public long parseAsLong(String input) throws ExpressionException {
		ExpressionValue expressionValue = parse(input);
		if (expressionValue instanceof LongExpressionValue longValue) {
			return longValue.getLongValue();
		}
		throw new ExpressionException("Expression did not evalute to a long! Got a " +
			expressionValue.getClass() + " instead.");
	}
Parses the given expression input, expecting the result to be long value.
@param input the expression string
@return the long value result.
@throws ExpressionException if the expression could not be evaluated to a long value.
Ghidra/Framework/Generic/src/main/java/generic/expressions/ExpressionEvaluator.java