Module: Axn::Internal::Memoization

Defined in:
lib/axn/internal/memoization.rb

Constant Summary collapse

UNSET = 
Object.new.freeze

Class Method Summary collapse

Class Method Details

.define_memoized_reader_method(target, field, &block) ⇒ Object 



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# File 'lib/axn/internal/memoization.rb', line 8

def self.define_memoized_reader_method(target, field, &block)
  target.define_method(field) do
    ivar = :"@_memoized_reader_#{field}"
    cached_val = instance_variable_defined?(ivar) ? instance_variable_get(ivar) : UNSET
    return cached_val unless cached_val == UNSET

    value = instance_exec(&block)
    instance_variable_set(ivar, value)
  end
end