return nil, errNotImplemented
	}
}

func coalesce(args []*Value) (res *Value, err error) {
	for _, arg := range args {
		if arg.IsNull() {
			continue
		}
		return arg, nil
	}
	return FromNull(), nil
}

func nullif(v1, v2 *Value) (res *Value, err error) {
	// Handle Null cases
	if v1.IsNull() || v2.IsNull() {
		return v1, nil
	}

	err = inferTypesForCmp(v1, v2)
	if err != nil {

import (
	"fmt"
	"math"
	"strconv"
	"testing"
	"time"
)

// valueBuilders contains one constructor for each value type.
// Values should match if type is the same.
var valueBuilders = []func() *Value{
	FromNull,
	func() *Value {
		return FromBool(true)
	},
	func() *Value {
		return FromBytes([]byte("byte contents"))
	},
	func() *Value {
		return FromFloat(math.Pi)
	},
	func() *Value {

			return nil, err
		}
		bs, err := elems.MarshalJSON()
		if err != nil {
			return nil, err
		}
		return FromBytes(bs), nil
	case []Value:
		return FromArray(rval), nil
	case nil:
		return FromNull(), nil
	case Missing:
		return FromMissing(), nil
	}
	return nil, fmt.Errorf("Unhandled value type: %T", result)
}

func (e *PrimaryTerm) evalNode(r Record, tableAlias string) (res *Value, err error) {

	return &Value{value: b}
}

// FromTimestamp creates a Value from a timestamp
func FromTimestamp(t time.Time) *Value {
	return &Value{value: t}
}

// FromNull creates a Value with Null value
func FromNull() *Value {
	return &Value{value: nil}
}

// FromMissing creates a Value with Missing value
func FromMissing() *Value {
	return &Value{value: Missing{}}
}