typechecker state committer has incorrect behavior for nested loops

[charles-cooper]

Version Information

What's your issue about?

per @trocher - as of 66930fd, this does not compile:

@external
def foo():
    for i in [1]:
        a:uint256 = i
        b:uint16 = i

while this compiles:

@external
def foo():
    for i in [1]:
        for j in [1]:
            a:uint256 = i
        b:uint16 = i

or this outputs an AssertionError: unreachable, uint256 != uint16:

@external
def foo():
    for i in [1,2,3]:
        for j in [1,2,3]:
            b:uint256 = j + i
        c:uint16 = i

How can it be fixed?

Fill this in if you know how to fix it.

[charles-cooper]

fixed in #3375, see:

vyper/tests/functional/semantics/analysis/test_for_loop.py

Lines 104 to 142 in 7c3cf61

	iterator_inference_codes = [
	"""
	@external
	def main():
	for j in range(3):
	x: uint256 = j
	y: uint16 = j
	""", # issue 3212
	"""
	@external
	def foo():
	for i in [1]:
	a:uint256 = i
	b:uint16 = i
	""", # issue 3374
	"""
	@external
	def foo():
	for i in [1]:
	for j in [1]:
	a:uint256 = i
	b:uint16 = i
	""", # issue 3374
	"""
	@external
	def foo():
	for i in [1,2,3]:
	for j in [1,2,3]:
	b:uint256 = j + i
	c:uint16 = i
	""", # issue 3374
	]
	@pytest.mark.parametrize("code", iterator_inference_codes)
	def test_iterator_type_inference_checker(namespace, code):
	vyper_module = parse_to_ast(code)
	with pytest.raises(TypeMismatch):
	validate_semantics(vyper_module, {})