Class: Dry::Logic::Rule::Interface

Inherits:
Module
  • Object
show all
Defined in:
lib/dry/logic/rule/interface.rb

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(arity, curried) ⇒ Interface

Returns a new instance of Interface.



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# File 'lib/dry/logic/rule/interface.rb', line 9

def initialize(arity, curried)
  @arity = arity
  @curried = curried

  if !variable_arity? && curried > arity
    raise ArgumentError, "wrong number of arguments (#{curried} for #{arity})"
  end

  define_constructor if curried?

  if variable_arity?
    define_splat_application
  elsif constant?
    define_constant_application
  else
    define_fixed_application
  end
end

Instance Attribute Details

#arity ⇒ Object (readonly)

Returns the value of attribute arity.



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# File 'lib/dry/logic/rule/interface.rb', line 5

def arity
  @arity
end

#curried ⇒ Object (readonly)

Returns the value of attribute curried.



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# File 'lib/dry/logic/rule/interface.rb', line 7

def curried
  @curried
end

Instance Method Details

#constant? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/dry/logic/rule/interface.rb', line 28

def constant?
  arity.zero?
end

#curried? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/dry/logic/rule/interface.rb', line 36

def curried?
  !curried.zero?
end

#curried_args ⇒ Object 



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# File 'lib/dry/logic/rule/interface.rb', line 134

def curried_args
  @curried_args ||= ::Array.new(curried) { |i| "@arg#{i}" }
end

#define_constant_application ⇒ Object 



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# File 'lib/dry/logic/rule/interface.rb', line 76

def define_constant_application
  module_exec do
    def call(*)
      if @predicate[]
        Result::SUCCESS
      else
        Result.new(false, id) { ast }
      end
    end

    def [](*)
      @predicate[]
    end
  end
end

#define_constructor ⇒ Object 



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# File 'lib/dry/logic/rule/interface.rb', line 59

def define_constructor
  assignment =
    if curried.equal?(1)
      '@arg0 = @args[0]'
    else
      "#{curried_args.join(', ')} = @args"
    end

  module_eval(<<~RUBY, __FILE__, __LINE__ + 1)
    def initialize(*)
      super

      #{assignment}
    end
  RUBY
end

#define_fixed_application ⇒ Object 



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# File 'lib/dry/logic/rule/interface.rb', line 115

def define_fixed_application
  parameters = unapplied_args.join(', ')
  application = "@predicate[#{ (curried_args + unapplied_args).join(', ') }]"

  module_eval(<<~RUBY, __FILE__, __LINE__ + 1)
    def call(#{parameters})
      if #{application}
        Result::SUCCESS
      else
        Result.new(false, id) { ast(#{parameters}) }
      end
    end

    def [](#{parameters})
      #{application}
    end
  RUBY
end

#define_splat_application ⇒ Object 



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# File 'lib/dry/logic/rule/interface.rb', line 92

def define_splat_application
  application =
    if curried?
      "@predicate[#{curried_args.join(', ')}, *input]"
    else
      '@predicate[*input]'
    end

  module_eval(<<~RUBY, __FILE__, __LINE__ + 1)
    def call(*input)
      if #{application}
        Result::SUCCESS
      else
        Result.new(false, id) { ast(*input) }
      end
    end

    def [](*input)
      #{application}
    end
  RUBY
end

#name ⇒ Object 



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# File 'lib/dry/logic/rule/interface.rb', line 48

def name
  if constant?
    'Constant'
  else
    arity_str = variable_arity? ? 'VariableArity' : "#{arity}Arity"
    curried_str = curried? ? "#{curried}Curried" : EMPTY_STRING

    "#{arity_str}#{curried_str}"
  end
end

#unapplied ⇒ Object 



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# File 'lib/dry/logic/rule/interface.rb', line 40

def unapplied
  if variable_arity?
    -1
  else
    arity - curried
  end
end

#unapplied_args ⇒ Object 



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# File 'lib/dry/logic/rule/interface.rb', line 138

def unapplied_args
  @unapplied_args ||= ::Array.new(unapplied) { |i| "input#{i}" }
end

#variable_arity? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/dry/logic/rule/interface.rb', line 32

def variable_arity?
  arity.equal?(-1)
end