false;
+            const int lhs_code = typecode_for_comparison(lhs_bufinfo.typecode, &is_unsigned);
+            const int rhs_code = typecode_for_comparison(rhs_bufinfo.typecode, &is_unsigned);
+            if (lhs_code == rhs_code && lhs_code != 'f' && lhs_code != 'd' && (op == MP_BINARY_OP_EQUAL || is_unsigned)) {
+                return mp_obj_new_bool(mp_seq_cmp_bytes(op, lhs_bufinfo.buf, lhs_bufinfo.len, rhs_bufinfo.buf, rhs_bufinfo.len));
+            }
+            // mp_obj_equal_not_equal treats returning MP_OBJ_NULL as 'fall back to pointer comparison'
+            // for MP_BINARY_OP_EQUAL but that is incompatible with CPython.
+            mp_raise_NotImplementedError(NULL);
+        }
+
+        default:
+            return MP_OBJ_NULL; // op not supported
+    }
+}
+
+#if MICROPY_PY_BUILTINS_BYTEARRAY || MICROPY_PY_ARRAY
+STATIC mp_obj_t array_append(mp_obj_t self_in, mp_obj_t arg) {
+    // self is not a memoryview, so we don't need to use (& TYPECODE_MASK)
+    assert((MICROPY_PY_BUILTINS_BYTEARRAY && mp_obj_is_type(self_in, &mp_type_bytearray))
+        || (MICROPY_PY_ARRAY && mp_obj_is_type(self_in, &mp_type_array)));
+    mp_obj_array_t *self = MP_OBJ_TO_PTR(self_in);
+
+    if (self->free == 0) {
+        size_t item_sz = mp_binary_get_size('@', self->typecode, NULL);
+        // TODO: alloc policy
+        self->free = 8;
+        self->items = m_renew(byte, 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);
+    // only update length/free if set succeeded
+    self->len++;
+    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_extend(mp_obj_t self_in, mp_obj_t arg_in) {
+    // self is not a memoryview, so we don't need to use (& TYPECODE_MASK)
+    assert((MICROPY_PY_BUILTINS_BYTEARRAY && mp_obj_is_type(self_in, &mp_type_bytearray))
+        || (MICROPY_PY_ARRAY && mp_obj_is_type(self_in, &mp_type_array)));
+    mp_obj_array_t *self = MP_OBJ_TO_PTR(self_in);
+
+    // allow to extend by anything that has the buffer protocol (extension to CPython)
+    mp_buffer_info_t arg_bufinfo;
+    mp_get_buffer_raise(arg_in, &arg_bufinfo, MP_BUFFER_READ);
+
+    size_t sz = mp_binary_get_size('@', self->typecode, NULL);
+
+    // convert byte count to element count
+    size_t len = arg_bufinfo.len / sz;
+
+    // make sure we have enough room to extend
+    // TODO: alloc policy; at the moment we go conservative
+    if (self->free < len) {
+        self->items = m_renew(byte, self->items, (self->len + self->free) * sz, (self->len + len) * sz);
+        self->free = 0;
+    } else {
+        self->free -= len;
+    }
+
+    // extend
+    mp_seq_copy((byte *)self->items + self->len * sz, arg_bufinfo.buf, len * sz, byte);
+    self->len += len;
+
+    return mp_const_none;
+}
+STATIC MP_DEFINE_CONST_FUN_OBJ_2(array_extend_obj, array_extend);
+#endif
+
+#if MICROPY_PY_BUILTINS_BYTEARRAY && MICROPY_CPYTHON_COMPAT
+STATIC mp_obj_t buffer_finder(size_t n_args, const mp_obj_t *args, int direction, bool is_index) {
+    mp_check_self(mp_obj_is_type(args[0], &mp_type_bytearray));
+    const mp_obj_type_t *self_type = mp_obj_get_type(args[0]);
+
+    mp_buffer_info_t haystack_bufinfo;
+    mp_get_buffer_raise(args[0], &haystack_bufinfo, MP_BUFFER_READ);
+
+    mp_buffer_info_t needle_bufinfo;
+    mp_get_buffer_raise(args[1], &needle_bufinfo, MP_BUFFER_READ);
+
+    if (mp_binary_get_size('@', needle_bufinfo.typecode, NULL) != 1) {
+        mp_raise_TypeError(MP_ERROR_TEXT("a bytes-like object is required"));
+    }
+
+    const byte *start = haystack_bufinfo.buf;
+    const byte *end = ((const byte *)haystack_bufinfo.buf) + haystack_bufinfo.len;
+    if (n_args >= 3 && args[2] != mp_const_none) {
+        start += mp_get_index(self_type, haystack_bufinfo.len, args[2], true);
+    }
+    if (n_args >= 4 && args[3] != mp_const_none) {
+        end = ((const byte *)haystack_bufinfo.buf) + mp_get_index(self_type, haystack_bufinfo.len, args[3], true);
+    }
+
+    const byte *p = NULL;
+    if (end >= start) {
+        p = find_subbytes(start, end - start, needle_bufinfo.buf, needle_bufinfo.len, direction);
+    }
+
+    if (p == NULL) {
+        if (is_index) {
+            mp_raise_ValueError(MP_ERROR_TEXT("substring not found"));
+        } else {
+            return MP_OBJ_NEW_SMALL_INT(-1);
+        }
+    }
+    return MP_OBJ_NEW_SMALL_INT(p - (const byte *)haystack_bufinfo.buf);
+}
+
+STATIC mp_obj_t buffer_find(size_t n_args, const mp_obj_t *args) {
+    return buffer_finder(n_args, args, 1, false);
+}
+MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(buffer_find_obj, 2, 4, buffer_find);
+
+STATIC mp_obj_t buffer_rfind(size_t n_args, const mp_obj_t *args) {
+    return buffer_finder(n_args, args, -1, false);
+}
+MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(buffer_rfind_obj, 2, 4, buffer_rfind);
+
+STATIC mp_obj_t buffer_index(size_t n_args, const mp_obj_t *args) {
+    return buffer_finder(n_args, args, 1, true);
+}
+MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(buffer_index_obj, 2, 4, buffer_index);
+
+STATIC mp_obj_t buffer_rindex(size_t n_args, const mp_obj_t *args) {
+    return buffer_finder(n_args, args, -1, true);
+}
+MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(buffer_rindex_obj, 2, 4, buffer_rindex);
+#endif
+
+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 = MP_OBJ_TO_PTR(self_in);
+        #if MICROPY_PY_BUILTINS_SLICE
+        if (mp_obj_is_type(index_in, &mp_type_slice)) {
+            mp_bound_slice_t slice;
+            if (!mp_seq_get_fast_slice_indexes(o->len, index_in, &slice)) {
+                mp_raise_NotImplementedError(MP_ERROR_TEXT("only slices with step=1 (aka None) are supported"));
+            }
+            if (value != MP_OBJ_SENTINEL) {
+                #if MICROPY_PY_ARRAY_SLICE_ASSIGN
+                // Assign
+                size_t src_len;
+                void *src_items;
+                size_t item_sz = mp_binary_get_size('@', o->typecode & TYPECODE_MASK, NULL);
+                if (mp_obj_is_obj(value) && mp_type_get_subscr_slot(((mp_obj_base_t *)MP_OBJ_TO_PTR(value))->type) == array_subscr) {
+                    // value is array, bytearray or memoryview
+                    mp_obj_array_t *src_slice = MP_OBJ_TO_PTR(value);
+                    if (item_sz != mp_binary_get_size('@', src_slice->typecode & TYPECODE_MASK, NULL)) {
+                    compat_error:
+                        mp_raise_ValueError(MP_ERROR_TEXT("lhs and rhs should be compatible"));
+                    }
+                    src_len = src_slice->len;
+                    src_items = src_slice->items;
+                    #if MICROPY_PY_BUILTINS_MEMORYVIEW
+                    if (mp_obj_is_type(value, &mp_type_memoryview)) {
+                        src_items = (uint8_t *)src_items + (src_slice->memview_offset * item_sz);
+                    }
+                    #endif
+                } else if (mp_obj_is_type(value, &mp_type_bytes)) {
+                    if (item_sz != 1) {
+                        goto compat_error;
+                    }
+                    mp_buffer_info_t bufinfo;
+                    mp_get_buffer_raise(value, &bufinfo, MP_BUFFER_READ);
+                    src_len = bufinfo.len;
+                    src_items = bufinfo.buf;
+                } else {
+                    mp_raise_NotImplementedError(MP_ERROR_TEXT("array/bytes required on right side"));
+                }
+
+                // TODO: check src/dst compat
+                mp_int_t len_adj = src_len - (slice.stop - slice.start);
+                uint8_t *dest_items = o->items;
+                #if MICROPY_PY_BUILTINS_MEMORYVIEW
+                if (o->base.type == &mp_type_memoryview) {
+                    if (!(o->typecode & MP_OBJ_ARRAY_TYPECODE_FLAG_RW)) {
+                        // store to read-only memoryview not allowed
+                        return MP_OBJ_NULL;
+                    }
+                    if (len_adj != 0) {
+                        goto compat_error;
+                    }
+                    dest_items += o->memview_offset * item_sz;
+                }
+                #endif
+                if (len_adj > 0) {
+                    if ((size_t)len_adj > o->free) {
+                        // TODO: alloc policy; at the moment we go conservative
+                        o->items = m_renew(byte, o->items, (o->len + o->free) * item_sz, (o->len + len_adj) * item_sz);
+                        o->free = len_adj;
+                        dest_items = o->items;
+                    }
+                    mp_seq_replace_slice_grow_inplace(dest_items, o->len,
+                        slice.start, slice.stop, src_items, src_len, len_adj, item_sz);
+                } else {
+                    mp_seq_replace_slice_no_grow(dest_items, o->len,
+                        slice.start, slice.stop, src_items, src_len, item_sz);
+                    #if MICROPY_NONSTANDARD_TYPECODES
+                    // Clear "freed" elements at the end of list
+                    // TODO: This is actually only needed for typecode=='O'
+                    mp_seq_clear(dest_items, o->len + len_adj, o->len, item_sz);
+                    #endif
+                    // TODO: alloc policy after shrinking
+                }
+                o->free -= len_adj;
+                o->len += len_adj;
+                return mp_const_none;
+                #else
+                return MP_OBJ_NULL; // op not supported
+                #endif
+            }
+
+            mp_obj_array_t *res;
+            size_t sz = mp_binary_get_size('@', o->typecode & TYPECODE_MASK, NULL);
+            assert(sz > 0);
+            #if MICROPY_PY_BUILTINS_MEMORYVIEW
+            if (o->base.type == &mp_type_memoryview) {
+                res = m_new_obj(mp_obj_array_t);
+                *res = *o;
+                res->memview_offset += slice.start;
+                res->len = slice.stop - slice.start;
+            } else
+            #endif
+            {
+                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 MP_OBJ_FROM_PTR(res);
+        } else
+        #endif
+        {
+            size_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->memview_offset;
+                if (value != MP_OBJ_SENTINEL && !(o->typecode & MP_OBJ_ARRAY_TYPECODE_FLAG_RW)) {
+                    // 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 = MP_OBJ_TO_PTR(o_in);
+    size_t 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 & MP_OBJ_ARRAY_TYPECODE_FLAG_RW) && (flags & MP_BUFFER_WRITE)) {
+            // read-only memoryview
+            return 1;
+        }
+        bufinfo->buf = (uint8_t *)bufinfo->buf + (size_t)o->memview_offset * sz;
+    }
+    #else
+    (void)flags;
+    #endif
+    return 0;
+}
+
+
+#if MICROPY_CPYTHON_COMPAT && MICROPY_PY_BUILTINS_BYTEARRAY
+// Directly lifted from objstr.c
+STATIC mp_obj_t array_decode(size_t n_args, const mp_obj_t *args) {
+    mp_obj_t new_args[2];
+    if (n_args == 1) {
+        new_args[0] = args[0];
+        new_args[1] = MP_OBJ_NEW_QSTR(MP_QSTR_utf_hyphen_8);
+        args = new_args;
+        n_args++;
+    }
+    return mp_obj_str_make_new(&mp_type_str, n_args, 0, args);
+}
+MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(array_decode_obj, 1, 3, array_decode);
+#endif
+
+
+#if MICROPY_PY_ARRAY
+STATIC const mp_rom_map_elem_t array_locals_dict_table[] = {
+    { MP_ROM_QSTR(MP_QSTR_append), MP_ROM_PTR(&array_append_obj) },
+    { MP_ROM_QSTR(MP_QSTR_extend), MP_ROM_PTR(&array_extend_obj) },
+    #if MICROPY_CPYTHON_COMPAT
+    { MP_ROM_QSTR(MP_QSTR_decode), MP_ROM_PTR(&bytes_decode_obj) },
+    #endif
+};
+
+STATIC MP_DEFINE_CONST_DICT(array_locals_dict, array_locals_dict_table);
+#endif
+
+#if MICROPY_PY_BUILTINS_BYTEARRAY
+STATIC const mp_rom_map_elem_t bytearray_locals_dict_table[] = {
+    { MP_ROM_QSTR(MP_QSTR_append), MP_ROM_PTR(&array_append_obj) },
+    { MP_ROM_QSTR(MP_QSTR_extend), MP_ROM_PTR(&array_extend_obj) },
+
+    #if MICROPY_CPYTHON_COMPAT
+    { MP_ROM_QSTR(MP_QSTR_find), MP_ROM_PTR(&buffer_find_obj) },
+    { MP_ROM_QSTR(MP_QSTR_rfind), MP_ROM_PTR(&buffer_rfind_obj) },
+    { MP_ROM_QSTR(MP_QSTR_index), MP_ROM_PTR(&buffer_index_obj) },
+    { MP_ROM_QSTR(MP_QSTR_rindex), MP_ROM_PTR(&buffer_rindex_obj) },
+
+    { MP_ROM_QSTR(MP_QSTR_decode), MP_ROM_PTR(&array_decode_obj) },
+    #endif
+};
+
+STATIC MP_DEFINE_CONST_DICT(bytearray_locals_dict, bytearray_locals_dict_table);
+#endif
+
+
+#if MICROPY_PY_ARRAY
+const mp_obj_type_t mp_type_array = {
+    { &mp_type_type },
+    .flags = MP_TYPE_FLAG_EXTENDED,
+    .name = MP_QSTR_array,
+    .print = array_print,
+    .make_new = array_make_new,
+    .locals_dict = (mp_obj_dict_t *)&array_locals_dict,
+    MP_TYPE_EXTENDED_FIELDS(
+        .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
+
+#if MICROPY_PY_BUILTINS_BYTEARRAY
+const mp_obj_type_t mp_type_bytearray = {
+    { &mp_type_type },
+    .flags = MP_TYPE_FLAG_EQ_CHECKS_OTHER_TYPE | MP_TYPE_FLAG_EXTENDED,
+    .name = MP_QSTR_bytearray,
+    .print = array_print,
+    .make_new = bytearray_make_new,
+    .locals_dict = (mp_obj_dict_t *)&bytearray_locals_dict,
+    MP_TYPE_EXTENDED_FIELDS(
+        .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
+
+#if MICROPY_PY_BUILTINS_MEMORYVIEW
+
+#if MICROPY_CPYTHON_COMPAT
+STATIC const mp_rom_map_elem_t memoryview_locals_dict_table[] = {
+    { MP_ROM_QSTR(MP_QSTR_cast), MP_ROM_PTR(&memoryview_cast_obj) },
+};
+
+STATIC MP_DEFINE_CONST_DICT(memoryview_locals_dict, memoryview_locals_dict_table);
+#endif
+
+const mp_obj_type_t mp_type_memoryview = {
+    { &mp_type_type },
+    .flags = MP_TYPE_FLAG_EQ_CHECKS_OTHER_TYPE | MP_TYPE_FLAG_EXTENDED,
+    .name = MP_QSTR_memoryview,
+    .make_new = memoryview_make_new,
+    #if MICROPY_CPYTHON_COMPAT
+    .locals_dict = (mp_obj_dict_t *)&memoryview_locals_dict,
+    #endif
+    #if MICROPY_PY_BUILTINS_MEMORYVIEW_ITEMSIZE
+    .attr = memoryview_attr,
+    #endif
+    MP_TYPE_EXTENDED_FIELDS(
+        .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
+size_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(size_t n, void *items) {
+    mp_obj_array_t *o = array_new(BYTEARRAY_TYPECODE, n);
+    memcpy(o->items, items, n);
+    return MP_OBJ_FROM_PTR(o);
+}
+
+mp_obj_t mp_obj_new_bytearray_of_zeros(size_t n) {
+    mp_obj_array_t *o = array_new(BYTEARRAY_TYPECODE, n);
+    memset(o->items, 0, n);
+    return MP_OBJ_FROM_PTR(o);
+}
+
+// Create bytearray which references specified memory area
+mp_obj_t mp_obj_new_bytearray_by_ref(size_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 MP_OBJ_FROM_PTR(o);
+}
+#endif
+
+/******************************************************************************/
+// array iterator
+
+typedef struct _mp_obj_array_it_t {
+    mp_obj_base_t base;
+    mp_obj_array_t *array;
+    size_t offset;
+    size_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 = MP_OBJ_TO_PTR(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 mp_type_array_it = {
+    { &mp_type_type },
+    .flags = MP_TYPE_FLAG_EXTENDED,
+    .name = MP_QSTR_iterator,
+    MP_TYPE_EXTENDED_FIELDS(
+        .getiter = mp_identity_getiter,
+        .iternext = array_it_iternext,
+        ),
+};
+
+STATIC mp_obj_t array_iterator_new(mp_obj_t array_in, mp_obj_iter_buf_t *iter_buf) {
+    assert(sizeof(mp_obj_array_t) <= sizeof(mp_obj_iter_buf_t));
+    mp_obj_array_t *array = MP_OBJ_TO_PTR(array_in);
+    mp_obj_array_it_t *o = (mp_obj_array_it_t *)iter_buf;
+    o->base.type = &mp_type_array_it;
+    o->array = array;
+    o->offset = 0;
+    o->cur = 0;
+    #if MICROPY_PY_BUILTINS_MEMORYVIEW
+    if (array->base.type == &mp_type_memoryview) {
+        o->offset = array->memview_offset;
+    }
+    #endif
+    return MP_OBJ_FROM_PTR(o);
+}
+
+#endif // MICROPY_PY_ARRAY || MICROPY_PY_BUILTINS_BYTEARRAY || MICROPY_PY_BUILTINS_MEMORYVIEW