switch funcName {
	case sqlFnCast:
		return e.Cast.Expr.analyze(s)

	case sqlFnExtract:
		return e.Extract.From.analyze(s)

	case sqlFnDateAdd:
		result.combine(e.DateAdd.Quantity.analyze(s))
		result.combine(e.DateAdd.Timestamp.analyze(s))
		return result

	case sqlFnDateDiff:
		result.combine(e.DateDiff.Timestamp1.analyze(s))
		result.combine(e.DateDiff.Timestamp2.analyze(s))