✨ Add unary operations to NumericType

[Mahhheshh]

Fixes #5911

The changes made to the NumericType class include adding two new methods, __pos__ and __neg__, to support unary operations. __pos__ overloads the unary plus operator + and returns the value of the object as-is, while __neg__ overloads the unary minus operator - and returns a new instance of the same class with the negation of the value of the original object.

[ltalirz]

@sphuber would you be able to review this?

[sphuber]

Yes, I will take care of this when I have time

[sphuber]

Thanks for the contribution @Mahhheshh . I have left two comments in the code.

[sphuber]

Maybe we should also add the abs operator which is listed together with +, - and ~ as the unary operators in the official Python documentation. We can omit the ~ invert operator since that doesn't make sense for floats and I doubt anyone would want to use it for Int.

Suggested change

	return self.new(-self.value)
	return self.new(-self.value)

[sphuber]

I would split this test in two (three when you implement abs as well) and use parametrization to do both numeric types

Suggested change

	def test_unary():
	"""Test Unary operations for orm.Int and orm.Float"""
	# Int
	int_a = Int(5)
	int_b = Int(-5)
	# Float
	float_a = Float(10.0)
	float_b = Float(-10.0)
	# Test __pos__
	assert +int_a == int_a # True +5 > 5 == 5
	assert +int_b == int_b # True +(-5) > -5 == -5
	assert +float_a == float_a # True +10.0 > 10 == 10
	assert +float_b == float_b # True +(-10.0) > -10.0 == 10.0
	# Test __neg__
	assert -int_a != int_a # True -(5) != 5
	assert -int_b != int_b # True -(-5) != -5
	assert -float_a != float_a # True (-10.0) != 10.0
	assert -float_b != float_b # True -(-10.0) > 10.0 != -10.0
	assert -int_a == -int_a # True -5 == -5
	@pytest.mark.parametrize('numeric_type', (Float, Int))
	def test_unary_pos(numeric_type):
	"""Test the ``__pos__`` unary operator for all ``NumericType`` subclasses."""
	node_positive = numeric_type(1)
	node_negative = numeric_type(-1)
	assert +node_positive == node_positive
	assert +node_negative == node_negative
	@pytest.mark.parametrize('numeric_type', (Float, Int))
	def test_unary_neg(numeric_type):
	"""Test the ``__neg__`` unary operator for all ``NumericType`` subclasses."""
	node_positive = numeric_type(1)
	node_negative = numeric_type(-1)
	assert -node_positive != node_positive
	assert -node_negative != node_negative
	assert -node_positive == node_negative
	assert -node_negative == node_positive

[Mahhheshh]

test for __abs__ is failing, I don't have idea about how it should be handled. Also I have made typo in the method name (realized now). Because of that tests were passing when ran locally.

[sphuber]

The __abs__ method is invoked by the abs built-in, so I would test it as follows:

Suggested change

	# Test positive number
	abs_positive = node_positive.abs()
	assert abs_positive == node_positive
	# Test negative number
	abs_negative = node_negative.abs()
	assert abs_negative != node_negative
	assert abs(node_positive) == node_positive
	assert abs(node_negative) != node_negative
	assert abs(node_negative) == node_positive

[sphuber]

Good to go. Thanks a lot for the contribution @Mahhheshh