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ruby--ruby/compar.c
nobu d5a0b8e3cc Comparable#clamp
* compar.c (cmp_clamp): Introduce Comparable#clamp.  [Feature ]

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@55863 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
2016-08-11 07:24:25 +00:00

262 lines
6.1 KiB
C

/**********************************************************************
compar.c -
$Author$
created at: Thu Aug 26 14:39:48 JST 1993
Copyright (C) 1993-2007 Yukihiro Matsumoto
**********************************************************************/
#include "ruby/ruby.h"
#include "id.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;
if (rb_cmpint(c, x, y) == 0) return Qtrue;
return Qfalse;
}
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 1.
*/
static VALUE
cmp_gt(VALUE x, VALUE y)
{
if (cmpint(x, y) > 0) return Qtrue;
return Qfalse;
}
/*
* call-seq:
* obj >= other -> true or false
*
* Compares two objects based on the receiver's <code><=></code>
* method, returning true if it returns 0 or 1.
*/
static VALUE
cmp_ge(VALUE x, VALUE y)
{
if (cmpint(x, y) >= 0) return Qtrue;
return Qfalse;
}
/*
* call-seq:
* obj < other -> true or false
*
* Compares two objects based on the receiver's <code><=></code>
* method, returning true if it returns -1.
*/
static VALUE
cmp_lt(VALUE x, VALUE y)
{
if (cmpint(x, y) < 0) return Qtrue;
return Qfalse;
}
/*
* call-seq:
* obj <= other -> true or false
*
* Compares two objects based on the receiver's <code><=></code>
* method, returning true if it returns -1 or 0.
*/
static VALUE
cmp_le(VALUE x, VALUE y)
{
if (cmpint(x, y) <= 0) return Qtrue;
return Qfalse;
}
/*
* call-seq:
* obj.between?(min, max) -> true or false
*
* Returns <code>false</code> if <i>obj</i> <code><=></code>
* <i>min</i> is less than zero or if <i>anObject</i> <code><=></code>
* <i>max</i> 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
*
* Returns <i>min</i> if <i>obj</i> <code><=></code> <i>min</i> is less
* than zero, <i>max</i> if <i>obj</i> <code><=></code> <i>max</i> is
* greater than zero and <i>obj</i> 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'
*/
static VALUE
cmp_clamp(VALUE x, VALUE min, VALUE max)
{
int c;
if (cmpint(min, max) > 0) {
rb_raise(rb_eArgError, "min argument must be smaller than max argument");
}
c = cmpint(x, min);
if (c == 0) return x;
if (c < 0) return min;
c = cmpint(x, max);
if (c > 0) return max;
return x;
}
/*
* The <code>Comparable</code> 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 -1, 0,
* or +1 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.
* <code>Comparable</code> 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]
*
*/
void
Init_Comparable(void)
{
#undef rb_intern
#define rb_intern(str) rb_intern_const(str)
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, 2);
}