Module: Comparable
- Included in:
- File::Stat, Numeric, String, Symbol, Time
- Defined in:
- compar.c
Overview
The Comparable
mixin is used by classes whose objects may be ordered. The class must define the <=>
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 <=>
operator should return nil. Comparable
uses <=>
to implement the conventional comparison operators (<
, <=
, ==
, >=
, and >
) and the method between?
.
class SizeMatters
include Comparable
attr :str
def <=>(anOther)
str.size <=> anOther.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]
Instance Method Summary collapse
-
#<(other) ⇒ Boolean
Compares two objects based on the receiver's
<=>
method, returning true if it returns -1. -
#<=(other) ⇒ Boolean
Compares two objects based on the receiver's
<=>
method, returning true if it returns -1 or 0. -
#==(other) ⇒ Boolean
Compares two objects based on the receiver's
<=>
method, returning true if it returns 0. -
#>(other) ⇒ Boolean
Compares two objects based on the receiver's
<=>
method, returning true if it returns 1. -
#>=(other) ⇒ Boolean
Compares two objects based on the receiver's
<=>
method, returning true if it returns 0 or 1. -
#between?(min, max) ⇒ Boolean
Returns
false
if obj<=>
min is less than zero or if anObject<=>
max is greater than zero,true
otherwise.
Instance Method Details
#<(other) ⇒ Boolean
Compares two objects based on the receiver's <=>
method, returning true if it returns -1.
|
# File 'compar.c'
/*
* 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)
{
VALUE c = rb_funcall(x, cmp, 1, y);
if (rb_cmpint(c, x, y) < 0) return Qtrue;
return Qfalse;
}
|
#<=(other) ⇒ Boolean
Compares two objects based on the receiver's <=>
method, returning true if it returns -1 or 0.
|
# File 'compar.c'
/*
* 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)
{
VALUE c = rb_funcall(x, cmp, 1, y);
if (rb_cmpint(c, x, y) <= 0) return Qtrue;
return Qfalse;
}
|
#==(other) ⇒ Boolean
Compares two objects based on the receiver's <=>
method, returning true if it returns 0. Also returns true if obj and other are the same object.
|
# File 'compar.c'
/*
* 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 a[2];
if (x == y) return Qtrue;
a[0] = x; a[1] = y;
return rb_rescue(cmp_eq, (VALUE)a, cmp_failed, 0);
}
|
#>(other) ⇒ Boolean
Compares two objects based on the receiver's <=>
method, returning true if it returns 1.
|
# File 'compar.c'
/*
* 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)
{
VALUE c = rb_funcall(x, cmp, 1, y);
if (rb_cmpint(c, x, y) > 0) return Qtrue;
return Qfalse;
}
|
#>=(other) ⇒ Boolean
Compares two objects based on the receiver's <=>
method, returning true if it returns 0 or 1.
|
# File 'compar.c'
/*
* 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)
{
VALUE c = rb_funcall(x, cmp, 1, y);
if (rb_cmpint(c, x, y) >= 0) return Qtrue;
return Qfalse;
}
|
#between?(min, max) ⇒ Boolean
Returns false
if obj <=>
min is less than zero or if anObject <=>
max is greater than zero, true
otherwise.
3.between?(1, 5) #=> true
6.between?(1, 5) #=> false
'cat'.between?('ant', 'dog') #=> true
'gnu'.between?('ant', 'dog') #=> false
|
# File 'compar.c'
/*
* 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 (RTEST(cmp_lt(x, min))) return Qfalse;
if (RTEST(cmp_gt(x, max))) return Qfalse;
return Qtrue;
}
|