from bulletml.errors import Error
+__all__ = ["ExprError", "NumberDef", "INumberDef"]
+
class ExprError(Error):
"""Raised when an invalid expression is evaluated/compiled."""
pass
"""BulletML numeric expression.
This translates BulletML numeric expressions into Python expressions.
- The
Examples:
35
expr = expr.string
except AttributeError:
pass
- self.string = expr
+ try:
+ if "__" in expr:
+ # nedbatchelder.com/blog/201206/eval_really_is_dangerous.html
+ raise ExprError(expr)
+ except TypeError:
+ pass
+ self.string = expr = str(expr)
repl = lambda match: "params[%d]" % (int(match.group()[1:]) - 1)
expr = re.sub(r"\$\d+", repl, expr.lower())
self.__expr = expr.replace("$rand", "random()").replace("$rank", "rank")
if not isinstance(value, (int, float)):
raise TypeError(expr)
self._value = None
+ self.expr = self.string
+ else:
+ self.expr = self._value
except Exception:
raise ExprError(expr)
self.__expr = compile(self.__expr, __file__, "eval")
return eval(self.__expr, self.GLOBALS, variables)
def __repr__(self):
- return "%s(%r)" % (type(self).__name__, self.string)
+ return "%s(%r)" % (type(self).__name__, self.expr)
class INumberDef(NumberDef):
"""A NumberDef, but returns rounded integer results."""
self._value = int(round(self._value))
def __call__(self, params, rank):
+ # Avoid int(round(__call__())) overhead for constants.
if self._value is not None:
return self._value
return int(round(super(INumberDef, self).__call__(params, rank)))