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 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 <=> operator should return nil. Comparable uses <=> to implement the conventional comparison operators (<, <=, ==, >=, and >) and the method between?.

class StringSorter
  include Comparable

  attr :str
  def <=>(other)
    str.size <=> other.str.size
  end

  def initialize(str)
    @str = str
  end

  def inspect
    @str
  end
end

s1 = StringSorter.new("Z")
s2 = StringSorter.new("YY")
s3 = StringSorter.new("XXX")
s4 = StringSorter.new("WWWW")
s5 = StringSorter.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 #<=>:

<: 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 the given object.
>=: Returns whether self is greater than or equal to the given object.
between?: Returns true if self is between two given objects.
clamp: For given objects min and max, or range (min..max), returns:
- min if (self <=> min) < 0.
- max if (self <=> max) > 0.
- self otherwise.

Public Instance Methods

(untyped other) → bool

Source

# File vendor/bundle/ruby/4.0.0/gems/rbs-4.0.3/core/comparable.rbs, line 69
def <: (untyped other) -> bool

Returns whether self is “less than” other; equivalent to (self <=> other) < 0:

'foo' < 'foo'  # => false
'foo' < 'food' # => true

(untyped other) → bool

Source

# File vendor/bundle/ruby/4.0.0/gems/rbs-4.0.3/core/comparable.rbs, line 82
def <=: (untyped other) -> bool

Returns whether self is “less than or equal to” other; equivalent to (self <=> other) <= 0:

'foo' <= 'foo'  # => true
'foo' <= 'food' # => true
'food' <= 'foo' # => false

(untyped other) → bool

Source

# File vendor/bundle/ruby/4.0.0/gems/rbs-4.0.3/core/comparable.rbs, line 92
def ==: (untyped other) -> bool

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.

(untyped other) → bool

Source

# File vendor/bundle/ruby/4.0.0/gems/rbs-4.0.3/core/comparable.rbs, line 101
def >: (untyped other) -> bool

Compares two objects based on the receiver’s <=> method, returning true if it returns a value greater than 0.

(untyped other) → bool

Source

# File vendor/bundle/ruby/4.0.0/gems/rbs-4.0.3/core/comparable.rbs, line 110
def >=: (untyped other) -> bool

Compares two objects based on the receiver’s <=> method, returning true if it returns a value greater than or equal to 0.

between?

(untyped min, untyped max) → bool

Source

# File vendor/bundle/ruby/4.0.0/gems/rbs-4.0.3/core/comparable.rbs, line 124
def between?: (untyped min, untyped max) -> bool

Returns false if obj <=> min is less than zero or if obj <=> 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

[A, B] (A min, B max) → (self | A | B)
[A] (Range[A]) → (self | A)

Source

# File vendor/bundle/ruby/4.0.0/gems/rbs-4.0.3/core/comparable.rbs, line 170
def clamp: [A, B] (A min, B max) -> (self | A | B)
           | [A] (Range[A]) -> (self | A)

In (min, max) form, 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'

If min is nil, it is considered smaller than obj, and if max is nil, it is considered greater than obj.

-20.clamp(0, nil)           #=> 0
523.clamp(nil, 100)         #=> 100

In (range) form, returns range.begin if obj <=> range.begin is less than zero, range.end if obj <=> 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