Ivo
A library for creating immutable value objects.
Installation
gem install ivo
Benchmarks
See benchmarks.rb. Performed on ruby 2.7.1.
- immutable-struct
- values
- concurrent-ruby
- struct (core)
- ostruct (core)
user system total real
StructClass.new 0.197386 0.000671 0.198057 ( 0.199379)
IvoClass.new 0.217936 0.000635 0.218571 ( 0.219348)
IvoClass.with 0.246758 0.000268 0.247026 ( 0.247232)
ConcurrentImmutableStruct.new 0.782822 0.000924 0.783746 ( 0.784684)
ValueClass.new 1.365290 0.001162 1.366452 ( 1.368131)
ValueClass.with 1.990921 0.001786 1.992707 ( 1.994895)
ImmutableStructClass.new 1.939959 0.001735 1.941694 ( 1.943927)
user system total real
OpenStruct.new 0.542196 0.000978 0.543174 ( 0.544024)
Ivo.call 0.592088 0.001324 0.593412 ( 0.595383)Usage
Car = Ivo.new(:make, :model)
car = Car.new('Honda', 'Accord')
car.make # "Honda"
car.model # "Accord"
car.frozen? # trueObjects can also be instantiated with keywords:
car = Car.with(make: 'Honda', model: 'Accord')Ivo.new also accepts a block for additional definitions:
Car = Ivo.new(:make, :model) do
def to_s
"#{make} #{model}"
end
endFor one-off value objects (similar to OpenStruct):
car = Ivo.(make: 'Honda', model: 'Accord')
car.make # "Honda"
car.model # "Accord"
car.frozen? # trueUnder the hood
This:
Car = Ivo.new(:make, :model) do
def to_s
"#{make} #{model}"
end
endis equivalent to:
class Car
def self.with(make: nil, model: nil)
new(make, model)
end
def initialize(make = nil, model = nil)
@make = make
@model = model
freeze
end
attr_reader :make, :model
def to_s
"#{make} #{model}"
end
def ==(other)
self.class == other.class && make == other.make && model == other.model
end
alias_method :eql?, :==
def hash
make.hash ^ model.hash
end
end