def object(arg, scope):
obj = Object()
while arg is not nil:
assert type(arg) is Pair
slot = arg.car
if type(slot) is FormNode:
func = eval_node(slot.car, scope)
slot = FormNode(ValueNode('CACHE', func), slot.cdr) # this ensures we only eval the car of the form once
if func is cons:
assert type(slot.cdr) is Pair
obj.set(slot.cdr, scope)
elif func is get:
assert type(slot.cdr) is Pair
assert type(slot.cdr.cdr) is Pair
key_node = slot.cdr.cdr.car
obj.set(Pair(key_node, Pair(slot, nil)), scope)
else:
raise Exception("I don't know what to do with that yet")
elif type(slot) is IdentifierNode:
obj.set(Pair(slot, Pair(slot, nil)), scope)
else:
raise Exception("syntax error!")
arg = arg.cdr
return obj
def test_eval_builtin_id(self):
self.assertEqual(2, isheval('(id 2)'))
self.assertEqual(5, isheval('(id (add 2 3))'))
self.assertEqual(Pair(1, nil), isheval('(id (list 1))'))
self.assertEqual(Pair(1, nil), isheval('(id [1])'))
self.assertEqual(Pair(1, 2), isheval('(id [1 | 2])'))
self.assertEqual(1, isheval('(id 1)'))
self.assertEqual(20, isheval('((id id) 20)'))
def test_eval_builtins(self):
self.assertEqual(1, isheval('(car [1])'))
self.assertEqual(1, isheval('(car (id [1]))'))
self.assertEqual(nil, isheval('(cdr [1])'))
self.assertEqual(Pair(1, 2), isheval('(call cons 1 2)'))
self.assertEqual(Pair(1, 2), isheval('(apply cons (list 1 2))'))
self.assertEqual(Pair(1, 2), isheval('(apply cons [1 2])'))
self.assertEqual(1, isheval('(apply car [[1 2]])'))
self.assertEqual(Pair(1, Pair(2, nil)), isheval('((curry list 1) 2)'))
def test_eval_functions_in_scope(self):
my_id = isheval('(fn x x)')
scope = Scope({'my_id': my_id}, root)
self.assertEqual(my_id, isheval('my_id', scope))
self.assertEqual(my_id, isheval('(my_id | (my_id | my_id))', scope))
self.assertEqual(3, isheval('(my_id | 3)', scope))
self.assertEqual(Pair(my_id, nil), isheval('(my_id my_id)', scope))
self.assertEqual(my_id, isheval('(my_id | my_id)', scope))
self.assertEqual(Pair(20, nil), isheval('(my_id 20)', scope))
def test_dictionaries_can_still_have_attributes(self):
self.assertEqual(
Pair(10, Pair(20, 30)),
isheval('''
(dict = (dictionary))
(set dict 5 10)
(set dict foo 20)
(set dict #foo 30)
dict.5 : dict.foo : dict.#foo'''))
def dictionary(arg, scope):
dct = Dictionary()
while arg is not nil:
assert type(arg) is Pair
pair = eval_node(arg.car, scope)
dct.set(Pair(ValueNode('CACHE', pair.car), Pair(ValueNode('CACHE', pair.cdr), nil)), scope)
arg = arg.cdr
return dct
def test_eval_square_brackets(self):
self.assertEqual(Pair(1, nil), isheval('[1]'))
self.assertEqual(Pair(1, Pair(2, Pair(3, nil))), isheval('[1 2 3]'))
self.assertEqual(Pair(1, 2), isheval('[1 | 2]'))
self.assertEqual(Pair(1, Pair(2, 3)), isheval('[1 2 | 3]'))
self.assertEqual(Pair(10, nil), isheval('[(add 5 5)]'))
self.assertEqual(Pair(10, 20), isheval('[(add 5 5) | (add 10 10)]'))
def test_cons_pattern_match_list(self):
self._test_pattern('(pattern [a b | c])', '[1 2 | 3]', {
'a': 1,
'b': 2,
'c': 3
})
self._test_pattern('(pattern [a b | c])', '[1 2]', {
'a': 1,
'b': 2,
'c': nil
})
self._test_pattern_fails('(pattern [a b | c])', '[1]')
self._test_pattern_fails('(pattern [a b | c])', 'nil')
self._test_pattern('(pattern [a b c])', '[1 2 3]', {
'a': 1,
'b': 2,
'c': 3
})
self._test_pattern_fails('(pattern [a b c])', '[1 2 | 3]')
self._test_pattern_fails('(pattern [a b c])', '[1 2]')
self._test_pattern_fails('(pattern [a b c])', '[1]')
self._test_pattern_fails('(pattern [a b c])', 'nil')
self._test_pattern('(pattern []:[])', 'nil:nil', {})
self._test_pattern_fails('(pattern []:[])', 'nil')
self._test_pattern('(pattern []:[]:[]:[])', 'nil:nil:nil:nil', {})
self._test_pattern_fails('(pattern []:[]:[]:[])', 'nil')
self._test_pattern('(pattern []:a)', 'nil:1', {'a': 1})
self._test_pattern_fails('(pattern []:a)', 'nil')
self._test_pattern('(pattern a:b)', '1:2', {'a': 1, 'b': 2})
self._test_pattern('(pattern a:b)', '[1 | 2]', {'a': 1, 'b': 2})
self._test_pattern('(pattern a:b)', '[1 2 3]', {
'a': 1,
'b': Pair(2, Pair(3, nil))
})
self._test_pattern_fails('(pattern a:b)', 'nil')
self._test_pattern('(pattern a:b:c)', '1:2:3', {
'a': 1,
'b': 2,
'c': 3
})
self._test_pattern('(pattern a:b:c)', '[1 2 3]', {
'a': 1,
'b': 2,
'c': Pair(3, nil)
})
self._test_pattern_fails('(pattern a:b:c)', '1:2')
self._test_pattern_fails('(pattern a:b:c)', 'nil')
def eval_node(node, scope):
if type(node) is Pair:
return Pair(eval_node(node.car, scope), eval_node(node.cdr, scope))
# we're re-evaluating something that's already been evaluated. this might be a terrible idea.
# currently used by the apply and curry builtins to pre-apply arguments before calling a built-in function
# should just use ValueNodes in all cases
if not isinstance(node, Node):
return node
if type(node) is FormNode:
fn = eval_node(node.car, scope)
if type(fn) is FunctionType:
return fn(node.cdr, scope)
else:
return fn.call(node.cdr, scope)
elif type(node) is IdentifierNode:
return scope.get(node.identifier)
elif type(node) is NumericLiteralNode:
return int(node.value)
elif type(node) is SymbolLiteralNode:
return Symbol(node.value)
elif type(node) is ValueNode:
return node.value
else:
raise Exception("I don't know how to eval %s (%s)" %
(str(node), type(node)))
def test_curry_only_evaluates_arguments_once(self):
count = 0
def increment_count(args, scope):
nonlocal count
count += 1
return 5
scope = Scope({'inc': increment_count}, root)
self.assertEqual(0, count)
curried = isheval('(curry list (inc))', scope)
self.assertEqual(1, count)
scope.set('curried', curried)
self.assertEqual(Pair(5, Pair(10, Pair(20, nil))),
isheval('(curried 10 20)', scope))
self.assertEqual(1, count)
def test_promises(self):
self.assertEqual(
Pair(0, Pair(0, Pair(1, 1))),
isheval('''
(x = 0)
(side-effect = (fn -
(x = (add x 1))
20))
(a = x)
(def y (delay (side-effect)))
(b = x)
(force y)
(c = x)
(force y)
(d = x)
a:b:c:d'''))
def test_eval_functions(self):
self.assertEqual(20, isheval('((fn x 20))'))
self.assertEqual(5, isheval('((fn x x) | 5)'))
self.assertEqual(5, isheval('((fn x (car x)) | [5])'))
self.assertEqual(5, isheval('((fn x (car x)) 5)'))
self.assertEqual(Pair(5, nil), isheval('((fn x x) (add 2 3))'))
self.assertEqual(30, isheval('((fn x (add 10 (car x))) 20)'))
self.assertRaises(Exception, isheval, '((add 1 2))')
def test_eval_nested_functions(self):
compose = isheval('(fn x (fn y ((car (cdr x)) ((car x) (car y)))))')
self.assertEqual(Function, type(compose))
scope = Scope({'compose': compose}, root)
self.assertEqual(compose, isheval('compose', scope))
self.assertEqual(10, isheval('((compose id id) 10)', scope))
self.assertEqual(Pair(10, nil), isheval('((compose id id) [10])',
scope))
def test_multi_functions(self):
self.assertEqual(
Pair(11, 30),
isheval('''
(def multi-test (mfn
([a] (add a 1))
([a b] (add a b))
))
(multi-test 10):(multi-test 10 20)'''))
def test_pairs_force_cdrs(self):
self.assertEqual(
Pair(0, Pair(0, Pair(1, 1))),
isheval('''
(x = 0)
(side-effect = (fn -
(x = (add x 1))
20))
(a = x)
(pair = 10:(delay (side-effect)))
pair.cdr-slot
(b = x)
pair.cdr
(c = x)
(force pair.cdr-slot)
(d = x)
a:b:c:d'''))
def test_eval_list_special_form(self):
self.assertEqual(Pair(7, Pair(8, Pair(9, nil))),
isheval('(list 7 8 9)'))
self.assertEqual(Pair(10, 20), isheval('(list 10 | 20)'))
self.assertEqual(Pair(1, Pair(2, 3)), isheval('(list 1 2 | 3)'))
self.assertEqual(Pair(10, 20),
isheval('(list (add 5 5) | (add 10 10))'))
self.assertRaises(Exception, isheval, '(list | 1)')
self.assertRaises(Exception, isheval, '(list | [4 5 6])')
def __init__(self, arg, scope):
self.functions = []
while arg is not nil:
assert type(arg) is Pair
assert type(arg.car) is FormNode
func_arg = Pair(arg.car.car, arg.car.cdr)
function = Function(func_arg, scope)
self.functions.append(function)
# print(function)
arg = arg.cdr
def test_read_square_brackets_with_cdr_converts_to_list_special_form(self):
self.assertEqual(
FormNode(ValueNode('_list', specials.list_),
Pair(IdentifierNode('a'), IdentifierNode('b'))),
read_one('[a | b]'))
def cons(arg, scope):
car = arg.car
cdr = arg.cdr.car
return Pair(eval_node(car, scope), eval_node(cdr, scope))
def cdr(arg, scope):
assert type(arg) is Pair
assert eval_node(arg.cdr, scope) is nil
val = eval_node(arg.car, scope)
return val.get(Pair(IdentifierNode('cdr'), nil), scope)
def test_read_misc(self):
self.assertEqual(
FormNode(IdentifierNode('id'), Pair(NumericLiteralNode('1'), nil)),
read_one('(id 1)'))
self.assertEqual(
FormNode(
IdentifierNode('id'),
Pair(NumericLiteralNode('1'), Pair(NumericLiteralNode('2'),
nil))),
read_one('(id 1 2)'))
self.assertEqual(Forms(IdentifierNode('id'), NumericLiteralNode('1')),
read_one('(id 1)'))
self.assertEqual(
Forms(
IdentifierNode('id'),
FormNode(
IdentifierNode('add'),
Pair(NumericLiteralNode('1'),
Pair(NumericLiteralNode('2'), nil)))),
read_one('(id (add 1 2))'))
self.assertEqual(
Forms(
IdentifierNode('id'),
FormNode(
ValueNode('_list', specials.list_),
Pair(NumericLiteralNode('1'),
Pair(NumericLiteralNode('2'), nil)))),
read_one('(id [1 2])'))
self.assertEqual(
Forms(
IdentifierNode('id'),
FormNode(
ValueNode('_list', specials.list_),
Pair(NumericLiteralNode('1'), NumericLiteralNode('2')))),
read_one('(id [1 | 2])'))
self.assertEqual(
Forms(Forms(IdentifierNode('id'), IdentifierNode('id')),
NumericLiteralNode('1')), read_one('((id id) 1)'))
self.assertEqual(
Forms(
IdentifierNode('print'),
Forms(IdentifierNode('add'), NumericLiteralNode('5'),
NumericLiteralNode('6'))), read_one('(print (add 5 6))'))
self.assertEqual(
Forms(
IdentifierNode('print'),
FormNode(
ValueNode('_list', specials.list_),
Pair(NumericLiteralNode('7'), NumericLiteralNode('8')))),
read_one('(print [7 | 8])'))
self.assertEqual(
Forms(
IdentifierNode('print'),
Forms(
ValueNode('_list', specials.list_),
Forms(IdentifierNode('add'), NumericLiteralNode('10'),
NumericLiteralNode('20'))),
), read_one('(print [(add 10 20)])'))
def test_identifier_pattern_match(self):
self._test_pattern('(pattern a)', '10', {'a': 10})
self._test_pattern('(pattern a)', 'nil', {'a': nil})
self._test_pattern('(pattern a)', '[1 2 3]',
{'a': Pair(1, Pair(2, Pair(3, nil)))})
def function_shorthand(arg, scope):
if arg is nil:
return Function(Pair(ValueNode('_default_pattern', default_arguments_pattern_singleton), nil), scope)
assert type(arg) is Pair
return Function(Pair(ValueNode('_default_pattern', default_arguments_pattern_singleton), Pair(FormNode(arg.car, arg.cdr), nil)), scope)
def list_(arg, scope):
if arg is nil:
return nil
if type(arg) is not Pair:
raise Exception('cannot have a cdr without a car')
return Pair(eval_node(arg.car, scope), eval_node(arg.cdr, scope))
def test_defaulted_patterns(self):
self._test_pattern('(pattern [a | b])', '1:2', {'a': 1, 'b': 2})
self._test_pattern('(pattern [a | b])', '[1]', {'a': 1, 'b': nil})
self._test_pattern('(pattern [a | b])', '1:2:3', {
'a': 1,
'b': Pair(2, 3)
})
self._test_pattern_fails('(pattern [a | b])', 'nil')
# This is a somewhat useless pattern -- the default can never be triggered,
# since you can never have a cons cell without a cdr (although nil can be
# thought of as a cons cell without a car).
self._test_pattern('(pattern [a | b = 20])', '1:2', {'a': 1, 'b': 2})
self._test_pattern_fails('(pattern [a | b = 20])', '1')
self._test_pattern_fails('(pattern [a | b = 20])', 'nil')
self._test_pattern('(pattern [a = 10 | b])', '1:2', {'a': 1, 'b': 2})
# THIS IS COUNTER-INTUITIVE.
# At least, it's not what I expected when I first wrote these tests.
# To explain why it works, though, think of it as nothing:nil -- nothing cons nil is
# just nil -- you didn't cons anything onto it, so it didn't change. And you can
# match nothing:nil -- nothing goes to (pattern a = 10), which can accept nothing
# and simply returns its default value. Then nil goes to b. And it works.
self._test_pattern('(pattern [a = 10 | b])', 'nil', {
'a': 10,
'b': nil
})
self._test_pattern_fails('(pattern [a = 10 | b])', '1')
self._test_pattern('(pattern [a = 10 | b = 20])', '1:2', {
'a': 1,
'b': 2
})
# This is equivalent to nothing:nil, as explained above.
self._test_pattern('(pattern [a = 10 | b = 20])', 'nil', {
'a': 10,
'b': nil
})
self._test_pattern_fails('(pattern [a = 10 | b = 20])', '1')
self._test_pattern('(pattern [a = 10 | b = 20]:c)', '[1 | 2]:3', {
'a': 1,
'b': 2,
'c': 3
})
self._test_pattern('(pattern [a = 10 | b = 20]:c)', 'nil', {
'a': 10,
'b': 20,
'c': nil
})
self._test_pattern('(pattern [a b]:c)', '[1 2]:nil', {
'a': 1,
'b': 2,
'c': nil
})
self._test_pattern_fails('(pattern [a = 10 b = 20]:c)', 'nil')
# This is a little weird when you think of it as a list, but if you think of it as a ConsPattern
# whose cdr_pattern is a ConsPattern then this does make sense.
self._test_pattern('(pattern [a = 10 b = 20 | c = 30]:d)', 'nil', {
'a': 10,
'b': 20,
'c': 30,
'd': nil
})
self._test_pattern('(pattern [a b]:c)', '[1 2]:nil', {
'a': 1,
'b': 2,
'c': nil
})
self._test_pattern('(pattern [[a | b] | c])', '[1|2]:3', {
'a': 1,
'b': 2,
'c': 3
})
self._test_pattern_fails('(pattern [[a | b] | c])', '[1|2]')
self._test_pattern_fails('(pattern [[a | b] | c])', '[1]')
self._test_pattern_fails('(pattern [[a | b] | c])', 'nil')
self._test_pattern('(pattern [[a | b] c])', '[1:2 3]', {
'a': 1,
'b': 2,
'c': 3
})
self._test_pattern_fails('(pattern [[a | b] c])', '[1|2]')
self._test_pattern_fails('(pattern [[a | b] c])', '[1 3]')
self._test_pattern_fails('(pattern [[a | b] c])', '[1]')
self._test_pattern_fails('(pattern [[a | b] c])', 'nil')
self._test_pattern('(pattern a::even? = 10)', '7', {'a': 10})
self._test_pattern('(pattern a::even? = 10)', '8', {'a': 8})
self._test_pattern('(pattern [a b = 20])', '[1 2]', {'a': 1, 'b': 2})
self._test_pattern('(pattern [a b = 20])', '[1]', {'a': 1, 'b': 20})
self._test_pattern('(pattern [a b = 20])', '1:2:nil', {'a': 1, 'b': 2})
self._test_pattern_fails('(pattern [a b = 20])', '1:2:3')
self._test_pattern_fails('(pattern [a b = 20])', 'nil')
self._test_pattern('(pattern [a b c = 30])', '[1 2 3]', {
'a': 1,
'b': 2,
'c': 3
})
self._test_pattern('(pattern [a b c = 30])', '[1 2]', {
'a': 1,
'b': 2,
'c': 30
})
self._test_pattern_fails('(pattern [a b c = 30])', '[1]')
self._test_pattern_fails('(pattern [a b c = 30])', 'nil')
self._test_pattern('(pattern [a b = 20 c = 30])', '[1 2 3]', {
'a': 1,
'b': 2,
'c': 3
})
self._test_pattern('(pattern [a b = 20 c = 30])', '[1 2]', {
'a': 1,
'b': 2,
'c': 30
})
self._test_pattern('(pattern [a b = 20 c = 30])', '[1]', {
'a': 1,
'b': 20,
'c': 30
})
self._test_pattern_fails('(pattern [a b = 20 c = 30])', 'nil')
self._test_pattern('(pattern [a = 10 b = 20 c = 30])', '[1 2 3]', {
'a': 1,
'b': 2,
'c': 3
})
self._test_pattern('(pattern [a = 10 b = 20 c = 30])', '[1 2]', {
'a': 1,
'b': 2,
'c': 30
})
self._test_pattern('(pattern [a = 10 b = 20 c = 30])', '[1]', {
'a': 1,
'b': 20,
'c': 30
})
self._test_pattern('(pattern [a = 10 b = 20 c = 30])', 'nil', {
'a': 10,
'b': 20,
'c': 30
})
self._test_pattern_fails('(pattern [a = 10 b = 20 c = 30])', '1')
self._test_pattern('(pattern [a b = 20 []:[]])', '[1 2 nil:nil]', {
'a': 1,
'b': 2
})
self._test_pattern_fails('(pattern [a b = 20 []:[]])', '[1]')
self._test_pattern_fails('(pattern [a b = 20 []:[]])', '[1 2 nil]')
self._test_pattern('(pattern [a b = 20 | []:[]])', '[1 2 | nil:nil]', {
'a': 1,
'b': 2
})
self._test_pattern('(pattern [a b = 20 | []:[]])', '[1 2 nil]', {
'a': 1,
'b': 2
})
self._test_pattern_fails('(pattern [a b = 20 | []:[]])', '[1]')
self._test_pattern_fails('(pattern [a b = 20 | []:[]])', '[1 nil]')
self._test_pattern('(pattern [a b = 20 c])', '[1 2 3]', {
'a': 1,
'b': 2,
'c': 3
})
self._test_pattern('(pattern [a b = 20 c])', '[1 2 nil]', {
'a': 1,
'b': 2,
'c': nil
})
self._test_pattern_fails('(pattern [a b = 20 c])', '[1 2]')
self._test_pattern_fails('(pattern [a b = 20 c])', '[1]')
self._test_pattern_fails('(pattern [a b = 20 c])', 'nil')
self._test_pattern('(pattern [a b = 20 | c = 30])', '[1 2 | 3]', {
'a': 1,
'b': 2,
'c': 3
})
self._test_pattern('(pattern [a b = 20 | c = 30])', '[1 2]', {
'a': 1,
'b': 2,
'c': nil
})
self._test_pattern('(pattern [a b = 20 | c = 30])', '[1]', {
'a': 1,
'b': 20,
'c': nil
}) # counter-intuitive!
self._test_pattern_fails('(pattern [a b = 20 | c = 30])', 'nil')
self._test_pattern('(pattern [a b = 20 | c])', '[1 2 | 3]', {
'a': 1,
'b': 2,
'c': 3
})
self._test_pattern('(pattern [a b = 20 | c])', '[1 2]', {
'a': 1,
'b': 2,
'c': nil
})
self._test_pattern('(pattern [a b = 20 | c])', '[1]', {
'a': 1,
'b': 20,
'c': nil
}) # counter-intuitive!
self._test_pattern_fails('(pattern [a b = 20 | c])', 'nil')
self._test_pattern('(pattern [a b = 20 3])', '[1 2 3]', {
'a': 1,
'b': 2
})
self._test_pattern_fails('(pattern [a b = 20 3])', '[1 2]')
self._test_pattern_fails('(pattern [a b = 20 3])', '[1 3]')
self._test_pattern_fails('(pattern [a b = 20 3])', '[1]')
self._test_pattern_fails('(pattern [a b = 20 3])', 'nil')
self._test_pattern('(pattern [a b = 20 | 3])', '[1 2 | 3]', {
'a': 1,
'b': 2
})
self._test_pattern_fails('(pattern [a b = 20 | 3])', '[1 2]')
self._test_pattern_fails('(pattern [a b = 20 | 3])', '[1 3]')
self._test_pattern_fails('(pattern [a b = 20 | 3])', '[1 | 2]')
self._test_pattern_fails('(pattern [a b = 20 | 3])', '[1 | 3]')
self._test_pattern_fails('(pattern [a b = 20 | 3])', '[1]')
self._test_pattern_fails('(pattern [a b = 20 | 3])', 'nil')
self._test_pattern('(pattern [a b = 20 []])', '[1 2 nil]', {
'a': 1,
'b': 2
})
self._test_pattern('(pattern [a b = 20 []])', '[1 nil nil]', {
'a': 1,
'b': nil
})
self._test_pattern_fails('(pattern [a b = 20 []])', '[1 nil]')
self._test_pattern_fails('(pattern [a b = 20 []])', '[1]')
self._test_pattern_fails('(pattern [a b = 20 []])', 'nil')
self._test_pattern('(pattern [a b = 20 | []])', '[1 2]', {
'a': 1,
'b': 2
})
self._test_pattern('(pattern [a b = 20 | []])', '[1]', {
'a': 1,
'b': 20
})
self._test_pattern_fails('(pattern [a b = 20 | []])', '[1 2 nil]')
