def test_null(self):
program = "(null? 1)"
self.assertEvaluatesTo(program, Boolean(False))
program = "(null? '())"
self.assertEvaluatesTo(program, Boolean(True))
program = "(null? '(1 2))"
self.assertEvaluatesTo(program, Boolean(False))
def equality(arguments):
for argument in arguments:
if not isinstance(argument, Number):
raise SchemeTypeError("Numerical equality test is only defined for numbers, "
"you gave me %s." % argument.__class__)
if argument != arguments[0]:
return Boolean(False)
return Boolean(True)
def inexact(arguments):
check_argument_number('inexact?', arguments, 1, 1)
if isinstance(arguments[0], FloatingPoint):
return Boolean(True)
elif isinstance(arguments[0], Integer):
return Boolean(False)
else:
raise SchemeTypeError("exact? only takes integers or floating point "
"numbers as arguments, you gave me ""%s." % \
len(arguments))
def char_less_than(arguments):
check_argument_number('char<?', arguments, 2, 2)
if not isinstance(arguments[0], Character) or not isinstance(
arguments[1], Character):
raise SchemeTypeError("char<? takes only character arguments, got a "
"%s and a %s." %
(arguments[0].__class__, arguments[1].__class__))
if arguments[0].value < arguments[1].value:
return Boolean(True)
return Boolean(False)
def test_equivalence(arguments):
check_argument_number('eqv?', arguments, 2, 2)
if isinstance(arguments[0], Atom):
# __eq__ is defined on Atom
return Boolean(arguments[0] == arguments[1])
if isinstance(arguments[0], Cons):
# __eq__ on Cons is deep equality
return Boolean(arguments[0] is arguments[1])
else:
# __eq__ is defined on Nil
# todo: test vectors
return Boolean(arguments[0] == arguments[1])
def test_equality(self):
program = "(=)"
self.assertEvaluatesTo(program, Boolean(True))
program = "(= 0)"
self.assertEvaluatesTo(program, Boolean(True))
program = "(= 0 0)"
self.assertEvaluatesTo(program, Boolean(True))
program = "(= 0 1)"
self.assertEvaluatesTo(program, Boolean(False))
program = "(= 1.0 1)"
self.assertEvaluatesTo(program, Boolean(True))
def test_eqv(self):
program = "(eqv? 1 1)"
self.assertEvaluatesTo(program, Boolean(True))
program = "(eqv? (quote foo) (quote foo))"
self.assertEvaluatesTo(program, Boolean(True))
program = "(eqv? car car)"
self.assertEvaluatesTo(program, Boolean(True))
program = "(eqv? (quote ()) (quote ()))"
self.assertEvaluatesTo(program, Boolean(True))
program = "(eqv? (cons 1 2) (cons 1 2))"
self.assertEvaluatesTo(program, Boolean(False))
def if_function(arguments, environment):
check_argument_number('if', arguments, 2, 3)
condition, environment = eval_s_expression(arguments[0], environment)
# everything except an explicit false boolean is true
if not condition == Boolean(False):
then_expression = arguments[1]
return eval_s_expression(then_expression, environment)
else:
if len(arguments) == 3:
else_expression = arguments[2]
return eval_s_expression(else_expression, environment)
def test_equality(self):
program = "(char=? #\\ #\\space)"
self.assertEvaluatesTo(program, Boolean(True))
def test_even_predicate(self):
program = "(even? 6)"
self.assertEvaluatesTo(program, Boolean(True))
program = "(even? 7)"
self.assertEvaluatesTo(program, Boolean(False))
def test_less_or_equal(self):
program = "(<= 1 1)"
self.assertEvaluatesTo(program, Boolean(True))
program = "(<= 1 0)"
self.assertEvaluatesTo(program, Boolean(False))
def test_and(self):
program = "(and (= 2 2) (> 2 1))"
self.assertEvaluatesTo(program, Boolean(True))
program = "(and \"foo\" \"bar\")"
self.assertEvaluatesTo(program, String("bar"))
def test_not(self):
program = '(not #f)'
self.assertEvaluatesTo(program, Boolean(True))
program = '(not \'())'
self.assertEvaluatesTo(program, Boolean(False))
def test_exact(self):
program = "(exact? 1)"
self.assertEvaluatesTo(program, Boolean(True))
program = "(exact? 1.0)"
self.assertEvaluatesTo(program, Boolean(False))
def test_real(self):
program = "(real? 1.2)"
self.assertEvaluatesTo(program, Boolean(True))
def test_rational(self):
program = "(rational? 1.1)"
self.assertEvaluatesTo(program, Boolean(True))
def test_complex(self):
program = "(complex? 0)"
self.assertEvaluatesTo(program, Boolean(True))
def test_greater_or_equal(self):
program = "(>= 1 1)"
self.assertEvaluatesTo(program, Boolean(True))
program = "(>= 1 3 2)"
self.assertEvaluatesTo(program, Boolean(False))
def test_greater_than(self):
program = "(> 1 1)"
self.assertEvaluatesTo(program, Boolean(False))
program = "(> 11 10 0)"
self.assertEvaluatesTo(program, Boolean(True))
def test_char_less_than(self):
program = "(char<? #\\A #\\B)"
self.assertEvaluatesTo(program, Boolean(True))
def test_string_predicate(self):
program = '(string? "foo")'
self.assertEvaluatesTo(program, Boolean(True))
program = '(string? (quote ("foo")))'
self.assertEvaluatesTo(program, Boolean(False))
def test_inexact(self):
program = "(inexact? 0)"
self.assertEvaluatesTo(program, Boolean(False))
program = "(inexact? 0.0)"
self.assertEvaluatesTo(program, Boolean(True))
def test_is_boolean(self):
program = "(boolean? #t)"
self.assertEvaluatesTo(program, Boolean(True))
program = "(boolean? 1)"
self.assertEvaluatesTo(program, Boolean(False))
def test_boolean(self):
program = "#t"
self.assertEvaluatesTo(program, Boolean(True))
def test_is_vector(self):
program = "(vector? '())"
self.assertEvaluatesTo(program, Boolean(False))
program = "(vector? (make-vector 1))"
self.assertEvaluatesTo(program, Boolean(True))
def test_negative_predicate(self):
program = "(negative? -1)"
self.assertEvaluatesTo(program, Boolean(True))
program = "(negative? 3)"
self.assertEvaluatesTo(program, Boolean(False))
def test_is_list(self):
program = "(list? '())"
self.assertEvaluatesTo(program, Boolean(True))
program = "(list? 1)"
self.assertEvaluatesTo(program, Boolean(False))
def test_odd_predicate(self):
program = "(odd? 1)"
self.assertEvaluatesTo(program, Boolean(True))
program = "(odd? 0)"
self.assertEvaluatesTo(program, Boolean(False))
def test_zero_predicate(self):
program = "(zero? 0)"
self.assertEvaluatesTo(program, Boolean(True))
def test_less_than(self):
program = "(< 1 1)"
self.assertEvaluatesTo(program, Boolean(False))
program = "(< 1 2 4)"
self.assertEvaluatesTo(program, Boolean(True))