demonstrate LLL features used by vyper

lll_features.vy

# example contract demonstrating LLL features

x: public(uint256)
y: public(Bytes[32])
z: public(int128)
w: public(bool)

@external
def __init__(x: uint256, y: Bytes[32], z: int128, w: bool):
    self.x = x
    self.y = y
    self.z = z
    self.w = w

@internal
def _branch(x: uint256, y: Bytes[32], z: bool) -> uint256:
    if z:
        self.y = slice(y, 0, x)
        return 1
    else:
        return 0

@internal
def _loop(x: uint256):
    for i in range(3):
        self.x += i

@external
def branch(x: uint256, y: Bytes[32], z: bool) -> uint256:
    if z:
        self.y = slice(y, 0, x)
        return 1
    else:
        return 0

@external
def do_stuff():
    self._loop(self._branch(self.x, self.y, self.z >= 0))

@external
def external_no_args_no_return():
    pass

@external
def external_kwargs(x: uint256 = 7):
    pass

@external
def external_int_marshalling(x: uint256) -> uint256:
    return x

@external
@nonreentrant("key")
def external_nonreentrant():
    pass

@external
def external_bytes_marshalling(x: Bytes[33]) -> Bytes[33]:
    return x

@internal
def internal_no_args_no_return():
    pass

@internal
def internal_kwargs(x: uint256 = 7):
    pass

@internal
def internal_int_marshalling(x: uint256) -> uint256:
    return x

@internal
def internal_nonreentrant():
    pass

@internal
def internal_bytes_marshalling(x: Bytes[33]) -> Bytes[33]:
    return x