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ruby--ruby/range.c
Koichi Sasada 0096d2b895 freeze all Range objects.
Matz want to try to freeze all Range objects.
[Feature #15504]
2020-09-25 22:16:55 +09:00

1854 lines
47 KiB
C

/**********************************************************************
range.c -
$Author$
created at: Thu Aug 19 17:46:47 JST 1993
Copyright (C) 1993-2007 Yukihiro Matsumoto
**********************************************************************/
#include "ruby/internal/config.h"
#include <assert.h>
#include <math.h>
#ifdef HAVE_FLOAT_H
#include <float.h>
#endif
#include "id.h"
#include "internal.h"
#include "internal/array.h"
#include "internal/compar.h"
#include "internal/enum.h"
#include "internal/enumerator.h"
#include "internal/error.h"
#include "internal/numeric.h"
#include "internal/range.h"
VALUE rb_cRange;
static ID id_beg, id_end, id_excl;
#define id_cmp idCmp
#define id_succ idSucc
#define id_min idMin
#define id_max idMax
static VALUE r_cover_p(VALUE, VALUE, VALUE, VALUE);
#define RANGE_SET_BEG(r, v) (RSTRUCT_SET(r, 0, v))
#define RANGE_SET_END(r, v) (RSTRUCT_SET(r, 1, v))
#define RANGE_SET_EXCL(r, v) (RSTRUCT_SET(r, 2, v))
#define RBOOL(v) ((v) ? Qtrue : Qfalse)
#define EXCL(r) RTEST(RANGE_EXCL(r))
static void
range_init(VALUE range, VALUE beg, VALUE end, VALUE exclude_end)
{
if ((!FIXNUM_P(beg) || !FIXNUM_P(end)) && !NIL_P(beg) && !NIL_P(end)) {
VALUE v;
v = rb_funcall(beg, id_cmp, 1, end);
if (NIL_P(v))
rb_raise(rb_eArgError, "bad value for range");
}
RANGE_SET_EXCL(range, exclude_end);
RANGE_SET_BEG(range, beg);
RANGE_SET_END(range, end);
if (CLASS_OF(range) == rb_cRange) {
rb_obj_freeze(range);
}
}
VALUE
rb_range_new(VALUE beg, VALUE end, int exclude_end)
{
VALUE range = rb_obj_alloc(rb_cRange);
range_init(range, beg, end, RBOOL(exclude_end));
return range;
}
static void
range_modify(VALUE range)
{
rb_check_frozen(range);
/* Ranges are immutable, so that they should be initialized only once. */
if (RANGE_EXCL(range) != Qnil) {
rb_name_err_raise("`initialize' called twice", range, ID2SYM(idInitialize));
}
}
/*
* call-seq:
* Range.new(begin, end, exclude_end=false) -> rng
*
* Constructs a range using the given +begin+ and +end+. If the +exclude_end+
* parameter is omitted or is <code>false</code>, the range will include
* the end object; otherwise, it will be excluded.
*/
static VALUE
range_initialize(int argc, VALUE *argv, VALUE range)
{
VALUE beg, end, flags;
rb_scan_args(argc, argv, "21", &beg, &end, &flags);
range_modify(range);
range_init(range, beg, end, RBOOL(RTEST(flags)));
return Qnil;
}
/* :nodoc: */
static VALUE
range_initialize_copy(VALUE range, VALUE orig)
{
range_modify(range);
rb_struct_init_copy(range, orig);
return range;
}
/*
* call-seq:
* rng.exclude_end? -> true or false
*
* Returns <code>true</code> if the range excludes its end value.
*
* (1..5).exclude_end? #=> false
* (1...5).exclude_end? #=> true
*/
static VALUE
range_exclude_end_p(VALUE range)
{
return EXCL(range) ? Qtrue : Qfalse;
}
static VALUE
recursive_equal(VALUE range, VALUE obj, int recur)
{
if (recur) return Qtrue; /* Subtle! */
if (!rb_equal(RANGE_BEG(range), RANGE_BEG(obj)))
return Qfalse;
if (!rb_equal(RANGE_END(range), RANGE_END(obj)))
return Qfalse;
if (EXCL(range) != EXCL(obj))
return Qfalse;
return Qtrue;
}
/*
* call-seq:
* rng == obj -> true or false
*
* Returns <code>true</code> only if +obj+ is a Range, has equivalent
* begin and end items (by comparing them with <code>==</code>), and has
* the same #exclude_end? setting as the range.
*
* (0..2) == (0..2) #=> true
* (0..2) == Range.new(0,2) #=> true
* (0..2) == (0...2) #=> false
*
*/
static VALUE
range_eq(VALUE range, VALUE obj)
{
if (range == obj)
return Qtrue;
if (!rb_obj_is_kind_of(obj, rb_cRange))
return Qfalse;
return rb_exec_recursive_paired(recursive_equal, range, obj, obj);
}
/* compares _a_ and _b_ and returns:
* < 0: a < b
* = 0: a = b
* > 0: a > b or non-comparable
*/
static int
r_less(VALUE a, VALUE b)
{
VALUE r = rb_funcall(a, id_cmp, 1, b);
if (NIL_P(r))
return INT_MAX;
return rb_cmpint(r, a, b);
}
static VALUE
recursive_eql(VALUE range, VALUE obj, int recur)
{
if (recur) return Qtrue; /* Subtle! */
if (!rb_eql(RANGE_BEG(range), RANGE_BEG(obj)))
return Qfalse;
if (!rb_eql(RANGE_END(range), RANGE_END(obj)))
return Qfalse;
if (EXCL(range) != EXCL(obj))
return Qfalse;
return Qtrue;
}
/*
* call-seq:
* rng.eql?(obj) -> true or false
*
* Returns <code>true</code> only if +obj+ is a Range, has equivalent
* begin and end items (by comparing them with <code>eql?</code>),
* and has the same #exclude_end? setting as the range.
*
* (0..2).eql?(0..2) #=> true
* (0..2).eql?(Range.new(0,2)) #=> true
* (0..2).eql?(0...2) #=> false
*
*/
static VALUE
range_eql(VALUE range, VALUE obj)
{
if (range == obj)
return Qtrue;
if (!rb_obj_is_kind_of(obj, rb_cRange))
return Qfalse;
return rb_exec_recursive_paired(recursive_eql, range, obj, obj);
}
/*
* call-seq:
* rng.hash -> integer
*
* Compute a hash-code for this range. Two ranges with equal
* begin and end points (using <code>eql?</code>), and the same
* #exclude_end? value will generate the same hash-code.
*
* See also Object#hash.
*/
static VALUE
range_hash(VALUE range)
{
st_index_t hash = EXCL(range);
VALUE v;
hash = rb_hash_start(hash);
v = rb_hash(RANGE_BEG(range));
hash = rb_hash_uint(hash, NUM2LONG(v));
v = rb_hash(RANGE_END(range));
hash = rb_hash_uint(hash, NUM2LONG(v));
hash = rb_hash_uint(hash, EXCL(range) << 24);
hash = rb_hash_end(hash);
return ST2FIX(hash);
}
static void
range_each_func(VALUE range, int (*func)(VALUE, VALUE), VALUE arg)
{
int c;
VALUE b = RANGE_BEG(range);
VALUE e = RANGE_END(range);
VALUE v = b;
if (EXCL(range)) {
while (r_less(v, e) < 0) {
if ((*func)(v, arg)) break;
v = rb_funcallv(v, id_succ, 0, 0);
}
}
else {
while ((c = r_less(v, e)) <= 0) {
if ((*func)(v, arg)) break;
if (!c) break;
v = rb_funcallv(v, id_succ, 0, 0);
}
}
}
static int
sym_step_i(VALUE i, VALUE arg)
{
VALUE *iter = (VALUE *)arg;
if (FIXNUM_P(iter[0])) {
iter[0] -= INT2FIX(1) & ~FIXNUM_FLAG;
}
else {
iter[0] = rb_funcall(iter[0], '-', 1, INT2FIX(1));
}
if (iter[0] == INT2FIX(0)) {
rb_yield(rb_str_intern(i));
iter[0] = iter[1];
}
return 0;
}
static int
step_i(VALUE i, VALUE arg)
{
VALUE *iter = (VALUE *)arg;
if (FIXNUM_P(iter[0])) {
iter[0] -= INT2FIX(1) & ~FIXNUM_FLAG;
}
else {
iter[0] = rb_funcall(iter[0], '-', 1, INT2FIX(1));
}
if (iter[0] == INT2FIX(0)) {
rb_yield(i);
iter[0] = iter[1];
}
return 0;
}
static int
discrete_object_p(VALUE obj)
{
if (rb_obj_is_kind_of(obj, rb_cTime)) return FALSE; /* until Time#succ removed */
return rb_respond_to(obj, id_succ);
}
static int
linear_object_p(VALUE obj)
{
if (FIXNUM_P(obj) || FLONUM_P(obj)) return TRUE;
if (SPECIAL_CONST_P(obj)) return FALSE;
switch (BUILTIN_TYPE(obj)) {
case T_FLOAT:
case T_BIGNUM:
return TRUE;
default:
break;
}
if (rb_obj_is_kind_of(obj, rb_cNumeric)) return TRUE;
if (rb_obj_is_kind_of(obj, rb_cTime)) return TRUE;
return FALSE;
}
static VALUE
check_step_domain(VALUE step)
{
VALUE zero = INT2FIX(0);
int cmp;
if (!rb_obj_is_kind_of(step, rb_cNumeric)) {
step = rb_to_int(step);
}
cmp = rb_cmpint(rb_funcallv(step, idCmp, 1, &zero), step, zero);
if (cmp < 0) {
rb_raise(rb_eArgError, "step can't be negative");
}
else if (cmp == 0) {
rb_raise(rb_eArgError, "step can't be 0");
}
return step;
}
static VALUE
range_step_size(VALUE range, VALUE args, VALUE eobj)
{
VALUE b = RANGE_BEG(range), e = RANGE_END(range);
VALUE step = INT2FIX(1);
if (args) {
step = check_step_domain(RARRAY_AREF(args, 0));
}
if (rb_obj_is_kind_of(b, rb_cNumeric) && rb_obj_is_kind_of(e, rb_cNumeric)) {
return ruby_num_interval_step_size(b, e, step, EXCL(range));
}
return Qnil;
}
/*
* Document-method: Range#step
* Document-method: Range#%
* call-seq:
* rng.step(n=1) {| obj | block } -> rng
* rng.step(n=1) -> an_enumerator
* rng.step(n=1) -> an_arithmetic_sequence
* rng % n -> an_enumerator
* rng % n -> an_arithmetic_sequence
*
* Iterates over the range, passing each <code>n</code>th element to the block.
* If begin and end are numeric, +n+ is added for each iteration.
* Otherwise #step invokes #succ to iterate through range elements.
*
* If no block is given, an enumerator is returned instead.
* Especially, the enumerator is an Enumerator::ArithmeticSequence
* if begin and end of the range are numeric.
*
* range = Xs.new(1)..Xs.new(10)
* range.step(2) {|x| puts x}
* puts
* range.step(3) {|x| puts x}
*
* <em>produces:</em>
*
* 1 x
* 3 xxx
* 5 xxxxx
* 7 xxxxxxx
* 9 xxxxxxxxx
*
* 1 x
* 4 xxxx
* 7 xxxxxxx
* 10 xxxxxxxxxx
*
* See Range for the definition of class Xs.
*/
static VALUE
range_step(int argc, VALUE *argv, VALUE range)
{
VALUE b, e, step, tmp;
b = RANGE_BEG(range);
e = RANGE_END(range);
step = (!rb_check_arity(argc, 0, 1) ? INT2FIX(1) : argv[0]);
if (!rb_block_given_p()) {
const VALUE b_num_p = rb_obj_is_kind_of(b, rb_cNumeric);
const VALUE e_num_p = rb_obj_is_kind_of(e, rb_cNumeric);
if ((b_num_p && (NIL_P(e) || e_num_p)) || (NIL_P(b) && e_num_p)) {
return rb_arith_seq_new(range, ID2SYM(rb_frame_this_func()), argc, argv,
range_step_size, b, e, step, EXCL(range));
}
RETURN_SIZED_ENUMERATOR(range, argc, argv, range_step_size);
}
step = check_step_domain(step);
if (FIXNUM_P(b) && NIL_P(e) && FIXNUM_P(step)) {
long i = FIX2LONG(b), unit = FIX2LONG(step);
do {
rb_yield(LONG2FIX(i));
i += unit; /* FIXABLE+FIXABLE never overflow */
} while (FIXABLE(i));
b = LONG2NUM(i);
for (;; b = rb_big_plus(b, step))
rb_yield(b);
}
else if (FIXNUM_P(b) && FIXNUM_P(e) && FIXNUM_P(step)) { /* fixnums are special */
long end = FIX2LONG(e);
long i, unit = FIX2LONG(step);
if (!EXCL(range))
end += 1;
i = FIX2LONG(b);
while (i < end) {
rb_yield(LONG2NUM(i));
if (i + unit < i) break;
i += unit;
}
}
else if (SYMBOL_P(b) && (NIL_P(e) || SYMBOL_P(e))) { /* symbols are special */
VALUE iter[2];
iter[0] = INT2FIX(1);
iter[1] = step;
b = rb_sym2str(b);
if (NIL_P(e)) {
rb_str_upto_endless_each(b, sym_step_i, (VALUE)iter);
}
else {
rb_str_upto_each(b, rb_sym2str(e), EXCL(range), sym_step_i, (VALUE)iter);
}
}
else if (ruby_float_step(b, e, step, EXCL(range), TRUE)) {
/* done */
}
else if (rb_obj_is_kind_of(b, rb_cNumeric) ||
!NIL_P(rb_check_to_integer(b, "to_int")) ||
!NIL_P(rb_check_to_integer(e, "to_int"))) {
ID op = EXCL(range) ? '<' : idLE;
VALUE v = b;
int i = 0;
while (NIL_P(e) || RTEST(rb_funcall(v, op, 1, e))) {
rb_yield(v);
i++;
v = rb_funcall(b, '+', 1, rb_funcall(INT2NUM(i), '*', 1, step));
}
}
else {
tmp = rb_check_string_type(b);
if (!NIL_P(tmp)) {
VALUE iter[2];
b = tmp;
iter[0] = INT2FIX(1);
iter[1] = step;
if (NIL_P(e)) {
rb_str_upto_endless_each(b, step_i, (VALUE)iter);
}
else {
rb_str_upto_each(b, e, EXCL(range), step_i, (VALUE)iter);
}
}
else {
VALUE args[2];
if (!discrete_object_p(b)) {
rb_raise(rb_eTypeError, "can't iterate from %s",
rb_obj_classname(b));
}
args[0] = INT2FIX(1);
args[1] = step;
range_each_func(range, step_i, (VALUE)args);
}
}
return range;
}
static VALUE
range_percent_step(VALUE range, VALUE step)
{
return range_step(1, &step, range);
}
#if SIZEOF_DOUBLE == 8 && defined(HAVE_INT64_T)
union int64_double {
int64_t i;
double d;
};
static VALUE
int64_as_double_to_num(int64_t i)
{
union int64_double convert;
if (i < 0) {
convert.i = -i;
return DBL2NUM(-convert.d);
}
else {
convert.i = i;
return DBL2NUM(convert.d);
}
}
static int64_t
double_as_int64(double d)
{
union int64_double convert;
convert.d = fabs(d);
return d < 0 ? -convert.i : convert.i;
}
#endif
static int
is_integer_p(VALUE v)
{
ID id_integer_p;
VALUE is_int;
CONST_ID(id_integer_p, "integer?");
is_int = rb_check_funcall(v, id_integer_p, 0, 0);
return RTEST(is_int) && is_int != Qundef;
}
static VALUE
bsearch_integer_range(VALUE beg, VALUE end, int excl)
{
VALUE satisfied = Qnil;
int smaller;
#define BSEARCH_CHECK(expr) \
do { \
VALUE val = (expr); \
VALUE v = rb_yield(val); \
if (FIXNUM_P(v)) { \
if (v == INT2FIX(0)) return val; \
smaller = (SIGNED_VALUE)v < 0; \
} \
else if (v == Qtrue) { \
satisfied = val; \
smaller = 1; \
} \
else if (v == Qfalse || v == Qnil) { \
smaller = 0; \
} \
else if (rb_obj_is_kind_of(v, rb_cNumeric)) { \
int cmp = rb_cmpint(rb_funcall(v, id_cmp, 1, INT2FIX(0)), v, INT2FIX(0)); \
if (!cmp) return val; \
smaller = cmp < 0; \
} \
else { \
rb_raise(rb_eTypeError, "wrong argument type %"PRIsVALUE \
" (must be numeric, true, false or nil)", \
rb_obj_class(v)); \
} \
} while (0)
VALUE low = rb_to_int(beg);
VALUE high = rb_to_int(end);
VALUE mid, org_high;
ID id_div;
CONST_ID(id_div, "div");
if (excl) high = rb_funcall(high, '-', 1, INT2FIX(1));
org_high = high;
while (rb_cmpint(rb_funcall(low, id_cmp, 1, high), low, high) < 0) {
mid = rb_funcall(rb_funcall(high, '+', 1, low), id_div, 1, INT2FIX(2));
BSEARCH_CHECK(mid);
if (smaller) {
high = mid;
}
else {
low = rb_funcall(mid, '+', 1, INT2FIX(1));
}
}
if (rb_equal(low, org_high)) {
BSEARCH_CHECK(low);
if (!smaller) return Qnil;
}
return satisfied;
}
/*
* call-seq:
* rng.bsearch {|obj| block } -> value
*
* By using binary search, finds a value in range which meets the given
* condition in O(log n) where n is the size of the range.
*
* You can use this method in two use cases: a find-minimum mode and
* a find-any mode. In either case, the elements of the range must be
* monotone (or sorted) with respect to the block.
*
* In find-minimum mode (this is a good choice for typical use case),
* the block must return true or false, and there must be a value x
* so that:
*
* - the block returns false for any value which is less than x, and
* - the block returns true for any value which is greater than or
* equal to x.
*
* If x is within the range, this method returns the value x.
* Otherwise, it returns nil.
*
* ary = [0, 4, 7, 10, 12]
* (0...ary.size).bsearch {|i| ary[i] >= 4 } #=> 1
* (0...ary.size).bsearch {|i| ary[i] >= 6 } #=> 2
* (0...ary.size).bsearch {|i| ary[i] >= 8 } #=> 3
* (0...ary.size).bsearch {|i| ary[i] >= 100 } #=> nil
*
* (0.0...Float::INFINITY).bsearch {|x| Math.log(x) >= 0 } #=> 1.0
*
* In find-any mode (this behaves like libc's bsearch(3)), the block
* must return a number, and there must be two values x and y (x <= y)
* so that:
*
* - the block returns a positive number for v if v < x,
* - the block returns zero for v if x <= v < y, and
* - the block returns a negative number for v if y <= v.
*
* This method returns any value which is within the intersection of
* the given range and x...y (if any). If there is no value that
* satisfies the condition, it returns nil.
*
* ary = [0, 100, 100, 100, 200]
* (0..4).bsearch {|i| 100 - ary[i] } #=> 1, 2 or 3
* (0..4).bsearch {|i| 300 - ary[i] } #=> nil
* (0..4).bsearch {|i| 50 - ary[i] } #=> nil
*
* You must not mix the two modes at a time; the block must always
* return either true/false, or always return a number. It is
* undefined which value is actually picked up at each iteration.
*/
static VALUE
range_bsearch(VALUE range)
{
VALUE beg, end, satisfied = Qnil;
int smaller;
/* Implementation notes:
* Floats are handled by mapping them to 64 bits integers.
* Apart from sign issues, floats and their 64 bits integer have the
* same order, assuming they are represented as exponent followed
* by the mantissa. This is true with or without implicit bit.
*
* Finding the average of two ints needs to be careful about
* potential overflow (since float to long can use 64 bits)
* as well as the fact that -1/2 can be 0 or -1 in C89.
*
* Note that -0.0 is mapped to the same int as 0.0 as we don't want
* (-1...0.0).bsearch to yield -0.0.
*/
#define BSEARCH(conv) \
do { \
RETURN_ENUMERATOR(range, 0, 0); \
if (EXCL(range)) high--; \
org_high = high; \
while (low < high) { \
mid = ((high < 0) == (low < 0)) ? low + ((high - low) / 2) \
: (low < -high) ? -((-1 - low - high)/2 + 1) : (low + high) / 2; \
BSEARCH_CHECK(conv(mid)); \
if (smaller) { \
high = mid; \
} \
else { \
low = mid + 1; \
} \
} \
if (low == org_high) { \
BSEARCH_CHECK(conv(low)); \
if (!smaller) return Qnil; \
} \
return satisfied; \
} while (0)
beg = RANGE_BEG(range);
end = RANGE_END(range);
if (FIXNUM_P(beg) && FIXNUM_P(end)) {
long low = FIX2LONG(beg);
long high = FIX2LONG(end);
long mid, org_high;
BSEARCH(INT2FIX);
}
#if SIZEOF_DOUBLE == 8 && defined(HAVE_INT64_T)
else if (RB_TYPE_P(beg, T_FLOAT) || RB_TYPE_P(end, T_FLOAT)) {
int64_t low = double_as_int64(NIL_P(beg) ? -HUGE_VAL : RFLOAT_VALUE(rb_Float(beg)));
int64_t high = double_as_int64(NIL_P(end) ? HUGE_VAL : RFLOAT_VALUE(rb_Float(end)));
int64_t mid, org_high;
BSEARCH(int64_as_double_to_num);
}
#endif
else if (is_integer_p(beg) && is_integer_p(end)) {
RETURN_ENUMERATOR(range, 0, 0);
return bsearch_integer_range(beg, end, EXCL(range));
}
else if (is_integer_p(beg) && NIL_P(end)) {
VALUE diff = LONG2FIX(1);
RETURN_ENUMERATOR(range, 0, 0);
while (1) {
VALUE mid = rb_funcall(beg, '+', 1, diff);
BSEARCH_CHECK(mid);
if (smaller) {
return bsearch_integer_range(beg, mid, 0);
}
diff = rb_funcall(diff, '*', 1, LONG2FIX(2));
}
}
else if (NIL_P(beg) && is_integer_p(end)) {
VALUE diff = LONG2FIX(-1);
RETURN_ENUMERATOR(range, 0, 0);
while (1) {
VALUE mid = rb_funcall(end, '+', 1, diff);
BSEARCH_CHECK(mid);
if (!smaller) {
return bsearch_integer_range(mid, end, 0);
}
diff = rb_funcall(diff, '*', 1, LONG2FIX(2));
}
}
else {
rb_raise(rb_eTypeError, "can't do binary search for %s", rb_obj_classname(beg));
}
return range;
}
static int
each_i(VALUE v, VALUE arg)
{
rb_yield(v);
return 0;
}
static int
sym_each_i(VALUE v, VALUE arg)
{
rb_yield(rb_str_intern(v));
return 0;
}
/*
* call-seq:
* rng.size -> num
*
* Returns the number of elements in the range. Both the begin and the end of
* the Range must be Numeric, otherwise nil is returned.
*
* (10..20).size #=> 11
* ('a'..'z').size #=> nil
* (-Float::INFINITY..Float::INFINITY).size #=> Infinity
*/
static VALUE
range_size(VALUE range)
{
VALUE b = RANGE_BEG(range), e = RANGE_END(range);
if (rb_obj_is_kind_of(b, rb_cNumeric)) {
if (rb_obj_is_kind_of(e, rb_cNumeric)) {
return ruby_num_interval_step_size(b, e, INT2FIX(1), EXCL(range));
}
if (NIL_P(e)) {
return DBL2NUM(HUGE_VAL);
}
}
else if (NIL_P(b)) {
return DBL2NUM(HUGE_VAL);
}
return Qnil;
}
/*
* call-seq:
* rng.to_a -> array
* rng.entries -> array
*
* Returns an array containing the items in the range.
*
* (1..7).to_a #=> [1, 2, 3, 4, 5, 6, 7]
* (1..).to_a #=> RangeError: cannot convert endless range to an array
*/
static VALUE
range_to_a(VALUE range)
{
if (NIL_P(RANGE_END(range))) {
rb_raise(rb_eRangeError, "cannot convert endless range to an array");
}
return rb_call_super(0, 0);
}
static VALUE
range_enum_size(VALUE range, VALUE args, VALUE eobj)
{
return range_size(range);
}
RBIMPL_ATTR_NORETURN()
static void
range_each_bignum_endless(VALUE beg)
{
for (;; beg = rb_big_plus(beg, INT2FIX(1))) {
rb_yield(beg);
}
UNREACHABLE;
}
RBIMPL_ATTR_NORETURN()
static void
range_each_fixnum_endless(VALUE beg)
{
for (long i = FIX2LONG(beg); FIXABLE(i); i++) {
rb_yield(LONG2FIX(i));
}
range_each_bignum_endless(LONG2NUM(RUBY_FIXNUM_MAX + 1));
UNREACHABLE;
}
static VALUE
range_each_fixnum_loop(VALUE beg, VALUE end, VALUE range)
{
long lim = FIX2LONG(end) + !EXCL(range);
for (long i = FIX2LONG(beg); i < lim; i++) {
rb_yield(LONG2FIX(i));
}
return range;
}
/*
* call-seq:
* rng.each {| i | block } -> rng
* rng.each -> an_enumerator
*
* Iterates over the elements of range, passing each in turn to the
* block.
*
* The +each+ method can only be used if the begin object of the range
* supports the +succ+ method. A TypeError is raised if the object
* does not have +succ+ method defined (like Float).
*
* If no block is given, an enumerator is returned instead.
*
* (10..15).each {|n| print n, ' ' }
* # prints: 10 11 12 13 14 15
*
* (2.5..5).each {|n| print n, ' ' }
* # raises: TypeError: can't iterate from Float
*/
static VALUE
range_each(VALUE range)
{
VALUE beg, end;
long i;
RETURN_SIZED_ENUMERATOR(range, 0, 0, range_enum_size);
beg = RANGE_BEG(range);
end = RANGE_END(range);
if (FIXNUM_P(beg) && NIL_P(end)) {
range_each_fixnum_endless(beg);
}
else if (FIXNUM_P(beg) && FIXNUM_P(end)) { /* fixnums are special */
return range_each_fixnum_loop(beg, end, range);
}
else if (RB_INTEGER_TYPE_P(beg) && (NIL_P(end) || RB_INTEGER_TYPE_P(end))) {
if (SPECIAL_CONST_P(end) || RBIGNUM_POSITIVE_P(end)) { /* end >= FIXNUM_MIN */
if (!FIXNUM_P(beg)) {
if (RBIGNUM_NEGATIVE_P(beg)) {
do {
rb_yield(beg);
} while (!FIXNUM_P(beg = rb_big_plus(beg, INT2FIX(1))));
if (NIL_P(end)) range_each_fixnum_endless(beg);
if (FIXNUM_P(end)) return range_each_fixnum_loop(beg, end, range);
}
else {
if (NIL_P(end)) range_each_bignum_endless(beg);
if (FIXNUM_P(end)) return range;
}
}
if (FIXNUM_P(beg)) {
i = FIX2LONG(beg);
do {
rb_yield(LONG2FIX(i));
} while (POSFIXABLE(++i));
beg = LONG2NUM(i);
}
ASSUME(!FIXNUM_P(beg));
ASSUME(!SPECIAL_CONST_P(end));
}
if (!FIXNUM_P(beg) && RBIGNUM_SIGN(beg) == RBIGNUM_SIGN(end)) {
if (EXCL(range)) {
while (rb_big_cmp(beg, end) == INT2FIX(-1)) {
rb_yield(beg);
beg = rb_big_plus(beg, INT2FIX(1));
}
}
else {
VALUE c;
while ((c = rb_big_cmp(beg, end)) != INT2FIX(1)) {
rb_yield(beg);
if (c == INT2FIX(0)) break;
beg = rb_big_plus(beg, INT2FIX(1));
}
}
}
}
else if (SYMBOL_P(beg) && (NIL_P(end) || SYMBOL_P(end))) { /* symbols are special */
beg = rb_sym2str(beg);
if (NIL_P(end)) {
rb_str_upto_endless_each(beg, sym_each_i, 0);
}
else {
rb_str_upto_each(beg, rb_sym2str(end), EXCL(range), sym_each_i, 0);
}
}
else {
VALUE tmp = rb_check_string_type(beg);
if (!NIL_P(tmp)) {
if (!NIL_P(end)) {
rb_str_upto_each(tmp, end, EXCL(range), each_i, 0);
}
else {
rb_str_upto_endless_each(tmp, each_i, 0);
}
}
else {
if (!discrete_object_p(beg)) {
rb_raise(rb_eTypeError, "can't iterate from %s",
rb_obj_classname(beg));
}
if (!NIL_P(end))
range_each_func(range, each_i, 0);
else
for (;; beg = rb_funcallv(beg, id_succ, 0, 0))
rb_yield(beg);
}
}
return range;
}
/*
* call-seq:
* rng.begin -> obj
*
* Returns the object that defines the beginning of the range.
*
* (1..10).begin #=> 1
*/
static VALUE
range_begin(VALUE range)
{
return RANGE_BEG(range);
}
/*
* call-seq:
* rng.end -> obj
*
* Returns the object that defines the end of the range.
*
* (1..10).end #=> 10
* (1...10).end #=> 10
*/
static VALUE
range_end(VALUE range)
{
return RANGE_END(range);
}
static VALUE
first_i(RB_BLOCK_CALL_FUNC_ARGLIST(i, cbarg))
{
VALUE *ary = (VALUE *)cbarg;
long n = NUM2LONG(ary[0]);
if (n <= 0) {
rb_iter_break();
}
rb_ary_push(ary[1], i);
n--;
ary[0] = LONG2NUM(n);
return Qnil;
}
/*
* call-seq:
* rng.first -> obj
* rng.first(n) -> an_array
*
* Returns the first object in the range, or an array of the first +n+
* elements.
*
* (10..20).first #=> 10
* (10..20).first(3) #=> [10, 11, 12]
*/
static VALUE
range_first(int argc, VALUE *argv, VALUE range)
{
VALUE n, ary[2];
if (NIL_P(RANGE_BEG(range))) {
rb_raise(rb_eRangeError, "cannot get the first element of beginless range");
}
if (argc == 0) return RANGE_BEG(range);
rb_scan_args(argc, argv, "1", &n);
ary[0] = n;
ary[1] = rb_ary_new2(NUM2LONG(n));
rb_block_call(range, idEach, 0, 0, first_i, (VALUE)ary);
return ary[1];
}
static VALUE
rb_int_range_last(int argc, VALUE *argv, VALUE range)
{
static const VALUE ONE = INT2FIX(1);
VALUE b, e, len_1, len, nv, ary;
int x;
long n;
assert(argc > 0);
b = RANGE_BEG(range);
e = RANGE_END(range);
assert(RB_INTEGER_TYPE_P(b) && RB_INTEGER_TYPE_P(e));
x = EXCL(range);
len_1 = rb_int_minus(e, b);
if (FIXNUM_ZERO_P(len_1) || rb_num_negative_p(len_1)) {
return rb_ary_new_capa(0);
}
if (x) {
e = rb_int_minus(e, ONE);
len = len_1;
}
else {
len = rb_int_plus(len_1, ONE);
}
rb_scan_args(argc, argv, "1", &nv);
n = NUM2LONG(nv);
if (n < 0) {
rb_raise(rb_eArgError, "negative array size");
}
nv = LONG2NUM(n);
if (RTEST(rb_int_gt(nv, len))) {
nv = len;
n = NUM2LONG(nv);
}
ary = rb_ary_new_capa(n);
b = rb_int_minus(e, nv);
while (n) {
b = rb_int_plus(b, ONE);
rb_ary_push(ary, b);
--n;
}
return ary;
}
/*
* call-seq:
* rng.last -> obj
* rng.last(n) -> an_array
*
* Returns the last object in the range,
* or an array of the last +n+ elements.
*
* Note that with no arguments +last+ will return the object that defines
* the end of the range even if #exclude_end? is +true+.
*
* (10..20).last #=> 20
* (10...20).last #=> 20
* (10..20).last(3) #=> [18, 19, 20]
* (10...20).last(3) #=> [17, 18, 19]
*/
static VALUE
range_last(int argc, VALUE *argv, VALUE range)
{
VALUE b, e;
if (NIL_P(RANGE_END(range))) {
rb_raise(rb_eRangeError, "cannot get the last element of endless range");
}
if (argc == 0) return RANGE_END(range);
b = RANGE_BEG(range);
e = RANGE_END(range);
if (RB_INTEGER_TYPE_P(b) && RB_INTEGER_TYPE_P(e) &&
RB_LIKELY(rb_method_basic_definition_p(rb_cRange, idEach))) {
return rb_int_range_last(argc, argv, range);
}
return rb_ary_last(argc, argv, rb_Array(range));
}
/*
* call-seq:
* rng.min -> obj
* rng.min {| a,b | block } -> obj
* rng.min(n) -> array
* rng.min(n) {| a,b | block } -> array
*
* Returns the minimum value in the range. Returns +nil+ if the begin
* value of the range is larger than the end value. Returns +nil+ if
* the begin value of an exclusive range is equal to the end value.
*
* Can be given an optional block to override the default comparison
* method <code>a <=> b</code>.
*
* (10..20).min #=> 10
*/
static VALUE
range_min(int argc, VALUE *argv, VALUE range)
{
if (NIL_P(RANGE_BEG(range))) {
rb_raise(rb_eRangeError, "cannot get the minimum of beginless range");
}
if (rb_block_given_p()) {
if (NIL_P(RANGE_END(range))) {
rb_raise(rb_eRangeError, "cannot get the minimum of endless range with custom comparison method");
}
return rb_call_super(argc, argv);
}
else if (argc != 0) {
return range_first(argc, argv, range);
}
else {
struct cmp_opt_data cmp_opt = { 0, 0 };
VALUE b = RANGE_BEG(range);
VALUE e = RANGE_END(range);
int c = NIL_P(e) ? -1 : OPTIMIZED_CMP(b, e, cmp_opt);
if (c > 0 || (c == 0 && EXCL(range)))
return Qnil;
return b;
}
}
/*
* call-seq:
* rng.max -> obj
* rng.max {| a,b | block } -> obj
* rng.max(n) -> obj
* rng.max(n) {| a,b | block } -> obj
*
* Returns the maximum value in the range, or an array of maximum
* values in the range if given an \Integer argument.
*
* For inclusive ranges with an end, the maximum value of the range
* is the same as the end of the range.
*
* If an argument or block is given, or +self+ is an exclusive,
* non-numeric range, calls Enumerable#max (via +super+) with the
* argument and/or block to get the maximum values, unless +self+ is
* a beginless range, in which case it raises a RangeError.
*
* If +self+ is an exclusive, integer range (both start and end of the
* range are integers), and no arguments or block are provided, returns
* last value in the range (1 before the end). Otherwise, if +self+ is
* an exclusive, numeric range, raises a TypeError.
*
* Returns +nil+ if the begin value of the range larger than the
* end value. Returns +nil+ if the begin value of an exclusive
* range is equal to the end value. Raises a RangeError if called on
* an endless range.
*
* Examples:
* (10..20).max #=> 20
* (10..20).max(2) #=> [20, 19]
* (10...20).max #=> 19
* (10...20).max(2) #=> [19, 18]
* (10...20).max{|x, y| -x <=> -y } #=> 10
* (10...20).max(2){|x, y| -x <=> -y } #=> [10, 11]
*/
static VALUE
range_max(int argc, VALUE *argv, VALUE range)
{
VALUE e = RANGE_END(range);
int nm = FIXNUM_P(e) || rb_obj_is_kind_of(e, rb_cNumeric);
if (NIL_P(RANGE_END(range))) {
rb_raise(rb_eRangeError, "cannot get the maximum of endless range");
}
VALUE b = RANGE_BEG(range);
if (rb_block_given_p() || (EXCL(range) && !nm) || argc) {
if (NIL_P(b)) {
rb_raise(rb_eRangeError, "cannot get the maximum of beginless range with custom comparison method");
}
return rb_call_super(argc, argv);
}
else {
struct cmp_opt_data cmp_opt = { 0, 0 };
int c = NIL_P(b) ? -1 : OPTIMIZED_CMP(b, e, cmp_opt);
if (c > 0)
return Qnil;
if (EXCL(range)) {
if (!RB_INTEGER_TYPE_P(e)) {
rb_raise(rb_eTypeError, "cannot exclude non Integer end value");
}
if (c == 0) return Qnil;
if (!RB_INTEGER_TYPE_P(b)) {
rb_raise(rb_eTypeError, "cannot exclude end value with non Integer begin value");
}
if (FIXNUM_P(e)) {
return LONG2NUM(FIX2LONG(e) - 1);
}
return rb_funcall(e, '-', 1, INT2FIX(1));
}
return e;
}
}
/*
* call-seq:
* rng.minmax -> [obj, obj]
* rng.minmax {| a,b | block } -> [obj, obj]
*
* Returns a two element array which contains the minimum and the
* maximum value in the range.
*
* Can be given an optional block to override the default comparison
* method <code>a <=> b</code>.
*/
static VALUE
range_minmax(VALUE range)
{
if (rb_block_given_p()) {
return rb_call_super(0, NULL);
}
return rb_assoc_new(
rb_funcall(range, id_min, 0),
rb_funcall(range, id_max, 0)
);
}
int
rb_range_values(VALUE range, VALUE *begp, VALUE *endp, int *exclp)
{
VALUE b, e;
int excl;
if (rb_obj_is_kind_of(range, rb_cRange)) {
b = RANGE_BEG(range);
e = RANGE_END(range);
excl = EXCL(range);
}
else if (RTEST(rb_obj_is_kind_of(range, rb_cArithSeq))) {
return (int)Qfalse;
}
else {
VALUE x;
b = rb_check_funcall(range, id_beg, 0, 0);
if (b == Qundef) return (int)Qfalse;
e = rb_check_funcall(range, id_end, 0, 0);
if (e == Qundef) return (int)Qfalse;
x = rb_check_funcall(range, rb_intern("exclude_end?"), 0, 0);
if (x == Qundef) return (int)Qfalse;
excl = RTEST(x);
}
*begp = b;
*endp = e;
*exclp = excl;
return (int)Qtrue;
}
VALUE
rb_range_beg_len(VALUE range, long *begp, long *lenp, long len, int err)
{
long beg, end, origbeg, origend;
VALUE b, e;
int excl;
if (!rb_range_values(range, &b, &e, &excl))
return Qfalse;
beg = NIL_P(b) ? 0 : NUM2LONG(b);
end = NIL_P(e) ? -1 : NUM2LONG(e);
if (NIL_P(e)) excl = 0;
origbeg = beg;
origend = end;
if (beg < 0) {
beg += len;
if (beg < 0)
goto out_of_range;
}
if (end < 0)
end += len;
if (!excl)
end++; /* include end point */
if (err == 0 || err == 2) {
if (beg > len)
goto out_of_range;
if (end > len)
end = len;
}
len = end - beg;
if (len < 0)
len = 0;
*begp = beg;
*lenp = len;
return Qtrue;
out_of_range:
if (err) {
rb_raise(rb_eRangeError, "%ld..%s%ld out of range",
origbeg, excl ? "." : "", origend);
}
return Qnil;
}
/*
* call-seq:
* rng.to_s -> string
*
* Convert this range object to a printable form (using #to_s to convert the
* begin and end objects).
*/
static VALUE
range_to_s(VALUE range)
{
VALUE str, str2;
str = rb_obj_as_string(RANGE_BEG(range));
str2 = rb_obj_as_string(RANGE_END(range));
str = rb_str_dup(str);
rb_str_cat(str, "...", EXCL(range) ? 3 : 2);
rb_str_append(str, str2);
return str;
}
static VALUE
inspect_range(VALUE range, VALUE dummy, int recur)
{
VALUE str, str2 = Qundef;
if (recur) {
return rb_str_new2(EXCL(range) ? "(... ... ...)" : "(... .. ...)");
}
if (!NIL_P(RANGE_BEG(range)) || NIL_P(RANGE_END(range))) {
str = rb_str_dup(rb_inspect(RANGE_BEG(range)));
}
else {
str = rb_str_new(0, 0);
}
rb_str_cat(str, "...", EXCL(range) ? 3 : 2);
if (NIL_P(RANGE_BEG(range)) || !NIL_P(RANGE_END(range))) {
str2 = rb_inspect(RANGE_END(range));
}
if (str2 != Qundef) rb_str_append(str, str2);
return str;
}
/*
* call-seq:
* rng.inspect -> string
*
* Convert this range object to a printable form (using #inspect to
* convert the begin and end objects).
*/
static VALUE
range_inspect(VALUE range)
{
return rb_exec_recursive(inspect_range, range, 0);
}
static VALUE range_include_internal(VALUE range, VALUE val, int string_use_cover);
/*
* call-seq:
* rng === obj -> true or false
*
* Returns <code>true</code> if +obj+ is between begin and end of range,
* <code>false</code> otherwise (same as #cover?). Conveniently,
* <code>===</code> is the comparison operator used by <code>case</code>
* statements.
*
* case 79
* when 1..50 then puts "low"
* when 51..75 then puts "medium"
* when 76..100 then puts "high"
* end
* # Prints "high"
*
* case "2.6.5"
* when ..."2.4" then puts "EOL"
* when "2.4"..."2.5" then puts "maintenance"
* when "2.5"..."2.7" then puts "stable"
* when "2.7".. then puts "upcoming"
* end
* # Prints "stable"
*
*/
static VALUE
range_eqq(VALUE range, VALUE val)
{
VALUE ret = range_include_internal(range, val, 1);
if (ret != Qundef) return ret;
return r_cover_p(range, RANGE_BEG(range), RANGE_END(range), val);
}
/*
* call-seq:
* rng.member?(obj) -> true or false
* rng.include?(obj) -> true or false
*
* Returns <code>true</code> if +obj+ is an element of
* the range, <code>false</code> otherwise.
*
* ("a".."z").include?("g") #=> true
* ("a".."z").include?("A") #=> false
* ("a".."z").include?("cc") #=> false
*
* If you need to ensure +obj+ is between +begin+ and +end+, use #cover?
*
* ("a".."z").cover?("cc") #=> true
*
* If begin and end are numeric, #include? behaves like #cover?
*
* (1..3).include?(1.5) # => true
*/
static VALUE
range_include(VALUE range, VALUE val)
{
VALUE ret = range_include_internal(range, val, 0);
if (ret != Qundef) return ret;
return rb_call_super(1, &val);
}
static VALUE
range_include_internal(VALUE range, VALUE val, int string_use_cover)
{
VALUE beg = RANGE_BEG(range);
VALUE end = RANGE_END(range);
int nv = FIXNUM_P(beg) || FIXNUM_P(end) ||
linear_object_p(beg) || linear_object_p(end);
if (nv ||
!NIL_P(rb_check_to_integer(beg, "to_int")) ||
!NIL_P(rb_check_to_integer(end, "to_int"))) {
return r_cover_p(range, beg, end, val);
}
else if (RB_TYPE_P(beg, T_STRING) || RB_TYPE_P(end, T_STRING)) {
if (RB_TYPE_P(beg, T_STRING) && RB_TYPE_P(end, T_STRING)) {
if (string_use_cover) {
return r_cover_p(range, beg, end, val);
}
else {
VALUE rb_str_include_range_p(VALUE beg, VALUE end, VALUE val, VALUE exclusive);
return rb_str_include_range_p(beg, end, val, RANGE_EXCL(range));
}
}
else if (NIL_P(beg)) {
VALUE r = rb_funcall(val, id_cmp, 1, end);
if (NIL_P(r)) return Qfalse;
if (rb_cmpint(r, val, end) <= 0) return Qtrue;
return Qfalse;
}
else if (NIL_P(end)) {
VALUE r = rb_funcall(beg, id_cmp, 1, val);
if (NIL_P(r)) return Qfalse;
if (rb_cmpint(r, beg, val) <= 0) return Qtrue;
return Qfalse;
}
}
return Qundef;
}
static int r_cover_range_p(VALUE range, VALUE beg, VALUE end, VALUE val);
/*
* call-seq:
* rng.cover?(obj) -> true or false
* rng.cover?(range) -> true or false
*
* Returns <code>true</code> if +obj+ is between the begin and end of
* the range.
*
* This tests <code>begin <= obj <= end</code> when #exclude_end? is +false+
* and <code>begin <= obj < end</code> when #exclude_end? is +true+.
*
* If called with a Range argument, returns <code>true</code> when the
* given range is covered by the receiver,
* by comparing the begin and end values. If the argument can be treated as
* a sequence, this method treats it that way. In the specific case of
* <code>(a..b).cover?(c...d)</code> with <code>a <= c && b < d</code>,
* the end of the sequence must be calculated, which may exhibit poor
* performance if <code>c</code> is non-numeric.
* Returns <code>false</code> if the begin value of the
* range is larger than the end value. Also returns +false+ if one of the
* internal calls to <code><=></code> returns +nil+ (indicating the objects
* are not comparable).
*
* ("a".."z").cover?("c") #=> true
* ("a".."z").cover?("5") #=> false
* ("a".."z").cover?("cc") #=> true
* ("a".."z").cover?(1) #=> false
* (1..5).cover?(2..3) #=> true
* (1..5).cover?(0..6) #=> false
* (1..5).cover?(1...6) #=> true
*/
static VALUE
range_cover(VALUE range, VALUE val)
{
VALUE beg, end;
beg = RANGE_BEG(range);
end = RANGE_END(range);
if (rb_obj_is_kind_of(val, rb_cRange)) {
return RBOOL(r_cover_range_p(range, beg, end, val));
}
return r_cover_p(range, beg, end, val);
}
static VALUE
r_call_max(VALUE r)
{
return rb_funcallv(r, rb_intern("max"), 0, 0);
}
static int
r_cover_range_p(VALUE range, VALUE beg, VALUE end, VALUE val)
{
VALUE val_beg, val_end, val_max;
int cmp_end;
val_beg = RANGE_BEG(val);
val_end = RANGE_END(val);
if (!NIL_P(end) && NIL_P(val_end)) return FALSE;
if (!NIL_P(beg) && NIL_P(val_beg)) return FALSE;
if (!NIL_P(val_beg) && !NIL_P(val_end) && r_less(val_beg, val_end) > (EXCL(val) ? -1 : 0)) return FALSE;
if (!NIL_P(val_beg) && !r_cover_p(range, beg, end, val_beg)) return FALSE;
cmp_end = r_less(end, val_end);
if (EXCL(range) == EXCL(val)) {
return cmp_end >= 0;
}
else if (EXCL(range)) {
return cmp_end > 0;
}
else if (cmp_end >= 0) {
return TRUE;
}
val_max = rb_rescue2(r_call_max, val, 0, Qnil, rb_eTypeError, (VALUE)0);
if (val_max == Qnil) return FALSE;
return r_less(end, val_max) >= 0;
}
static VALUE
r_cover_p(VALUE range, VALUE beg, VALUE end, VALUE val)
{
if (NIL_P(beg) || r_less(beg, val) <= 0) {
int excl = EXCL(range);
if (NIL_P(end) || r_less(val, end) <= -excl)
return Qtrue;
}
return Qfalse;
}
static VALUE
range_dumper(VALUE range)
{
VALUE v;
NEWOBJ_OF(m, struct RObject, rb_cObject, T_OBJECT | (RGENGC_WB_PROTECTED_OBJECT ? FL_WB_PROTECTED : 1));
v = (VALUE)m;
rb_ivar_set(v, id_excl, RANGE_EXCL(range));
rb_ivar_set(v, id_beg, RANGE_BEG(range));
rb_ivar_set(v, id_end, RANGE_END(range));
return v;
}
static VALUE
range_loader(VALUE range, VALUE obj)
{
VALUE beg, end, excl;
if (!RB_TYPE_P(obj, T_OBJECT) || RBASIC(obj)->klass != rb_cObject) {
rb_raise(rb_eTypeError, "not a dumped range object");
}
range_modify(range);
beg = rb_ivar_get(obj, id_beg);
end = rb_ivar_get(obj, id_end);
excl = rb_ivar_get(obj, id_excl);
if (!NIL_P(excl)) {
range_init(range, beg, end, RBOOL(RTEST(excl)));
}
return range;
}
static VALUE
range_alloc(VALUE klass)
{
/* rb_struct_alloc_noinit itself should not be used because
* rb_marshal_define_compat uses equality of allocation function */
return rb_struct_alloc_noinit(klass);
}
/*
* call-seq:
* range.count -> int
* range.count(item) -> int
* range.count { |obj| block } -> int
*
* Identical to Enumerable#count, except it returns Infinity for endless
* ranges.
*
*/
static VALUE
range_count(int argc, VALUE *argv, VALUE range)
{
if (argc != 0) {
/* It is odd for instance (1...).count(0) to return Infinity. Just let
* it loop. */
return rb_call_super(argc, argv);
}
else if (rb_block_given_p()) {
/* Likewise it is odd for instance (1...).count {|x| x == 0 } to return
* Infinity. Just let it loop. */
return rb_call_super(argc, argv);
}
else if (NIL_P(RANGE_END(range))) {
/* We are confident that the answer is Infinity. */
return DBL2NUM(HUGE_VAL);
}
else if (NIL_P(RANGE_BEG(range))) {
/* We are confident that the answer is Infinity. */
return DBL2NUM(HUGE_VAL);
}
else {
return rb_call_super(argc, argv);
}
}
/* A Range represents an interval---a set of values with a
* beginning and an end. Ranges may be constructed using the
* <em>s</em><code>..</code><em>e</em> and
* <em>s</em><code>...</code><em>e</em> literals, or with
* Range::new. Ranges constructed using <code>..</code>
* run from the beginning to the end inclusively. Those created using
* <code>...</code> exclude the end value. When used as an iterator,
* ranges return each value in the sequence.
*
* (-1..-5).to_a #=> []
* (-5..-1).to_a #=> [-5, -4, -3, -2, -1]
* ('a'..'e').to_a #=> ["a", "b", "c", "d", "e"]
* ('a'...'e').to_a #=> ["a", "b", "c", "d"]
*
* == Beginless/Endless Ranges
*
* A "beginless range" and "endless range" represents a semi-infinite
* range. Literal notation for a beginless range is:
*
* (..1)
* # or
* (...1)
*
* Literal notation for an endless range is:
*
* (1..)
* # or similarly
* (1...)
*
* Which is equivalent to
*
* (1..nil) # or similarly (1...nil)
* Range.new(1, nil) # or Range.new(1, nil, true)
*
* Beginless/endless ranges are useful, for example, for idiomatic
* slicing of arrays:
*
* [1, 2, 3, 4, 5][...2] # => [1, 2]
* [1, 2, 3, 4, 5][2...] # => [3, 4, 5]
*
* Some implementation details:
*
* * +begin+ of beginless range and +end+ of endless range are +nil+;
* * +each+ of beginless range raises an exception;
* * +each+ of endless range enumerates infinite sequence (may be
* useful in combination with Enumerable#take_while or similar
* methods);
* * <code>(1..)</code> and <code>(1...)</code> are not equal,
* although technically representing the same sequence.
*
* == Custom Objects in Ranges
*
* Ranges can be constructed using any objects that can be compared
* using the <code><=></code> operator.
* Methods that treat the range as a sequence (#each and methods inherited
* from Enumerable) expect the begin object to implement a
* <code>succ</code> method to return the next object in sequence.
* The #step and #include? methods require the begin
* object to implement <code>succ</code> or to be numeric.
*
* In the <code>Xs</code> class below both <code><=></code> and
* <code>succ</code> are implemented so <code>Xs</code> can be used
* to construct ranges. Note that the Comparable module is included
* so the <code>==</code> method is defined in terms of <code><=></code>.
*
* class Xs # represent a string of 'x's
* include Comparable
* attr :length
* def initialize(n)
* @length = n
* end
* def succ
* Xs.new(@length + 1)
* end
* def <=>(other)
* @length <=> other.length
* end
* def to_s
* sprintf "%2d #{inspect}", @length
* end
* def inspect
* 'x' * @length
* end
* end
*
* An example of using <code>Xs</code> to construct a range:
*
* r = Xs.new(3)..Xs.new(6) #=> xxx..xxxxxx
* r.to_a #=> [xxx, xxxx, xxxxx, xxxxxx]
* r.member?(Xs.new(5)) #=> true
*
*/
void
Init_Range(void)
{
#undef rb_intern
#define rb_intern(str) rb_intern_const(str)
id_beg = rb_intern("begin");
id_end = rb_intern("end");
id_excl = rb_intern("excl");
rb_cRange = rb_struct_define_without_accessor(
"Range", rb_cObject, range_alloc,
"begin", "end", "excl", NULL);
rb_include_module(rb_cRange, rb_mEnumerable);
rb_marshal_define_compat(rb_cRange, rb_cObject, range_dumper, range_loader);
rb_define_method(rb_cRange, "initialize", range_initialize, -1);
rb_define_method(rb_cRange, "initialize_copy", range_initialize_copy, 1);
rb_define_method(rb_cRange, "==", range_eq, 1);
rb_define_method(rb_cRange, "===", range_eqq, 1);
rb_define_method(rb_cRange, "eql?", range_eql, 1);
rb_define_method(rb_cRange, "hash", range_hash, 0);
rb_define_method(rb_cRange, "each", range_each, 0);
rb_define_method(rb_cRange, "step", range_step, -1);
rb_define_method(rb_cRange, "%", range_percent_step, 1);
rb_define_method(rb_cRange, "bsearch", range_bsearch, 0);
rb_define_method(rb_cRange, "begin", range_begin, 0);
rb_define_method(rb_cRange, "end", range_end, 0);
rb_define_method(rb_cRange, "first", range_first, -1);
rb_define_method(rb_cRange, "last", range_last, -1);
rb_define_method(rb_cRange, "min", range_min, -1);
rb_define_method(rb_cRange, "max", range_max, -1);
rb_define_method(rb_cRange, "minmax", range_minmax, 0);
rb_define_method(rb_cRange, "size", range_size, 0);
rb_define_method(rb_cRange, "to_a", range_to_a, 0);
rb_define_method(rb_cRange, "entries", range_to_a, 0);
rb_define_method(rb_cRange, "to_s", range_to_s, 0);
rb_define_method(rb_cRange, "inspect", range_inspect, 0);
rb_define_method(rb_cRange, "exclude_end?", range_exclude_end_p, 0);
rb_define_method(rb_cRange, "member?", range_include, 1);
rb_define_method(rb_cRange, "include?", range_include, 1);
rb_define_method(rb_cRange, "cover?", range_cover, 1);
rb_define_method(rb_cRange, "count", range_count, -1);
}