Class: Null

Inherits:
Object show all
Defined in:
lib/functional-light-service/functional/null.rb

Overview

The simplest NullObject there can be

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(methods) ⇒ Null

Returns a new instance of Null.



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# File 'lib/functional-light-service/functional/null.rb', line 48

def initialize(methods)
  @methods = methods
end

Dynamic Method Handling

This class handles dynamic methods through the method_missing method

#method_missing(m, *args) ⇒ Object 



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# File 'lib/functional-light-service/functional/null.rb', line 61

def method_missing(m, *args)
  return self if respond_to_missing?(m)

  super
end

Class Method Details

.==(other) ⇒ Object 



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# File 'lib/functional-light-service/functional/null.rb', line 42

def ==(other)
  other.respond_to?(:null?) && other.null?
end

.instance ⇒ Object 



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# File 'lib/functional-light-service/functional/null.rb', line 18

def instance
  FunctionalLightService::Deprecations.warn(
    "Maybe()/Null are deprecated and will be removed in a future release; " \
    "use FunctionalLightService::Option (Some/None) instead"
  )
  @instance ||= new([])
end

.method_missing(m, *args) ⇒ Object 



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# File 'lib/functional-light-service/functional/null.rb', line 6

def method_missing(m, *args)
  if m == :new
    super
  else
    Null.instance
  end
end

.mimic(klas) ⇒ Object 



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# File 'lib/functional-light-service/functional/null.rb', line 34

def mimic(klas)
  FunctionalLightService::Deprecations.warn(
    "Maybe()/Null are deprecated and will be removed in a future release; " \
    "use FunctionalLightService::Option (Some/None) instead"
  )
  new(klas.instance_methods(false))
end

.null? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/functional-light-service/functional/null.rb', line 26

def null?
  true
end

.respond_to_missing?(m, _include_all = false) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/functional-light-service/functional/null.rb', line 14

def respond_to_missing?(m, _include_all = false)
  m != :new || super
end

.some? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/functional-light-service/functional/null.rb', line 30

def some?
  false
end

Instance Method Details

#==(other) ⇒ Object 



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# File 'lib/functional-light-service/functional/null.rb', line 85

def ==(other)
  other.respond_to?(:null?) && other.null?
end

#inspect ⇒ Object 



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# File 'lib/functional-light-service/functional/null.rb', line 81

def inspect
  'Null'
end

#null? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/functional-light-service/functional/null.rb', line 67

def null?
  true
end

#respond_to_missing?(m, _include_all = false) ⇒ Boolean

Convenzione Ruby: si estende respond_to_missing?, mai respond_to? (il vecchio override aveva anche la firma sbagliata: mancava include_all)

Returns:

  • (Boolean) 


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# File 'lib/functional-light-service/functional/null.rb', line 77

def respond_to_missing?(m, _include_all = false)
  @methods.empty? || @methods.include?(m) || super
end

#some? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/functional-light-service/functional/null.rb', line 71

def some?
  false
end

#to_ary ⇒ Object 



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# File 'lib/functional-light-service/functional/null.rb', line 57

def to_ary
  []
end

#to_str ⇒ Object

implicit conversions



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# File 'lib/functional-light-service/functional/null.rb', line 53

def to_str
  ''
end