Rtype: ruby with type

require 'rtype'

class Test
  rtype [:to_i, Numeric] => Numeric
  def sum(a, b)
    a.to_i + b
  end

  rtype [{state: Boolean}] => Boolean
  def self.invert(state:)
    !state
  end

  # Hashes of hashes params require () to prevent invalid syntax
  rtype({state: Boolean} => Boolean)
  def self.invert2(state:)
    !state
  end
end

Test.new.sum(123, "asd")
# (Rtype::ArgumentTypeError) for 2nd argument:
# Expected "asd" to be a Numeric

Test.invert(state: 0)
# (Rtype::ArgumentTypeError) for 'state' argument:
# Expected 0 to be a Boolean

Test.invert2(state: 0)
# (Rtype::ArgumentTypeError) for 'state' argument:
# Expected 0 to be a Boolean

Requirements

• Ruby >= 2.1
  • If you need to use old ruby, see rtype-legacy for ruby 1.9+
• MRI
  • If C native extension is used. otherwise it is not required
• JRuby (JRuby 9000+)
  • If Java extension is used. otherwise it is not required

Features

• Provides type checking for arguments and return
• Provides type checking for Keyword Argument
• Type checking for hash elements
• Duck Typing
• Typed Array, Typed Set, Typed Hash
• Numeric check. e.g. Int >= 0
• Type checking for getter and setter
• float_accessor, bool_accessor
• Custom type behavior
• ...

Installation

Run gem install rtype or add gem 'rtype' to your Gemfile

And add to your .rb source file:

require 'rtype'

Native extension

Rtype itself is pure-ruby gem. but you can make it more faster by using native extension.

Native extension for MRI

Run

gem install rtype-native

or add to your Gemfile:

gem 'rtype-native'

then, Rtype uses it. (Do not require 'rtype-native')

Java extension for JRuby is automatic

Do not require 'rtype-java'

Usage

Supported Type Behaviors

• Module : Value must be of this module (is_a?)
  • Any : Alias for BasicObject (means Any Object)
  • Boolean : true or false
• Symbol : Value must respond to a method with this name
• Regexp : Value must match this regexp pattern
• Range : Value must be included in this range
• Array : Value can be any type in this array
• Proc : Value must return a truthy value for this proc
• true : Value must be truthy
• false : Value must be falsy
• nil : Value must be nil

• Hash

  • Value must be a hash
  • Each of elements must be valid
  • Keys of the value must be equal to keys of this hash
  • String key is different from symbol key
  • vs. Keyword arguments (e.g.)
  • [{}] is not hash argument. it is keyword argument, because its position is last
  • [{}, {}] is hash argument (first) and keyword argument (second)
  • [{}, {}, {}] is two hash argument (first, second) and keyword argument (last)
  • {} is keyword argument. non-keyword arguments must be in array.
  • Of course, nested hash works
  • Example: Hash

• Special Behaviors

  • TypedArray, TypedSet, TypedHash, Num, Int, Flo, And, Xor, Not, Nilable

Examples

Basic

require 'rtype'

class Example
  rtype [Integer] => nil
  def test(i)
  end

  rtype [Any] => nil
  def any_type_arg(arg)
  end

  rtype [] => Integer
  def return_type_test
    "not integer"
  end
end

e = Example.new
e.test("not integer")
# (Rtype::ArgumentTypeError) for 1st argument:
# Expected "not integer" to be a Integer

e.any_type_arg("Any argument!") # Works

e.return_type_test
# (Rtype::ReturnTypeError) for return:
# Expected "not integer" to be a Integer

Keyword argument

require 'rtype'

class Example
  rtype {name: String} => Any
  def say_your_name(name:)
    puts "My name is #{name}"
  end

  # Mixing positional arguments and keyword arguments
  rtype [String, {age: Integer}] => Any
  def name_and_age(name, age:)
    puts "Name: #{name}, Age: #{age}"
  end
end

Example.new.say_your_name(name: "Babo") # My name is Babo
Example.new.name_and_age("Bamboo", age: 100) # Name: Bamboo, Age: 100

Example.new.say_your_name(name: 12345)
# (Rtype::ArgumentTypeError) for 'name' argument:
# Expected 12345 to be a String

Duck typing

require 'rtype'

class Duck
  rtype [:to_i] => Any
  def says(i)
    puts "duck:" + " quack"*i.to_i
  end
end

Duck.new.says("2") # duck: quack quack

Array

rtype :ruby!, [[String, Integer]] => Any
def ruby!(arg)
    puts "ruby!"
end

func("str") # ruby!
func(123) # ruby!

func(nil)
# (Rtype::ArgumentTypeError) for 1st argument:
# Expected nil to be a String
# OR Expected nil to be a Integer

Hash

# last hash element is keyword arguments
rtype :func, [{msg: String}, {}] => Any
def func(hash)
  puts hash[:msg]
end

func({})
# (Rtype::ArgumentTypeError) for 1st argument:
# Expected {} to be a hash with 1 elements:
# - msg : Expected nil to be a String

func({msg: 123})
# (Rtype::ArgumentTypeError) for 1st argument:
# Expected {:msg=>123} to be a hash with 1 elements:
# - msg : Expected 123 to be a String

func({msg: "hello", key: 'value'})
# (Rtype::ArgumentTypeError) for 1st argument:
# Expected {:msg=>"hello", :key=>"value"} to be a hash with 1 elements:
# - msg : Expected "hello" to be a String

func({"msg" => "hello hash"})
# (Rtype::ArgumentTypeError) for 1st argument:
# Expected {"msg"=>"hello hash"} to be a hash with 1 elements:
# - msg : Expected nil to be a String

func({msg: "hello hash"}) # hello hash

attr_accessor with rtype

• rtype_accessor(*names, type) : calls attr_accessor if the accessor methods(getter/setter) are not defined. and makes it typed
• rtype_reader(*names, type) : calls attr_reader if the getters are not defined. and makes it typed
• rtype_writer(*names, type) : calls attr_writer if the setters are not defined. and makes it typed

You can use rtype_accessor_self for static accessor. (rtype_reader_self, rtype_writer_self also exist)

require 'rtype'

class Example
  rtype_accessor :value, String

  def initialize
    @value = 456
  end
end

Example.new.value = 123
# (Rtype::ArgumentTypeError) for 1st argument:
# Expected 123 to be a String

Example.new.value
# (Rtype::ReturnTypeError) for return:
# Expected 456 to be a String

Typed Array

### TEST 1 ###
class Test
    rtype [Array.of(Integer)] => Any
    def sum(args)
        num = 0
        args.each { |e| num += e }
    end
end

sum([1, 2, 3]) # => 6

sum([1.0, 2, 3])
# (Rtype::ArgumentTypeError) for 1st argument:
# Expected [1.0, 2, 3] to be an array with type Integer"

### TEST 2 ###
class Test
    rtype [ Array.of([Integer, Float]) ] => Any
    def sum(args)
        num = 0
        args.each { |e| num += e }
    end
end

sum([1, 2, 3]) # => 6
sum([1.0, 2, 3]) # => 6.0

float_accessor

class Point
  float_accessor :x, :y
end

v = Point.new
v.x = 1
v.x # => 1.0 (always Float)

bool_accessor

class Human
  bool_accessor :hungry
end

a = Human.new
a.hungry = true
a.hungry? # => true
a.hungry # NoMethodError

rtype

require 'rtype'

class Example
  # Recommended. With annotation mode (no method name required)
  rtype [Integer, String] => String
  def hello_world(i, str)
    puts "Hello? #{i} #{st
  end

  # Works (with specifying method name)
  rtype :hello_world, [Integer, String] => String
  def hello_world(i, str)
    puts "Hello? #{i} #{st
  end

  # Works
  def hello_world_two(i, str)
    puts "Hello? #{i} #{str}"
  end
  rtype :hello_world_two, [Integer, String] => String

  # Also works (String will be converted to Symbol)
  rtype 'hello_world_three', [Integer, String] => String
  def hello_world_three(i, str)
    puts "Hello? #{i} #{str}"
  end

  # Doesn't work. annotation mode works for following (next) method
  def hello_world_four(i, str)
    puts "Hello? #{i} #{str}"
  end
  rtype [Integer, String] => String
end

In the outside of module (root)

In the outside of module, annotation mode doesn't work. You must specify method name.

rtype :say, [String] => Any
def say(message)
  puts message
end

Test.new.say "Hello" # Hello

rtype [String] => Any
# (ArgumentError) Annotation mode not working in the outside of module

Class method

Annotation mode works for both instance method and class method

require 'rtype'

class Example
  rtype [:to_i] => Any
  def self.say_ya(i)
    puts "say" + " ya"*i.to_i
  end
end

Example::say_ya(3) #say ya ya ya

if you specify method name, however, you must use rtype_self instead of rtype

require 'rtype'

class Example
  rtype_self :say_ya, [:to_i] => Any
  def self.say_ya(i)
    puts "say" + " ya"*i.to_i
  end
end

Example::say_ya(3) #say ya ya ya

Type information

This is just 'information'

Any change of this doesn't affect type checking

require 'rtype'

class Example
  rtype [:to_i] => Any
  def test(i)
  end
end

Example.new.method(:test).type_info
# => [:to_i] => Any
Example.new.method(:test).argument_type
# => [:to_i]
Example.new.method(:test).return_type
# => Any

Special Behaviors

• TypedArray : Ensures value is an array with the type (type signature)

  • Array.of(type) (recommended)
  • Example: TypedArray

• TypedSet : Ensures value is a set with the type (type signature)

  • Set.of(type) (recommended)

• TypedHash : Ensures value is a hash with the type (type signature)

  • Hash.of(key_type, value_type) (recommended)

• Num, Int, Flo : Numeric check

  • Num/Int/Flo >/>=/</<=/== x
  • e.g. Num >= 2 means value must be a Numeric and >= 2
  • e.g. Int >= 2 means value must be a Integer and >= 2
  • e.g. Flo >= 2 means value must be a Float and >= 2

• And : Ensures value is valid for all given types

  • Rtype.and(*types), Rtype::Behavior::And[*types]
  • or Array#comb, Object#and(*others)

• Xor : Ensures value is valid for only one of given types

  • Rtype.xor(*types), Rtype::Behavior::Xor[*types]
  • or Object#xor(*others)

• Not : Ensures value is not valid for all given types

  • Rtype.not(*types), Rtype::Behavior::Not[*types]
  • or Object#not

• Nilable : Value can be nil

  • Rtype.nilable(type), Rtype::Behavior::Nilable[type]
  • or Object#nilable, Object#or_nil

• You can create custom behaviors by extending Rtype::Behavior::Base

Documentation

RubyDoc.info

Benchmarks

Result of rake benchmark (source)

MRI

Rtype with C native extension
Ruby version: 2.1.7
Ruby engine: ruby
Ruby description: ruby 2.1.7p400 (2015-08-18 revision 51632) [x64-mingw32]
Rtype version: 0.3.0
Rubype version: 0.3.1
Sig version: 1.0.1
Contracts version: 0.13.0
Typecheck version: 0.1.2
Warming up --------------------------------------
                pure    85.328k i/100ms
               rtype    25.665k i/100ms
              rubype    21.414k i/100ms
                 sig     8.921k i/100ms
           contracts     4.638k i/100ms
           typecheck     1.110k i/100ms
Calculating -------------------------------------
                pure      3.282M (± 2.7%) i/s -     16.468M
               rtype    339.065k (± 2.6%) i/s -      1.720M
              rubype    266.893k (± 5.9%) i/s -      1.349M
                 sig     99.952k (± 2.1%) i/s -    499.576k
           contracts     49.693k (± 1.5%) i/s -    250.452k
           typecheck     11.356k (± 1.6%) i/s -     57.720k

Comparison:
                pure:  3282431.9 i/s
               rtype:   339064.9 i/s - 9.68x slower
              rubype:   266892.9 i/s - 12.30x slower
                 sig:    99952.2 i/s - 32.84x slower
           contracts:    49693.0 i/s - 66.05x slower
           typecheck:    11355.9 i/s - 289.05x slower

JRuby

Without Rubype that doesn't support JRuby

Rtype with Java extension
Ruby version: 2.2.3
Ruby engine: jruby
Ruby description: jruby 9.0.5.0 (2.2.3) 2016-01-26 7bee00d Java HotSpot(TM) 64-Bit Server VM 25.60-b23 on 1.8.0_60-b27 +jit [Windows 10-amd64]
Rtype version: 0.3.0
Sig version: 1.0.1
Contracts version: 0.13.0
Typecheck version: 0.1.2
Warming up --------------------------------------
                pure     9.994k i/100ms
               rtype     6.181k i/100ms
                 sig     4.041k i/100ms
           contracts   951.000  i/100ms
           typecheck   970.000  i/100ms
Calculating -------------------------------------
                pure      7.128M (?±35.6%) i/s -     30.831M
               rtype    121.556k (?± 6.2%) i/s -    605.738k
                 sig     72.187k (?± 6.4%) i/s -    359.649k
           contracts     24.984k (?± 3.9%) i/s -    125.532k
           typecheck     12.041k (?± 9.5%) i/s -     60.140k

Comparison:
                pure:  7128373.0 i/s
               rtype:   121555.8 i/s - 58.64x slower
                 sig:    72186.8 i/s - 98.75x slower
           contracts:    24984.5 i/s - 285.31x slower
           typecheck:    12041.0 i/s - 592.01x slower

Rubype, Sig

Rtype is influenced by Rubype and Sig.

If you don't like Rtype, You can use other library such as Contracts, Rubype, Rtc, Typecheck, Sig.

Author

Sputnik Gugja (sputnikgugja@gmail.com)

License

MIT license (@ Sputnik Gugja)

See LICENSE file.