/**********************************************************************
compar.c -
$Author$
created at: Thu Aug 26 14:39:48 JST 1993
Copyright (C) 1993-2007 Yukihiro Matsumoto
**********************************************************************/
#include "id.h"
#include "internal.h"
#include "internal/compar.h"
#include "internal/error.h"
#include "internal/vm.h"
#include "ruby/ruby.h"
VALUE rb_mComparable;
static VALUE
rb_cmp(VALUE x, VALUE y)
{
return rb_funcallv(x, idCmp, 1, &y);
}
void
rb_cmperr(VALUE x, VALUE y)
{
VALUE classname;
if (SPECIAL_CONST_P(y) || BUILTIN_TYPE(y) == T_FLOAT) {
classname = rb_inspect(y);
}
else {
classname = rb_obj_class(y);
}
rb_raise(rb_eArgError, "comparison of %"PRIsVALUE" with %"PRIsVALUE" failed",
rb_obj_class(x), classname);
}
static VALUE
invcmp_recursive(VALUE x, VALUE y, int recursive)
{
if (recursive) return Qnil;
return rb_cmp(y, x);
}
VALUE
rb_invcmp(VALUE x, VALUE y)
{
VALUE invcmp = rb_exec_recursive(invcmp_recursive, x, y);
if (invcmp == Qundef || NIL_P(invcmp)) {
return Qnil;
}
else {
int result = -rb_cmpint(invcmp, x, y);
return INT2FIX(result);
}
}
static VALUE
cmp_eq_recursive(VALUE arg1, VALUE arg2, int recursive)
{
if (recursive) return Qnil;
return rb_cmp(arg1, arg2);
}
/*
* call-seq:
* obj == other -> true or false
*
* Compares two objects based on the receiver's <code><=></code>
* method, returning true if it returns 0. Also returns true if
* _obj_ and _other_ are the same object.
*/
static VALUE
cmp_equal(VALUE x, VALUE y)
{
VALUE c;
if (x == y) return Qtrue;
c = rb_exec_recursive_paired_outer(cmp_eq_recursive, x, y, y);
if (NIL_P(c)) return Qfalse;
return RBOOL(rb_cmpint(c, x, y) == 0);
}
static int
cmpint(VALUE x, VALUE y)
{
return rb_cmpint(rb_cmp(x, y), x, y);
}
/*
* call-seq:
* obj > other -> true or false
*
* Compares two objects based on the receiver's <code><=></code>
* method, returning true if it returns a value greater than 0.
*/
static VALUE
cmp_gt(VALUE x, VALUE y)
{
return RBOOL(cmpint(x, y) > 0);
}
/*
* call-seq:
* obj >= other -> true or false
*
* Compares two objects based on the receiver's <code><=></code>
* method, returning true if it returns a value greater than or equal to 0.
*/
static VALUE
cmp_ge(VALUE x, VALUE y)
{
return RBOOL(cmpint(x, y) >= 0);
}
/*
* call-seq:
* obj < other -> true or false
*
* Compares two objects based on the receiver's <code><=></code>
* method, returning true if it returns a value less than 0.
*/
static VALUE
cmp_lt(VALUE x, VALUE y)
{
return RBOOL(cmpint(x, y) < 0);
}
/*
* call-seq:
* obj <= other -> true or false
*
* Compares two objects based on the receiver's <code><=></code>
* method, returning true if it returns a value less than or equal to 0.
*/
static VALUE
cmp_le(VALUE x, VALUE y)
{
return RBOOL(cmpint(x, y) <= 0);
}
/*
* call-seq:
* obj.between?(min, max) -> true or false
*
* Returns <code>false</code> if _obj_ <code><=></code> _min_ is less
* than zero or if _obj_ <code><=></code> _max_ is greater than zero,
* <code>true</code> otherwise.
*
* 3.between?(1, 5) #=> true
* 6.between?(1, 5) #=> false
* 'cat'.between?('ant', 'dog') #=> true
* 'gnu'.between?('ant', 'dog') #=> false
*
*/
static VALUE
cmp_between(VALUE x, VALUE min, VALUE max)
{
if (cmpint(x, min) < 0) return Qfalse;
if (cmpint(x, max) > 0) return Qfalse;
return Qtrue;
}
/*
* call-seq:
* obj.clamp(min, max) -> obj
* obj.clamp(range) -> obj
*
* In <code>(min, max)</code> form, returns _min_ if _obj_
* <code><=></code> _min_ is less than zero, _max_ if _obj_
* <code><=></code> _max_ is greater than zero, and _obj_
* otherwise.
*
* 12.clamp(0, 100) #=> 12
* 523.clamp(0, 100) #=> 100
* -3.123.clamp(0, 100) #=> 0
*
* 'd'.clamp('a', 'f') #=> 'd'
* 'z'.clamp('a', 'f') #=> 'f'
*
* In <code>(range)</code> form, returns _range.begin_ if _obj_
* <code><=></code> _range.begin_ is less than zero, _range.end_
* if _obj_ <code><=></code> _range.end_ is greater than zero, and
* _obj_ otherwise.
*
* 12.clamp(0..100) #=> 12
* 523.clamp(0..100) #=> 100
* -3.123.clamp(0..100) #=> 0
*
* 'd'.clamp('a'..'f') #=> 'd'
* 'z'.clamp('a'..'f') #=> 'f'
*
* If _range.begin_ is +nil+, it is considered smaller than _obj_,
* and if _range.end_ is +nil+, it is considered greater than
* _obj_.
*
* -20.clamp(0..) #=> 0
* 523.clamp(..100) #=> 100
*
* When _range.end_ is excluded and not +nil+, an exception is
* raised.
*
* 100.clamp(0...100) # ArgumentError
*/
static VALUE
cmp_clamp(int argc, VALUE *argv, VALUE x)
{
VALUE min, max;
int c, excl = 0;
if (rb_scan_args(argc, argv, "11", &min, &max) == 1) {
VALUE range = min;
if (!rb_range_values(range, &min, &max, &excl)) {
rb_raise(rb_eTypeError, "wrong argument type %s (expected Range)",
rb_builtin_class_name(range));
}
if (!NIL_P(max)) {
if (excl) rb_raise(rb_eArgError, "cannot clamp with an exclusive range");
}
}
if (!NIL_P(min) && !NIL_P(max) && cmpint(min, max) > 0) {
rb_raise(rb_eArgError, "min argument must be smaller than max argument");
}
if (!NIL_P(min)) {
c = cmpint(x, min);
if (c == 0) return x;
if (c < 0) return min;
}
if (!NIL_P(max)) {
c = cmpint(x, max);
if (c > 0) return max;
}
return x;
}
/*
* The Comparable mixin is used by classes whose objects may be
* ordered. The class must define the <code><=></code> operator,
* which compares the receiver against another object, returning a
* value less than 0, returning 0, or returning a value greater than 0,
* depending on whether the receiver is less than, equal to,
* or greater than the other object. If the other object is not
* comparable then the <code><=></code> operator should return +nil+.
* Comparable uses <code><=></code> to implement the conventional
* comparison operators (<code><</code>, <code><=</code>,
* <code>==</code>, <code>>=</code>, and <code>></code>) and the
* method <code>between?</code>.
*
* class SizeMatters
* include Comparable
* attr :str
* def <=>(other)
* str.size <=> other.str.size
* end
* def initialize(str)
* @str = str
* end
* def inspect
* @str
* end
* end
*
* s1 = SizeMatters.new("Z")
* s2 = SizeMatters.new("YY")
* s3 = SizeMatters.new("XXX")
* s4 = SizeMatters.new("WWWW")
* s5 = SizeMatters.new("VVVVV")
*
* s1 < s2 #=> true
* s4.between?(s1, s3) #=> false
* s4.between?(s3, s5) #=> true
* [ s3, s2, s5, s4, s1 ].sort #=> [Z, YY, XXX, WWWW, VVVVV]
*
* == What's Here
*
* \Module \Comparable provides these methods, all of which use method <tt><=></tt>:
*
* - #<:: Returns whether +self+ is less than the given object.
* - #<=:: Returns whether +self+ is less than or equal to the given object.
* - #==:: Returns whether +self+ is equal to the given object.
* - #>:: Returns whether +self+ is greater than or equal to the given object.
* - #>=:: Returns whether +self+ is greater than the given object.
* - #between? Returns +true+ if +self+ is between two given objects.
* - #clamp:: For given objects +min+ and +max+, or range <tt>(min..max)</tt>, returns:
* - +min+ if <tt>(self <=> min) < 0</tt>.
* - +max+ if <tt>(self <=> max) > 0</tt>.
* - +self+ otherwise.
*/
void
Init_Comparable(void)
{
rb_mComparable = rb_define_module("Comparable");
rb_define_method(rb_mComparable, "==", cmp_equal, 1);
rb_define_method(rb_mComparable, ">", cmp_gt, 1);
rb_define_method(rb_mComparable, ">=", cmp_ge, 1);
rb_define_method(rb_mComparable, "<", cmp_lt, 1);
rb_define_method(rb_mComparable, "<=", cmp_le, 1);
rb_define_method(rb_mComparable, "between?", cmp_between, 2);
rb_define_method(rb_mComparable, "clamp", cmp_clamp, -1);
}
