/*

** array.c - Array class

**

** See Copyright Notice in mruby.h

*/

#include <mruby.h>

#include <mruby/array.h>

#include <mruby/class.h>

#include <mruby/string.h>

#include <mruby/range.h>

#include <mruby/proc.h>

#include <mruby/internal.h>

#include <mruby/presym.h>

#include "value_array.h"

#define ARY_DEFAULT_LEN 4

#define ARY_SHRINK_RATIO 5 /* must be larger than 2 */

#define ARY_C_MAX_SIZE (SIZE_MAX / sizeof(mrb_value))

#ifndef MRB_ARY_LENGTH_MAX

#define MRB_ARY_LENGTH_MAX 131072

#endif

#define ARY_MAX_SIZE ((mrb_int)((ARY_C_MAX_SIZE < (size_t)MRB_INT_MAX) ? ARY_C_MAX_SIZE : MRB_INT_MAX-1))

static void

ary_too_big(mrb_state *mrb)

{

mrb_raise(mrb, E_ARGUMENT_ERROR, "array size too big");

}

static inline void

ary_check_too_big(mrb_state *mrb, mrb_int a, mrb_int b)

{

if (a > ARY_MAX_SIZE - b || a < 0)

ary_too_big(mrb);

#if MRB_ARY_LENGTH_MAX != 0

if (a > MRB_ARY_LENGTH_MAX - b || a < 0)

ary_too_big(mrb);

#endif

}

static struct RArray*

ary_new_capa(mrb_state *mrb, mrb_int capa)

{

struct RArray *a;

size_t blen;

ary_check_too_big(mrb, capa, 0);

blen = capa * sizeof(mrb_value);

a = MRB_OBJ_ALLOC(mrb, MRB_TT_ARRAY, mrb->array_class);

if (capa <= MRB_ARY_EMBED_LEN_MAX) {

ARY_SET_EMBED_LEN(a, 0);

}

else {

a->as.heap.ptr = (mrb_value *)mrb_malloc(mrb, blen);

a->as.heap.aux.capa = capa;

a->as.heap.len = 0;

}

return a;

}

MRB_API mrb_value

mrb_ary_new_capa(mrb_state *mrb, mrb_int capa)

{

struct RArray *a = ary_new_capa(mrb, capa);

return mrb_obj_value(a);

}

MRB_API mrb_value

mrb_ary_new(mrb_state *mrb)

{

return mrb_ary_new_capa(mrb, 0);

}

/*

* To copy array, use this instead of memcpy because of portability

* * gcc on ARM may fail optimization of memcpy

* https://gcc.gnu.org/bugzilla/show_bug.cgi?id=56620

* * gcc on MIPS also fail

* https://gcc.gnu.org/bugzilla/show_bug.cgi?id=39755

* * memcpy doesn't exist on freestanding environment

*

* If you optimize for binary size, use memcpy instead of this at your own risk

* of above portability issue.

*

* See also https://togetter.com/li/462898 (Japanese)

*/

static inline void

array_copy(mrb_value *dst, const mrb_value *src, mrb_int size)

{

mrb_int i;

for (i = 0; i < size; i++) {

dst[i] = src[i];

}

}

static struct RArray*

ary_new_from_values(mrb_state *mrb, mrb_int size, const mrb_value *vals)

{

struct RArray *a = ary_new_capa(mrb, size);

array_copy(ARY_PTR(a), vals, size);

ARY_SET_LEN(a, size);

return a;

}

MRB_API mrb_value

mrb_ary_new_from_values(mrb_state *mrb, mrb_int size, const mrb_value *vals)

{

struct RArray *a = ary_new_from_values(mrb, size, vals);

return mrb_obj_value(a);

}

MRB_API mrb_value

mrb_assoc_new(mrb_state *mrb, mrb_value car, mrb_value cdr)

{

struct RArray *a;

mrb_value *p;

a = ary_new_capa(mrb, 2);

p = ARY_PTR(a);

p[0] = car;

p[1] = cdr;

ARY_SET_LEN(a, 2);

return mrb_obj_value(a);

}

static void

ary_fill_with_nil(mrb_value *ptr, mrb_int size)

{

mrb_value nil = mrb_nil_value();

while (size--) {

*ptr++ = nil;

}

}

static void

ary_modify_check(mrb_state *mrb, struct RArray *a)

{

mrb_check_frozen(mrb, a);

}

static void

ary_modify(mrb_state *mrb, struct RArray *a)

{

ary_modify_check(mrb, a);

if (ARY_SHARED_P(a)) {

mrb_shared_array *shared = a->as.heap.aux.shared;

if (shared->refcnt == 1 && a->as.heap.ptr == shared->ptr) {

a->as.heap.ptr = shared->ptr;

a->as.heap.aux.capa = a->as.heap.len;

mrb_free(mrb, shared);

}

else {

mrb_value *ptr, *p;

mrb_int len;

p = a->as.heap.ptr;

len = a->as.heap.len * sizeof(mrb_value);

ptr = (mrb_value *)mrb_malloc(mrb, len);

if (p) {

array_copy(ptr, p, a->as.heap.len);

}

a->as.heap.ptr = ptr;

a->as.heap.aux.capa = a->as.heap.len;

mrb_ary_decref(mrb, shared);

}

ARY_UNSET_SHARED_FLAG(a);

}

}

MRB_API void

mrb_ary_modify(mrb_state *mrb, struct RArray* a)

{

mrb_write_barrier(mrb, (struct RBasic*)a);

ary_modify(mrb, a);

}

static void

ary_make_shared(mrb_state *mrb, struct RArray *a)

{

if (!ARY_SHARED_P(a) && !ARY_EMBED_P(a)) {

mrb_shared_array *shared = (mrb_shared_array *)mrb_malloc(mrb, sizeof(mrb_shared_array));

mrb_value *ptr = a->as.heap.ptr;

mrb_int len = a->as.heap.len;

shared->refcnt = 1;

if (a->as.heap.aux.capa > len) {

a->as.heap.ptr = shared->ptr = (mrb_value *)mrb_realloc(mrb, ptr, sizeof(mrb_value)*len+1);

}

else {

shared->ptr = ptr;

}

shared->len = len;

a->as.heap.aux.shared = shared;

ARY_SET_SHARED_FLAG(a);

}

}

static void

ary_expand_capa(mrb_state *mrb, struct RArray *a, mrb_int len)

{

mrb_int capa = ARY_CAPA(a);

ary_check_too_big(mrb, len, 0);

if (capa < ARY_DEFAULT_LEN) {

capa = ARY_DEFAULT_LEN;

}

while (capa < len) {

if (capa <= ARY_MAX_SIZE / 2) {

capa *= 2;

}

else {

capa = len;

}

}

if (capa < len || capa > ARY_MAX_SIZE) {

ary_too_big(mrb);

}

if (ARY_EMBED_P(a)) {

mrb_value *ptr = ARY_EMBED_PTR(a);

mrb_int len = ARY_EMBED_LEN(a);

mrb_value *expanded_ptr = (mrb_value *)mrb_malloc(mrb, sizeof(mrb_value)*capa);

ARY_UNSET_EMBED_FLAG(a);

array_copy(expanded_ptr, ptr, len);

a->as.heap.len = len;

a->as.heap.aux.capa = capa;

a->as.heap.ptr = expanded_ptr;

}

else if (capa > a->as.heap.aux.capa) {

mrb_value *expanded_ptr = (mrb_value *)mrb_realloc(mrb, a->as.heap.ptr, sizeof(mrb_value)*capa);

a->as.heap.aux.capa = capa;

a->as.heap.ptr = expanded_ptr;

}

}

static void

ary_shrink_capa(mrb_state *mrb, struct RArray *a)

{

mrb_int capa;

if (ARY_EMBED_P(a)) return;

capa = a->as.heap.aux.capa;

if (capa < ARY_DEFAULT_LEN * 2) return;

if (capa <= a->as.heap.len * ARY_SHRINK_RATIO) return;

do {

capa /= 2;

if (capa < ARY_DEFAULT_LEN) {

capa = ARY_DEFAULT_LEN;

break;

}

} while (capa > a->as.heap.len * ARY_SHRINK_RATIO);

if (capa > a->as.heap.len && capa < a->as.heap.aux.capa) {

a->as.heap.aux.capa = capa;

a->as.heap.ptr = (mrb_value *)mrb_realloc(mrb, a->as.heap.ptr, sizeof(mrb_value)*capa);

}

}

MRB_API mrb_value

mrb_ary_resize(mrb_state *mrb, mrb_value ary, mrb_int new_len)

{

mrb_int old_len;

struct RArray *a = mrb_ary_ptr(ary);

ary_modify(mrb, a);

old_len = RARRAY_LEN(ary);

if (old_len != new_len) {

if (new_len < old_len) {

ary_shrink_capa(mrb, a);

}

else {

ary_expand_capa(mrb, a, new_len);

ary_fill_with_nil(ARY_PTR(a) + old_len, new_len - old_len);

}

ARY_SET_LEN(a, new_len);

}

return ary;

}

static mrb_value

mrb_ary_s_create(mrb_state *mrb, mrb_value klass)

{

mrb_value ary;

const mrb_value *vals;

mrb_int len;

struct RArray *a;

mrb_get_args(mrb, "*!", &vals, &len);

ary = mrb_ary_new_from_values(mrb, len, vals);

a = mrb_ary_ptr(ary);

a->c = mrb_class_ptr(klass);

return ary;

}

static void ary_replace(mrb_state*, struct RArray*, struct RArray*);

static void

ary_concat(mrb_state *mrb, struct RArray *a, struct RArray *a2)

{

mrb_int len;

if (ARY_LEN(a) == 0) {

ary_replace(mrb, a, a2);

return;

}

ary_check_too_big(mrb, ARY_LEN(a2), ARY_LEN(a));

len = ARY_LEN(a) + ARY_LEN(a2);

ary_modify(mrb, a);

if (ARY_CAPA(a) < len) {

ary_expand_capa(mrb, a, len);

}

array_copy(ARY_PTR(a)+ARY_LEN(a), ARY_PTR(a2), ARY_LEN(a2));

mrb_write_barrier(mrb, (struct RBasic*)a);

ARY_SET_LEN(a, len);

}

MRB_API void

mrb_ary_concat(mrb_state *mrb, mrb_value self, mrb_value other)

{

struct RArray *a2 = mrb_ary_ptr(other);

ary_concat(mrb, mrb_ary_ptr(self), a2);

}

/*

* call-seq:

* array.concat(*other_arrays) -> self

*

* Adds to +array+ all elements from each \Array in +other_arrays+; returns +self+:

*

* a = [0, 1]

* a.concat([2, 3], [4, 5]) # => [0, 1, 2, 3, 4, 5]

*/

static mrb_value

mrb_ary_concat_m(mrb_state *mrb, mrb_value self)

{

mrb_value *args;

mrb_int len;

mrb_get_args(mrb, "*!", &args, &len);

for (int i=0; i<len; i++) {

mrb_ensure_array_type(mrb, args[i]);

}

for (int i=0; i<len; i++) {

mrb_ary_concat(mrb, self, args[i]);

}

return self;

}

static mrb_value

mrb_ary_plus(mrb_state *mrb, mrb_value self)

{

struct RArray *a1 = mrb_ary_ptr(self);

struct RArray *a2;

const mrb_value *ptr;

mrb_int blen, len1;

mrb_get_args(mrb, "a", &ptr, &blen);

ary_check_too_big(mrb, ARY_LEN(a1), blen);

len1 = ARY_LEN(a1);

a2 = ary_new_capa(mrb, len1 + blen);

array_copy(ARY_PTR(a2), ARY_PTR(a1), len1);

array_copy(ARY_PTR(a2) + len1, ptr, blen);

ARY_SET_LEN(a2, len1+blen);

return mrb_obj_value(a2);

}

#define ARY_REPLACE_SHARED_MIN 20

static void

ary_replace(mrb_state *mrb, struct RArray *a, struct RArray *b)

{

mrb_int len = ARY_LEN(b);

ary_modify_check(mrb, a);

if (a == b) return;

if (ARY_SHARED_P(a)) {

mrb_ary_decref(mrb, a->as.heap.aux.shared);

a->as.heap.aux.capa = 0;

a->as.heap.len = 0;

a->as.heap.ptr = NULL;

ARY_UNSET_SHARED_FLAG(a);

}

if (ARY_SHARED_P(b)) {

shared_b:

if (ARY_EMBED_P(a)) {

ARY_UNSET_EMBED_FLAG(a);

}

else {

mrb_free(mrb, a->as.heap.ptr);

}

a->as.heap.ptr = b->as.heap.ptr;

a->as.heap.len = len;

a->as.heap.aux.shared = b->as.heap.aux.shared;

a->as.heap.aux.shared->refcnt++;

ARY_SET_SHARED_FLAG(a);

mrb_write_barrier(mrb, (struct RBasic*)a);

return;

}

if (!mrb_frozen_p(b) && len > ARY_REPLACE_SHARED_MIN) {

ary_make_shared(mrb, b);

goto shared_b;

}

if (ARY_CAPA(a) < len)

ary_expand_capa(mrb, a, len);

array_copy(ARY_PTR(a), ARY_PTR(b), len);

mrb_write_barrier(mrb, (struct RBasic*)a);

ARY_SET_LEN(a, len);

}

MRB_API void

mrb_ary_replace(mrb_state *mrb, mrb_value self, mrb_value other)

{

struct RArray *a1 = mrb_ary_ptr(self);

struct RArray *a2 = mrb_ary_ptr(other);

if (a1 != a2) {

ary_replace(mrb, a1, a2);

}

}

static mrb_value

mrb_ary_replace_m(mrb_state *mrb, mrb_value self)

{

mrb_value other;

mrb_get_args(mrb, "A", &other);

mrb_ary_replace(mrb, self, other);

return self;

}

static mrb_value

mrb_ary_times(mrb_state *mrb, mrb_value self)

{

struct RArray *a1 = mrb_ary_ptr(self);

struct RArray *a2;

mrb_value *ptr, sep, tmp;

mrb_int times, len1;

mrb_get_args(mrb, "o", &sep);

tmp = mrb_check_string_type(mrb, sep);

if (!mrb_nil_p(tmp)) {

return mrb_ary_join(mrb, self, tmp);

}

mrb_get_args(mrb, "i", &times);

if (times < 0) {

mrb_raise(mrb, E_ARGUMENT_ERROR, "negative argument");

}

if (times == 0) return mrb_ary_new(mrb);

if (ARY_MAX_SIZE / times < ARY_LEN(a1)) {

ary_too_big(mrb);

}

len1 = ARY_LEN(a1);

a2 = ary_new_capa(mrb, len1 * times);

ARY_SET_LEN(a2, len1 * times);

ptr = ARY_PTR(a2);

while (times--) {

array_copy(ptr, ARY_PTR(a1), len1);

ptr += len1;

}

return mrb_obj_value(a2);

}

static mrb_value

mrb_ary_reverse_bang(mrb_state *mrb, mrb_value self)

{

struct RArray *a = mrb_ary_ptr(self);

mrb_int len = ARY_LEN(a);

if (len > 1) {

mrb_value *p1, *p2;

ary_modify(mrb, a);

p1 = ARY_PTR(a);

p2 = p1 + len - 1;

while (p1 < p2) {

mrb_value tmp = *p1;

*p1++ = *p2;

*p2-- = tmp;

}

}

return self;

}

static mrb_value

mrb_ary_reverse(mrb_state *mrb, mrb_value self)

{

struct RArray *a = mrb_ary_ptr(self), *b = ary_new_capa(mrb, ARY_LEN(a));

mrb_int len = ARY_LEN(a);

if (len > 0) {

mrb_value *p1, *p2, *e;

p1 = ARY_PTR(a);

e = p1 + len;

p2 = ARY_PTR(b) + len - 1;

while (p1 < e) {

*p2-- = *p1++;

}

ARY_SET_LEN(b, len);

}

return mrb_obj_value(b);

}

MRB_API void

mrb_ary_push(mrb_state *mrb, mrb_value ary, mrb_value elem)

{

struct RArray *a = mrb_ary_ptr(ary);

mrb_int len = ARY_LEN(a);

ary_modify(mrb, a);

if (len == ARY_CAPA(a))

ary_expand_capa(mrb, a, len + 1);

ARY_PTR(a)[len] = elem;

ARY_SET_LEN(a, len+1);

mrb_field_write_barrier_value(mrb, (struct RBasic*)a, elem);

}

static mrb_value

mrb_ary_push_m(mrb_state *mrb, mrb_value self)

{

mrb_int argc;

const mrb_value *argv;

mrb_int len, len2;

struct RArray *a;

argc = mrb_get_argc(mrb);

argv = mrb_get_argv(mrb);

a = mrb_ary_ptr(self);

ary_modify(mrb, a);

len = ARY_LEN(a);

len2 = len + argc;

if (ARY_CAPA(a) < len2) {

ary_expand_capa(mrb, a, len2);

}

array_copy(ARY_PTR(a)+len, argv, argc);

ARY_SET_LEN(a, len2);

while (argc--) {

mrb_field_write_barrier_value(mrb, (struct RBasic*)a, *argv);

argv++;

}

return self;

}

MRB_API mrb_value

mrb_ary_pop(mrb_state *mrb, mrb_value ary)

{

struct RArray *a = mrb_ary_ptr(ary);

mrb_int len = ARY_LEN(a);

ary_modify_check(mrb, a);

if (len == 0) return mrb_nil_value();

ARY_SET_LEN(a, len-1);

return ARY_PTR(a)[len-1];

}

#define ARY_SHIFT_SHARED_MIN 10

MRB_API mrb_value

mrb_ary_shift(mrb_state *mrb, mrb_value self)

{

struct RArray *a = mrb_ary_ptr(self);

mrb_int len = ARY_LEN(a);

mrb_value val;

ary_modify_check(mrb, a);

if (len == 0) return mrb_nil_value();

if (ARY_SHARED_P(a)) {

L_SHIFT:

val = a->as.heap.ptr[0];

a->as.heap.ptr++;

a->as.heap.len--;

return val;

}

if (len > ARY_SHIFT_SHARED_MIN) {

ary_make_shared(mrb, a);

goto L_SHIFT;

}

else {

mrb_value *ptr = ARY_PTR(a);

mrb_int size = len;

val = *ptr;

while (--size) {

*ptr = *(ptr+1);

++ptr;

}

ARY_SET_LEN(a, len-1);

}

return val;

}

static mrb_value

mrb_ary_shift_m(mrb_state *mrb, mrb_value self)

{

mrb_int n;

if (mrb_get_args(mrb, "|i", &n) == 0) {

return mrb_ary_shift(mrb, self);

}

struct RArray *a = mrb_ary_ptr(self);

mrb_int len = ARY_LEN(a);

mrb_value val;

ary_modify_check(mrb, a);

if (len == 0 || n == 0) return mrb_ary_new(mrb);

if (n < 0) mrb_raise(mrb, E_ARGUMENT_ERROR, "negative array shift");

if (n > len) n = len;

val = mrb_ary_new_from_values(mrb, n, ARY_PTR(a));

if (ARY_SHARED_P(a)) {

L_SHIFT:

a->as.heap.ptr+=n;

a->as.heap.len-=n;

return val;

}

if (len > ARY_SHIFT_SHARED_MIN) {

ary_make_shared(mrb, a);

goto L_SHIFT;

}

else if (len == n) {

ARY_SET_LEN(a, 0);

}

else {

mrb_value *ptr = ARY_PTR(a);

mrb_int size = len-n;

while (size--) {

*ptr = *(ptr+n);

++ptr;

}

ARY_SET_LEN(a, len-n);

}

return val;

}

/* self = [1,2,3]

item = 0

self.unshift item

p self #=> [0, 1, 2, 3] */

MRB_API mrb_value

mrb_ary_unshift(mrb_state *mrb, mrb_value self, mrb_value item)

{

struct RArray *a = mrb_ary_ptr(self);

mrb_int len = ARY_LEN(a);

if (ARY_SHARED_P(a)

&& a->as.heap.aux.shared->refcnt == 1 /* shared only referenced from this array */

&& a->as.heap.ptr - a->as.heap.aux.shared->ptr >= 1) /* there's room for unshifted item */ {

a->as.heap.ptr--;

a->as.heap.ptr[0] = item;

}

else {

mrb_value *ptr;

ary_modify(mrb, a);

if (ARY_CAPA(a) < len + 1)

ary_expand_capa(mrb, a, len + 1);

ptr = ARY_PTR(a);

value_move(ptr + 1, ptr, len);

ptr[0] = item;

}

ARY_SET_LEN(a, len+1);

mrb_field_write_barrier_value(mrb, (struct RBasic*)a, item);

return self;

}

/*

* call-seq:

* array.unshift(*objects) -> self

*

* Prepends the given +objects+ to +self+:

*

* a = [:foo, 'bar', 2]

* a.unshift(:bam, :bat) # => [:bam, :bat, :foo, "bar", 2]

*

* Array#prepend is an alias for Array#unshift.

*

* Related: #push, #pop, #shift.

*/

static mrb_value

mrb_ary_unshift_m(mrb_state *mrb, mrb_value self)

{

struct RArray *a = mrb_ary_ptr(self);

const mrb_value *vals;

mrb_value *ptr;

mrb_int alen, len;

mrb_get_args(mrb, "*!", &vals, &alen);

if (alen == 0) {

ary_modify_check(mrb, a);

return self;

}

len = ARY_LEN(a);

if (alen > ARY_MAX_SIZE - len) {

mrb_raise(mrb, E_ARGUMENT_ERROR, "array size too big");

}

if (ARY_SHARED_P(a)

&& a->as.heap.aux.shared->refcnt == 1 /* shared only referenced from this array */

&& a->as.heap.ptr - a->as.heap.aux.shared->ptr >= alen) /* there's room for unshifted item */ {

ary_modify_check(mrb, a);

a->as.heap.ptr -= alen;

ptr = a->as.heap.ptr;

}

else {

mrb_bool same = vals == ARY_PTR(a);

ary_modify(mrb, a);

if (ARY_CAPA(a) < len + alen)

ary_expand_capa(mrb, a, len + alen);

ptr = ARY_PTR(a);

value_move(ptr + alen, ptr, len);

if (same) vals = ptr;

}

array_copy(ptr, vals, alen);

ARY_SET_LEN(a, len+alen);

while (alen--) {

mrb_field_write_barrier_value(mrb, (struct RBasic*)a, vals[alen]);

}

return self;

}

MRB_API void

mrb_ary_set(mrb_state *mrb, mrb_value ary, mrb_int n, mrb_value val)

{

struct RArray *a = mrb_ary_ptr(ary);

mrb_int len = ARY_LEN(a);

ary_modify(mrb, a);

/* range check */

if (n < 0) {

n += len;

if (n < 0) {

mrb_raisef(mrb, E_INDEX_ERROR, "index %i out of array", n - len);

}

}

if (n >= ARY_MAX_SIZE) {

mrb_raise(mrb, E_INDEX_ERROR, "index too big");

}

if (len <= n) {

if (ARY_CAPA(a) <= n)

ary_expand_capa(mrb, a, n + 1);

ary_fill_with_nil(ARY_PTR(a) + len, n + 1 - len);

ARY_SET_LEN(a, n+1);

}

ARY_PTR(a)[n] = val;

mrb_field_write_barrier_value(mrb, (struct RBasic*)a, val);

}

static struct RArray*

ary_dup(mrb_state *mrb, struct RArray *a)

{

return ary_new_from_values(mrb, ARY_LEN(a), ARY_PTR(a));

}

MRB_API mrb_value

mrb_ary_splice(mrb_state *mrb, mrb_value ary, mrb_int head, mrb_int len, mrb_value rpl)

{

struct RArray *a = mrb_ary_ptr(ary);

mrb_int alen = ARY_LEN(a);

const mrb_value *argv;

mrb_int argc;

mrb_int tail;

ary_modify(mrb, a);

/* len check */

if (len < 0) mrb_raisef(mrb, E_INDEX_ERROR, "negative length (%i)", len);

/* range check */

if (head < 0) {

head += alen;

if (head < 0) goto out_of_range;

}

if (head > ARY_MAX_SIZE - len) {

out_of_range:

mrb_raisef(mrb, E_INDEX_ERROR, "index %i is out of array", head);

}

tail = head + len;

if (alen < len || alen < tail) {

len = alen - head;

tail = head + len;

}

/* size check */

if (mrb_array_p(rpl)) {

argc = RARRAY_LEN(rpl);

argv = RARRAY_PTR(rpl);

if (argv == ARY_PTR(a)) {

struct RArray *r;

if (argc > 32767) {

mrb_raise(mrb, E_ARGUMENT_ERROR, "too big recursive splice");

}

r = ary_dup(mrb, a);

argv = ARY_PTR(r);

}

}

else if (mrb_undef_p(rpl)) {

argc = 0;

argv = NULL;

}

else {

argc = 1;

argv = &rpl;

}

if (head >= alen) {

if (head > ARY_MAX_SIZE - argc) goto out_of_range;

len = head + argc;

if (len > ARY_CAPA(a)) {

ary_expand_capa(mrb, a, len);

}

ary_fill_with_nil(ARY_PTR(a) + alen, head - alen);

if (argc > 0) {

array_copy(ARY_PTR(a) + head, argv, argc);

}

ARY_SET_LEN(a, len);

}

else {

mrb_int newlen;

if (alen - len > ARY_MAX_SIZE - argc) {

head = alen + argc - len;

goto out_of_range;

}

newlen = alen + argc - len;

if (newlen > ARY_CAPA(a)) {

ary_expand_capa(mrb, a, newlen);

}

if (len != argc) {

mrb_value *ptr = ARY_PTR(a);

value_move(ptr + head + argc, ptr + tail, alen - tail);

ARY_SET_LEN(a, newlen);

}

if (argc > 0) {

value_move(ARY_PTR(a) + head, argv, argc);

}

}

mrb_write_barrier(mrb, (struct RBasic*)a);

return ary;

}

void

mrb_ary_decref(mrb_state *mrb, mrb_shared_array *shared)

{

shared->refcnt--;

if (shared->refcnt == 0) {

mrb_free(mrb, shared->ptr);

mrb_free(mrb, shared);

}

}

static mrb_value

ary_subseq(mrb_state *mrb, struct RArray *a, mrb_int beg, mrb_int len)

{

struct RArray *b;

if (!ARY_SHARED_P(a) && len <= ARY_SHIFT_SHARED_MIN) {

return mrb_ary_new_from_values(mrb, len, ARY_PTR(a)+beg);

}

ary_make_shared(mrb, a);

b = MRB_OBJ_ALLOC(mrb, MRB_TT_ARRAY, mrb->array_class);

b->as.heap.ptr = a->as.heap.ptr + beg;

b->as.heap.len = len;

b->as.heap.aux.shared = a->as.heap.aux.shared;

b->as.heap.aux.shared->refcnt++;

ARY_SET_SHARED_FLAG(b);

return mrb_obj_value(b);

}

mrb_value

mrb_ary_subseq(mrb_state *mrb, mrb_value ary, mrb_int beg, mrb_int len)

{

struct RArray *a = mrb_ary_ptr(ary);

return ary_subseq(mrb, a, beg, len);

}

static mrb_int

aget_index(mrb_state *mrb, mrb_value index)

{

if (mrb_integer_p(index)) {

return mrb_integer(index);

}

#ifndef MRB_NO_FLOAT

else if (mrb_float_p(index)) {

return (mrb_int)mrb_float(index);

}

#endif

else {

mrb_int i, argc;

const mrb_value *argv;

mrb_get_args(mrb, "i*!", &i, &argv, &argc);

return i;

}

}

/*

* call-seq:

* ary[index] -> obj or nil

* ary[start, length] -> new_ary or nil

* ary[range] -> new_ary or nil

* ary.slice(index) -> obj or nil

* ary.slice(start, length) -> new_ary or nil

* ary.slice(range) -> new_ary or nil

*

* Element Reference --- Returns the element at +index+, or returns a

* subarray starting at the +start+ index and continuing for +length+

* elements, or returns a subarray specified by +range+ of indices.

*

* Negative indices count backward from the end of the array (-1 is the last

* element). For +start+ and +range+ cases the starting index is just before

* an element. Additionally, an empty array is returned when the starting

* index for an element range is at the end of the array.

*

* Returns +nil+ if the index (or starting index) are out of range.

*

* a = [ "a", "b", "c", "d", "e" ]

* a[1] => "b"

* a[1,2] => ["b", "c"]

* a[1..-2] => ["b", "c", "d"]

*

*/

static mrb_value

mrb_ary_aget(mrb_state *mrb, mrb_value self)

{

struct RArray *a = mrb_ary_ptr(self);

mrb_int i;

mrb_int len, alen;

mrb_value index;

if (mrb_get_argc(mrb) == 1) {

index = mrb_get_arg1(mrb);

switch (mrb_type(index)) {

/* a[n..m] */

case MRB_TT_RANGE:

if (mrb_range_beg_len(mrb, index, &i, &len, ARY_LEN(a), TRUE) == MRB_RANGE_OK) {

return ary_subseq(mrb, a, i, len);

}

else {

return mrb_nil_value();

}

case MRB_TT_INTEGER:

return mrb_ary_ref(mrb, self, mrb_integer(index));

default:

return mrb_ary_ref(mrb, self, aget_index(mrb, index));

}

}

mrb_get_args(mrb, "oi", &index, &len);

i = aget_index(mrb, index);

alen = ARY_LEN(a);

if (i < 0) i += alen;

if (i < 0 || alen < i) return mrb_nil_value();

if (len < 0) return mrb_nil_value();

if (alen == i) return mrb_ary_new(mrb);

if (len > alen - i) len = alen - i;

return ary_subseq(mrb, a, i, len);

}

/*

* call-seq:

* ary[index] = obj -> obj

* ary[start, length] = obj or other_ary or nil -> obj or other_ary or nil

* ary[range] = obj or other_ary or nil -> obj or other_ary or nil

*

* Element Assignment --- Sets the element at +index+, or replaces a subarray

* from the +start+ index for +length+ elements, or replaces a subarray

* specified by the +range+ of indices.

*