ruby/range.c

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/**********************************************************************
range.c -
$Author$
$Date$
created at: Thu Aug 19 17:46:47 JST 1993
Copyright (C) 1993-2003 Yukihiro Matsumoto
**********************************************************************/
#include "ruby.h"
VALUE rb_cRange;
static ID id_cmp, id_succ, id_beg, id_end, id_excl;
#define EXCL(r) RTEST(rb_ivar_get((r), id_excl))
#define SET_EXCL(r,v) rb_ivar_set((r), id_excl, (v) ? Qtrue : Qfalse)
static VALUE
range_failed()
{
rb_raise(rb_eArgError, "bad value for range");
return Qnil; /* dummy */
}
static VALUE
range_check(args)
VALUE *args;
{
VALUE v;
v = rb_funcall(args[0], id_cmp, 1, args[1]);
if (NIL_P(v)) range_failed();
return Qnil;
}
static void
range_init(range, beg, end, exclude_end)
VALUE range, beg, end;
int exclude_end;
{
VALUE args[2];
args[0] = beg;
args[1] = end;
if (!FIXNUM_P(beg) || !FIXNUM_P(end)) {
rb_rescue(range_check, (VALUE)args, range_failed, 0);
}
SET_EXCL(range, exclude_end);
rb_ivar_set(range, id_beg, beg);
rb_ivar_set(range, id_end, end);
}
VALUE
rb_range_new(beg, end, exclude_end)
VALUE beg, end;
int exclude_end;
{
VALUE range = rb_obj_alloc(rb_cRange);
range_init(range, beg, end, exclude_end);
return range;
}
/*
* call-seq:
* Range.new(start, end, exclusive=false) => range
*
* Constructs a range using the given <i>start</i> and <i>end</i>. If the third
* parameter is omitted or is <code>false</code>, the <i>range</i> will include
* the end object; otherwise, it will be excluded.
*/
static VALUE
range_initialize(argc, argv, range)
int argc;
VALUE *argv;
VALUE range;
{
VALUE beg, end, flags;
rb_scan_args(argc, argv, "21", &beg, &end, &flags);
/* Ranges are immutable, so that they should be initialized only once. */
if (rb_ivar_defined(range, id_beg)) {
rb_name_error(rb_intern("initialize"), "`initialize' called twice");
}
range_init(range, beg, end, RTEST(flags));
return Qnil;
}
/*
* call-seq:
* rng.exclude_end? => true or false
*
* Returns <code>true</code> if <i>rng</i> excludes its end value.
*/
static VALUE
range_exclude_end_p(range)
VALUE range;
{
return EXCL(range) ? Qtrue : Qfalse;
}
/*
* call-seq:
* rng == obj => true or false
*
* Returns <code>true</code> only if <i>obj</i> is a Range, has equivalent
* beginning and end items (by comparing them with <code>==</code>), and has
* the same #exclude_end? setting as <i>rng</t>.
*
* (0..2) == (0..2) #=> true
* (0..2) == Range.new(0,2) #=> true
* (0..2) == (0...2) #=> false
*
*/
static VALUE
range_eq(range, obj)
VALUE range, obj;
{
if (range == obj) return Qtrue;
if (!rb_obj_is_instance_of(obj, rb_obj_class(range)))
return Qfalse;
if (!rb_equal(rb_ivar_get(range, id_beg), rb_ivar_get(obj, id_beg)))
return Qfalse;
if (!rb_equal(rb_ivar_get(range, id_end), rb_ivar_get(obj, id_end)))
return Qfalse;
if (EXCL(range) != EXCL(obj)) return Qfalse;
return Qtrue;
}
static int
r_lt(a, b)
VALUE a, b;
{
VALUE r = rb_funcall(a, id_cmp, 1, b);
if (NIL_P(r)) return Qfalse;
if (rb_cmpint(r, a, b) < 0) return Qtrue;
return Qfalse;
}
static int
r_le(a, b)
VALUE a, b;
{
VALUE r = rb_funcall(a, id_cmp, 1, b);
if (NIL_P(r)) return Qfalse;
if (rb_cmpint(r, a, b) <= 0) return Qtrue;
return Qfalse;
}
/*
* call-seq:
* rng.eql?(obj) => true or false
*
* Returns <code>true</code> only if <i>obj</i> is a Range, has equivalent
* beginning and end items (by comparing them with #eql?), and has the same
* #exclude_end? setting as <i>rng</i>.
*
* (0..2) == (0..2) #=> true
* (0..2) == Range.new(0,2) #=> true
* (0..2) == (0...2) #=> false
*
*/
static VALUE
range_eql(range, obj)
VALUE range, obj;
{
if (range == obj) return Qtrue;
if (!rb_obj_is_instance_of(obj, rb_obj_class(range)))
return Qfalse;
if (!rb_eql(rb_ivar_get(range, id_beg), rb_ivar_get(obj, id_beg)))
return Qfalse;
if (!rb_eql(rb_ivar_get(range, id_end), rb_ivar_get(obj, id_end)))
return Qfalse;
if (EXCL(range) != EXCL(obj)) return Qfalse;
return Qtrue;
}
/*
* call-seq:
* rng.hash => fixnum
*
* Generate a hash value such that two ranges with the same start and
* end points, and the same value for the "exclude end" flag, generate
* the same hash value.
*/
static VALUE
range_hash(range)
VALUE range;
{
long hash = EXCL(range);
VALUE v;
v = rb_hash(rb_ivar_get(range, id_beg));
hash ^= v << 1;
v = rb_hash(rb_ivar_get(range, id_end));
hash ^= v << 9;
hash ^= EXCL(range) << 24;
return LONG2FIX(hash);
}
static VALUE
str_step(args)
VALUE *args;
{
return rb_str_upto(args[0], args[1], EXCL(args[2]));
}
static VALUE
step_i(i, iter)
VALUE i;
long *iter;
{
iter[0]--;
if (iter[0] == 0) {
rb_yield(i);
iter[0] = iter[1];
}
return Qnil;
}
static void
range_each_func(range, func, v, e, arg)
VALUE range;
VALUE (*func) _((VALUE, void*));
VALUE v, e;
void *arg;
{
if (EXCL(range)) {
while (r_lt(v, e)) {
(*func)(v, arg);
v = rb_funcall(v, id_succ, 0, 0);
}
}
else {
while (r_le(v, e)) {
(*func)(v, arg);
v = rb_funcall(v, id_succ, 0, 0);
}
}
}
/*
* call-seq:
* rng.step(n=1) {| obj | block } => rng
*
* Iterates over <i>rng</i>, passing each <i>n</i>th element to the block. If
* the range contains numbers or strings, natural ordering is used. Otherwise
* <code>step</code> invokes <code>succ</code> to iterate through range
* elements. The following code uses class <code>Xs</code>, which is defined
* in the class-level documentation.
*
* range = Xs.new(1)..Xs.new(10)
* range.step(2) {|x| puts x}
* 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
*/
static VALUE
range_step(argc, argv, range)
int argc;
VALUE *argv;
VALUE range;
{
VALUE b, e, step;
long unit;
b = rb_ivar_get(range, id_beg);
e = rb_ivar_get(range, id_end);
if (rb_scan_args(argc, argv, "01", &step) == 0) {
step = INT2FIX(1);
}
unit = NUM2LONG(step);
if (unit < 0) {
rb_raise(rb_eArgError, "step can't be negative");
}
if (FIXNUM_P(b) && FIXNUM_P(e)) { /* fixnums are special */
long end = FIX2LONG(e);
long i;
if (unit == 0) rb_raise(rb_eArgError, "step can't be 0");
if (!EXCL(range)) end += 1;
for (i=FIX2LONG(b); i<end; i+=unit) {
rb_yield(LONG2NUM(i));
}
}
else {
VALUE tmp = rb_check_string_type(b);
if (!NIL_P(tmp)) {
VALUE args[5];
long iter[2];
b = tmp;
if (unit == 0) rb_raise(rb_eArgError, "step can't be 0");
args[0] = b; args[1] = e; args[2] = range;
iter[0] = 1; iter[1] = unit;
rb_iterate((VALUE(*)_((VALUE)))str_step, (VALUE)args, step_i, (VALUE)iter);
}
else if (rb_obj_is_kind_of(b, rb_cNumeric)) {
ID c = rb_intern(EXCL(range) ? "<" : "<=");
if (rb_equal(step, INT2FIX(0))) rb_raise(rb_eArgError, "step can't be 0");
while (RTEST(rb_funcall(b, c, 1, e))) {
rb_yield(b);
b = rb_funcall(b, '+', 1, step);
}
}
else {
long args[2];
if (unit == 0) rb_raise(rb_eArgError, "step can't be 0");
if (!rb_respond_to(b, id_succ)) {
rb_raise(rb_eTypeError, "cannot iterate from %s",
rb_obj_classname(b));
}
args[0] = 1;
args[1] = unit;
range_each_func(range, step_i, b, e, args);
}
}
return range;
}
static VALUE
each_i(v, arg)
VALUE v;
void *arg;
{
return rb_yield(v);
}
/*
* call-seq:
* rng.each {| i | block } => rng
*
* Iterates over the elements <i>rng</i>, passing each in turn to the
* block. You can only iterate if the start object of the range
* supports the +succ+ method (which means that you can't iterate over
* ranges of +Float+ objects).
*
* (10..15).each do |n|
* print n, ' '
* end
*
* <em>produces:</em>
*
* 10 11 12 13 14 15
*/
static VALUE
range_each(range)
VALUE range;
{
VALUE beg, end;
beg = rb_ivar_get(range, id_beg);
end = rb_ivar_get(range, id_end);
if (!rb_respond_to(beg, id_succ)) {
rb_raise(rb_eTypeError, "cannot iterate from %s",
rb_obj_classname(beg));
}
if (FIXNUM_P(beg) && FIXNUM_P(end)) { /* fixnums are special */
long lim = FIX2LONG(end);
long i;
if (!EXCL(range)) lim += 1;
for (i=FIX2LONG(beg); i<lim; i++) {
rb_yield(LONG2NUM(i));
}
}
else if (TYPE(beg) == T_STRING) {
VALUE args[5];
long iter[2];
args[0] = beg; args[1] = end; args[2] = range;
iter[0] = 1; iter[1] = 1;
rb_iterate((VALUE(*)_((VALUE)))str_step, (VALUE)args, step_i, (VALUE)iter);
}
else {
range_each_func(range, each_i, beg, end, NULL);
}
return range;
}
/*
* call-seq:
* rng.first => obj
* rng.begin => obj
*
* Returns the first object in <i>rng</i>.
*/
static VALUE
range_first(range)
VALUE range;
{
return rb_ivar_get(range, id_beg);
}
/*
* call-seq:
* rng.end => obj
* rng.last => obj
*
* Returns the object that defines the end of <i>rng</i>.
*
* (1..10).end #=> 10
* (1...10).end #=> 10
*/
static VALUE
range_last(range)
VALUE range;
{
return rb_ivar_get(range, id_end);
}
VALUE
rb_range_beg_len(range, begp, lenp, len, err)
VALUE range;
long *begp, *lenp;
long len;
int err;
{
long beg, end, b, e;
if (!rb_obj_is_kind_of(range, rb_cRange)) return Qfalse;
beg = b = NUM2LONG(rb_ivar_get(range, id_beg));
end = e = NUM2LONG(rb_ivar_get(range, id_end));
if (beg < 0) {
beg += len;
if (beg < 0) goto out_of_range;
}
if (err == 0 || err == 2) {
if (beg > len) goto out_of_range;
if (end > len)
end = len;
}
if (end < 0) end += len;
if (!EXCL(range)) end++; /* include end point */
if (end < 0) goto out_of_range;
len = end - beg;
if (len < 0) goto out_of_range;
*begp = beg;
*lenp = len;
return Qtrue;
out_of_range:
if (err) {
rb_raise(rb_eRangeError, "%ld..%s%ld out of range",
b, EXCL(range)? "." : "", e);
}
return Qnil;
}
/*
* call-seq:
* rng.to_s => string
*
* Convert this range object to a printable form.
*/
static VALUE
range_to_s(range)
VALUE range;
{
VALUE str, str2;
str = rb_obj_as_string(rb_ivar_get(range, id_beg));
str2 = rb_obj_as_string(rb_ivar_get(range, id_end));
str = rb_str_dup(str);
rb_str_cat(str, "...", EXCL(range)?3:2);
rb_str_append(str, str2);
OBJ_INFECT(str, str2);
return str;
}
/*
* call-seq:
* rng.inspect => string
*
* Convert this range object to a printable form (using
* <code>inspect</code> to convert the start and end
* objects).
*/
static VALUE
range_inspect(range)
VALUE range;
{
VALUE str, str2;
str = rb_inspect(rb_ivar_get(range, id_beg));
str2 = rb_inspect(rb_ivar_get(range, id_end));
str = rb_str_dup(str);
rb_str_cat(str, "...", EXCL(range)?3:2);
rb_str_append(str, str2);
OBJ_INFECT(str, str2);
return str;
}
static void
member_i(v, args)
VALUE v;
VALUE *args;
{
if (rb_equal(v, args[0])) {
args[1] = Qtrue;
}
}
/*
* call-seq:
* rng.member?(val) => true or false
*
* Return +true+ if _val_ is one of the values in _rng_ (that is if
* <code>Range#each</code> would return _val_ at some point).
*/
static VALUE
range_member(range, val)
VALUE range, val;
{
VALUE beg, end;
VALUE args[2];
beg = rb_ivar_get(range, id_beg);
end = rb_ivar_get(range, id_end);
if (!rb_respond_to(beg, id_succ)) {
rb_raise(rb_eTypeError, "cannot iterate from %s",
rb_obj_classname(beg));
}
args[0] = val;
args[1] = Qfalse;
range_each_func(range, member_i, beg, end, args);
return args[1];
}
/*
* call-seq:
* rng === obj => true or false
*
* Returns <code>true</code> if <i>obj</i> is an element of
* <i>rng</i>, <code>false</code> otherwise. Conveniently,
* <code>===</code> is the comparison operator used by
* <code>case</code> statements.
*
* case 79
* when 1..50 then print "low\n"
* when 51..75 then print "medium\n"
* when 76..100 then print "high\n"
* end
*
* <em>produces:</em>
*
* high
*/
static VALUE
range_include(range, val)
VALUE range, val;
{
VALUE beg, end;
beg = rb_ivar_get(range, id_beg);
end = rb_ivar_get(range, id_end);
if (r_le(beg, val)) {
if (EXCL(range)) {
if (r_lt(val, end)) return Qtrue;
}
else {
if (r_le(val, end)) return Qtrue;
}
}
return Qfalse;
}
/* A <code>Range</code> represents an interval---a set of values with a
* start 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
* <code>Range::new</code>. Ranges constructed using <code>..</code>
* run from the start 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"]
*
* Ranges can be constructed using objects of any type, as long as the
* objects can be compared using their <code><=></code> operator and
* they support the <code>succ</code> method to return the next object
* in sequence.
*
* 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
*
* r = Xs.new(3)..Xs.new(6) #=> xxx..xxxxxx
* r.to_a #=> [xxx, xxxx, xxxxx, xxxxxx]
* r.member?(Xs.new(5)) #=> true
*
* In the previous code example, class <code>Xs</code> includes the
* <code>Comparable</code> module. This is because
* <code>Enumerable#member?</code> checks for equality using
* <code>==</code>. Including <code>Comparable</code> ensures that the
* <code>==</code> method is defined in terms of the <code><=></code>
* method implemented in <code>Xs</code>.
*
*/
void
Init_Range()
{
rb_cRange = rb_define_class("Range", rb_cObject);
rb_include_module(rb_cRange, rb_mEnumerable);
rb_define_method(rb_cRange, "initialize", range_initialize, -1);
rb_define_method(rb_cRange, "==", range_eq, 1);
rb_define_method(rb_cRange, "===", range_include, 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, "first", range_first, 0);
rb_define_method(rb_cRange, "last", range_last, 0);
rb_define_method(rb_cRange, "begin", range_first, 0);
rb_define_method(rb_cRange, "end", range_last, 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_member, 1);
rb_define_method(rb_cRange, "include?", range_include, 1);
id_cmp = rb_intern("<=>");
id_succ = rb_intern("succ");
id_beg = rb_intern("begin");
id_end = rb_intern("end");
id_excl = rb_intern("excl");
}