def __getitem__(self, name: Token):
if name.lexeme in self.memory:
return self.memory[name.lexeme]
if self.parent is not None:
return self.parent[name]
raise PyLOXRuntimeError(
name, "{name} is not defined in the current "
"environment".format(name=name.lexeme))
def assign(self, name: Token, value: object) -> None:
if name.lexeme not in self.memory:
if self.parent is not None:
self.parent.assign(name, value)
return
raise PyLOXRuntimeError(
name, "{name} is not defined in the current"
" environment".format(name=name.lexeme))
self.memory[name.lexeme] = value
def addition(self, operator: Token, lhs: object, rhs: object) -> object:
if isinstance(lhs, float) and isinstance(rhs, float):
return lhs + rhs
if isinstance(lhs, str) and isinstance(rhs, str):
return lhs + rhs
raise PyLOXRuntimeError(
operator, "PLUS was expecting (float, float) or "
"(str, str) instead found ({lhs}, "
"{rhs})".format(lhs=type(lhs), rhs=type(rhs)))
def wrapped(self, operator, *args):
for expected_type, arg in zip(types, args):
if type(arg) != expected_type:
received_type_message = format_type(type(arg) for arg in args)
raise PyLOXRuntimeError(
operator, "{operator} was expecting "
"{expected} instead received "
"{given}".format(operator=operator.type,
expected=expected_type_message,
given=received_type_message))
return fn(self, operator, *args)
def division(self, operator: Token, lhs: float, rhs: float) -> float:
if rhs == 0:
raise PyLOXRuntimeError(operator, "Zero division error")
return lhs / rhs
def not_implemented(self, operator, *args) -> None:
raise PyLOXRuntimeError(
operator, "unary operator {operator} is not "
"implemented".format(operator=operator))
def visit_break(self, stmt: Break):
raise PyLOXRuntimeError(stmt.token, "break statement seen outside of "
"a loop")