module Comparable
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 <=>(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]
Public Instance Methods
obj < other → true or false Show source
static VALUE
cmp_lt(VALUE x, VALUE y)
{
if (cmpint(x, y) < 0) return Qtrue;
return Qfalse;
}Compares two objects based on the receiver's <=> method, returning true if it returns -1.
obj <= other → true or false Show source
static VALUE
cmp_le(VALUE x, VALUE y)
{
if (cmpint(x, y) <= 0) return Qtrue;
return Qfalse;
}Compares two objects based on the receiver's <=> method, returning true if it returns -1 or 0.
obj == other → true or false Show source
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;
}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.
obj > other → true or false Show source
static VALUE
cmp_gt(VALUE x, VALUE y)
{
if (cmpint(x, y) > 0) return Qtrue;
return Qfalse;
}Compares two objects based on the receiver's <=> method, returning true if it returns 1.
obj >= other → true or false Show source
static VALUE
cmp_ge(VALUE x, VALUE y)
{
if (cmpint(x, y) >= 0) return Qtrue;
return Qfalse;
}Compares two objects based on the receiver's <=> method, returning true if it returns 0 or 1.
between?(min, max) → true or false Show source
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;
}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
clamp(min, max) → obj Show source
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;
}Returns min if obj <=> min is less than zero, max if obj <=> 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'
Ruby Core © 1993–2017 Yukihiro Matsumoto
Licensed under the Ruby License.
Ruby Standard Library © contributors
Licensed under their own licenses.