// Aggregation Function name constants
const (
	aggFnAvg   FuncName = "AVG"
	aggFnCount FuncName = "COUNT"
	aggFnMax   FuncName = "MAX"
	aggFnMin   FuncName = "MIN"
	aggFnSum   FuncName = "SUM"
)

var (
	errNonNumericArg = func(fnStr FuncName) error {
		return fmt.Errorf("%s() requires a numeric argument", fnStr)
	}
	errInvalidAggregation = errors.New("Invalid aggregation seen")
)

type aggVal struct {