module Comparable(T)

Overview

TheComparable mixin is used by classes whose objects may be ordered.

Including types must provide an<=> method, which compares the receiver against another object, returning:

Comparable uses<=> to implement the conventional comparison operators (<,<=,#==,>=, and>). All of these returnfalse when<=> returnsnil.

Note that returningnil is only useful when defining a partial comparable relationship. One such example is float values: they are generally comparable, except forNaN. If none of the values of a type are comparable between each other,Comparable shouldn't be included.

NOTE Whennil is returned from<=>,Array#sort and related sorting methods will perform slightly slower.

Direct including types

Defined in:

comparable.cr

Instance Method Summary

Instance Method Detail

def <(other : T) : Bool #

Compares this object toother based on the receiver’s<=> method, returningtrue if it returns a negative number.


def <=(other : T) #

Compares this object toother based on the receiver’s<=> method, returningtrue if it returns a value equal or less then0.


abstract def <=>(other : T) #

The comparison operator. Returns0 if the two objects are equal, a negative number if this object is considered less thanother, a positive number if this object is considered greater thanother, ornil if the two objects are not comparable.

Subclasses define this method to provide class-specific ordering.

The comparison operator is usually used to sort values:

# Sort in a descending way:
[3, 1, 2].sort { |x, y| y <=> x } # => [3, 2, 1]

# Sort in an ascending way:
[3, 1, 2].sort { |x, y| x <=> y } # => [1, 2, 3]

def ==(other : T) #

Compares this object toother based on the receiver’s<=> method, returningtrue if it returns0.

Also returnstrue if this andother are the same object.


def >(other : T) : Bool #

Compares this object toother based on the receiver’s<=> method, returningtrue if it returns a value greater then0.


def >=(other : T) #

Compares this object toother based on the receiver’s<=> method, returningtrue if it returns a value equal or greater than0.


def clamp(min, max) #

Clamps a value betweenmin andmax.

5.clamp(10, 100)   # => 10
50.clamp(10, 100)  # => 50
500.clamp(10, 100) # => 100

5.clamp(10, nil)  # => 10
50.clamp(10, nil) # => 50

5.clamp(nil, 10)  # => 5
50.clamp(nil, 10) # => 10

def clamp(range : Range) #

Clamps a value withinrange.

5.clamp(10..100)   # => 10
50.clamp(10..100)  # => 50
500.clamp(10..100) # => 100

5.clamp(10..)  # => 10
50.clamp(10..) # => 50

5.clamp(..10)  # => 5
50.clamp(..10) # => 10