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Feature #6515 » array.c

lellisga (Li Ellis Galardo), 05/30/2012 12:14 PM

 
/**********************************************************************

array.c -

$Author$
created at: Fri Aug 6 09:46:12 JST 1993

Copyright (C) 1993-2007 Yukihiro Matsumoto
Copyright (C) 2000 Network Applied Communication Laboratory, Inc.
Copyright (C) 2000 Information-technology Promotion Agency, Japan

**********************************************************************/

#include "ruby/ruby.h"
#include "ruby/util.h"
#include "ruby/st.h"
#include "ruby/encoding.h"
#include "internal.h"

#ifndef ARRAY_DEBUG
# define NDEBUG
#endif
#include <assert.h>

#define numberof(array) (int)(sizeof(array) / sizeof((array)[0]))

VALUE rb_cArray;

static ID id_cmp;

#define ARY_DEFAULT_SIZE 16
#define ARY_MAX_SIZE (LONG_MAX / (int)sizeof(VALUE))

void
rb_mem_clear(register VALUE *mem, register long size)
{
while (size--) {
*mem++ = Qnil;
}
}

static inline void
memfill(register VALUE *mem, register long size, register VALUE val)
{
while (size--) {
*mem++ = val;
}
}

# define ARY_SHARED_P(ary) \
(assert(!FL_TEST((ary), ELTS_SHARED) || !FL_TEST((ary), RARRAY_EMBED_FLAG)), \
FL_TEST((ary),ELTS_SHARED)!=0)
# define ARY_EMBED_P(ary) \
(assert(!FL_TEST((ary), ELTS_SHARED) || !FL_TEST((ary), RARRAY_EMBED_FLAG)), \
FL_TEST((ary), RARRAY_EMBED_FLAG)!=0)

#define ARY_HEAP_PTR(a) (assert(!ARY_EMBED_P(a)), RARRAY(a)->as.heap.ptr)
#define ARY_HEAP_LEN(a) (assert(!ARY_EMBED_P(a)), RARRAY(a)->as.heap.len)
#define ARY_EMBED_PTR(a) (assert(ARY_EMBED_P(a)), RARRAY(a)->as.ary)
#define ARY_EMBED_LEN(a) \
(assert(ARY_EMBED_P(a)), \
(long)((RBASIC(a)->flags >> RARRAY_EMBED_LEN_SHIFT) & \
(RARRAY_EMBED_LEN_MASK >> RARRAY_EMBED_LEN_SHIFT)))

#define ARY_OWNS_HEAP_P(a) (!FL_TEST((a), ELTS_SHARED|RARRAY_EMBED_FLAG))
#define FL_SET_EMBED(a) do { \
assert(!ARY_SHARED_P(a)); \
assert(!OBJ_FROZEN(a)); \
FL_SET((a), RARRAY_EMBED_FLAG); \
} while (0)
#define FL_UNSET_EMBED(ary) FL_UNSET((ary), RARRAY_EMBED_FLAG|RARRAY_EMBED_LEN_MASK)
#define FL_SET_SHARED(ary) do { \
assert(!ARY_EMBED_P(ary)); \
FL_SET((ary), ELTS_SHARED); \
} while (0)
#define FL_UNSET_SHARED(ary) FL_UNSET((ary), ELTS_SHARED)

#define ARY_SET_PTR(ary, p) do { \
assert(!ARY_EMBED_P(ary)); \
assert(!OBJ_FROZEN(ary)); \
RARRAY(ary)->as.heap.ptr = (p); \
} while (0)
#define ARY_SET_EMBED_LEN(ary, n) do { \
long tmp_n = (n); \
assert(ARY_EMBED_P(ary)); \
assert(!OBJ_FROZEN(ary)); \
RBASIC(ary)->flags &= ~RARRAY_EMBED_LEN_MASK; \
RBASIC(ary)->flags |= (tmp_n) << RARRAY_EMBED_LEN_SHIFT; \
} while (0)
#define ARY_SET_HEAP_LEN(ary, n) do { \
assert(!ARY_EMBED_P(ary)); \
RARRAY(ary)->as.heap.len = (n); \
} while (0)
#define ARY_SET_LEN(ary, n) do { \
if (ARY_EMBED_P(ary)) { \
ARY_SET_EMBED_LEN((ary), (n)); \
} \
else { \
ARY_SET_HEAP_LEN((ary), (n)); \
} \
assert(RARRAY_LEN(ary) == (n)); \
} while (0)
#define ARY_INCREASE_PTR(ary, n) do { \
assert(!ARY_EMBED_P(ary)); \
assert(!OBJ_FROZEN(ary)); \
RARRAY(ary)->as.heap.ptr += (n); \
} while (0)
#define ARY_INCREASE_LEN(ary, n) do { \
assert(!OBJ_FROZEN(ary)); \
if (ARY_EMBED_P(ary)) { \
ARY_SET_EMBED_LEN((ary), RARRAY_LEN(ary)+(n)); \
} \
else { \
RARRAY(ary)->as.heap.len += (n); \
} \
} while (0)

#define ARY_CAPA(ary) (ARY_EMBED_P(ary) ? RARRAY_EMBED_LEN_MAX : \
ARY_SHARED_ROOT_P(ary) ? RARRAY_LEN(ary) : RARRAY(ary)->as.heap.aux.capa)
#define ARY_SET_CAPA(ary, n) do { \
assert(!ARY_EMBED_P(ary)); \
assert(!ARY_SHARED_P(ary)); \
assert(!OBJ_FROZEN(ary)); \
RARRAY(ary)->as.heap.aux.capa = (n); \
} while (0)

#define ARY_SHARED(ary) (assert(ARY_SHARED_P(ary)), RARRAY(ary)->as.heap.aux.shared)
#define ARY_SET_SHARED(ary, value) do { \
assert(!ARY_EMBED_P(ary)); \
assert(ARY_SHARED_P(ary)); \
assert(ARY_SHARED_ROOT_P(value)); \
RARRAY(ary)->as.heap.aux.shared = (value); \
} while (0)
#define RARRAY_SHARED_ROOT_FLAG FL_USER5
#define ARY_SHARED_ROOT_P(ary) (FL_TEST((ary), RARRAY_SHARED_ROOT_FLAG))
#define ARY_SHARED_NUM(ary) \
(assert(ARY_SHARED_ROOT_P(ary)), RARRAY(ary)->as.heap.aux.capa)
#define ARY_SET_SHARED_NUM(ary, value) do { \
assert(ARY_SHARED_ROOT_P(ary)); \
RARRAY(ary)->as.heap.aux.capa = (value); \
} while (0)
#define FL_SET_SHARED_ROOT(ary) do { \
assert(!ARY_EMBED_P(ary)); \
FL_SET((ary), RARRAY_SHARED_ROOT_FLAG); \
} while (0)

static void
ary_resize_capa(VALUE ary, long capacity)
{
assert(RARRAY_LEN(ary) <= capacity);
assert(!OBJ_FROZEN(ary));
assert(!ARY_SHARED_P(ary));
if (capacity > RARRAY_EMBED_LEN_MAX) {
if (ARY_EMBED_P(ary)) {
long len = ARY_EMBED_LEN(ary);
VALUE *ptr = ALLOC_N(VALUE, (capacity));
MEMCPY(ptr, ARY_EMBED_PTR(ary), VALUE, len);
FL_UNSET_EMBED(ary);
ARY_SET_PTR(ary, ptr);
ARY_SET_HEAP_LEN(ary, len);
}
else {
REALLOC_N(RARRAY(ary)->as.heap.ptr, VALUE, (capacity));
}
ARY_SET_CAPA(ary, (capacity));
}
else {
if (!ARY_EMBED_P(ary)) {
long len = RARRAY_LEN(ary);
VALUE *ptr = RARRAY_PTR(ary);
if (len > capacity) len = capacity;
MEMCPY(RARRAY(ary)->as.ary, ptr, VALUE, len);
FL_SET_EMBED(ary);
ARY_SET_LEN(ary, len);
xfree(ptr);
}
}
}

static void
ary_double_capa(VALUE ary, long min)
{
long new_capa = ARY_CAPA(ary) / 2;

if (new_capa < ARY_DEFAULT_SIZE) {
new_capa = ARY_DEFAULT_SIZE;
}
if (new_capa >= ARY_MAX_SIZE - min) {
new_capa = (ARY_MAX_SIZE - min) / 2;
}
new_capa += min;
ary_resize_capa(ary, new_capa);
}

static void
rb_ary_decrement_share(VALUE shared)
{
if (shared) {
long num = ARY_SHARED_NUM(shared) - 1;
if (num == 0) {
rb_ary_free(shared);
rb_gc_force_recycle(shared);
}
else if (num > 0) {
ARY_SET_SHARED_NUM(shared, num);
}
}
}

static void
rb_ary_unshare(VALUE ary)
{
VALUE shared = RARRAY(ary)->as.heap.aux.shared;
rb_ary_decrement_share(shared);
FL_UNSET_SHARED(ary);
}

static inline void
rb_ary_unshare_safe(VALUE ary)
{
if (ARY_SHARED_P(ary) && !ARY_EMBED_P(ary)) {
rb_ary_unshare(ary);
}
}

static VALUE
rb_ary_increment_share(VALUE shared)
{
long num = ARY_SHARED_NUM(shared);
if (num >= 0) {
ARY_SET_SHARED_NUM(shared, num + 1);
}
return shared;
}

static void
rb_ary_set_shared(VALUE ary, VALUE shared)
{
rb_ary_increment_share(shared);
FL_SET_SHARED(ary);
ARY_SET_SHARED(ary, shared);
}

static inline void
rb_ary_modify_check(VALUE ary)
{
rb_check_frozen(ary);
if (!OBJ_UNTRUSTED(ary) && rb_safe_level() >= 4)
rb_raise(rb_eSecurityError, "Insecure: can't modify array");
}

void
rb_ary_modify(VALUE ary)
{
rb_ary_modify_check(ary);
if (ARY_SHARED_P(ary)) {
long len = RARRAY_LEN(ary);
if (len <= RARRAY_EMBED_LEN_MAX) {
VALUE *ptr = ARY_HEAP_PTR(ary);
VALUE shared = ARY_SHARED(ary);
FL_UNSET_SHARED(ary);
FL_SET_EMBED(ary);
MEMCPY(ARY_EMBED_PTR(ary), ptr, VALUE, len);
rb_ary_decrement_share(shared);
ARY_SET_EMBED_LEN(ary, len);
}
else {
VALUE *ptr = ALLOC_N(VALUE, len);
MEMCPY(ptr, RARRAY_PTR(ary), VALUE, len);
rb_ary_unshare(ary);
ARY_SET_CAPA(ary, len);
ARY_SET_PTR(ary, ptr);
}
}
}

VALUE
rb_ary_freeze(VALUE ary)
{
return rb_obj_freeze(ary);
}

/*
* call-seq:
* ary.frozen? -> true or false
*
* Return <code>true</code> if this array is frozen (or temporarily frozen
* while being sorted).
*/

static VALUE
rb_ary_frozen_p(VALUE ary)
{
if (OBJ_FROZEN(ary)) return Qtrue;
return Qfalse;
}

static VALUE
ary_alloc(VALUE klass)
{
NEWOBJ(ary, struct RArray);
OBJSETUP(ary, klass, T_ARRAY);
FL_SET_EMBED((VALUE)ary);
ARY_SET_EMBED_LEN((VALUE)ary, 0);

return (VALUE)ary;
}

static VALUE
ary_new(VALUE klass, long capa)
{
VALUE ary;

if (capa < 0) {
rb_raise(rb_eArgError, "negative array size (or size too big)");
}
if (capa > ARY_MAX_SIZE) {
rb_raise(rb_eArgError, "array size too big");
}
ary = ary_alloc(klass);
if (capa > RARRAY_EMBED_LEN_MAX) {
FL_UNSET_EMBED(ary);
ARY_SET_PTR(ary, ALLOC_N(VALUE, capa));
ARY_SET_CAPA(ary, capa);
ARY_SET_HEAP_LEN(ary, 0);
}

return ary;
}

VALUE
rb_ary_new2(long capa)
{
return ary_new(rb_cArray, capa);
}


VALUE
rb_ary_new(void)
{
return rb_ary_new2(RARRAY_EMBED_LEN_MAX);
}

#include <stdarg.h>

VALUE
rb_ary_new3(long n, ...)
{
va_list ar;
VALUE ary;
long i;

ary = rb_ary_new2(n);

va_start(ar, n);
for (i=0; i<n; i++) {
RARRAY_PTR(ary)[i] = va_arg(ar, VALUE);
}
va_end(ar);

ARY_SET_LEN(ary, n);
return ary;
}

VALUE
rb_ary_new4(long n, const VALUE *elts)
{
VALUE ary;

ary = rb_ary_new2(n);
if (n > 0 && elts) {
MEMCPY(RARRAY_PTR(ary), elts, VALUE, n);
ARY_SET_LEN(ary, n);
}

return ary;
}

VALUE
rb_ary_tmp_new(long capa)
{
return ary_new(0, capa);
}

void
rb_ary_free(VALUE ary)
{
if (ARY_OWNS_HEAP_P(ary)) {
xfree(ARY_HEAP_PTR(ary));
}
}

RUBY_FUNC_EXPORTED size_t
rb_ary_memsize(VALUE ary)
{
if (ARY_OWNS_HEAP_P(ary)) {
return RARRAY(ary)->as.heap.aux.capa * sizeof(VALUE);
}
else {
return 0;
}
}

static inline void
ary_discard(VALUE ary)
{
rb_ary_free(ary);
RBASIC(ary)->flags |= RARRAY_EMBED_FLAG;
RBASIC(ary)->flags &= ~RARRAY_EMBED_LEN_MASK;
}

static VALUE
ary_make_shared(VALUE ary)
{
assert(!ARY_EMBED_P(ary));
if (ARY_SHARED_P(ary)) {
return ARY_SHARED(ary);
}
else if (ARY_SHARED_ROOT_P(ary)) {
return ary;
}
else if (OBJ_FROZEN(ary)) {
ary_resize_capa(ary, ARY_HEAP_LEN(ary));
FL_SET_SHARED_ROOT(ary);
ARY_SET_SHARED_NUM(ary, 1);
return ary;
}
else {
NEWOBJ(shared, struct RArray);
OBJSETUP(shared, 0, T_ARRAY);
FL_UNSET_EMBED(shared);

ARY_SET_LEN((VALUE)shared, RARRAY_LEN(ary));
ARY_SET_PTR((VALUE)shared, RARRAY_PTR(ary));
FL_SET_SHARED_ROOT(shared);
ARY_SET_SHARED_NUM((VALUE)shared, 1);
FL_SET_SHARED(ary);
ARY_SET_SHARED(ary, (VALUE)shared);
OBJ_FREEZE(shared);
return (VALUE)shared;
}
}


static VALUE
ary_make_substitution(VALUE ary)
{
if (RARRAY_LEN(ary) <= RARRAY_EMBED_LEN_MAX) {
VALUE subst = rb_ary_new2(RARRAY_LEN(ary));
MEMCPY(ARY_EMBED_PTR(subst), RARRAY_PTR(ary), VALUE, RARRAY_LEN(ary));
ARY_SET_EMBED_LEN(subst, RARRAY_LEN(ary));
return subst;
}
else {
return rb_ary_increment_share(ary_make_shared(ary));
}
}

VALUE
rb_assoc_new(VALUE car, VALUE cdr)
{
return rb_ary_new3(2, car, cdr);
}

static VALUE
to_ary(VALUE ary)
{
return rb_convert_type(ary, T_ARRAY, "Array", "to_ary");
}

VALUE
rb_check_array_type(VALUE ary)
{
return rb_check_convert_type(ary, T_ARRAY, "Array", "to_ary");
}

/*
* call-seq:
* Array.try_convert(obj) -> array or nil
*
* Tries to convert +obj+ into an array, using +to_ary+ method. Returns the
* converted array or +nil+ if +obj+ cannot be converted for any reason.
* This method can be used to check if an argument is an array.
*
* Array.try_convert([1]) #=> [1]
* Array.try_convert("1") #=> nil
*
* if tmp = Array.try_convert(arg)
* # the argument is an array
* elsif tmp = String.try_convert(arg)
* # the argument is a string
* end
*
*/

static VALUE
rb_ary_s_try_convert(VALUE dummy, VALUE ary)
{
return rb_check_array_type(ary);
}

/*
* call-seq:
* Array.new(size=0, obj=nil)
* Array.new(array)
* Array.new(size) {|index| block }
*
* Returns a new array.
*
* In the first form, if no arguments are sent, the new array will be empty.
* When a +size+ and an optional +obj+ are sent, an array is created with
* +size+ copies of +obj+. Take notice that all elements will reference the
* same object +obj+.
*
* The second form creates a copy of the array passed as a parameter (the
* array is generated by calling to_ary on the parameter).
*
* first_array = ["Matz", "Guido"]
*
* second_array = Array.new(first_array) #=> ["Matz", "Guido"]
*
* first_array.equal? second_array #=> false
*
* In the last form, an array of the given size is created. Each element in
* this array is created by passing the element's index to the given block
* and storing the return value.
*
* Array.new(3){ |index| index ** 2 }
* # => [0, 1, 4]
*
* == Common gotchas
*
* When sending the second parameter, the same object will be used as the
* value for all the array elements:
*
* a = Array.new(2, Hash.new)
* # => [{}, {}]
*
* a[0]['cat'] = 'feline'
* a # => [{"cat"=>"feline"}, {"cat"=>"feline"}]
*
* a[1]['cat'] = 'Felix'
* a # => [{"cat"=>"Felix"}, {"cat"=>"Felix"}]
*
* Since all the Array elements store the same hash, changes to one of them
* will affect them all.
*
* If multiple copies are what you want, you should use the block
* version which uses the result of that block each time an element
* of the array needs to be initialized:
*
* a = Array.new(2) { Hash.new }
* a[0]['cat'] = 'feline'
* a # => [{"cat"=>"feline"}, {}]
*
*/

static VALUE
rb_ary_initialize(int argc, VALUE *argv, VALUE ary)
{
long len;
VALUE size, val;

rb_ary_modify(ary);
if (argc == 0) {
if (ARY_OWNS_HEAP_P(ary) && RARRAY_PTR(ary)) {
xfree(RARRAY_PTR(ary));
}
rb_ary_unshare_safe(ary);
FL_SET_EMBED(ary);
ARY_SET_EMBED_LEN(ary, 0);
if (rb_block_given_p()) {
rb_warning("given block not used");
}
return ary;
}
rb_scan_args(argc, argv, "02", &size, &val);
if (argc == 1 && !FIXNUM_P(size)) {
val = rb_check_array_type(size);
if (!NIL_P(val)) {
rb_ary_replace(ary, val);
return ary;
}
}

len = NUM2LONG(size);
if (len < 0) {
rb_raise(rb_eArgError, "negative array size");
}
if (len > ARY_MAX_SIZE) {
rb_raise(rb_eArgError, "array size too big");
}
rb_ary_modify(ary);
ary_resize_capa(ary, len);
if (rb_block_given_p()) {
long i;

if (argc == 2) {
rb_warn("block supersedes default value argument");
}
for (i=0; i<len; i++) {
rb_ary_store(ary, i, rb_yield(LONG2NUM(i)));
ARY_SET_LEN(ary, i + 1);
}
}
else {
memfill(RARRAY_PTR(ary), len, val);
ARY_SET_LEN(ary, len);
}
return ary;
}

/*
* Returns a new array populated with the given objects.
*
* Array.[]( 1, 'a', /^A/ ) # => [1, "a", /^A/]
* Array[ 1, 'a', /^A/ ] # => [1, "a", /^A/]
* [ 1, 'a', /^A/ ] # => [1, "a", /^A/]
*/

static VALUE
rb_ary_s_create(int argc, VALUE *argv, VALUE klass)
{
VALUE ary = ary_new(klass, argc);
if (argc > 0 && argv) {
MEMCPY(RARRAY_PTR(ary), argv, VALUE, argc);
ARY_SET_LEN(ary, argc);
}

return ary;
}

void
rb_ary_store(VALUE ary, long idx, VALUE val)
{
if (idx < 0) {
idx += RARRAY_LEN(ary);
if (idx < 0) {
rb_raise(rb_eIndexError, "index %ld too small for array; minimum: %ld",
idx - RARRAY_LEN(ary), -RARRAY_LEN(ary));
}
}
else if (idx >= ARY_MAX_SIZE) {
rb_raise(rb_eIndexError, "index %ld too big", idx);
}

rb_ary_modify(ary);
if (idx >= ARY_CAPA(ary)) {
ary_double_capa(ary, idx);
}
if (idx > RARRAY_LEN(ary)) {
rb_mem_clear(RARRAY_PTR(ary) + RARRAY_LEN(ary),
idx-RARRAY_LEN(ary) + 1);
}

if (idx >= RARRAY_LEN(ary)) {
ARY_SET_LEN(ary, idx + 1);
}
RARRAY_PTR(ary)[idx] = val;
}

static VALUE
ary_make_partial(VALUE ary, VALUE klass, long offset, long len)
{
assert(offset >= 0);
assert(len >= 0);
assert(offset+len <= RARRAY_LEN(ary));

if (len <= RARRAY_EMBED_LEN_MAX) {
VALUE result = ary_alloc(klass);
MEMCPY(ARY_EMBED_PTR(result), RARRAY_PTR(ary) + offset, VALUE, len);
ARY_SET_EMBED_LEN(result, len);
return result;
}
else {
VALUE shared, result = ary_alloc(klass);
FL_UNSET_EMBED(result);

shared = ary_make_shared(ary);
ARY_SET_PTR(result, RARRAY_PTR(ary));
ARY_SET_LEN(result, RARRAY_LEN(ary));
rb_ary_set_shared(result, shared);

ARY_INCREASE_PTR(result, offset);
ARY_SET_LEN(result, len);
return result;
}
}

static VALUE
ary_make_shared_copy(VALUE ary)
{
return ary_make_partial(ary, rb_obj_class(ary), 0, RARRAY_LEN(ary));
}

enum ary_take_pos_flags
{
ARY_TAKE_FIRST = 0,
ARY_TAKE_LAST = 1
};

static VALUE
ary_take_first_or_last(int argc, VALUE *argv, VALUE ary, enum ary_take_pos_flags last)
{
VALUE nv;
long n;
long offset = 0;

rb_scan_args(argc, argv, "1", &nv);
n = NUM2LONG(nv);
if (n > RARRAY_LEN(ary)) {
n = RARRAY_LEN(ary);
}
else if (n < 0) {
rb_raise(rb_eArgError, "negative array size");
}
if (last) {
offset = RARRAY_LEN(ary) - n;
}
return ary_make_partial(ary, rb_cArray, offset, n);
}

static VALUE rb_ary_push_1(VALUE ary, VALUE item);

/*
* call-seq:
* ary << obj -> ary
*
* Append---Pushes the given object on to the end of this array. This
* expression returns the array itself, so several appends
* may be chained together.
*
* [ 1, 2 ] << "c" << "d" << [ 3, 4 ]
* #=> [ 1, 2, "c", "d", [ 3, 4 ] ]
*
*/

VALUE
rb_ary_push(VALUE ary, VALUE item)
{
rb_ary_modify(ary);
return rb_ary_push_1(ary, item);
}

static VALUE
rb_ary_push_1(VALUE ary, VALUE item)
{
long idx = RARRAY_LEN(ary);

if (idx >= ARY_CAPA(ary)) {
ary_double_capa(ary, idx);
}
RARRAY_PTR(ary)[idx] = item;
ARY_SET_LEN(ary, idx + 1);
return ary;
}

VALUE
rb_ary_cat(VALUE ary, const VALUE *ptr, long len)
{
long oldlen;

rb_ary_modify(ary);
oldlen = RARRAY_LEN(ary);
ary_resize_capa(ary, oldlen + len);
MEMCPY(RARRAY_PTR(ary) + oldlen, ptr, VALUE, len);
ARY_SET_LEN(ary, oldlen + len);
return ary;
}

/*
* call-seq:
* ary.push(obj, ... ) -> ary
*
* Append---Pushes the given object(s) on to the end of this array. This
* expression returns the array itself, so several appends
* may be chained together.
*
* a = [ "a", "b", "c" ]
* a.push("d", "e", "f")
* #=> ["a", "b", "c", "d", "e", "f"]
*/

static VALUE
rb_ary_push_m(int argc, VALUE *argv, VALUE ary)
{
return rb_ary_cat(ary, argv, argc);
}

VALUE
rb_ary_pop(VALUE ary)
{
long n;
rb_ary_modify_check(ary);
if (RARRAY_LEN(ary) == 0) return Qnil;
if (ARY_OWNS_HEAP_P(ary) &&
RARRAY_LEN(ary) * 3 < ARY_CAPA(ary) &&
ARY_CAPA(ary) > ARY_DEFAULT_SIZE)
{
ary_resize_capa(ary, RARRAY_LEN(ary) * 2);
}
n = RARRAY_LEN(ary)-1;
ARY_SET_LEN(ary, n);
return RARRAY_PTR(ary)[n];
}

/*
* call-seq:
* ary.pop -> obj or nil
* ary.pop(n) -> new_ary
*
* Removes the last element from +self+ and returns it, or
* <code>nil</code> if the array is empty.
*
* If a number +n+ is given, returns an array of the last n elements
* (or less) just like <code>array.slice!(-n, n)</code> does.
*
* a = [ "a", "b", "c", "d" ]
* a.pop #=> "d"
* a.pop(2) #=> ["b", "c"]
* a #=> ["a"]
*/

static VALUE
rb_ary_pop_m(int argc, VALUE *argv, VALUE ary)
{
VALUE result;

if (argc == 0) {
return rb_ary_pop(ary);
}

rb_ary_modify_check(ary);
result = ary_take_first_or_last(argc, argv, ary, ARY_TAKE_LAST);
ARY_INCREASE_LEN(ary, -RARRAY_LEN(result));
return result;
}

VALUE
rb_ary_shift(VALUE ary)
{
VALUE top;

rb_ary_modify_check(ary);
if (RARRAY_LEN(ary) == 0) return Qnil;
top = RARRAY_PTR(ary)[0];
if (!ARY_SHARED_P(ary)) {
if (RARRAY_LEN(ary) < ARY_DEFAULT_SIZE) {
MEMMOVE(RARRAY_PTR(ary), RARRAY_PTR(ary)+1, VALUE, RARRAY_LEN(ary)-1);
ARY_INCREASE_LEN(ary, -1);
return top;
}
assert(!ARY_EMBED_P(ary)); /* ARY_EMBED_LEN_MAX < ARY_DEFAULT_SIZE */

RARRAY_PTR(ary)[0] = Qnil;
ary_make_shared(ary);
}
else if (ARY_SHARED_NUM(ARY_SHARED(ary)) == 1) {
RARRAY_PTR(ary)[0] = Qnil;
}
ARY_INCREASE_PTR(ary, 1); /* shift ptr */
ARY_INCREASE_LEN(ary, -1);

return top;
}

/*
* call-seq:
* ary.shift -> obj or nil
* ary.shift(n) -> new_ary
*
* Returns the first element of +self+ and removes it (shifting all
* other elements down by one). Returns <code>nil</code> if the array
* is empty.
*
* If a number +n+ is given, returns an array of the first n elements
* (or less) just like <code>array.slice!(0, n)</code> does.
*
* args = [ "-m", "-q", "filename" ]
* args.shift #=> "-m"
* args #=> ["-q", "filename"]
*
* args = [ "-m", "-q", "filename" ]
* args.shift(2) #=> ["-m", "-q"]
* args #=> ["filename"]
*/

static VALUE
rb_ary_shift_m(int argc, VALUE *argv, VALUE ary)
{
VALUE result;
long n;

if (argc == 0) {
return rb_ary_shift(ary);
}

rb_ary_modify_check(ary);
result = ary_take_first_or_last(argc, argv, ary, ARY_TAKE_FIRST);
n = RARRAY_LEN(result);
if (ARY_SHARED_P(ary)) {
if (ARY_SHARED_NUM(ARY_SHARED(ary)) == 1) {
rb_mem_clear(RARRAY_PTR(ary), n);
}
ARY_INCREASE_PTR(ary, n);
}
else {
MEMMOVE(RARRAY_PTR(ary), RARRAY_PTR(ary)+n, VALUE, RARRAY_LEN(ary)-n);
}
ARY_INCREASE_LEN(ary, -n);

return result;
}

/*
* call-seq:
* ary.unshift(obj, ...) -> ary
*
* Prepends objects to the front of +self+,
* moving other elements upwards.
*
* a = [ "b", "c", "d" ]
* a.unshift("a") #=> ["a", "b", "c", "d"]
* a.unshift(1, 2) #=> [ 1, 2, "a", "b", "c", "d"]
*/

static VALUE
rb_ary_unshift_m(int argc, VALUE *argv, VALUE ary)
{
long len;

rb_ary_modify(ary);
if (argc == 0) return ary;
if (ARY_CAPA(ary) <= (len = RARRAY_LEN(ary)) + argc) {
ary_double_capa(ary, len + argc);
}

/* sliding items */
MEMMOVE(RARRAY_PTR(ary) + argc, RARRAY_PTR(ary), VALUE, len);
MEMCPY(RARRAY_PTR(ary), argv, VALUE, argc);
ARY_INCREASE_LEN(ary, argc);

return ary;
}

VALUE
rb_ary_unshift(VALUE ary, VALUE item)
{
return rb_ary_unshift_m(1,&item,ary);
}

/* faster version - use this if you don't need to treat negative offset */
static inline VALUE
rb_ary_elt(VALUE ary, long offset)
{
if (RARRAY_LEN(ary) == 0) return Qnil;
if (offset < 0 || RARRAY_LEN(ary) <= offset) {
return Qnil;
}
return RARRAY_PTR(ary)[offset];
}

VALUE
rb_ary_entry(VALUE ary, long offset)
{
if (offset < 0) {
offset += RARRAY_LEN(ary);
}
return rb_ary_elt(ary, offset);
}

VALUE
rb_ary_subseq(VALUE ary, long beg, long len)
{
VALUE klass;

if (beg > RARRAY_LEN(ary)) return Qnil;
if (beg < 0 || len < 0) return Qnil;

if (RARRAY_LEN(ary) < len || RARRAY_LEN(ary) < beg + len) {
len = RARRAY_LEN(ary) - beg;
}
klass = rb_obj_class(ary);
if (len == 0) return ary_new(klass, 0);

return ary_make_partial(ary, klass, beg, len);
}

/*
* 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 +start+ and
* continuing for +length+ elements, or returns a subarray
* specified by +range+.
* Negative indices count backward from the end of the
* array (-1 is the last element). Returns +nil+ if the index
* (or starting index) are out of range.
*
* a = [ "a", "b", "c", "d", "e" ]
* a[2] + a[0] + a[1] #=> "cab"
* a[6] #=> nil
* a[1, 2] #=> [ "b", "c" ]
* a[1..3] #=> [ "b", "c", "d" ]
* a[4..7] #=> [ "e" ]
* a[6..10] #=> nil
* a[-3, 3] #=> [ "c", "d", "e" ]
* # special cases
* a[5] #=> nil
* a[5, 1] #=> []
* a[5..10] #=> []
*
*/

VALUE
rb_ary_aref(int argc, VALUE *argv, VALUE ary)
{
VALUE arg;
long beg, len;

if (argc == 2) {
beg = NUM2LONG(argv[0]);
len = NUM2LONG(argv[1]);
if (beg < 0) {
beg += RARRAY_LEN(ary);
}
return rb_ary_subseq(ary, beg, len);
}
if (argc != 1) {
rb_scan_args(argc, argv, "11", 0, 0);
}
arg = argv[0];
/* special case - speeding up */
if (FIXNUM_P(arg)) {
return rb_ary_entry(ary, FIX2LONG(arg));
}
/* check if idx is Range */
switch (rb_range_beg_len(arg, &beg, &len, RARRAY_LEN(ary), 0)) {
case Qfalse:
break;
case Qnil:
return Qnil;
default:
return rb_ary_subseq(ary, beg, len);
}
return rb_ary_entry(ary, NUM2LONG(arg));
}

/*
* call-seq:
* ary.at(index) -> obj or nil
*
* Returns the element at +index+. A
* negative index counts from the end of +self+. Returns +nil+
* if the index is out of range. See also <code>Array#[]</code>.
*
* a = [ "a", "b", "c", "d", "e" ]
* a.at(0) #=> "a"
* a.at(-1) #=> "e"
*/

static VALUE
rb_ary_at(VALUE ary, VALUE pos)
{
return rb_ary_entry(ary, NUM2LONG(pos));
}

/*
* call-seq:
* ary.first -> obj or nil
* ary.first(n) -> new_ary
*
* Returns the first element, or the first +n+ elements, of the array.
* If the array is empty, the first form returns <code>nil</code>, and the
* second form returns an empty array.
*
* a = [ "q", "r", "s", "t" ]
* a.first #=> "q"
* a.first(2) #=> ["q", "r"]
*/

static VALUE
rb_ary_first(int argc, VALUE *argv, VALUE ary)
{
if (argc == 0) {
if (RARRAY_LEN(ary) == 0) return Qnil;
return RARRAY_PTR(ary)[0];
}
else {
return ary_take_first_or_last(argc, argv, ary, ARY_TAKE_FIRST);
}
}

/*
* call-seq:
* ary.last -> obj or nil
* ary.last(n) -> new_ary
*
* Returns the last element(s) of +self+. If the array is empty,
* the first form returns <code>nil</code>.
*
* a = [ "w", "x", "y", "z" ]
* a.last #=> "z"
* a.last(2) #=> ["y", "z"]
*/

VALUE
rb_ary_last(int argc, VALUE *argv, VALUE ary)
{
if (argc == 0) {
if (RARRAY_LEN(ary) == 0) return Qnil;
return RARRAY_PTR(ary)[RARRAY_LEN(ary)-1];
}
else {
return ary_take_first_or_last(argc, argv, ary, ARY_TAKE_LAST);
}
}

/*
* call-seq:
* ary.fetch(index) -> obj
* ary.fetch(index, default ) -> obj
* ary.fetch(index) {|index| block } -> obj
*
* Tries to return the element at position +index+. If the index lies outside
* the array, the first form throws an IndexError exception, the second form
* returns +default+, and the third form returns the value of invoking the
* block, passing in the index. Negative values of +index+ count from the end
* of the array.
*
* Tries to return the element at position +index+, but throws an IndexError
* exception if the referenced index lies outside of the array bounds. This
* error can be prevented by supplying a second argument, which will act as a
* +default+ value. Alternatively, if the second argument is a block it will
* only be executed when an invalid index is referenced. Negative values of
* +index+ count from the end of the array.
*
* a = [ 11, 22, 33, 44 ]
* a.fetch(1) #=> 22
* a.fetch(-1) #=> 44
* a.fetch(4, 'cat') #=> "cat"
* a.fetch(100) { |i| puts "#{i} is out of bounds" }
* #=> "100 is out of bounds"
*/

static VALUE
rb_ary_fetch(int argc, VALUE *argv, VALUE ary)
{
VALUE pos, ifnone;
long block_given;
long idx;

rb_scan_args(argc, argv, "11", &pos, &ifnone);
block_given = rb_block_given_p();
if (block_given && argc == 2) {
rb_warn("block supersedes default value argument");
}
idx = NUM2LONG(pos);

if (idx < 0) {
idx += RARRAY_LEN(ary);
}
if (idx < 0 || RARRAY_LEN(ary) <= idx) {
if (block_given) return rb_yield(pos);
if (argc == 1) {
rb_raise(rb_eIndexError, "index %ld outside of array bounds: %ld...%ld",
idx - (idx < 0 ? RARRAY_LEN(ary) : 0), -RARRAY_LEN(ary), RARRAY_LEN(ary));
}
return ifnone;
}
return RARRAY_PTR(ary)[idx];
}

/*
* call-seq:
* ary.index(obj) -> int or nil
* ary.index {|item| block} -> int or nil
* ary.index -> an_enumerator
*
* Returns the index of the first object in +self+ such that the object is
* <code>==</code> to +obj+. If a block is given instead of an
* argument, returns index of first object for which <em>block</em> is true.
* Returns <code>nil</code> if no match is found.
* See also <code>Array#rindex</code>.
*
* If neither block nor argument is given, an enumerator is returned instead.
*
* a = [ "a", "b", "c" ]
* a.index("b") #=> 1
* a.index("z") #=> nil
* a.index{|x|x=="b"} #=> 1
*
* This is an alias of <code>#find_index</code>.
*/

static VALUE
rb_ary_index(int argc, VALUE *argv, VALUE ary)
{
VALUE val;
long i;

if (argc == 0) {
RETURN_ENUMERATOR(ary, 0, 0);
for (i=0; i<RARRAY_LEN(ary); i++) {
if (RTEST(rb_yield(RARRAY_PTR(ary)[i]))) {
return LONG2NUM(i);
}
}
return Qnil;
}
rb_scan_args(argc, argv, "1", &val);
if (rb_block_given_p())
rb_warn("given block not used");
for (i=0; i<RARRAY_LEN(ary); i++) {
if (rb_equal(RARRAY_PTR(ary)[i], val))
return LONG2NUM(i);
}
return Qnil;
}

/*
* call-seq:
* ary.rindex(obj) -> int or nil
* ary.rindex {|item| block} -> int or nil
* ary.rindex -> an_enumerator
*
* Returns the index of the last object in +self+
* <code>==</code> to +obj+. If a block is given instead of an
* argument, returns index of first object for which <em>block</em> is
* true, starting from the last object.
* Returns <code>nil</code> if no match is found.
* See also Array#index.
*
* If neither block nor argument is given, an enumerator is returned instead.
*
* a = [ "a", "b", "b", "b", "c" ]
* a.rindex("b") #=> 3
* a.rindex("z") #=> nil
* a.rindex { |x| x == "b" } #=> 3
*/

static VALUE
rb_ary_rindex(int argc, VALUE *argv, VALUE ary)
{
VALUE val;
long i = RARRAY_LEN(ary);

if (argc == 0) {
RETURN_ENUMERATOR(ary, 0, 0);
while (i--) {
if (RTEST(rb_yield(RARRAY_PTR(ary)[i])))
return LONG2NUM(i);
if (i > RARRAY_LEN(ary)) {
i = RARRAY_LEN(ary);
}
}
return Qnil;
}
rb_scan_args(argc, argv, "1", &val);
if (rb_block_given_p())
rb_warn("given block not used");
while (i--) {
if (rb_equal(RARRAY_PTR(ary)[i], val))
return LONG2NUM(i);
if (i > RARRAY_LEN(ary)) {
i = RARRAY_LEN(ary);
}
}
return Qnil;
}

VALUE
rb_ary_to_ary(VALUE obj)
{
VALUE tmp = rb_check_array_type(obj);

if (!NIL_P(tmp)) return tmp;
return rb_ary_new3(1, obj);
}

static void
rb_ary_splice(VALUE ary, long beg, long len, VALUE rpl)
{
long rlen;

if (len < 0) rb_raise(rb_eIndexError, "negative length (%ld)", len);
if (beg < 0) {
beg += RARRAY_LEN(ary);
if (beg < 0) {
rb_raise(rb_eIndexError, "index %ld too small for array; minimum: %ld",
beg - RARRAY_LEN(ary), -RARRAY_LEN(ary));
}
}
if (RARRAY_LEN(ary) < len || RARRAY_LEN(ary) < beg + len) {
len = RARRAY_LEN(ary) - beg;
}

if (rpl == Qundef) {
rlen = 0;
}
else {
rpl = rb_ary_to_ary(rpl);
rlen = RARRAY_LEN(rpl);
}
rb_ary_modify(ary);
if (beg >= RARRAY_LEN(ary)) {
if (beg > ARY_MAX_SIZE - rlen) {
rb_raise(rb_eIndexError, "index %ld too big", beg);
}
len = beg + rlen;
if (len >= ARY_CAPA(ary)) {
ary_double_capa(ary, len);
}
rb_mem_clear(RARRAY_PTR(ary) + RARRAY_LEN(ary), beg - RARRAY_LEN(ary));
if (rlen > 0) {
MEMCPY(RARRAY_PTR(ary) + beg, RARRAY_PTR(rpl), VALUE, rlen);
}
ARY_SET_LEN(ary, len);
}
else {
long alen;

alen = RARRAY_LEN(ary) + rlen - len;
if (alen >= ARY_CAPA(ary)) {
ary_double_capa(ary, alen);
}

if (len != rlen) {
MEMMOVE(RARRAY_PTR(ary) + beg + rlen, RARRAY_PTR(ary) + beg + len,
VALUE, RARRAY_LEN(ary) - (beg + len));
ARY_SET_LEN(ary, alen);
}
if (rlen > 0) {
MEMMOVE(RARRAY_PTR(ary) + beg, RARRAY_PTR(rpl), VALUE, rlen);
}
}
}

void
rb_ary_set_len(VALUE ary, long len)
{
long capa;

rb_ary_modify_check(ary);
if (ARY_SHARED_P(ary)) {
rb_raise(rb_eRuntimeError, "can't set length of shared ");
}
if (len > (capa = (long)ARY_CAPA(ary))) {
rb_bug("probable buffer overflow: %ld for %ld", len, capa);
}
ARY_SET_LEN(ary, len);
}

/*!
* expands or shrinks \a ary to \a len elements.
* expanded region will be filled with Qnil.
* \param ary an array
* \param len new size
* \return \a ary
* \post the size of \a ary is \a len.
*/
VALUE
rb_ary_resize(VALUE ary, long len)
{
long olen;

rb_ary_modify(ary);
olen = RARRAY_LEN(ary);
if (len == olen) return ary;
if (len > ARY_MAX_SIZE) {
rb_raise(rb_eIndexError, "index %ld too big", len);
}
if (len > olen) {
if (len >= ARY_CAPA(ary)) {
ary_double_capa(ary, len);
}
rb_mem_clear(RARRAY_PTR(ary) + olen, len - olen);
ARY_SET_LEN(ary, len);
}
else if (ARY_EMBED_P(ary)) {
ARY_SET_EMBED_LEN(ary, len);
}
else if (len <= RARRAY_EMBED_LEN_MAX) {
VALUE tmp[RARRAY_EMBED_LEN_MAX];
MEMCPY(tmp, ARY_HEAP_PTR(ary), VALUE, len);
ary_discard(ary);
MEMCPY(ARY_EMBED_PTR(ary), tmp, VALUE, len);
ARY_SET_EMBED_LEN(ary, len);
}
else {
if (olen > len + ARY_DEFAULT_SIZE) {
REALLOC_N(RARRAY(ary)->as.heap.ptr, VALUE, len);
ARY_SET_CAPA(ary, len);
}
ARY_SET_HEAP_LEN(ary, len);
}
return ary;
}

/*
* 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 starting at +start+ and
* continuing for +length+ elements, or replaces a subarray
* specified by +range+. If indices are greater than
* the current capacity of the array, the array grows
* automatically. A negative indices will count backward
* from the end of the array. Inserts elements if +length+ is
* zero. An IndexError is raised if a negative index points
* past the beginning of the array. See also
* Array#push, and Array#unshift.
*
* a = Array.new
* a[4] = "4"; #=> [nil, nil, nil, nil, "4"]
* a[0, 3] = [ 'a', 'b', 'c' ] #=> ["a", "b", "c", nil, "4"]
* a[1..2] = [ 1, 2 ] #=> ["a", 1, 2, nil, "4"]
* a[0, 2] = "?" #=> ["?", 2, nil, "4"]
* a[0..2] = "A" #=> ["A", "4"]
* a[-1] = "Z" #=> ["A", "Z"]
* a[1..-1] = nil #=> ["A", nil]
* a[1..-1] = [] #=> ["A"]
*/

static VALUE
rb_ary_aset(int argc, VALUE *argv, VALUE ary)
{
long offset, beg, len;

if (argc == 3) {
rb_ary_modify_check(ary);
beg = NUM2LONG(argv[0]);
len = NUM2LONG(argv[1]);
rb_ary_splice(ary, beg, len, argv[2]);
return argv[2];
}
rb_check_arity(argc, 2, 2);
rb_ary_modify_check(ary);
if (FIXNUM_P(argv[0])) {
offset = FIX2LONG(argv[0]);
goto fixnum;
}
if (rb_range_beg_len(argv[0], &beg, &len, RARRAY_LEN(ary), 1)) {
/* check if idx is Range */
rb_ary_splice(ary, beg, len, argv[1]);
return argv[1];
}

offset = NUM2LONG(argv[0]);
fixnum:
rb_ary_store(ary, offset, argv[1]);
return argv[1];
}

/*
* call-seq:
* ary.insert(index, obj...) -> ary
*
* Inserts the given values before the element with the given index
* (which may be negative).
*
* a = %w{ a b c d }
* a.insert(2, 99) #=> ["a", "b", 99, "c", "d"]
* a.insert(-2, 1, 2, 3) #=> ["a", "b", 99, "c", 1, 2, 3, "d"]
*/

static VALUE
rb_ary_insert(int argc, VALUE *argv, VALUE ary)
{
long pos;

rb_check_arity(argc, 1, UNLIMITED_ARGUMENTS);
rb_ary_modify_check(ary);
if (argc == 1) return ary;
pos = NUM2LONG(argv[0]);
if (pos == -1) {
pos = RARRAY_LEN(ary);
}
if (pos < 0) {
pos++;
}
rb_ary_splice(ary, pos, 0, rb_ary_new4(argc - 1, argv + 1));
return ary;
}

/*
* call-seq:
* ary.each {|item| block } -> ary
* ary.each -> an_enumerator
*
* Calls +block+ once for each element in +self+, passing that
* element as a parameter.
*
* If no block is given, an enumerator is returned instead.
*
* a = [ "a", "b", "c" ]
* a.each {|x| print x, " -- " }
*
* produces:
*
* a -- b -- c --
*/

VALUE
rb_ary_each(VALUE array)
{
long i;
volatile VALUE ary = array;

RETURN_ENUMERATOR(ary, 0, 0);
for (i=0; i<RARRAY_LEN(ary); i++) {
rb_yield(RARRAY_PTR(ary)[i]);
}
return ary;
}

/*
* call-seq:
* ary.each_index {|index| block } -> ary
* ary.each_index -> an_enumerator
*
* Same as Array#each, but passes the index of the element instead of the
* element itself.
*
* If no block is given, an enumerator is returned instead.
*
*
* a = [ "a", "b", "c" ]
* a.each_index {|x| print x, " -- " }
*
* produces:
*
* 0 -- 1 -- 2 --
*/

static VALUE
rb_ary_each_index(VALUE ary)
{
long i;
RETURN_ENUMERATOR(ary, 0, 0);

for (i=0; i<RARRAY_LEN(ary); i++) {
rb_yield(LONG2NUM(i));
}
return ary;
}

/*
* call-seq:
* ary.reverse_each {|item| block } -> ary
* ary.reverse_each -> an_enumerator
*
* Same as Array#each, but traverses +self+ in reverse order.
*
* a = [ "a", "b", "c" ]
* a.reverse_each {|x| print x, " " }
*
* produces:
*
* c b a
*/

static VALUE
rb_ary_reverse_each(VALUE ary)
{
long len;

RETURN_ENUMERATOR(ary, 0, 0);
len = RARRAY_LEN(ary);
while (len--) {
rb_yield(RARRAY_PTR(ary)[len]);
if (RARRAY_LEN(ary) < len) {
len = RARRAY_LEN(ary);
}
}
return ary;
}

/*
* call-seq:
* ary.length -> int
*
* Returns the number of elements in +self+. May be zero.
*
* [ 1, 2, 3, 4, 5 ].length #=> 5
*/

static VALUE
rb_ary_length(VALUE ary)
{
long len = RARRAY_LEN(ary);
return LONG2NUM(len);
}

/*
* call-seq:
* ary.empty? -> true or false
*
* Returns <code>true</code> if +self+ contains no elements.
*
* [].empty? #=> true
*/

static VALUE
rb_ary_empty_p(VALUE ary)
{
if (RARRAY_LEN(ary) == 0)
return Qtrue;
return Qfalse;
}

VALUE
rb_ary_dup(VALUE ary)
{
VALUE dup = rb_ary_new2(RARRAY_LEN(ary));
MEMCPY(RARRAY_PTR(dup), RARRAY_PTR(ary), VALUE, RARRAY_LEN(ary));
ARY_SET_LEN(dup, RARRAY_LEN(ary));
return dup;
}

VALUE
rb_ary_resurrect(VALUE ary)
{
return rb_ary_new4(RARRAY_LEN(ary), RARRAY_PTR(ary));
}

extern VALUE rb_output_fs;

static void ary_join_1(VALUE obj, VALUE ary, VALUE sep, long i, VALUE result, int *first);

static VALUE
recursive_join(VALUE obj, VALUE argp, int recur)
{
VALUE *arg = (VALUE *)argp;
VALUE ary = arg[0];
VALUE sep = arg[1];
VALUE result = arg[2];
int *first = (int *)arg[3];

if (recur) {
rb_raise(rb_eArgError, "recursive array join");
}
else {
ary_join_1(obj, ary, sep, 0, result, first);
}
return Qnil;
}

static void
ary_join_0(VALUE ary, VALUE sep, long max, VALUE result)
{
long i;
VALUE val;

if (max > 0) rb_enc_copy(result, RARRAY_PTR(ary)[0]);
for (i=0; i<max; i++) {
val = RARRAY_PTR(ary)[i];
if (i > 0 && !NIL_P(sep))
rb_str_buf_append(result, sep);
rb_str_buf_append(result, val);
if (OBJ_TAINTED(val)) OBJ_TAINT(result);
if (OBJ_UNTRUSTED(val)) OBJ_TAINT(result);
}
}

static void
ary_join_1(VALUE obj, VALUE ary, VALUE sep, long i, VALUE result, int *first)
{
VALUE val, tmp;

for (; i<RARRAY_LEN(ary); i++) {
if (i > 0 && !NIL_P(sep))
rb_str_buf_append(result, sep);

val = RARRAY_PTR(ary)[i];
switch (TYPE(val)) {
case T_STRING:
str_join:
rb_str_buf_append(result, val);
*first = FALSE;
break;
case T_ARRAY:
obj = val;
ary_join:
if (val == ary) {
rb_raise(rb_eArgError, "recursive array join");
}
else {
VALUE args[4];

args[0] = val;
args[1] = sep;
args[2] = result;
args[3] = (VALUE)first;
rb_exec_recursive(recursive_join, obj, (VALUE)args);
}
break;
default:
tmp = rb_check_string_type(val);
if (!NIL_P(tmp)) {
val = tmp;
goto str_join;
}
tmp = rb_check_convert_type(val, T_ARRAY, "Array", "to_ary");
if (!NIL_P(tmp)) {
obj = val;
val = tmp;
goto ary_join;
}
val = rb_obj_as_string(val);
if (*first) {
rb_enc_copy(result, val);
*first = FALSE;
}
goto str_join;
}
}
}

VALUE
rb_ary_join(VALUE ary, VALUE sep)
{
long len = 1, i;
int taint = FALSE;
int untrust = FALSE;
VALUE val, tmp, result;

if (RARRAY_LEN(ary) == 0) return rb_usascii_str_new(0, 0);
if (OBJ_TAINTED(ary) || OBJ_TAINTED(sep)) taint = TRUE;
if (OBJ_UNTRUSTED(ary) || OBJ_UNTRUSTED(sep)) untrust = TRUE;

if (!NIL_P(sep)) {
StringValue(sep);
len += RSTRING_LEN(sep) * (RARRAY_LEN(ary) - 1);
}
for (i=0; i<RARRAY_LEN(ary); i++) {
val = RARRAY_PTR(ary)[i];
tmp = rb_check_string_type(val);

if (NIL_P(tmp) || tmp != val) {
int first;
result = rb_str_buf_new(len + (RARRAY_LEN(ary)-i)*10);
rb_enc_associate(result, rb_usascii_encoding());
if (taint) OBJ_TAINT(result);
if (untrust) OBJ_UNTRUST(result);
ary_join_0(ary, sep, i, result);
first = i == 0;
ary_join_1(ary, ary, sep, i, result, &first);
return result;
}

len += RSTRING_LEN(tmp);
}

result = rb_str_buf_new(len);
if (taint) OBJ_TAINT(result);
if (untrust) OBJ_UNTRUST(result);
ary_join_0(ary, sep, RARRAY_LEN(ary), result);

return result;
}

/*
* call-seq:
* ary.join(sep=$,) -> str
*
* Returns a string created by converting each element of the array to
* a string, separated by +sep+.
*
* [ "a", "b", "c" ].join #=> "abc"
* [ "a", "b", "c" ].join("-") #=> "a-b-c"
*/

static VALUE
rb_ary_join_m(int argc, VALUE *argv, VALUE ary)
{
VALUE sep;

rb_scan_args(argc, argv, "01", &sep);
if (NIL_P(sep)) sep = rb_output_fs;

return rb_ary_join(ary, sep);
}

static VALUE
inspect_ary(VALUE ary, VALUE dummy, int recur)
{
int tainted = OBJ_TAINTED(ary);
int untrust = OBJ_UNTRUSTED(ary);
long i;
VALUE s, str;

if (recur) return rb_usascii_str_new_cstr("[...]");
str = rb_str_buf_new2("[");
for (i=0; i<RARRAY_LEN(ary); i++) {
s = rb_inspect(RARRAY_PTR(ary)[i]);
if (OBJ_TAINTED(s)) tainted = TRUE;
if (OBJ_UNTRUSTED(s)) untrust = TRUE;
if (i > 0) rb_str_buf_cat2(str, ", ");
else rb_enc_copy(str, s);
rb_str_buf_append(str, s);
}
rb_str_buf_cat2(str, "]");
if (tainted) OBJ_TAINT(str);
if (untrust) OBJ_UNTRUST(str);
return str;
}

/*
* call-seq:
* ary.to_s -> string
* ary.inspect -> string
*
* Creates a string representation of +self+.
*/

static VALUE
rb_ary_inspect(VALUE ary)
{
if (RARRAY_LEN(ary) == 0) return rb_usascii_str_new2("[]");
return rb_exec_recursive(inspect_ary, ary, 0);
}

VALUE
rb_ary_to_s(VALUE ary)
{
return rb_ary_inspect(ary);
}

/*
* call-seq:
* ary.to_a -> ary
*
* Returns +self+. If called on a subclass of Array, converts
* the receiver to an Array object.
*/

static VALUE
rb_ary_to_a(VALUE ary)
{
if (rb_obj_class(ary) != rb_cArray) {
VALUE dup = rb_ary_new2(RARRAY_LEN(ary));
rb_ary_replace(dup, ary);
return dup;
}
return ary;
}

/*
* call-seq:
* ary.to_ary -> ary
*
* Returns +self+.
*/

static VALUE
rb_ary_to_ary_m(VALUE ary)
{
return ary;
}

static void
ary_reverse(p1, p2)
VALUE *p1, *p2;
{
while (p1 < p2) {
VALUE tmp = *p1;
*p1++ = *p2;
*p2-- = tmp;
}
}

VALUE
rb_ary_reverse(VALUE ary)
{
VALUE *p1, *p2;

rb_ary_modify(ary);
if (RARRAY_LEN(ary) > 1) {
p1 = RARRAY_PTR(ary);
p2 = p1 + RARRAY_LEN(ary) - 1; /* points last item */
ary_reverse(p1, p2);
}
return ary;
}

/*
* call-seq:
* ary.reverse! -> ary
*
* Reverses +self+ in place.
*
* a = [ "a", "b", "c" ]
* a.reverse! #=> ["c", "b", "a"]
* a #=> ["c", "b", "a"]
*/

static VALUE
rb_ary_reverse_bang(VALUE ary)
{
return rb_ary_reverse(ary);
}

/*
* call-seq:
* ary.reverse -> new_ary
*
* Returns a new array containing +self+'s elements in reverse order.
*
* [ "a", "b", "c" ].reverse #=> ["c", "b", "a"]
* [ 1 ].reverse #=> [1]
*/

static VALUE
rb_ary_reverse_m(VALUE ary)
{
long len = RARRAY_LEN(ary);
VALUE dup = rb_ary_new2(len);

if (len > 0) {
VALUE *p1 = RARRAY_PTR(ary);
VALUE *p2 = RARRAY_PTR(dup) + len - 1;
do *p2-- = *p1++; while (--len > 0);
}
ARY_SET_LEN(dup, RARRAY_LEN(ary));
return dup;
}

static inline long
rotate_count(long cnt, long len)
{
return (cnt < 0) ? (len - (~cnt % len) - 1) : (cnt % len);
}

VALUE
rb_ary_rotate(VALUE ary, long cnt)
{
rb_ary_modify(ary);

if (cnt != 0) {
VALUE *ptr = RARRAY_PTR(ary);
long len = RARRAY_LEN(ary);

if (len > 0 && (cnt = rotate_count(cnt, len)) > 0) {
--len;
if (cnt < len) ary_reverse(ptr + cnt, ptr + len);
if (--cnt > 0) ary_reverse(ptr, ptr + cnt);
if (len > 0) ary_reverse(ptr, ptr + len);
return ary;
}
}

return Qnil;
}

/*
* call-seq:
* ary.rotate!(cnt=1) -> ary
*
* Rotates +self+ in place so that the element at +cnt+ comes first,
* and returns +self+. If +cnt+ is negative then it rotates in
* the opposite direction.
*
* a = [ "a", "b", "c", "d" ]
* a.rotate! #=> ["b", "c", "d", "a"]
* a #=> ["b", "c", "d", "a"]
* a.rotate!(2) #=> ["d", "a", "b", "c"]
* a.rotate!(-3) #=> ["a", "b", "c", "d"]
*/

static VALUE
rb_ary_rotate_bang(int argc, VALUE *argv, VALUE ary)
{
long n = 1;

switch (argc) {
case 1: n = NUM2LONG(argv[0]);
case 0: break;
default: rb_scan_args(argc, argv, "01", NULL);
}
rb_ary_rotate(ary, n);
return ary;
}

/*
* call-seq:
* ary.rotate(cnt=1) -> new_ary
*
* Returns new array by rotating +self+ so that the element at
* +cnt+ in +self+ is the first element of the new array. If +cnt+
* is negative then it rotates in the opposite direction.
*
* a = [ "a", "b", "c", "d" ]
* a.rotate #=> ["b", "c", "d", "a"]
* a #=> ["a", "b", "c", "d"]
* a.rotate(2) #=> ["c", "d", "a", "b"]
* a.rotate(-3) #=> ["b", "c", "d", "a"]
*/

static VALUE
rb_ary_rotate_m(int argc, VALUE *argv, VALUE ary)
{
VALUE rotated, *ptr, *ptr2;
long len, cnt = 1;

switch (argc) {
case 1: cnt = NUM2LONG(argv[0]);
case 0: break;
default: rb_scan_args(argc, argv, "01", NULL);
}

len = RARRAY_LEN(ary);
rotated = rb_ary_new2(len);
if (len > 0) {
cnt = rotate_count(cnt, len);
ptr = RARRAY_PTR(ary);
ptr2 = RARRAY_PTR(rotated);
len -= cnt;
MEMCPY(ptr2, ptr + cnt, VALUE, len);
MEMCPY(ptr2 + len, ptr, VALUE, cnt);
}
ARY_SET_LEN(rotated, RARRAY_LEN(ary));
return rotated;
}

struct ary_sort_data {
VALUE ary;
int opt_methods;
int opt_inited;
};

enum {
sort_opt_Fixnum,
sort_opt_String,
sort_optimizable_count
};

#define STRING_P(s) (RB_TYPE_P((s), T_STRING) && CLASS_OF(s) == rb_cString)

#define SORT_OPTIMIZABLE_BIT(type) (1U << TOKEN_PASTE(sort_opt_,type))
#define SORT_OPTIMIZABLE(data, type) \
(((data)->opt_inited & SORT_OPTIMIZABLE_BIT(type)) ? \
((data)->opt_methods & SORT_OPTIMIZABLE_BIT(type)) : \
(((data)->opt_inited |= SORT_OPTIMIZABLE_BIT(type)), \
rb_method_basic_definition_p(TOKEN_PASTE(rb_c,type), id_cmp) && \
((data)->opt_methods |= SORT_OPTIMIZABLE_BIT(type))))

static VALUE
sort_reentered(VALUE ary)
{
if (RBASIC(ary)->klass) {
rb_raise(rb_eRuntimeError, "sort reentered");
}
return Qnil;
}

static int
sort_1(const void *ap, const void *bp, void *dummy)
{
struct ary_sort_data *data = dummy;
VALUE retval = sort_reentered(data->ary);
VALUE a = *(const VALUE *)ap, b = *(const VALUE *)bp;
int n;

retval = rb_yield_values(2, a, b);
n = rb_cmpint(retval, a, b);
sort_reentered(data->ary);
return n;
}

static int
sort_2(const void *ap, const void *bp, void *dummy)
{
struct ary_sort_data *data = dummy;
VALUE retval = sort_reentered(data->ary);
VALUE a = *(const VALUE *)ap, b = *(const VALUE *)bp;
int n;

if (FIXNUM_P(a) && FIXNUM_P(b) && SORT_OPTIMIZABLE(data, Fixnum)) {
if ((long)a > (long)b) return 1;
if ((long)a < (long)b) return -1;
return 0;
}
if (STRING_P(a) && STRING_P(b) && SORT_OPTIMIZABLE(data, String)) {
return rb_str_cmp(a, b);
}

retval = rb_funcall(a, id_cmp, 1, b);
n = rb_cmpint(retval, a, b);
sort_reentered(data->ary);

return n;
}

/*
* call-seq:
* ary.sort! -> ary
* ary.sort! {| a,b | block } -> ary
*
* Sorts +self+. Comparisons for
* the sort will be done using the <code><=></code> operator or using
* an optional code block. The block implements a comparison between
* +a+ and +b+, returning -1, 0, or +1. See also
* Enumerable#sort_by.
*
* a = [ "d", "a", "e", "c", "b" ]
* a.sort! #=> ["a", "b", "c", "d", "e"]
* a.sort! {|x,y| y <=> x } #=> ["e", "d", "c", "b", "a"]
*/

VALUE
rb_ary_sort_bang(VALUE ary)
{
rb_ary_modify(ary);
assert(!ARY_SHARED_P(ary));
if (RARRAY_LEN(ary) > 1) {
VALUE tmp = ary_make_substitution(ary); /* only ary refers tmp */
struct ary_sort_data data;

RBASIC(tmp)->klass = 0;
data.ary = tmp;
data.opt_methods = 0;
data.opt_inited = 0;
ruby_qsort(RARRAY_PTR(tmp), RARRAY_LEN(tmp), sizeof(VALUE),
rb_block_given_p()?sort_1:sort_2, &data);

if (ARY_EMBED_P(tmp)) {
assert(ARY_EMBED_P(tmp));
if (ARY_SHARED_P(ary)) { /* ary might be destructively operated in the given block */
rb_ary_unshare(ary);
}
FL_SET_EMBED(ary);
MEMCPY(RARRAY_PTR(ary), ARY_EMBED_PTR(tmp), VALUE, ARY_EMBED_LEN(tmp));
ARY_SET_LEN(ary, ARY_EMBED_LEN(tmp));
}
else {
assert(!ARY_EMBED_P(tmp));
if (ARY_HEAP_PTR(ary) == ARY_HEAP_PTR(tmp)) {
assert(!ARY_EMBED_P(ary));
FL_UNSET_SHARED(ary);
ARY_SET_CAPA(ary, ARY_CAPA(tmp));
}
else {
assert(!ARY_SHARED_P(tmp));
if (ARY_EMBED_P(ary)) {
FL_UNSET_EMBED(ary);
}
else if (ARY_SHARED_P(ary)) {
/* ary might be destructively operated in the given block */
rb_ary_unshare(ary);
}
else {
xfree(ARY_HEAP_PTR(ary));
}
ARY_SET_PTR(ary, RARRAY_PTR(tmp));
ARY_SET_HEAP_LEN(ary, RARRAY_LEN(tmp));
ARY_SET_CAPA(ary, ARY_CAPA(tmp));
}
/* tmp was lost ownership for the ptr */
FL_UNSET(tmp, FL_FREEZE);
FL_SET_EMBED(tmp);
ARY_SET_EMBED_LEN(tmp, 0);
FL_SET(tmp, FL_FREEZE);
}
/* tmp will be GC'ed. */
RBASIC(tmp)->klass = rb_cArray;
}
return ary;
}

/*
* call-seq:
* ary.sort -> new_ary
* ary.sort {| a,b | block } -> new_ary
*
* Returns a new array created by sorting +self+. Comparisons for
* the sort will be done using the <code><=></code> operator or using
* an optional code block. The block implements a comparison between
* +a+ and +b+, returning -1, 0, or +1. See also
* Enumerable#sort_by.
*
* a = [ "d", "a", "e", "c", "b" ]
* a.sort #=> ["a", "b", "c", "d", "e"]
* a.sort {|x,y| y <=> x } #=> ["e", "d", "c", "b", "a"]
*/

VALUE
rb_ary_sort(VALUE ary)
{
ary = rb_ary_dup(ary);
rb_ary_sort_bang(ary);
return ary;
}


static VALUE
sort_by_i(VALUE i)
{
return rb_yield(i);
}

/*
* call-seq:
* ary.sort_by! {| obj | block } -> ary
* ary.sort_by! -> an_enumerator
*
* Sorts +self+ in place using a set of keys generated by mapping the
* values in +self+ through the given block.
*
* If no block is given, an enumerator is returned instead.
*
*/

static VALUE
rb_ary_sort_by_bang(VALUE ary)
{
VALUE sorted;

RETURN_ENUMERATOR(ary, 0, 0);
rb_ary_modify(ary);
sorted = rb_block_call(ary, rb_intern("sort_by"), 0, 0, sort_by_i, 0);
rb_ary_replace(ary, sorted);
return ary;
}


/*
* call-seq:
* ary.collect {|item| block } -> new_ary
* ary.map {|item| block } -> new_ary
* ary.collect -> an_enumerator
* ary.map -> an_enumerator
*
* Invokes +block+ once for each element of +self+. Creates a
* new array containing the values returned by the block.
* See also Enumerable#collect.
*
* If no block is given, an enumerator is returned instead.
*
* a = [ "a", "b", "c", "d" ]
* a.map {|x| x + "!" } #=> ["a!", "b!", "c!", "d!"]
* a #=> ["a", "b", "c", "d"]
*/

static VALUE
rb_ary_collect(VALUE ary)
{
long i;
VALUE collect;

RETURN_ENUMERATOR(ary, 0, 0);
collect = rb_ary_new2(RARRAY_LEN(ary));
for (i = 0; i < RARRAY_LEN(ary); i++) {
rb_ary_push(collect, rb_yield(RARRAY_PTR(ary)[i]));
}
return collect;
}


/*
* call-seq:
* ary.collect! {|item| block } -> ary
* ary.map! {|item| block } -> ary
* ary.collect -> an_enumerator
* ary.map -> an_enumerator
*
* Invokes the block once for each element of +self+, replacing the
* element with the value returned by +block+.
* See also Enumerable#collect.
*
* If no block is given, an enumerator is returned instead.
*
* a = [ "a", "b", "c", "d" ]
* a.map! {|x| x + "!" }
* a #=> [ "a!", "b!", "c!", "d!" ]
*/

static VALUE
rb_ary_collect_bang(VALUE ary)
{
long i;

RETURN_ENUMERATOR(ary, 0, 0);
rb_ary_modify(ary);
for (i = 0; i < RARRAY_LEN(ary); i++) {
rb_ary_store(ary, i, rb_yield(RARRAY_PTR(ary)[i]));
}
return ary;
}

VALUE
rb_get_values_at(VALUE obj, long olen, int argc, VALUE *argv, VALUE (*func) (VALUE, long))
{
VALUE result = rb_ary_new2(argc);
long beg, len, i, j;

for (i=0; i<argc; i++) {
if (FIXNUM_P(argv[i])) {
rb_ary_push(result, (*func)(obj, FIX2LONG(argv[i])));
continue;
}
/* check if idx is Range */
switch (rb_range_beg_len(argv[i], &beg, &len, olen, 0)) {
case Qfalse:
break;
case Qnil:
continue;
default:
for (j=0; j<len; j++) {
rb_ary_push(result, (*func)(obj, j+beg));
}
continue;
}
rb_ary_push(result, (*func)(obj, NUM2LONG(argv[i])));
}
return result;
}

/*
* call-seq:
* ary.values_at(selector,... ) -> new_ary
*
* Returns an array containing the elements in
* +self+ corresponding to the given selector(s). The selectors
* may be either integer indices or ranges.
* See also Array#select.
*
* a = %w{ a b c d e f }
* a.values_at(1, 3, 5)
* a.values_at(1, 3, 5, 7)
* a.values_at(-1, -3, -5, -7)
* a.values_at(1..3, 2...5)
*/

static VALUE
rb_ary_values_at(int argc, VALUE *argv, VALUE ary)
{
return rb_get_values_at(ary, RARRAY_LEN(ary), argc, argv, rb_ary_entry);
}


/*
* call-seq:
* ary.select {|item| block } -> new_ary
* ary.select -> an_enumerator
*
* Invokes the block passing in successive elements from +self+,
* returning an array containing those elements for which the block
* returns a true value (equivalent to Enumerable#select).
*
* If no block is given, an enumerator is returned instead.
*
* a = %w{ a b c d e f }
* a.select {|v| v =~ /[aeiou]/} #=> ["a", "e"]
*/

static VALUE
rb_ary_select(VALUE ary)
{
VALUE result;
long i;

RETURN_ENUMERATOR(ary, 0, 0);
result = rb_ary_new2(RARRAY_LEN(ary));
for (i = 0; i < RARRAY_LEN(ary); i++) {
if (RTEST(rb_yield(RARRAY_PTR(ary)[i]))) {
rb_ary_push(result, rb_ary_elt(ary, i));
}
}
return result;
}

/*
* call-seq:
* ary.select! {|item| block } -> ary or nil
* ary.select! -> an_enumerator
*
* Invokes the block passing in successive elements from
* +self+, deleting elements for which the block returns a
* false value. It returns +self+ if changes were made,
* otherwise it returns <code>nil</code>.
* See also Array#keep_if
*
* If no block is given, an enumerator is returned instead.
*
*/

static VALUE
rb_ary_select_bang(VALUE ary)
{
long i1, i2;

RETURN_ENUMERATOR(ary, 0, 0);
rb_ary_modify(ary);
for (i1 = i2 = 0; i1 < RARRAY_LEN(ary); i1++) {
VALUE v = RARRAY_PTR(ary)[i1];
if (!RTEST(rb_yield(v))) continue;
if (i1 != i2) {
rb_ary_store(ary, i2, v);
}
i2++;
}

if (RARRAY_LEN(ary) == i2) return Qnil;
if (i2 < RARRAY_LEN(ary))
ARY_SET_LEN(ary, i2);
return ary;
}

/*
* call-seq:
* ary.keep_if {|item| block } -> ary
* ary.keep_if -> an_enumerator
*
* Deletes every element of +self+ for which +block+ evaluates
* to false.
* See also Array#select!
*
* If no block is given, an enumerator is returned instead.
*
* a = %w{ a b c d e f }
* a.keep_if {|v| v =~ /[aeiou]/} #=> ["a", "e"]
*/

static VALUE
rb_ary_keep_if(VALUE ary)
{
RETURN_ENUMERATOR(ary, 0, 0);
rb_ary_select_bang(ary);
return ary;
}

/*
* call-seq:
* ary.delete(obj) -> obj or nil
* ary.delete(obj) { block } -> obj or nil
*
* Deletes items from +self+ that are equal to +obj+.
* If any items are found, returns +obj+. If
* the item is not found, returns <code>nil</code>. If the optional
* code block is given, returns the result of +block+ if the item
* is not found. (To remove <code>nil</code> elements and
* get an informative return value, use #compact!)
*
* a = [ "a", "b", "b", "b", "c" ]
* a.delete("b") #=> "b"
* a #=> ["a", "c"]
* a.delete("z") #=> nil
* a.delete("z") { "not found" } #=> "not found"
*/

VALUE
rb_ary_delete(VALUE ary, VALUE item)
{
VALUE v = item;
long i1, i2;

for (i1 = i2 = 0; i1 < RARRAY_LEN(ary); i1++) {
VALUE e = RARRAY_PTR(ary)[i1];

if (rb_equal(e, item)) {
v = e;
continue;
}
if (i1 != i2) {
rb_ary_store(ary, i2, e);
}
i2++;
}
if (RARRAY_LEN(ary) == i2) {
if (rb_block_given_p()) {
return rb_yield(item);
}
return Qnil;
}

rb_ary_modify(ary);
if (RARRAY_LEN(ary) > i2) {
ARY_SET_LEN(ary, i2);
if (i2 * 2 < ARY_CAPA(ary) &&
ARY_CAPA(ary) > ARY_DEFAULT_SIZE) {
ary_resize_capa(ary, i2*2);
}
}

return v;
}

VALUE
rb_ary_delete_at(VALUE ary, long pos)
{
long len = RARRAY_LEN(ary);
VALUE del;

if (pos >= len) return Qnil;
if (pos < 0) {
pos += len;
if (pos < 0) return Qnil;
}

rb_ary_modify(ary);
del = RARRAY_PTR(ary)[pos];
MEMMOVE(RARRAY_PTR(ary)+pos, RARRAY_PTR(ary)+pos+1, VALUE,
RARRAY_LEN(ary)-pos-1);
ARY_INCREASE_LEN(ary, -1);

return del;
}

/*
* call-seq:
* ary.delete_at(index) -> obj or nil
*
* Deletes the element at the specified index, returning that element,
* or <code>nil</code> if the index is out of range. See also
* Array#slice!.
*
* a = ["ant", "bat", "cat", "dog"]
* a.delete_at(2) #=> "cat"
* a #=> ["ant", "bat", "dog"]
* a.delete_at(99) #=> nil
*/

static VALUE
rb_ary_delete_at_m(VALUE ary, VALUE pos)
{
return rb_ary_delete_at(ary, NUM2LONG(pos));
}

/*
* call-seq:
* ary.slice!(index) -> obj or nil
* ary.slice!(start, length) -> new_ary or nil
* ary.slice!(range) -> new_ary or nil
*
* Deletes the element(s) given by an index (optionally with a length)
* or by a range. Returns the deleted object (or objects), or
* <code>nil</code> if the index is out of range.
*
* a = [ "a", "b", "c" ]
* a.slice!(1) #=> "b"
* a #=> ["a", "c"]
* a.slice!(-1) #=> "c"
* a #=> ["a"]
* a.slice!(100) #=> nil
* a #=> ["a"]
*/

static VALUE
rb_ary_slice_bang(int argc, VALUE *argv, VALUE ary)
{
VALUE arg1, arg2;
long pos, len, orig_len;

rb_ary_modify_check(ary);
if (argc == 2) {
pos = NUM2LONG(argv[0]);
len = NUM2LONG(argv[1]);
delete_pos_len:
if (len < 0) return Qnil;
orig_len = RARRAY_LEN(ary);
if (pos < 0) {
pos += orig_len;
if (pos < 0) return Qnil;
}
else if (orig_len < pos) return Qnil;
if (orig_len < pos + len) {
len = orig_len - pos;
}
if (len == 0) return rb_ary_new2(0);
arg2 = rb_ary_new4(len, RARRAY_PTR(ary)+pos);
RBASIC(arg2)->klass = rb_obj_class(ary);
rb_ary_splice(ary, pos, len, Qundef);
return arg2;
}

if (argc != 1) {
/* error report */
rb_scan_args(argc, argv, "11", NULL, NULL);
}
arg1 = argv[0];

if (!FIXNUM_P(arg1)) {
switch (rb_range_beg_len(arg1, &pos, &len, RARRAY_LEN(ary), 0)) {
case Qtrue:
/* valid range */
goto delete_pos_len;
case Qnil:
/* invalid range */
return Qnil;
default:
/* not a range */
break;
}
}

return rb_ary_delete_at(ary, NUM2LONG(arg1));
}

static VALUE
ary_reject(VALUE orig, VALUE result)
{
long i;

for (i = 0; i < RARRAY_LEN(orig); i++) {
VALUE v = RARRAY_PTR(orig)[i];
if (!RTEST(rb_yield(v))) {
rb_ary_push_1(result, v);
}
}
return result;
}

static VALUE
ary_reject_bang(VALUE ary)
{
long i;
VALUE result = Qnil;

rb_ary_modify_check(ary);
for (i = 0; i < RARRAY_LEN(ary); ) {
VALUE v = RARRAY_PTR(ary)[i];
if (RTEST(rb_yield(v))) {
rb_ary_delete_at(ary, i);
result = ary;
}
else {
i++;
}
}
return result;
}

/*
* call-seq:
* ary.reject! {|item| block } -> ary or nil
* ary.reject! -> an_enumerator
*
* Equivalent to Array#delete_if, deleting elements from
* +self+ for which the block evaluates to true, but returns
* <code>nil</code> if no changes were made.
* The array is changed instantly every time the block is called and
* not after the iteration is over.
* See also Enumerable#reject and Array#delete_if.
*
* If no block is given, an enumerator is returned instead.
*
*/

static VALUE
rb_ary_reject_bang(VALUE ary)
{
RETURN_ENUMERATOR(ary, 0, 0);
return ary_reject_bang(ary);
}

/*
* call-seq:
* ary.reject {|item| block } -> new_ary
* ary.reject -> an_enumerator
*
* Returns a new array containing the items in +self+
* for which the block is not true.
* See also Array#delete_if
*
* If no block is given, an enumerator is returned instead.
*
*/

static VALUE
rb_ary_reject(VALUE ary)
{
VALUE rejected_ary;

RETURN_ENUMERATOR(ary, 0, 0);
rejected_ary = rb_ary_new();
ary_reject(ary, rejected_ary);
return rejected_ary;
}

/*
* call-seq:
* ary.delete_if {|item| block } -> ary
* ary.delete_if -> an_enumerator
*
* Deletes every element of +self+ for which +block+ evaluates
* to true.
* The array is changed instantly every time the block is called and
* not after the iteration is over.
* See also Array#reject!
*
* If no block is given, an enumerator is returned instead.
*
* a = [ "a", "b", "c" ]
* a.delete_if {|x| x >= "b" } #=> ["a"]
*/

static VALUE
rb_ary_delete_if(VALUE ary)
{
RETURN_ENUMERATOR(ary, 0, 0);
ary_reject_bang(ary);
return ary;
}

static VALUE
take_i(VALUE val, VALUE *args, int argc, VALUE *argv)
{
if (args[1]-- == 0) rb_iter_break();
if (argc > 1) val = rb_ary_new4(argc, argv);
rb_ary_push(args[0], val);
return Qnil;
}

static VALUE
take_items(VALUE obj, long n)
{
VALUE result = rb_check_array_type(obj);
VALUE args[2];

if (!NIL_P(result)) return rb_ary_subseq(result, 0, n);
result = rb_ary_new2(n);
args[0] = result; args[1] = (VALUE)n;
rb_block_call(obj, rb_intern("each"), 0, 0, take_i, (VALUE)args);
return result;
}


/*
* call-seq:
* ary.zip(arg, ...) -> new_ary
* ary.zip(arg, ...) {| arr | block } -> nil
*
* Converts any arguments to arrays, then merges elements of
* +self+ with corresponding elements from each argument. This
* generates a sequence of <code>self.size</code> <em>n</em>-element
* arrays, where <em>n</em> is one more that the count of arguments. If
* the size of any argument is less than <code>enumObj.size</code>,
* <code>nil</code> values are supplied. If a block is given, it is
* invoked for each output array, otherwise an array of arrays is
* returned.
*
* a = [ 4, 5, 6 ]
* b = [ 7, 8, 9 ]
* [1,2,3].zip(a, b) #=> [[1, 4, 7], [2, 5, 8], [3, 6, 9]]
* [1,2].zip(a,b) #=> [[1, 4, 7], [2, 5, 8]]
* a.zip([1,2],[8]) #=> [[4,1,8], [5,2,nil], [6,nil,nil]]
*/

static VALUE
rb_ary_zip(int argc, VALUE *argv, VALUE ary)
{
int i, j;
long len;
VALUE result = Qnil;

len = RARRAY_LEN(ary);
for (i=0; i<argc; i++) {
argv[i] = take_items(argv[i], len);
}
if (!rb_block_given_p()) {
result = rb_ary_new2(len);
}

for (i=0; i<RARRAY_LEN(ary); i++) {
VALUE tmp = rb_ary_new2(argc+1);

rb_ary_push(tmp, rb_ary_elt(ary, i));
for (j=0; j<argc; j++) {
rb_ary_push(tmp, rb_ary_elt(argv[j], i));
}
if (NIL_P(result)) {
rb_yield(tmp);
}
else {
rb_ary_push(result, tmp);
}
}
return result;
}

/*
* call-seq:
* ary.transpose -> new_ary
*
* Assumes that +self+ is an array of arrays and transposes the
* rows and columns.
*
* a = [[1,2], [3,4], [5,6]]
* a.transpose #=> [[1, 3, 5], [2, 4, 6]]
*/

static VALUE
rb_ary_transpose(VALUE ary)
{
long elen = -1, alen, i, j;
VALUE tmp, result = 0;

alen = RARRAY_LEN(ary);
if (alen == 0) return rb_ary_dup(ary);
for (i=0; i<alen; i++) {
tmp = to_ary(rb_ary_elt(ary, i));
if (elen < 0) { /* first element */
elen = RARRAY_LEN(tmp);
result = rb_ary_new2(elen);
for (j=0; j<elen; j++) {
rb_ary_store(result, j, rb_ary_new2(alen));
}
}
else if (elen != RARRAY_LEN(tmp)) {
rb_raise(rb_eIndexError, "element size differs (%ld should be %ld)",
RARRAY_LEN(tmp), elen);
}
for (j=0; j<elen; j++) {
rb_ary_store(rb_ary_elt(result, j), i, rb_ary_elt(tmp, j));
}
}
return result;
}

/*
* call-seq:
* ary.replace(other_ary) -> ary
*
* Replaces the contents of +self+ with the contents of
* +other_ary+, truncating or expanding if necessary.
*
* a = [ "a", "b", "c", "d", "e" ]
* a.replace([ "x", "y", "z" ]) #=> ["x", "y", "z"]
* a #=> ["x", "y", "z"]
*/

VALUE
rb_ary_replace(VALUE copy, VALUE orig)
{
rb_ary_modify_check(copy);
orig = to_ary(orig);
if (copy == orig) return copy;

if (RARRAY_LEN(orig) <= RARRAY_EMBED_LEN_MAX) {
VALUE *ptr;
VALUE shared = 0;

if (ARY_OWNS_HEAP_P(copy)) {
xfree(RARRAY_PTR(copy));
}
else if (ARY_SHARED_P(copy)) {
shared = ARY_SHARED(copy);
FL_UNSET_SHARED(copy);
}
FL_SET_EMBED(copy);
ptr = RARRAY_PTR(orig);
MEMCPY(RARRAY_PTR(copy), ptr, VALUE, RARRAY_LEN(orig));
if (shared) {
rb_ary_decrement_share(shared);
}
ARY_SET_LEN(copy, RARRAY_LEN(orig));
}
else {
VALUE shared = ary_make_shared(orig);
if (ARY_OWNS_HEAP_P(copy)) {
xfree(RARRAY_PTR(copy));
}
else {
rb_ary_unshare_safe(copy);
}
FL_UNSET_EMBED(copy);
ARY_SET_PTR(copy, RARRAY_PTR(orig));
ARY_SET_LEN(copy, RARRAY_LEN(orig));
rb_ary_set_shared(copy, shared);
}
return copy;
}

/*
* call-seq:
* ary.clear -> ary
*
* Removes all elements from +self+.
*
* a = [ "a", "b", "c", "d", "e" ]
* a.clear #=> [ ]
*/

VALUE
rb_ary_clear(VALUE ary)
{
rb_ary_modify_check(ary);
ARY_SET_LEN(ary, 0);
if (ARY_SHARED_P(ary)) {
if (!ARY_EMBED_P(ary)) {
rb_ary_unshare(ary);
FL_SET_EMBED(ary);
}
}
else if (ARY_DEFAULT_SIZE * 2 < ARY_CAPA(ary)) {
ary_resize_capa(ary, ARY_DEFAULT_SIZE * 2);
}
return ary;
}

/*
* call-seq:
* ary.fill(obj) -> ary
* ary.fill(obj, start [, length]) -> ary
* ary.fill(obj, range ) -> ary
* ary.fill {|index| block } -> ary
* ary.fill(start [, length] ) {|index| block } -> ary
* ary.fill(range) {|index| block } -> ary
*
* The first three forms set the selected elements of +self+ (which
* may be the entire array) to +obj+. A +start+ of
* <code>nil</code> is equivalent to zero. A +length+ of
* <code>nil</code> is equivalent to <code>self.length</code>. The last three
* forms fill the array with the value of the block. The block is
* passed the absolute index of each element to be filled.
* Negative values of +start+ count from the end of the array.
*
* a = [ "a", "b", "c", "d" ]
* a.fill("x") #=> ["x", "x", "x", "x"]
* a.fill("z", 2, 2) #=> ["x", "x", "z", "z"]
* a.fill("y", 0..1) #=> ["y", "y", "z", "z"]
* a.fill {|i| i*i} #=> [0, 1, 4, 9]
* a.fill(-2) {|i| i*i*i} #=> [0, 1, 8, 27]
*/

static VALUE
rb_ary_fill(int argc, VALUE *argv, VALUE ary)
{
VALUE item, arg1, arg2;
long beg = 0, end = 0, len = 0;
VALUE *p, *pend;
int block_p = FALSE;

if (rb_block_given_p()) {
block_p = TRUE;
rb_scan_args(argc, argv, "02", &arg1, &arg2);
argc += 1; /* hackish */
}
else {
rb_scan_args(argc, argv, "12", &item, &arg1, &arg2);
}
switch (argc) {
case 1:
beg = 0;
len = RARRAY_LEN(ary);
break;
case 2:
if (rb_range_beg_len(arg1, &beg, &len, RARRAY_LEN(ary), 1)) {
break;
}
/* fall through */
case 3:
beg = NIL_P(arg1) ? 0 : NUM2LONG(arg1);
if (beg < 0) {
beg = RARRAY_LEN(ary) + beg;
if (beg < 0) beg = 0;
}
len = NIL_P(arg2) ? RARRAY_LEN(ary) - beg : NUM2LONG(arg2);
break;
}
rb_ary_modify(ary);
if (len < 0) {
return ary;
}
if (beg >= ARY_MAX_SIZE || len > ARY_MAX_SIZE - beg) {
rb_raise(rb_eArgError, "argument too big");
}
end = beg + len;
if (RARRAY_LEN(ary) < end) {
if (end >= ARY_CAPA(ary)) {
ary_resize_capa(ary, end);
}
rb_mem_clear(RARRAY_PTR(ary) + RARRAY_LEN(ary), end - RARRAY_LEN(ary));
ARY_SET_LEN(ary, end);
}

if (block_p) {
VALUE v;
long i;

for (i=beg; i<end; i++) {
v = rb_yield(LONG2NUM(i));
if (i>=RARRAY_LEN(ary)) break;
RARRAY_PTR(ary)[i] = v;
}
}
else {
p = RARRAY_PTR(ary) + beg;
pend = p + len;
while (p < pend) {
*p++ = item;
}
}
return ary;
}

/*
* call-seq:
* ary + other_ary -> new_ary
*
* Concatenation---Returns a new array built by concatenating the
* two arrays together to produce a third array.
*
* [ 1, 2, 3 ] + [ 4, 5 ] #=> [ 1, 2, 3, 4, 5 ]
*/

VALUE
rb_ary_plus(VALUE x, VALUE y)
{
VALUE z;
long len;

y = to_ary(y);
len = RARRAY_LEN(x) + RARRAY_LEN(y);
z = rb_ary_new2(len);
MEMCPY(RARRAY_PTR(z), RARRAY_PTR(x), VALUE, RARRAY_LEN(x));
MEMCPY(RARRAY_PTR(z) + RARRAY_LEN(x), RARRAY_PTR(y), VALUE, RARRAY_LEN(y));
ARY_SET_LEN(z, len);
return z;
}

/*
* call-seq:
* ary.concat(other_ary) -> ary
*
* Appends the elements of +other_ary+ to +self+.
*
* [ "a", "b" ].concat( ["c", "d"] ) #=> [ "a", "b", "c", "d" ]
*/


VALUE
rb_ary_concat(VALUE x, VALUE y)
{
rb_ary_modify_check(x);
y = to_ary(y);
if (RARRAY_LEN(y) > 0) {
rb_ary_splice(x, RARRAY_LEN(x), 0, y);
}
return x;
}


/*
* call-seq:
* ary * int -> new_ary
* ary * str -> new_string
*
* Repetition---With a String argument, equivalent to
* self.join(str). Otherwise, returns a new array
* built by concatenating the +int+ copies of +self+.
*
*
* [ 1, 2, 3 ] * 3 #=> [ 1, 2, 3, 1, 2, 3, 1, 2, 3 ]
* [ 1, 2, 3 ] * "," #=> "1,2,3"
*
*/

static VALUE
rb_ary_times(VALUE ary, VALUE times)
{
VALUE ary2, tmp, *ptr, *ptr2;
long t, len;

tmp = rb_check_string_type(times);
if (!NIL_P(tmp)) {
return rb_ary_join(ary, tmp);
}

len = NUM2LONG(times);
if (len == 0) {
ary2 = ary_new(rb_obj_class(ary), 0);
goto out;
}
if (len < 0) {
rb_raise(rb_eArgError, "negative argument");
}
if (ARY_MAX_SIZE/len < RARRAY_LEN(ary)) {
rb_raise(rb_eArgError, "argument too big");
}
len *= RARRAY_LEN(ary);

ary2 = ary_new(rb_obj_class(ary), len);
ARY_SET_LEN(ary2, len);

ptr = RARRAY_PTR(ary);
ptr2 = RARRAY_PTR(ary2);
t = RARRAY_LEN(ary);
if (0 < t) {
MEMCPY(ptr2, ptr, VALUE, t);
while (t <= len/2) {
MEMCPY(ptr2+t, ptr2, VALUE, t);
t *= 2;
}
if (t < len) {
MEMCPY(ptr2+t, ptr2, VALUE, len-t);
}
}
out:
OBJ_INFECT(ary2, ary);

return ary2;
}

/*
* call-seq:
* ary.assoc(obj) -> new_ary or nil
*
* Searches through an array whose elements are also arrays
* comparing +obj+ with the first element of each contained array
* using obj.==.
* Returns the first contained array that matches (that
* is, the first associated array),
* or +nil+ if no match is found.
* See also Array#rassoc.
*
* s1 = [ "colors", "red", "blue", "green" ]
* s2 = [ "letters", "a", "b", "c" ]
* s3 = "foo"
* a = [ s1, s2, s3 ]
* a.assoc("letters") #=> [ "letters", "a", "b", "c" ]
* a.assoc("foo") #=> nil
*/

VALUE
rb_ary_assoc(VALUE ary, VALUE key)
{
long i;
VALUE v;

for (i = 0; i < RARRAY_LEN(ary); ++i) {
v = rb_check_array_type(RARRAY_PTR(ary)[i]);
if (!NIL_P(v) && RARRAY_LEN(v) > 0 &&
rb_equal(RARRAY_PTR(v)[0], key))
return v;
}
return Qnil;
}

/*
* call-seq:
* ary.rassoc(obj) -> new_ary or nil
*
* Searches through the array whose elements are also arrays. Compares
* +obj+ with the second element of each contained array using
* <code>==</code>. Returns the first contained array that matches. See
* also Array#assoc.
*
* a = [ [ 1, "one"], [2, "two"], [3, "three"], ["ii", "two"] ]
* a.rassoc("two") #=> [2, "two"]
* a.rassoc("four") #=> nil
*/

VALUE
rb_ary_rassoc(VALUE ary, VALUE value)
{
long i;
VALUE v;

for (i = 0; i < RARRAY_LEN(ary); ++i) {
v = RARRAY_PTR(ary)[i];
if (RB_TYPE_P(v, T_ARRAY) &&
RARRAY_LEN(v) > 1 &&
rb_equal(RARRAY_PTR(v)[1], value))
return v;
}
return Qnil;
}

static VALUE
recursive_equal(VALUE ary1, VALUE ary2, int recur)
{
long i;

if (recur) return Qtrue; /* Subtle! */
for (i=0; i<RARRAY_LEN(ary1); i++) {
if (!rb_equal(rb_ary_elt(ary1, i), rb_ary_elt(ary2, i)))
return Qfalse;
}
return Qtrue;
}

/*
* call-seq:
* ary == other_ary -> bool
*
* Equality---Two arrays are equal if they contain the same number
* of elements and if each element is equal to (according to
* Object.==) the corresponding element in the other array.
*
* [ "a", "c" ] == [ "a", "c", 7 ] #=> false
* [ "a", "c", 7 ] == [ "a", "c", 7 ] #=> true
* [ "a", "c", 7 ] == [ "a", "d", "f" ] #=> false
*
*/

static VALUE
rb_ary_equal(VALUE ary1, VALUE ary2)
{
if (ary1 == ary2) return Qtrue;
if (!RB_TYPE_P(ary2, T_ARRAY)) {
if (!rb_respond_to(ary2, rb_intern("to_ary"))) {
return Qfalse;
}
return rb_equal(ary2, ary1);
}
if (RARRAY_LEN(ary1) != RARRAY_LEN(ary2)) return Qfalse;
return rb_exec_recursive_paired(recursive_equal, ary1, ary2, ary2);
}

static VALUE
recursive_eql(VALUE ary1, VALUE ary2, int recur)
{
long i;

if (recur) return Qtrue; /* Subtle! */
for (i=0; i<RARRAY_LEN(ary1); i++) {
if (!rb_eql(rb_ary_elt(ary1, i), rb_ary_elt(ary2, i)))
return Qfalse;
}
return Qtrue;
}

/*
* call-seq:
* ary.eql?(other) -> true or false
*
* Returns <code>true</code> if +self+ and +other+ are the same object,
* or are both arrays with the same content.
*/

static VALUE
rb_ary_eql(VALUE ary1, VALUE ary2)
{
if (ary1 == ary2) return Qtrue;
if (!RB_TYPE_P(ary2, T_ARRAY)) return Qfalse;
if (RARRAY_LEN(ary1) != RARRAY_LEN(ary2)) return Qfalse;
return rb_exec_recursive_paired(recursive_eql, ary1, ary2, ary2);
}

static VALUE
recursive_hash(VALUE ary, VALUE dummy, int recur)
{
long i;
st_index_t h;
VALUE n;

h = rb_hash_start(RARRAY_LEN(ary));
if (recur) {
h = rb_hash_uint(h, NUM2LONG(rb_hash(rb_cArray)));
}
else {
for (i=0; i<RARRAY_LEN(ary); i++) {
n = rb_hash(RARRAY_PTR(ary)[i]);
h = rb_hash_uint(h, NUM2LONG(n));
}
}
h = rb_hash_end(h);
return LONG2FIX(h);
}

/*
* call-seq:
* ary.hash -> fixnum
*
* Compute a hash-code for this array. Two arrays with the same content
* will have the same hash code (and will compare using <code>eql?</code>).
*/

static VALUE
rb_ary_hash(VALUE ary)
{
return rb_exec_recursive_outer(recursive_hash, ary, 0);
}

/*
* call-seq:
* ary.include?(object) -> true or false
*
* Returns <code>true</code> if the given +object+ is present in
* +self+ (that is, if any object <code>==</code> +object+),
* <code>false</code> otherwise.
*
* a = [ "a", "b", "c" ]
* a.include?("b") #=> true
* a.include?("z") #=> false
*/

VALUE
rb_ary_includes(VALUE ary, VALUE item)
{
long i;

for (i=0; i<RARRAY_LEN(ary); i++) {
if (rb_equal(RARRAY_PTR(ary)[i], item)) {
return Qtrue;
}
}
return Qfalse;
}


static VALUE
recursive_cmp(VALUE ary1, VALUE ary2, int recur)
{
long i, len;

if (recur) return Qundef; /* Subtle! */
len = RARRAY_LEN(ary1);
if (len > RARRAY_LEN(ary2)) {
len = RARRAY_LEN(ary2);
}
for (i=0; i<len; i++) {
VALUE v = rb_funcall(rb_ary_elt(ary1, i), id_cmp, 1, rb_ary_elt(ary2, i));
if (v != INT2FIX(0)) {
return v;
}
}
return Qundef;
}

/*
* call-seq:
* ary <=> other_ary -> -1, 0, +1 or nil
*
* Comparison---Returns an integer (-1, 0,
* or +1) if this array is less than, equal to, or greater than
* +other_ary+.
*
* Each object in each array is compared (using <=>). Arrays are compared in
* an "element-wise" manner; the first two elements that are not equal will
* determine the return value for the whole comparison. If all the values
* are equal, then the return is based on a comparison of the array lengths.
* Thus, two arrays are "equal" according to Array#<=> if and only if they
* have the same length and the value of each element is equal to the
* value of the corresponding element in the other array.
*
* [ "a", "a", "c" ] <=> [ "a", "b", "c" ] #=> -1
* [ 1, 2, 3, 4, 5, 6 ] <=> [ 1, 2 ] #=> +1
*
*/

VALUE
rb_ary_cmp(VALUE ary1, VALUE ary2)
{
long len;
VALUE v;

ary2 = rb_check_array_type(ary2);
if (NIL_P(ary2)) return Qnil;
if (ary1 == ary2) return INT2FIX(0);
v = rb_exec_recursive_paired(recursive_cmp, ary1, ary2, ary2);
if (v != Qundef) return v;
len = RARRAY_LEN(ary1) - RARRAY_LEN(ary2);
if (len == 0) return INT2FIX(0);
if (len > 0) return INT2FIX(1);
return INT2FIX(-1);
}

static VALUE
ary_add_hash(VALUE hash, VALUE ary)
{
long i;

for (i=0; i<RARRAY_LEN(ary); i++) {
rb_hash_aset(hash, RARRAY_PTR(ary)[i], Qtrue);
}
return hash;
}

static inline VALUE
ary_tmp_hash_new(void)
{
VALUE hash = rb_hash_new();

RBASIC(hash)->klass = 0;
return hash;
}

static VALUE
ary_make_hash(VALUE ary)
{
VALUE hash = ary_tmp_hash_new();
return ary_add_hash(hash, ary);
}

static VALUE
ary_add_hash_by(VALUE hash, VALUE ary)
{
long i;

for (i = 0; i < RARRAY_LEN(ary); ++i) {
VALUE v = rb_ary_elt(ary, i), k = rb_yield(v);
if (rb_hash_lookup2(hash, k, Qundef) == Qundef) {
rb_hash_aset(hash, k, v);
}
}
return hash;
}

static VALUE
ary_make_hash_by(VALUE ary)
{
VALUE hash = ary_tmp_hash_new();
return ary_add_hash_by(hash, ary);
}

static inline void
ary_recycle_hash(VALUE hash)
{
if (RHASH(hash)->ntbl) {
st_table *tbl = RHASH(hash)->ntbl;
RHASH(hash)->ntbl = 0;
st_free_table(tbl);
}
}

/*
* call-seq:
* ary - other_ary -> new_ary
*
* Array Difference---Returns a new array that is a copy of
* the original array, removing any items that also appear in
* +other_ary+. (If you need set-like behavior, see the
* library class Set.)
*
* [ 1, 1, 2, 2, 3, 3, 4, 5 ] - [ 1, 2, 4 ] #=> [ 3, 3, 5 ]
*/

static VALUE
rb_ary_diff(VALUE ary1, VALUE ary2)
{
VALUE ary3;
volatile VALUE hash;
long i;

hash = ary_make_hash(to_ary(ary2));
ary3 = rb_ary_new();

for (i=0; i<RARRAY_LEN(ary1); i++) {
if (st_lookup(RHASH_TBL(hash), RARRAY_PTR(ary1)[i], 0)) continue;
rb_ary_push(ary3, rb_ary_elt(ary1, i));
}
ary_recycle_hash(hash);
return ary3;
}

/*
* call-seq:
* ary & other_ary -> new_ary
*
* Set Intersection---Returns a new array
* containing elements common to the two arrays, with no duplicates.
*
* [ 1, 1, 3, 5 ] & [ 1, 2, 3 ] #=> [ 1, 3 ]
*/


static VALUE
rb_ary_and(VALUE ary1, VALUE ary2)
{
VALUE hash, ary3, v;
st_data_t vv;
long i;

ary2 = to_ary(ary2);
ary3 = rb_ary_new2(RARRAY_LEN(ary1) < RARRAY_LEN(ary2) ?
RARRAY_LEN(ary1) : RARRAY_LEN(ary2));
hash = ary_make_hash(ary2);

if (RHASH_EMPTY_P(hash))
return ary3;

for (i=0; i<RARRAY_LEN(ary1); i++) {
vv = (st_data_t)(v = rb_ary_elt(ary1, i));
if (st_delete(RHASH_TBL(hash), &vv, 0)) {
rb_ary_push(ary3, v);
}
}
ary_recycle_hash(hash);

return ary3;
}

/*
* call-seq:
* ary | other_ary -> new_ary
*
* Set Union---Returns a new array by joining this array with
* +other_ary+, removing duplicates.
*
* [ "a", "b", "c" ] | [ "c", "d", "a" ]
* #=> [ "a", "b", "c", "d" ]
*/

static VALUE
rb_ary_or(VALUE ary1, VALUE ary2)
{
VALUE hash, ary3, v;
st_data_t vv;
long i;

ary2 = to_ary(ary2);
ary3 = rb_ary_new2(RARRAY_LEN(ary1)+RARRAY_LEN(ary2));
hash = ary_add_hash(ary_make_hash(ary1), ary2);

for (i=0; i<RARRAY_LEN(ary1); i++) {
vv = (st_data_t)(v = rb_ary_elt(ary1, i));
if (st_delete(RHASH_TBL(hash), &vv, 0)) {
rb_ary_push(ary3, v);
}
}
for (i=0; i<RARRAY_LEN(ary2); i++) {
vv = (st_data_t)(v = rb_ary_elt(ary2, i));
if (st_delete(RHASH_TBL(hash), &vv, 0)) {
rb_ary_push(ary3, v);
}
}
ary_recycle_hash(hash);
return ary3;
}

static int
push_value(st_data_t key, st_data_t val, st_data_t ary)
{
rb_ary_push((VALUE)ary, (VALUE)val);
return ST_CONTINUE;
}

/*
* call-seq:
* ary.uniq! -> ary or nil
* ary.uniq! { |item| ... } -> ary or nil
*
* Removes duplicate elements from +self+. If a block is given,
* it will use the return value of the block for comparison.
* Returns <code>nil</code> if no changes are made (that is, no
* duplicates are found).
*
* a = [ "a", "a", "b", "b", "c" ]
* a.uniq! # => ["a", "b", "c"]
*
* b = [ "a", "b", "c" ]
* b.uniq! # => nil
*
* c = [["student","sam"], ["student","george"], ["teacher","matz"]]
* c.uniq! { |s| s.first } # => [["student", "sam"], ["teacher", "matz"]]
*
*/

static VALUE
rb_ary_uniq_bang(VALUE ary)
{
VALUE hash, v;
long i, j;

rb_ary_modify_check(ary);
if (RARRAY_LEN(ary) <= 1)
return Qnil;
if (rb_block_given_p()) {
hash = ary_make_hash_by(ary);
if (RARRAY_LEN(ary) == (i = RHASH_SIZE(hash))) {
return Qnil;
}
ARY_SET_LEN(ary, 0);
if (ARY_SHARED_P(ary) && !ARY_EMBED_P(ary)) {
rb_ary_unshare(ary);
FL_SET_EMBED(ary);
}
ary_resize_capa(ary, i);
st_foreach(RHASH_TBL(hash), push_value, ary);
}
else {
hash = ary_make_hash(ary);
if (RARRAY_LEN(ary) == (long)RHASH_SIZE(hash)) {
return Qnil;
}
for (i=j=0; i<RARRAY_LEN(ary); i++) {
st_data_t vv = (st_data_t)(v = rb_ary_elt(ary, i));
if (st_delete(RHASH_TBL(hash), &vv, 0)) {
rb_ary_store(ary, j++, v);
}
}
ARY_SET_LEN(ary, j);
}
ary_recycle_hash(hash);

return ary;
}

/*
* call-seq:
* ary.uniq -> ary or nil
* ary.uniq { |item| ... } -> ary or nil
*
* Returns a new array by removing duplicate values in +self+. If a block
* is given, it will use the return value of the block for comparison.
*
* a = [ "a", "a", "b", "b", "c" ]
* a.uniq # => ["a", "b", "c"]
*
* b = [["student","sam"], ["student","george"], ["teacher","matz"]]
* b.uniq { |s| s.first } # => [["student", "sam"], ["teacher", "matz"]]
*
*/

static VALUE
rb_ary_uniq(VALUE ary)
{
VALUE hash, uniq, v;
long i;

if (RARRAY_LEN(ary) <= 1)
return rb_ary_dup(ary);
if (rb_block_given_p()) {
hash = ary_make_hash_by(ary);
uniq = ary_new(rb_obj_class(ary), RHASH_SIZE(hash));
st_foreach(RHASH_TBL(hash), push_value, uniq);
}
else {
hash = ary_make_hash(ary);
uniq = ary_new(rb_obj_class(ary), RHASH_SIZE(hash));
for (i=0; i<RARRAY_LEN(ary); i++) {
st_data_t vv = (st_data_t)(v = rb_ary_elt(ary, i));
if (st_delete(RHASH_TBL(hash), &vv, 0)) {
rb_ary_push(uniq, v);
}
}
}
ary_recycle_hash(hash);

return uniq;
}

/*
* call-seq:
* ary.compact! -> ary or nil
*
* Removes +nil+ elements from the array.
* Returns +nil+ if no changes were made, otherwise returns the array.
*
* [ "a", nil, "b", nil, "c" ].compact! #=> [ "a", "b", "c" ]
* [ "a", "b", "c" ].compact! #=> nil
*/

static VALUE
rb_ary_compact_bang(VALUE ary)
{
VALUE *p, *t, *end;
long n;

rb_ary_modify(ary);
p = t = RARRAY_PTR(ary);
end = p + RARRAY_LEN(ary);

while (t < end) {
if (NIL_P(*t)) t++;
else *p++ = *t++;
}
n = p - RARRAY_PTR(ary);
if (RARRAY_LEN(ary) == n) {
return Qnil;
}
ARY_SET_LEN(ary, n);
if (n * 2 < ARY_CAPA(ary) && ARY_DEFAULT_SIZE * 2 < ARY_CAPA(ary)) {
ary_resize_capa(ary, n * 2);
}

return ary;
}

/*
* call-seq:
* ary.compact -> new_ary
*
* Returns a copy of +self+ with all +nil+ elements removed.
*
* [ "a", nil, "b", nil, "c", nil ].compact
* #=> [ "a", "b", "c" ]
*/

static VALUE
rb_ary_compact(VALUE ary)
{
ary = rb_ary_dup(ary);
rb_ary_compact_bang(ary);
return ary;
}

/*
* call-seq:
* ary.count -> int
* ary.count(obj) -> int
* ary.count { |item| block } -> int
*
* Returns the number of elements. If an argument is given, counts
* the number of elements which equals to +obj+. If a block is
* given, counts the number of elements for which the block returns a true
* value.
*
* ary = [1, 2, 4, 2]
* ary.count #=> 4
* ary.count(2) #=> 2
* ary.count{|x|x%2==0} #=> 3
*
*/

static VALUE
rb_ary_count(int argc, VALUE *argv, VALUE ary)
{
long n = 0;

if (argc == 0) {
VALUE *p, *pend;

if (!rb_block_given_p())
return LONG2NUM(RARRAY_LEN(ary));

for (p = RARRAY_PTR(ary), pend = p + RARRAY_LEN(ary); p < pend; p++) {
if (RTEST(rb_yield(*p))) n++;
}
}
else {
VALUE obj, *p, *pend;

rb_scan_args(argc, argv, "1", &obj);
if (rb_block_given_p()) {
rb_warn("given block not used");
}
for (p = RARRAY_PTR(ary), pend = p + RARRAY_LEN(ary); p < pend; p++) {
if (rb_equal(*p, obj)) n++;
}
}

return LONG2NUM(n);
}

static VALUE
flatten(VALUE ary, int level, int *modified)
{
long i = 0;
VALUE stack, result, tmp, elt;
st_table *memo;
st_data_t id;

stack = ary_new(0, ARY_DEFAULT_SIZE);
result = ary_new(0, RARRAY_LEN(ary));
memo = st_init_numtable();
st_insert(memo, (st_data_t)ary, (st_data_t)Qtrue);
*modified = 0;

while (1) {
while (i < RARRAY_LEN(ary)) {
elt = RARRAY_PTR(ary)[i++];
tmp = rb_check_array_type(elt);
if (RBASIC(result)->klass) {
rb_raise(rb_eRuntimeError, "flatten reentered");
}
if (NIL_P(tmp) || (level >= 0 && RARRAY_LEN(stack) / 2 >= level)) {
rb_ary_push(result, elt);
}
else {
*modified = 1;
id = (st_data_t)tmp;
if (st_lookup(memo, id, 0)) {
st_free_table(memo);
rb_raise(rb_eArgError, "tried to flatten recursive array");
}
st_insert(memo, id, (st_data_t)Qtrue);
rb_ary_push(stack, ary);
rb_ary_push(stack, LONG2NUM(i));
ary = tmp;
i = 0;
}
}
if (RARRAY_LEN(stack) == 0) {
break;
}
id = (st_data_t)ary;
st_delete(memo, &id, 0);
tmp = rb_ary_pop(stack);
i = NUM2LONG(tmp);
ary = rb_ary_pop(stack);
}

st_free_table(memo);

RBASIC(result)->klass = rb_class_of(ary);
return result;
}

/*
* call-seq:
* ary.flatten! -> ary or nil
* ary.flatten!(level) -> array or nil
*
* Flattens +self+ in place.
* Returns <code>nil</code> if no modifications were made (i.e.,
* the array contains no subarrays.) If the optional +level+
* argument determines the level of recursion to flatten.
*
* a = [ 1, 2, [3, [4, 5] ] ]
* a.flatten! #=> [1, 2, 3, 4, 5]
* a.flatten! #=> nil
* a #=> [1, 2, 3, 4, 5]
* a = [ 1, 2, [3, [4, 5] ] ]
* a.flatten!(1) #=> [1, 2, 3, [4, 5]]
*/

static VALUE
rb_ary_flatten_bang(int argc, VALUE *argv, VALUE ary)
{
int mod = 0, level = -1;
VALUE result, lv;

rb_scan_args(argc, argv, "01", &lv);
rb_ary_modify_check(ary);
if (!NIL_P(lv)) level = NUM2INT(lv);
if (level == 0) return Qnil;

result = flatten(ary, level, &mod);
if (mod == 0) {
ary_discard(result);
return Qnil;
}
if (!(mod = ARY_EMBED_P(result))) rb_obj_freeze(result);
rb_ary_replace(ary, result);
if (mod) ARY_SET_EMBED_LEN(result, 0);

return ary;
}

/*
* call-seq:
* ary.flatten -> new_ary
* ary.flatten(level) -> new_ary
*
* Returns a new array that is a one-dimensional flattening of this
* array (recursively). That is, for every element that is an array,
* extract its elements into the new array. If the optional
* +level+ argument determines the level of recursion to flatten.
*
* s = [ 1, 2, 3 ] #=> [1, 2, 3]
* t = [ 4, 5, 6, [7, 8] ] #=> [4, 5, 6, [7, 8]]
* a = [ s, t, 9, 10 ] #=> [[1, 2, 3], [4, 5, 6, [7, 8]], 9, 10]
* a.flatten #=> [1, 2, 3, 4, 5, 6, 7, 8, 9, 10]
* a = [ 1, 2, [3, [4, 5] ] ]
* a.flatten(1) #=> [1, 2, 3, [4, 5]]
*/

static VALUE
rb_ary_flatten(int argc, VALUE *argv, VALUE ary)
{
int mod = 0, level = -1;
VALUE result, lv;

rb_scan_args(argc, argv, "01", &lv);
if (!NIL_P(lv)) level = NUM2INT(lv);
if (level == 0) return ary_make_shared_copy(ary);

result = flatten(ary, level, &mod);
OBJ_INFECT(result, ary);

return result;
}

#define OPTHASH_GIVEN_P(opts) \
(argc > 0 && !NIL_P((opts) = rb_check_hash_type(argv[argc-1])) && (--argc, 1))
static VALUE sym_random;

#define RAND_UPTO(max) (long)(rb_random_real(randgen)*(max))

/*
* call-seq:
* ary.shuffle! -> ary
* ary.shuffle!(random: rng) -> ary
*
* Shuffles elements in +self+ in place.
* If +rng+ is given, it will be used as the random number generator.
*/

static VALUE
rb_ary_shuffle_bang(int argc, VALUE *argv, VALUE ary)
{
VALUE *ptr, opts, *snap_ptr, randgen = rb_cRandom;
long i, snap_len;

if (OPTHASH_GIVEN_P(opts)) {
randgen = rb_hash_lookup2(opts, sym_random, randgen);
}
rb_check_arity(argc, 0, 0);
rb_ary_modify(ary);
i = RARRAY_LEN(ary);
ptr = RARRAY_PTR(ary);
snap_len = i;
snap_ptr = ptr;
while (i) {
long j = RAND_UPTO(i);
VALUE tmp;
if (snap_len != RARRAY_LEN(ary) || snap_ptr != RARRAY_PTR(ary)) {
rb_raise(rb_eRuntimeError, "modified during shuffle");
}
tmp = ptr[--i];
ptr[i] = ptr[j];
ptr[j] = tmp;
}
return ary;
}


/*
* call-seq:
* ary.shuffle -> new_ary
* ary.shuffle(random: rng) -> new_ary
*
* Returns a new array with elements of this array shuffled.
*
* a = [ 1, 2, 3 ] #=> [1, 2, 3]
* a.shuffle #=> [2, 3, 1]
*
* If +rng+ is given, it will be used as the random number generator.
*
* a.shuffle(random: Random.new(1)) #=> [1, 3, 2]
*/

static VALUE
rb_ary_shuffle(int argc, VALUE *argv, VALUE ary)
{
ary = rb_ary_dup(ary);
rb_ary_shuffle_bang(argc, argv, ary);
return ary;
}


/*
* call-seq:
* ary.sample -> obj
* ary.sample(random: rng) -> obj
* ary.sample(n) -> new_ary
* ary.sample(n, random: rng) -> new_ary
*
* Choose a random element or +n+ random elements from the array. The elements
* are chosen by using random and unique indices into the array in order to
* ensure that an element doesn't repeat itself unless the array already
* contained duplicate elements. If the array is empty the first form returns
* <code>nil</code> and the second form returns an empty array.
*
* If +rng+ is given, it will be used as the random number generator.
*
* a = [ 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 ]
* a.sample #=> 7
* a.sample(4) #=> [6, 4, 2, 5]
*/


static VALUE
rb_ary_sample(int argc, VALUE *argv, VALUE ary)
{
VALUE nv, result, *ptr;
VALUE opts, randgen = rb_cRandom;
long n, len, i, j, k, idx[10];
double rnds[numberof(idx)];

if (OPTHASH_GIVEN_P(opts)) {
randgen = rb_hash_lookup2(opts, sym_random, randgen);
}
ptr = RARRAY_PTR(ary);
len = RARRAY_LEN(ary);
if (argc == 0) {
if (len == 0) return Qnil;
if (len == 1) {
i = 0;
}
else {
double x = rb_random_real(randgen);
if ((len = RARRAY_LEN(ary)) == 0) return Qnil;
i = (long)(x * len);
}
return RARRAY_PTR(ary)[i];
}
rb_scan_args(argc, argv, "1", &nv);
n = NUM2LONG(nv);
if (n < 0) rb_raise(rb_eArgError, "negative sample number");
if (n > len) n = len;
if (n <= numberof(idx)) {
for (i = 0; i < n; ++i) {
rnds[i] = rb_random_real(randgen);
}
}
len = RARRAY_LEN(ary);
ptr = RARRAY_PTR(ary);
if (n > len) n = len;
switch (n) {
case 0:
return rb_ary_new2(0);
case 1:
i = (long)(rnds[0] * len);
return rb_ary_new4(1, &ptr[i]);
case 2:
i = (long)(rnds[0] * len);
j = (long)(rnds[1] * (len-1));
if (j >= i) j++;
return rb_ary_new3(2, ptr[i], ptr[j]);
case 3:
i = (long)(rnds[0] * len);
j = (long)(rnds[1] * (len-1));
k = (long)(rnds[2] * (len-2));
{
long l = j, g = i;
if (j >= i) l = i, g = ++j;
if (k >= l && (++k >= g)) ++k;
}
return rb_ary_new3(3, ptr[i], ptr[j], ptr[k]);
}
if (n <= numberof(idx)) {
VALUE *ptr_result;
long sorted[numberof(idx)];
sorted[0] = idx[0] = (long)(rnds[0] * len);
for (i=1; i<n; i++) {
k = (long)(rnds[i] * --len);
for (j = 0; j < i; ++j) {
if (k < sorted[j]) break;
++k;
}
memmove(&sorted[j+1], &sorted[j], sizeof(sorted[0])*(i-j));
sorted[j] = idx[i] = k;
}
result = rb_ary_new2(n);
ptr_result = RARRAY_PTR(result);
for (i=0; i<n; i++) {
ptr_result[i] = ptr[idx[i]];
}
}
else {
VALUE *ptr_result;
result = rb_ary_new4(len, ptr);
RBASIC(result)->klass = 0;
ptr_result = RARRAY_PTR(result);
RB_GC_GUARD(ary);
for (i=0; i<n; i++) {
j = RAND_UPTO(len-i) + i;
nv = ptr_result[j];
ptr_result[j] = ptr_result[i];
ptr_result[i] = nv;
}
RBASIC(result)->klass = rb_cArray;
}
ARY_SET_LEN(result, n);

return result;
}


/*
* call-seq:
* ary.cycle(n=nil) {|obj| block } -> nil
* ary.cycle(n=nil) -> an_enumerator
*
* Calls +block+ for each element repeatedly +n+ times or
* forever if none or +nil+ is given. If a non-positive number is
* given or the array is empty, does nothing. Returns +nil+ if the
* loop has finished without getting interrupted.
*
* If no block is given, an enumerator is returned instead.
*
*
* a = ["a", "b", "c"]
* a.cycle {|x| puts x } # print, a, b, c, a, b, c,.. forever.
* a.cycle(2) {|x| puts x } # print, a, b, c, a, b, c.
*
*/

static VALUE
rb_ary_cycle(int argc, VALUE *argv, VALUE ary)
{
long n, i;
VALUE nv = Qnil;

rb_scan_args(argc, argv, "01", &nv);

RETURN_ENUMERATOR(ary, argc, argv);
if (NIL_P(nv)) {
n = -1;
}
else {
n = NUM2LONG(nv);
if (n <= 0) return Qnil;
}

while (RARRAY_LEN(ary) > 0 && (n < 0 || 0 < n--)) {
for (i=0; i<RARRAY_LEN(ary); i++) {
rb_yield(RARRAY_PTR(ary)[i]);
}
}
return Qnil;
}

#define tmpbuf(n, size) rb_str_tmp_new((n)*(size))
#define tmpbuf_discard(s) (rb_str_resize((s), 0L), RBASIC(s)->klass = rb_cString)
#define tmpary(n) rb_ary_tmp_new(n)
#define tmpary_discard(a) (ary_discard(a), RBASIC(a)->klass = rb_cArray)

/*
* Recursively compute permutations of r elements of the set [0..n-1].
* When we have a complete permutation of array indexes, copy the values
* at those indexes into a new array and yield that array.
*
* n: the size of the set
* r: the number of elements in each permutation
* p: the array (of size r) that we're filling in
* index: what index we're filling in now
* used: an array of booleans: whether a given index is already used
* values: the Ruby array that holds the actual values to permute
*/
static void
permute0(long n, long r, long *p, long index, char *used, VALUE values)
{
long i,j;
for (i = 0; i < n; i++) {
if (used[i] == 0) {
p[index] = i;
if (index < r-1) { /* if not done yet */
used[i] = 1; /* mark index used */
permute0(n, r, p, index+1, /* recurse */
used, values);
used[i] = 0; /* index unused */
}
else {
/* We have a complete permutation of array indexes */
/* Build a ruby array of the corresponding values */
/* And yield it to the associated block */
VALUE result = rb_ary_new2(r);
VALUE *result_array = RARRAY_PTR(result);
const VALUE *values_array = RARRAY_PTR(values);

for (j = 0; j < r; j++) result_array[j] = values_array[p[j]];
ARY_SET_LEN(result, r);
rb_yield(result);
if (RBASIC(values)->klass) {
rb_raise(rb_eRuntimeError, "permute reentered");
}
}
}
}
}

/*
* call-seq:
* ary.permutation { |p| block } -> ary
* ary.permutation -> an_enumerator
* ary.permutation(n) { |p| block } -> ary
* ary.permutation(n) -> an_enumerator
*
* When invoked with a block, yield all permutations of length +n+
* of the elements of the array, then return the array itself.
* If +n+ is not specified, yield all permutations of all elements.
* The implementation makes no guarantees about the order in which
* the permutations are yielded.
*
* If no block is given, an enumerator is returned instead.
*
* Examples:
*
* a = [1, 2, 3]
* a.permutation.to_a #=> [[1,2,3],[1,3,2],[2,1,3],[2,3,1],[3,1,2],[3,2,1]]
* a.permutation(1).to_a #=> [[1],[2],[3]]
* a.permutation(2).to_a #=> [[1,2],[1,3],[2,1],[2,3],[3,1],[3,2]]
* a.permutation(3).to_a #=> [[1,2,3],[1,3,2],[2,1,3],[2,3,1],[3,1,2],[3,2,1]]
* a.permutation(0).to_a #=> [[]] # one permutation of length 0
* a.permutation(4).to_a #=> [] # no permutations of length 4
*/

static VALUE
rb_ary_permutation(int argc, VALUE *argv, VALUE ary)
{
VALUE num;
long r, n, i;

n = RARRAY_LEN(ary); /* Array length */
RETURN_ENUMERATOR(ary, argc, argv); /* Return enumerator if no block */
rb_scan_args(argc, argv, "01", &num);
r = NIL_P(num) ? n : NUM2LONG(num); /* Permutation size from argument */

if (r < 0 || n < r) {
/* no permutations: yield nothing */
}
else if (r == 0) { /* exactly one permutation: the zero-length array */
rb_yield(rb_ary_new2(0));
}
else if (r == 1) { /* this is a special, easy case */
for (i = 0; i < RARRAY_LEN(ary); i++) {
rb_yield(rb_ary_new3(1, RARRAY_PTR(ary)[i]));
}
}
else { /* this is the general case */
volatile VALUE t0 = tmpbuf(n,sizeof(long));
long *p = (long*)RSTRING_PTR(t0);
volatile VALUE t1 = tmpbuf(n,sizeof(char));
char *used = (char*)RSTRING_PTR(t1);
VALUE ary0 = ary_make_shared_copy(ary); /* private defensive copy of ary */
RBASIC(ary0)->klass = 0;

MEMZERO(used, char, n); /* initialize array */

permute0(n, r, p, 0, used, ary0); /* compute and yield permutations */
tmpbuf_discard(t0);
tmpbuf_discard(t1);
RBASIC(ary0)->klass = rb_cArray;
}
return ary;
}

/*
* call-seq:
* ary.combination(n) { |c| block } -> ary
* ary.combination(n) -> an_enumerator
*
* When invoked with a block, yields all combinations of length +n+
* of elements from the array and then returns the array itself.
* The implementation makes no guarantees about the order in which
* the combinations are yielded.
*
* If no block is given, an enumerator is returned instead.
*
* Examples:
*
* a = [1, 2, 3, 4]
* a.combination(1).to_a #=> [[1],[2],[3],[4]]
* a.combination(2).to_a #=> [[1,2],[1,3],[1,4],[2,3],[2,4],[3,4]]
* a.combination(3).to_a #=> [[1,2,3],[1,2,4],[1,3,4],[2,3,4]]
* a.combination(4).to_a #=> [[1,2,3,4]]
* a.combination(0).to_a #=> [[]] # one combination of length 0
* a.combination(5).to_a #=> [] # no combinations of length 5
*
*/

static VALUE
rb_ary_combination(VALUE ary, VALUE num)
{
long n, i, len;

n = NUM2LONG(num);
RETURN_ENUMERATOR(ary, 1, &num);
len = RARRAY_LEN(ary);
if (n < 0 || len < n) {
/* yield nothing */
}
else if (n == 0) {
rb_yield(rb_ary_new2(0));
}
else if (n == 1) {
for (i = 0; i < len; i++) {
rb_yield(rb_ary_new3(1, RARRAY_PTR(ary)[i]));
}
}
else {
volatile VALUE t0 = tmpbuf(n+1, sizeof(long));
long *stack = (long*)RSTRING_PTR(t0);
volatile VALUE cc = tmpary(n);
VALUE *chosen = RARRAY_PTR(cc);
long lev = 0;

MEMZERO(stack, long, n);
stack[0] = -1;
for (;;) {
chosen[lev] = RARRAY_PTR(ary)[stack[lev+1]];
for (lev++; lev < n; lev++) {
chosen[lev] = RARRAY_PTR(ary)[stack[lev+1] = stack[lev]+1];
}
rb_yield(rb_ary_new4(n, chosen));
if (RBASIC(t0)->klass) {
rb_raise(rb_eRuntimeError, "combination reentered");
}
do {
if (lev == 0) goto done;
stack[lev--]++;
} while (stack[lev+1]+n == len+lev+1);
}
done:
tmpbuf_discard(t0);
tmpary_discard(cc);
}
return ary;
}

/*
* Recursively compute repeated permutations of r elements of the set
* [0..n-1].
* When we have a complete repeated permutation of array indexes, copy the
* values at those indexes into a new array and yield that array.
*
* n: the size of the set
* r: the number of elements in each permutation
* p: the array (of size r) that we're filling in
* index: what index we're filling in now
* values: the Ruby array that holds the actual values to permute
*/
static void
rpermute0(long n, long r, long *p, long index, VALUE values)
{
long i, j;
for (i = 0; i < n; i++) {
p[index] = i;
if (index < r-1) { /* if not done yet */
rpermute0(n, r, p, index+1, values); /* recurse */
}
else {
/* We have a complete permutation of array indexes */
/* Build a ruby array of the corresponding values */
/* And yield it to the associated block */
VALUE result = rb_ary_new2(r);
VALUE *result_array = RARRAY_PTR(result);
const VALUE *values_array = RARRAY_PTR(values);

for (j = 0; j < r; j++) result_array[j] = values_array[p[j]];
ARY_SET_LEN(result, r);
rb_yield(result);
if (RBASIC(values)->klass) {
rb_raise(rb_eRuntimeError, "repeated permute reentered");
}
}
}
}

/*
* call-seq:
* ary.repeated_permutation(n) { |p| block } -> ary
* ary.repeated_permutation(n) -> an_enumerator
*
* When invoked with a block, yield all repeated permutations of length
* +n+ of the elements of the array, then return the array itself.
* The implementation makes no guarantees about the order in which
* the repeated permutations are yielded.
*
* If no block is given, an enumerator is returned instead.
*
* Examples:
*
* a = [1, 2]
* a.repeated_permutation(1).to_a #=> [[1], [2]]
* a.repeated_permutation(2).to_a #=> [[1,1],[1,2],[2,1],[2,2]]
* a.repeated_permutation(3).to_a #=> [[1,1,1],[1,1,2],[1,2,1],[1,2,2],
* # [2,1,1],[2,1,2],[2,2,1],[2,2,2]]
* a.repeated_permutation(0).to_a #=> [[]] # one permutation of length 0
*/

static VALUE
rb_ary_repeated_permutation(VALUE ary, VALUE num)
{
long r, n, i;

n = RARRAY_LEN(ary); /* Array length */
RETURN_ENUMERATOR(ary, 1, &num); /* Return enumerator if no block */
r = NUM2LONG(num); /* Permutation size from argument */

if (r < 0) {
/* no permutations: yield nothing */
}
else if (r == 0) { /* exactly one permutation: the zero-length array */
rb_yield(rb_ary_new2(0));
}
else if (r == 1) { /* this is a special, easy case */
for (i = 0; i < RARRAY_LEN(ary); i++) {
rb_yield(rb_ary_new3(1, RARRAY_PTR(ary)[i]));
}
}
else { /* this is the general case */
volatile VALUE t0 = tmpbuf(r, sizeof(long));
long *p = (long*)RSTRING_PTR(t0);
VALUE ary0 = ary_make_shared_copy(ary); /* private defensive copy of ary */
RBASIC(ary0)->klass = 0;

rpermute0(n, r, p, 0, ary0); /* compute and yield repeated permutations */
tmpbuf_discard(t0);
RBASIC(ary0)->klass = rb_cArray;
}
return ary;
}

static void
rcombinate0(long n, long r, long *p, long index, long rest, VALUE values)
{
long j;
if (rest > 0) {
for (; index < n; ++index) {
p[r-rest] = index;
rcombinate0(n, r, p, index, rest-1, values);
}
}
else {
VALUE result = rb_ary_new2(r);
VALUE *result_array = RARRAY_PTR(result);
const VALUE *values_array = RARRAY_PTR(values);

for (j = 0; j < r; ++j) result_array[j] = values_array[p[j]];
ARY_SET_LEN(result, r);
rb_yield(result);
if (RBASIC(values)->klass) {
rb_raise(rb_eRuntimeError, "repeated combination reentered");
}
}
}

/*
* call-seq:
* ary.repeated_combination(n) { |c| block } -> ary
* ary.repeated_combination(n) -> an_enumerator
*
* When invoked with a block, yields all repeated combinations of
* length +n+ of elements from the array and then returns
* the array itself.
* The implementation makes no guarantees about the order in which
* the repeated combinations are yielded.
*
* If no block is given, an enumerator is returned instead.
*
* Examples:
*
* a = [1, 2, 3]
* a.repeated_combination(1).to_a #=> [[1], [2], [3]]
* a.repeated_combination(2).to_a #=> [[1,1],[1,2],[1,3],[2,2],[2,3],[3,3]]
* a.repeated_combination(3).to_a #=> [[1,1,1],[1,1,2],[1,1,3],[1,2,2],[1,2,3],
* # [1,3,3],[2,2,2],[2,2,3],[2,3,3],[3,3,3]]
* a.repeated_combination(4).to_a #=> [[1,1,1,1],[1,1,1,2],[1,1,1,3],[1,1,2,2],[1,1,2,3],
* # [1,1,3,3],[1,2,2,2],[1,2,2,3],[1,2,3,3],[1,3,3,3],
* # [2,2,2,2],[2,2,2,3],[2,2,3,3],[2,3,3,3],[3,3,3,3]]
* a.repeated_combination(0).to_a #=> [[]] # one combination of length 0
*
*/

static VALUE
rb_ary_repeated_combination(VALUE ary, VALUE num)
{
long n, i, len;

n = NUM2LONG(num); /* Combination size from argument */
RETURN_ENUMERATOR(ary, 1, &num); /* Return enumerator if no block */
len = RARRAY_LEN(ary);
if (n < 0) {
/* yield nothing */
}
else if (n == 0) {
rb_yield(rb_ary_new2(0));
}
else if (n == 1) {
for (i = 0; i < len; i++) {
rb_yield(rb_ary_new3(1, RARRAY_PTR(ary)[i]));
}
}
else if (len == 0) {
/* yield nothing */
}
else {
volatile VALUE t0 = tmpbuf(n, sizeof(long));
long *p = (long*)RSTRING_PTR(t0);
VALUE ary0 = ary_make_shared_copy(ary); /* private defensive copy of ary */
RBASIC(ary0)->klass = 0;

rcombinate0(len, n, p, 0, n, ary0); /* compute and yield repeated combinations */
tmpbuf_discard(t0);
RBASIC(ary0)->klass = rb_cArray;
}
return ary;
}

/*
* call-seq:
* ary.product(other_ary, ...) -> new_ary
* ary.product(other_ary, ...) { |p| block } -> ary
*
* Returns an array of all combinations of elements from all arrays.
* The length of the returned array is the product of the length
* of +self+ and the argument arrays.
* If given a block, #product will yield all combinations
* and return +self+ instead.
*
*
* [1,2,3].product([4,5]) #=> [[1,4],[1,5],[2,4],[2,5],[3,4],[3,5]]
* [1,2].product([1,2]) #=> [[1,1],[1,2],[2,1],[2,2]]
* [1,2].product([3,4],[5,6]) #=> [[1,3,5],[1,3,6],[1,4,5],[1,4,6],
* # [2,3,5],[2,3,6],[2,4,5],[2,4,6]]
* [1,2].product() #=> [[1],[2]]
* [1,2].product([]) #=> []
*/

static VALUE
rb_ary_product(int argc, VALUE *argv, VALUE ary)
{
int n = argc+1; /* How many arrays we're operating on */
volatile VALUE t0 = tmpary(n);
volatile VALUE t1 = tmpbuf(n, sizeof(int));
VALUE *arrays = RARRAY_PTR(t0); /* The arrays we're computing the product of */
int *counters = (int*)RSTRING_PTR(t1); /* The current position in each one */
VALUE result = Qnil; /* The array we'll be returning, when no block given */
long i,j;
long resultlen = 1;

RBASIC(t0)->klass = 0;
RBASIC(t1)->klass = 0;

/* initialize the arrays of arrays */
ARY_SET_LEN(t0, n);
arrays[0] = ary;
for (i = 1; i < n; i++) arrays[i] = Qnil;
for (i = 1; i < n; i++) arrays[i] = to_ary(argv[i-1]);

/* initialize the counters for the arrays */
for (i = 0; i < n; i++) counters[i] = 0;

/* Otherwise, allocate and fill in an array of results */
if (rb_block_given_p()) {
/* Make defensive copies of arrays; exit if any is empty */
for (i = 0; i < n; i++) {
if (RARRAY_LEN(arrays[i]) == 0) goto done;
arrays[i] = ary_make_shared_copy(arrays[i]);
}
}
else {
/* Compute the length of the result array; return [] if any is empty */
for (i = 0; i < n; i++) {
long k = RARRAY_LEN(arrays[i]), l = resultlen;
if (k == 0) {
result = rb_ary_new2(0);
goto done;
}
resultlen *= k;
if (resultlen < k || resultlen < l || resultlen / k != l) {
rb_raise(rb_eRangeError, "too big to product");
}
}
result = rb_ary_new2(resultlen);
}
for (;;) {
int m;
/* fill in one subarray */
VALUE subarray = rb_ary_new2(n);
for (j = 0; j < n; j++) {
rb_ary_push(subarray, rb_ary_entry(arrays[j], counters[j]));
}

/* put it on the result array */
if(NIL_P(result)) {
FL_SET(t0, FL_USER5);
rb_yield(subarray);
if (! FL_TEST(t0, FL_USER5)) {
rb_raise(rb_eRuntimeError, "product reentered");
}
else {
FL_UNSET(t0, FL_USER5);
}
}
else {
rb_ary_push(result, subarray);
}

/*
* Increment the last counter. If it overflows, reset to 0
* and increment the one before it.
*/
m = n-1;
counters[m]++;
while (counters[m] == RARRAY_LEN(arrays[m])) {
counters[m] = 0;
/* If the first counter overflows, we are done */
if (--m < 0) goto done;
counters[m]++;
}
}
done:
tmpary_discard(t0);
tmpbuf_discard(t1);

return NIL_P(result) ? ary : result;
}

/*
* call-seq:
* ary.take(n) -> new_ary
*
* Returns first +n+ elements from the array.
*
* a = [1, 2, 3, 4, 5, 0]
* a.take(3) #=> [1, 2, 3]
*
*/

static VALUE
rb_ary_take(VALUE obj, VALUE n)
{
long len = NUM2LONG(n);
if (len < 0) {
rb_raise(rb_eArgError, "attempt to take negative size");
}
return rb_ary_subseq(obj, 0, len);
}

/*
* call-seq:
* ary.take_while {|arr| block } -> new_ary
* ary.take_while -> an_enumerator
*
* Passes elements to the block until the block returns +nil+ or +false+,
* then stops iterating and returns an array of all prior elements.
*
* If no block is given, an enumerator is returned instead.
*
* a = [1, 2, 3, 4, 5, 0]
* a.take_while {|i| i < 3 } #=> [1, 2]
*
*/

static VALUE
rb_ary_take_while(VALUE ary)
{
long i;

RETURN_ENUMERATOR(ary, 0, 0);
for (i = 0; i < RARRAY_LEN(ary); i++) {
if (!RTEST(rb_yield(RARRAY_PTR(ary)[i]))) break;
}
return rb_ary_take(ary, LONG2FIX(i));
}

/*
* call-seq:
* ary.drop(n) -> new_ary
*
* Drops first n elements from +ary+ and returns the rest of
* the elements in an array.
*
* a = [1, 2, 3, 4, 5, 0]
* a.drop(3) #=> [4, 5, 0]
*
*/

static VALUE
rb_ary_drop(VALUE ary, VALUE n)
{
VALUE result;
long pos = NUM2LONG(n);
if (pos < 0) {
rb_raise(rb_eArgError, "attempt to drop negative size");
}

result = rb_ary_subseq(ary, pos, RARRAY_LEN(ary));
if (result == Qnil) result = rb_ary_new();
return result;
}

/*
* call-seq:
* ary.drop_while {|arr| block } -> new_ary
* ary.drop_while -> an_enumerator
*
* Drops elements up to, but not including, the first element for
* which the block returns +nil+ or +false+ and returns an array
* containing the remaining elements.
*
* If no block is given, an enumerator is returned instead.
*
* a = [1, 2, 3, 4, 5, 0]
* a.drop_while {|i| i < 3 } #=> [3, 4, 5, 0]
*
*/

static VALUE
rb_ary_drop_while(VALUE ary)
{
long i;

RETURN_ENUMERATOR(ary, 0, 0);
for (i = 0; i < RARRAY_LEN(ary); i++) {
if (!RTEST(rb_yield(RARRAY_PTR(ary)[i]))) break;
}
return rb_ary_drop(ary, LONG2FIX(i));
}

/*
* call-seq:
* ary.part_of? other_ary -> bool
*
* Array 'A' is part of another array 'B' if
* each element from 'A' are include in 'B'
*
* [ "a", "c" ].part_of? [ "a", "b", "c" ] #=> true
* [ "a", "d" ].part_of? [ "a", "b", "c" ] #=> false
* [].part_of [] #=> true
*
*/

static VALUE
rb_ary_part_of(VALUE ary1, VALUE ary2)
{

if (ary1 == ary2) return Qtrue;
VALUE ary3, ary4;
ary3 = rb_ary_and(ary1, ary2);
ary4 = rb_ary_diff(ary1, ary3);
return rb_ary_empty_p(ary4);
}

/*
* Arrays are ordered, integer-indexed collections of any object.
* Array indexing starts at 0, as in C or Java. A negative index is
* assumed to be relative to the end of the array---that is, an index of -1
* indicates the last element of the array, -2 is the next to last
* element in the array, and so on.
*
* == Creating Arrays
*
* A new array can be created by using the literal constructor
* <code>[]</code>. Arrays can contain different types of objects. For
* example, the array below contains an Integer, a String and a Float:
*
* ary = [1, "two", 3.0] #=> [1, "two", 3.0]
*
* An array can also be created by explicitly calling Array.new with zero,
* one (the initial size of the Array) or two arguments (the initial size and
* a default object).
*
* ary = Array.new #=> []
* Array.new(3) #=> [nil, nil, nil]
* Array.new(3, true) #=> [0, 0, 0]
*
* Note that the second argument populates the array with references the same
* object. Therefore, it is only recommended in cases when you need to
* instantiate arrays with natively immutable objects such Symbols, numbers,
* true or false.
*
* To create an array with separate objects a block can be passed instead.
* This method is safe to use with mutable objects such as hashes, strings or
* other arrays:
*
* Array.new(4) { Hash.new } #=> [{}, {}, {}, {}]
*
* This is also a quick way to build up multi-dimensional arrays:
*
* empty_table = Array.new(3) { Array.new(3) }
* #=> [[nil, nil, nil], [nil, nil, nil], [nil, nil, nil]]
*
* == Example Usage
*
* In addition to the methods it mixes in through the Enumerable module, the
* Array class has proprietary methods for accessing, searching and otherwise
* manipulating arrays. Some of the more common ones are illustrated below.
*
* == Accessing Elements
*
* Elements in an array can be retrieved using the Array#[] method. It can
* take a single integer argument (a numeric index), a pair of arguments
* (start and length) or a range.
*
* arr = [1, 2, 3, 4, 5, 6]
* arr[2] #=> 3
* arr[100] #=> nil
* arr[-3] #=> 4
* arr[2, 3] #=> [3, 4, 5]
* arr[1..4] #=> [2, 3, 4, 5]
*
* Another way to access a particular array element is by using the #at method
*
* arr.at(0) #=> 1
*
* The #slice method works in an identical manner to Array#[].
*
* To raise an error for indices outside of the array bounds or else to provide
* a default value when that happens, you can use #fetch.
*
* arr = ['a', 'b', 'c', 'd', 'e', 'f']
* arr.fetch(100) #=> IndexError: index 100 outside of array bounds: -6...6
* arr.fetch(100, "oops") #=> "oops"
*
* The special methods #first and #last will return the first and last
* elements of an array, respectively.
*
* arr.first #=> 1
* arr.last #=> 6
*
* To return the first n elements of an array, use #take
*
* arr.take(3) #=> [1, 2, 3]
*
* #drop does the opposite of #take, by returning the elements after n elements
* have been dropped:
*
* arr.drop(3) #=> [4, 5, 6]
*
* == Obtaining Information about an Array
*
* Arrays keep track of their own length at all times. To query an array about
* the number of elements it contains, use #length, #count or #size.
*
* browsers = ['Chrome', 'Firefox', 'Safari', 'Opera', 'IE']
* browsers.length #=> 5
* browsers.count #=> 5
*
* To check whether an array contains any elements at all
*
* browsers.empty? #=> false
*
* To check whether a particular item is included in the array
*
* browsers.include?('Konqueror') #=> false
*
* == Adding Items to Arrays
*
* Items can be added to the end of an array by using either #push or
* <code><<</code>
*
* arr = [1, 2, 3, 4]
* arr.push(5) #=> [1, 2, 3, 4, 5]
* arr << 6 #=> [1, 2, 3, 4, 5, 6]
*
* #unshift will add a new item to the beginning of an array.
*
* arr.unshift(0) #=> [0, 1, 2, 3, 4, 5, 6]
*
* With #insert you can add a new element to an array at any position.
*
* arr.insert(3, 'apple') #=> [0, 1, 2, 'apple', 3, 4, 5, 6]
*
* Using the #insert method, you can also insert multiple values at once:
*
* arr.insert(3, 'orange', 'pear', 'grapefruit')
* #=> [0, 1, 2, "orange", "pear", "grapefruit", "apple", 3, 4, 5, 6]
*
* == Removing Items from an Array
*
* The method #pop removes the last element in an array and returns it:
*
* arr = [1, 2, 3, 4, 5, 6]
* arr.pop #=> 6
* arr #=> [1, 2, 3, 4, 5]
*
* To retrieve and at the same time remove the first item, use #shift:
*
* arr.shift #=> 1
* arr #=> [2, 3, 4, 5]
*
* To delete an element at a particular index:
*
* arr.delete_at(2) #=> 4
* arr #=> [2, 3, 5]
*
* To delete a particular element anywhere in an array, use #delete:
*
* arr = [1, 2, 2, 3]
* arr.delete(2) #=> [1, 3]
*
* A useful method if you need to remove +nil+ values from an array is
* #compact:
*
* arr = ['foo', 0, nil, 'bar', 7, 'baz', nil]
* arr.compact #=> ['foo', 0, 'bar', 7, 'baz']
* arr #=> ['foo', 0, nil, 'bar', 7, 'baz', nil]
* arr.compact! #=> ['foo', 0, 'bar', 7, 'baz']
* arr #=> ['foo', 0, 'bar', 7, 'baz']
*
* Another common need is to remove duplicate elements from an array.
* It has a non-destructive (#uniq) and a destructive method (#uniq!)
*
* arr = [2, 5, 6, 556, 6, 6, 8, 9, 0, 123, 556]
* arr.uniq #=> [2, 5, 6, 556, 8, 9, 0, 123]
*
* == Iterating over Arrays
*
* Like all classes that include the Enumerable module, Array has an each
* method, which defines what elements should be iterated over and how. In
* case of Array's #each, all elements in the Array instance are yielded
* to the supplied block in sequence. Note that this
* operation leaves the array unchanged.
*
* arr = [1, 2, 3, 4, 5]
* arr.each { |a| print a -= 10, " " }
* # prints: -9 -8 -7 -6 -5
* #=> [1, 2, 3, 4, 5]
*
* Another sometimes useful iterator is #reverse_each which will iterate over
* the elements in the array in reverse order.
*
* words = %w[rats live on no evil star]
* str = ""
* words.reverse_each { |word| str += "#{word.reverse} " }
* str #=> "rats live on no evil star "
*
* The #map method can be used to create a new array based on the original
* array, but with the values modified by the supplied block:
*
* arr.map { |a| 2*a } #=> [2, 4, 6, 8, 10]
* arr #=> [1, 2, 3, 4, 5]
* arr.map! { |a| a**2 } #=> [1, 4, 9, 16, 25]
* arr #=> [1, 4, 9, 16, 25]
*
* == Selecting Items from an Array
*
* Elements can be selected from an array according to criteria defined in a
* block. The selection can happen in a destructive or a non-destructive
* manner. While the destructive operations will modify the array they were
* called on, the non-destructive methods usually return a new array with the
* selected elements, but leave the original array unchanged.
*
* === Non-destructive Selection
*
* arr = [1, 2, 3, 4, 5, 6]
* arr.select { |a| a > 3 } #=> [4, 5, 6]
* arr.reject { |a| a < 3 } #=> [4, 5, 6]
* arr.drop_while { |a| a < 4 } #=> [4, 5, 6]
* arr #=> [1, 2, 3, 4, 5, 6]
*
* === Destructive Selection
*
* #select! and #reject! are the corresponding destructive methods to #select
* and #reject
*
* Similar to #select vs. #reject, #delete_if and #keep_if have the exact
* opposite result when supplied with the same block:
*
* arr.delete_if { |a| a < 4 } #=> [4, 5, 6]
* arr #=> [4, 5, 6]
*
* arr = [1, 2, 3, 4, 5, 6]
* arr.keep_if { |a| a < 4 } #=> [1, 2, 3]
* arr #=> [1, 2, 3]
*
*/

void
Init_Array(void)
{
#undef rb_intern
#define rb_intern(str) rb_intern_const(str)

rb_cArray = rb_define_class("Array", rb_cObject);
rb_include_module(rb_cArray, rb_mEnumerable);

rb_define_alloc_func(rb_cArray, ary_alloc);
rb_define_singleton_method(rb_cArray, "[]", rb_ary_s_create, -1);
rb_define_singleton_method(rb_cArray, "try_convert", rb_ary_s_try_convert, 1);
rb_define_method(rb_cArray, "initialize", rb_ary_initialize, -1);
rb_define_method(rb_cArray, "initialize_copy", rb_ary_replace, 1);

rb_define_method(rb_cArray, "inspect", rb_ary_inspect, 0);
rb_define_alias(rb_cArray, "to_s", "inspect");
rb_define_method(rb_cArray, "to_a", rb_ary_to_a, 0);
rb_define_method(rb_cArray, "to_ary", rb_ary_to_ary_m, 0);
rb_define_method(rb_cArray, "frozen?", rb_ary_frozen_p, 0);

rb_define_method(rb_cArray, "==", rb_ary_equal, 1);
rb_define_method(rb_cArray, "eql?", rb_ary_eql, 1);
rb_define_method(rb_cArray, "hash", rb_ary_hash, 0);

rb_define_method(rb_cArray, "[]", rb_ary_aref, -1);
rb_define_method(rb_cArray, "[]=", rb_ary_aset, -1);
rb_define_method(rb_cArray, "at", rb_ary_at, 1);
rb_define_method(rb_cArray, "fetch", rb_ary_fetch, -1);
rb_define_method(rb_cArray, "first", rb_ary_first, -1);
rb_define_method(rb_cArray, "last", rb_ary_last, -1);
rb_define_method(rb_cArray, "concat", rb_ary_concat, 1);
rb_define_method(rb_cArray, "<<", rb_ary_push, 1);
rb_define_method(rb_cArray, "push", rb_ary_push_m, -1);
rb_define_method(rb_cArray, "pop", rb_ary_pop_m, -1);
rb_define_method(rb_cArray, "shift", rb_ary_shift_m, -1);
rb_define_method(rb_cArray, "unshift", rb_ary_unshift_m, -1);
rb_define_method(rb_cArray, "insert", rb_ary_insert, -1);
rb_define_method(rb_cArray, "each", rb_ary_each, 0);
rb_define_method(rb_cArray, "each_index", rb_ary_each_index, 0);
rb_define_method(rb_cArray, "reverse_each", rb_ary_reverse_each, 0);
rb_define_method(rb_cArray, "length", rb_ary_length, 0);
rb_define_alias(rb_cArray, "size", "length");
rb_define_method(rb_cArray, "empty?", rb_ary_empty_p, 0);
rb_define_method(rb_cArray, "find_index", rb_ary_index, -1);
rb_define_method(rb_cArray, "index", rb_ary_index, -1);
rb_define_method(rb_cArray, "rindex", rb_ary_rindex, -1);
rb_define_method(rb_cArray, "join", rb_ary_join_m, -1);
rb_define_method(rb_cArray, "reverse", rb_ary_reverse_m, 0);
rb_define_method(rb_cArray, "reverse!", rb_ary_reverse_bang, 0);
rb_define_method(rb_cArray, "rotate", rb_ary_rotate_m, -1);
rb_define_method(rb_cArray, "rotate!", rb_ary_rotate_bang, -1);
rb_define_method(rb_cArray, "sort", rb_ary_sort, 0);
rb_define_method(rb_cArray, "sort!", rb_ary_sort_bang, 0);
rb_define_method(rb_cArray, "sort_by!", rb_ary_sort_by_bang, 0);
rb_define_method(rb_cArray, "collect", rb_ary_collect, 0);
rb_define_method(rb_cArray, "collect!", rb_ary_collect_bang, 0);
rb_define_method(rb_cArray, "map", rb_ary_collect, 0);
rb_define_method(rb_cArray, "map!", rb_ary_collect_bang, 0);
rb_define_method(rb_cArray, "select", rb_ary_select, 0);
rb_define_method(rb_cArray, "select!", rb_ary_select_bang, 0);
rb_define_method(rb_cArray, "keep_if", rb_ary_keep_if, 0);
rb_define_method(rb_cArray, "values_at", rb_ary_values_at, -1);
rb_define_method(rb_cArray, "delete", rb_ary_delete, 1);
rb_define_method(rb_cArray, "delete_at", rb_ary_delete_at_m, 1);
rb_define_method(rb_cArray, "delete_if", rb_ary_delete_if, 0);
rb_define_method(rb_cArray, "reject", rb_ary_reject, 0);
rb_define_method(rb_cArray, "reject!", rb_ary_reject_bang, 0);
rb_define_method(rb_cArray, "zip", rb_ary_zip, -1);
rb_define_method(rb_cArray, "transpose", rb_ary_transpose, 0);
rb_define_method(rb_cArray, "replace", rb_ary_replace, 1);
rb_define_method(rb_cArray, "clear", rb_ary_clear, 0);
rb_define_method(rb_cArray, "fill", rb_ary_fill, -1);
rb_define_method(rb_cArray, "include?", rb_ary_includes, 1);
rb_define_method(rb_cArray, "<=>", rb_ary_cmp, 1);

rb_define_method(rb_cArray, "slice", rb_ary_aref, -1);
rb_define_method(rb_cArray, "slice!", rb_ary_slice_bang, -1);

rb_define_method(rb_cArray, "assoc", rb_ary_assoc, 1);
rb_define_method(rb_cArray, "rassoc", rb_ary_rassoc, 1);

rb_define_method(rb_cArray, "+", rb_ary_plus, 1);
rb_define_method(rb_cArray, "*", rb_ary_times, 1);

rb_define_method(rb_cArray, "-", rb_ary_diff, 1);
rb_define_method(rb_cArray, "&", rb_ary_and, 1);
rb_define_method(rb_cArray, "|", rb_ary_or, 1);

rb_define_method(rb_cArray, "uniq", rb_ary_uniq, 0);
rb_define_method(rb_cArray, "uniq!", rb_ary_uniq_bang, 0);
rb_define_method(rb_cArray, "compact", rb_ary_compact, 0);
rb_define_method(rb_cArray, "compact!", rb_ary_compact_bang, 0);
rb_define_method(rb_cArray, "flatten", rb_ary_flatten, -1);
rb_define_method(rb_cArray, "flatten!", rb_ary_flatten_bang, -1);
rb_define_method(rb_cArray, "count", rb_ary_count, -1);
rb_define_method(rb_cArray, "shuffle!", rb_ary_shuffle_bang, -1);
rb_define_method(rb_cArray, "shuffle", rb_ary_shuffle, -1);
rb_define_method(rb_cArray, "sample", rb_ary_sample, -1);
rb_define_method(rb_cArray, "cycle", rb_ary_cycle, -1);
rb_define_method(rb_cArray, "permutation", rb_ary_permutation, -1);
rb_define_method(rb_cArray, "combination", rb_ary_combination, 1);
rb_define_method(rb_cArray, "repeated_permutation", rb_ary_repeated_permutation, 1);
rb_define_method(rb_cArray, "repeated_combination", rb_ary_repeated_combination, 1);
rb_define_method(rb_cArray, "product", rb_ary_product, -1);

rb_define_method(rb_cArray, "take", rb_ary_take, 1);
rb_define_method(rb_cArray, "take_while", rb_ary_take_while, 0);
rb_define_method(rb_cArray, "drop", rb_ary_drop, 1);
rb_define_method(rb_cArray, "drop_while", rb_ary_drop_while, 0);
rb_define_method(rb_cArray, "part_of?", rb_ary_part_of, 1);

id_cmp = rb_intern("<=>");
sym_random = ID2SYM(rb_intern("random"));
}

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