Class: Maybe

Inherits:
Object
  • Object
show all
Defined in:
lib/indubitably.rb

Overview

base class for Some and None

Direct Known Subclasses

None, Some

Constant Summary collapse

@@none = 
nil

Class Method Summary collapse

Instance Method Summary collapse

Class Method Details

.concat(list, default = none) ⇒ Object 



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# File 'lib/indubitably.rb', line 27

def self.concat(list, default = none)
  if default == none
    list.select(&:is_some?).map(&:get)
  else
    list.map { |x| x.or_else(default) }
  end
end

.empty_value?(value) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/indubitably.rb', line 35

def self.empty_value?(value)
  value.nil? || (value.respond_to?(:length) && value.length == 0)
end

.join?(value) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/indubitably.rb', line 39

def self.join?(value)
  return value if value.is_a?(Maybe)
  Maybe(value)
end

.none ⇒ Object 



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# File 'lib/indubitably.rb', line 44

def self.none
  @@none ||= None.new
end

.seq(list, default = none) ⇒ Object 



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# File 'lib/indubitably.rb', line 48

def self.seq(list, default = none)
  Maybe(concat(list, default))
end

Instance Method Details

#==(other) ⇒ Object Also known as: eql? 



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# File 'lib/indubitably.rb', line 18

def ==(other)
  other.class == self.class
end

#or_nil ⇒ Object 



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# File 'lib/indubitably.rb', line 23

def or_nil
  or_else(nil)
end

#to_ary ⇒ Object Also known as: to_a 



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# File 'lib/indubitably.rb', line 13

def to_ary
  __enumerable_value
end