Attempt at translating MyToken example to viper.

my_token.v.py

# Viper Port of MyToken
# Originally found at https://www.ethereum.org/token

# Public variables of the token
name: public(bytes32)
symbol: public(bytes32)
totalSupply: public(num)
decimals: public(num)
balanceOf: public(num256[address])


def __init__(
        _name: bytes32, _symbol: bytes32, _decimals: num, initialSupply: num):

    self.name = _name
    self.symbol = _symbol
    self.decimals = _decimals
    self.totalSupply = initialSupply
    self.balanceOf[msg.sender] = initialSupply


# Send `_value` tokens to `_to` from your account
def transfer(_to: address, _value: num256):
    assert self.balanceOf[msg.sender] > _value
    assert self.balanceOf[_to] + _value > self.balanceOf[_to]

    self.balanceOf[msg.sender] -= _value  # Subtract from the sender
    self.balanceOf[_to] += _value  # Add the same to the recipient