desc = "Evaluate a mathematical expression"
)
public void calc(Actor actor, @Text String input) throws CommandException {
try {
Expression expression = Expression.compile(input);
actor.print("= " + expression.evaluate());
} catch (EvaluationException e) {
actor.printError(String.format(
"'%s' could not be parsed as a valid expression", input));
} catch (ExpressionException e) {
actor.printError(String.format(