Class: Dry::Types::Maybe

Inherits:

Object

• Object
• Dry::Types::Maybe

Includes:

Builder, Decorator, Printable, Type

Defined in:

lib/dry/types/extensions/maybe.rb

Overview

Maybe extension provides Maybe types where values are wrapped using Either monad

Instance Attribute Summary

• #options ⇒ Hash included from Options readonly private
• #type ⇒ Type included from Decorator readonly

Instance Method Summary

• #&(other) ⇒ Intersection, Intersection::Constrained included from Builder private

  Compose two types into an Intersection type.

• #>(other) ⇒ Implication, Implication::Constrained included from Builder private

  Compose two types into an Implication type.

• #call(input = Undefined, &block) ⇒ Object (also: #[]) included from Type

  Apply type to a value.

• #call_safe(input = Undefined) ⇒ Dry::Monads::Maybe private
• #call_unsafe(input = Undefined) ⇒ Dry::Monads::Maybe private
• #constrained ⇒ Constrained included from Builder

  Turn a type into a constrained type.

• #constrained? ⇒ Boolean included from Decorator
• #constrained_type ⇒ Class included from Builder private
• #constructor(constructor = nil, **options, &block) ⇒ Constructor (also: #append, #prepend, #>>, #<<) included from Builder

  Define a constructor for the type.

• #constructor_type ⇒ Class included from Builder private
• #default(value) ⇒ Object
• #default? ⇒ true
• #enum(*values) ⇒ Enum included from Builder

  Define an enum on top of the existing type.

• #fallback(value = Undefined, shared: false, &_fallback) ⇒ Constructor included from Builder

  Use the given value on type mismatch.

• #initialize(type) ⇒ Object included from Decorator
• #lax ⇒ Lax included from Builder

  Turn a type into a lax type that will rescue from type-errors and return the original input.

• #maybe ⇒ Maybe included from Builder

  Turn a type into a maybe type.

• #optional ⇒ Sum included from Builder

  Turn a type into an optional type.

• #respond_to_missing?(meth, include_private = false) ⇒ Boolean included from Decorator
• #to_proc ⇒ Proc included from Decorator

  Wrap the type with a proc.

• #to_s ⇒ String (also: #inspect) included from Printable private
• #try(input = Undefined) ⇒ Result::Success
• #valid?(input = Undefined) ⇒ Boolean (also: #===) included from Type private

  Whether a value is a valid member of the type.

• #with(**new_options) ⇒ Type included from Options private
• #|(other) ⇒ Sum, Sum::Constrained included from Builder private

  Compose two types into a Sum type.

Dynamic Method Handling

This class handles dynamic methods through the method_missing method in the class Dry::Types::Decorator

Instance Attribute Details

#options ⇒ Hash (readonly) Originally defined in module Options

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.

Returns:

• (Hash)

#type ⇒ Type (readonly) Originally defined in module Decorator

Returns:

• (Type)

Instance Method Details

#&(other) ⇒ Intersection, Intersection::Constrained Originally defined in module Builder

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.

Compose two types into an Intersection type

Parameters:

• other (Type)

Returns:

• (Intersection, Intersection::Constrained)

#>(other) ⇒ Implication, Implication::Constrained Originally defined in module Builder

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.

Compose two types into an Implication type

Parameters:

• other (Type)

Returns:

• (Implication, Implication::Constrained)

#call(input = Undefined) ⇒ Object #call(input = Undefined) {|output| ... } ⇒ Object Also known as: [] Originally defined in module Type

Apply type to a value

Overloads:

• #call(input = Undefined) ⇒ Object

  Possibly unsafe coercion attempt. If a value doesn't match the type, an exception will be raised.

  Parameters:

  • input (Object) (defaults to: Undefined)

  Returns:

  • (Object)
• #call(input = Undefined) {|output| ... } ⇒ Object

  When a block is passed, #call will never throw an exception on failed coercion, instead it will call the block.

  Parameters:

  • input (Object) (defaults to: Undefined)

  Yield Parameters:

  • output (Object) —

    Partially coerced value

  Returns:

  • (Object)

#call_safe(input = Undefined) ⇒ Dry::Monads::Maybe

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.

Parameters:

• input (Dry::Monads::Maybe, Object) (defaults to: Undefined)

Returns:

• (Dry::Monads::Maybe)

# File 'lib/dry/types/extensions/maybe.rb', line 44

def call_safe(input = Undefined)
  case input
  when ::Dry::Monads::Maybe
    input
  when Undefined
    None()
  else
    Maybe(type.call_safe(input) { |output = input| return yield(output) })
  end
end

#call_unsafe(input = Undefined) ⇒ Dry::Monads::Maybe

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.

Parameters:

• input (Dry::Monads::Maybe, Object) (defaults to: Undefined)

Returns:

• (Dry::Monads::Maybe)

# File 'lib/dry/types/extensions/maybe.rb', line 28

def call_unsafe(input = Undefined)
  case input
  when ::Dry::Monads::Maybe
    input
  when Undefined
    None()
  else
    Maybe(type.call_unsafe(input))
  end
end

#constrained ⇒ Constrained Originally defined in module Builder

Turn a type into a constrained type

Parameters:

• options (Hash) —

  constraining rule (see Dry::Types.Rule)

Returns:

• (Constrained)

#constrained? ⇒ Boolean Originally defined in module Decorator

Returns:

• (Boolean)

#constrained_type ⇒ Class Originally defined in module Builder

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.

Returns:

• (Class)

#constructor(constructor = nil, **options, &block) ⇒ Constructor Also known as: append, prepend, >>, << Originally defined in module Builder

Define a constructor for the type

Parameters:

• constructor (#call, nil) (defaults to: nil)
• options (Hash)
• block (#call, nil)

Returns:

• (Constructor)

#constructor_type ⇒ Class Originally defined in module Builder

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.

Returns:

• (Class)

#default(value) ⇒ Object

Parameters:

• value (Object)

Raises:

• (ArgumentError) —

  if nil provided as default value

See Also:

• Builder#default

# File 'lib/dry/types/extensions/maybe.rb', line 84

def default(value)
  if value.nil?
    raise ArgumentError, "nil cannot be used as a default of a maybe type"
  else
    super
  end
end

#default? ⇒ true

Returns:

• (true)

# File 'lib/dry/types/extensions/maybe.rb', line 73

def default?
  true
end

#enum(*values) ⇒ Enum Originally defined in module Builder

Define an enum on top of the existing type

Parameters:

• values (Array)

Returns:

• (Enum)

#fallback(value = Undefined, shared: false, &_fallback) ⇒ Constructor Originally defined in module Builder

Use the given value on type mismatch

Parameters:

• value (Object) (defaults to: Undefined)
• fallback (#call, nil)
• [Boolean] (Hash) —

  a customizable set of options

Returns:

• (Constructor)

#initialize(type) ⇒ Object Originally defined in module Decorator

Parameters:

• type (Type)

#lax ⇒ Lax Originally defined in module Builder

Turn a type into a lax type that will rescue from type-errors and return the original input

Returns:

• (Lax)

#maybe ⇒ Maybe Originally defined in module Builder

Turn a type into a maybe type

Returns:

• (Maybe)

#optional ⇒ Sum Originally defined in module Builder

Turn a type into an optional type

Returns:

• (Sum)

#respond_to_missing?(meth, include_private = false) ⇒ Boolean Originally defined in module Decorator

Parameters:

• meth (Symbol)
• include_private (Boolean) (defaults to: false)

Returns:

• (Boolean)

#to_proc ⇒ Proc Originally defined in module Decorator

Wrap the type with a proc

Returns:

• (Proc)

#to_s ⇒ String Also known as: inspect Originally defined in module Printable

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.

Returns:

• (String)

#try(input = Undefined) ⇒ Result::Success

Parameters:

• input (Object) (defaults to: Undefined)

Returns:

• (Result::Success)

# File 'lib/dry/types/extensions/maybe.rb', line 60

def try(input = Undefined)
  result = type.try(input)

  if result.success?
    Result::Success.new(Maybe(result.input))
  else
    result
  end
end

#valid?(input = Undefined) ⇒ Boolean Also known as: === Originally defined in module Type

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.

Whether a value is a valid member of the type

Returns:

• (Boolean)

#with(**new_options) ⇒ Type Originally defined in module Options

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.

Parameters:

• new_options (Hash)

Returns:

• (Type)

#|(other) ⇒ Sum, Sum::Constrained Originally defined in module Builder

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.

Compose two types into a Sum type

Parameters:

• other (Type)

Returns:

• (Sum, Sum::Constrained)