Module: Factbase::Term::Defn

Included in:
Factbase::Term
Defined in:
lib/factbase/terms/defn.rb

Overview

Defn terms.

Author

Yegor Bugayenko ([email protected])

Copyright

Copyright © 2024 Yegor Bugayenko

License

MIT

Instance Method Summary collapse

Instance Method Details

#defn(_fact, _maps) ⇒ Object 



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# File 'lib/factbase/terms/defn.rb', line 31

def defn(_fact, _maps)
  assert_args(2)
  fn = @operands[0]
  raise "A symbol expected as first argument of 'defn'" unless fn.is_a?(Symbol)
  raise "Can't use '#{fn}' name as a term" if Factbase::Term.instance_methods(true).include?(fn)
  raise "Term '#{fn}' is already defined" if Factbase::Term.private_instance_methods(false).include?(fn)
  raise "The '#{fn}' is a bad name for a term" unless fn.match?(/^[a-z_]+$/)
  e = "class Factbase::Term\nprivate\ndef #{fn}(fact, maps)\n#{@operands[1]}\nend\nend"
  # rubocop:disable Security/Eval
  eval(e)
  # rubocop:enable Security/Eval
  true
end

#undef(_fact, _maps) ⇒ Object 



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# File 'lib/factbase/terms/defn.rb', line 45

def undef(_fact, _maps)
  assert_args(1)
  fn = @operands[0]
  raise "A symbol expected as first argument of 'undef'" unless fn.is_a?(Symbol)
  if Factbase::Term.private_instance_methods(false).include?(fn)
    Factbase::Term.class_eval("undef :#{fn}", __FILE__, __LINE__ - 1) # undef :foo
  end
  true
end