def test_calling_builtin_forces_argument_evaluation(self):
"""Bultins (like the regular lambdas) are call-by-value
and the arguments thould therefore be evaluated first"""
env = Environment({
'x': integer(2),
'+': Builtin(lambda a, b: integer(value_of(a) + value_of(b)))
})
ast = ['+', ['cond',
[boolean(True), integer(2)],
[boolean(True), 'whatever']],
'x']
assert_equals(integer(4), evaluate(ast, env))
def test_false(self):
assert_false(value_of(tag('bool', False)))
def test_true(self):
assert_true(value_of(tag('bool', True)))
def test_getting_value_of_type(self):
t = tag('footype', 42)
assert_equals(42, value_of(t))
def test_calling_a_builtin_function(self):
"""Tests that calling a builtin function gives the expected result"""
env = Environment({'+': Builtin(lambda a, b: integer(value_of(a) + value_of(b)))})
assert_equals(integer(4), evaluate(["+", integer(2), integer(2)], env))