Golang dparval.NewValue函數代碼示例

func (this *FunctionCallLower) Evaluate(item *dparval.Value) (*dparval.Value, error) {
	// first evaluate the argument
	av, err := this.Operands[0].Expr.Evaluate(item)

	// the spec defines this functin to ONLY operate on strings
	// all other types result in NULL
	if err != nil {
		switch err := err.(type) {
		case *dparval.Undefined:
			// undefined returns null
			return dparval.NewValue(nil), nil
		default:
			// any other error return to caller
			return nil, err
		}
	}

	if av.Type() == dparval.STRING {
		avalue := av.Value()
		switch avalue := avalue.(type) {
		case string:
			return dparval.NewValue(strings.ToLower(avalue)), nil
		}
	}
	return dparval.NewValue(nil), nil
}

func TestCount(t *testing.T) {

	dataset := dparval.ValueCollection{
		dparval.NewValue(map[string]interface{}{
			"name":   "marty",
			"status": "alive",
		}),
		dparval.NewValue(map[string]interface{}{
			"name":   "gerald",
			"status": nil,
		}),
		dparval.NewValue(map[string]interface{}{
			"name": "steve",
		}),
	}

	tests := AggregateTestSet{
		// test * (counts all rows)
		{
			NewFunctionCall("COUNT", FunctionArgExpressionList{NewStarFunctionArgExpression()}),
			dparval.NewValue(3.0),
		},
		// test expression (eliminiates null and missing)
		{
			NewFunctionCall("COUNT", FunctionArgExpressionList{NewFunctionArgExpression(NewProperty("status"))}),
			dparval.NewValue(1.0),
		},
	}

	tests.Run(t, dataset)

}

func (this *FunctionCallCeil) Evaluate(item *dparval.Value) (*dparval.Value, error) {
	// first evaluate the argument
	av, err := this.Operands[0].Expr.Evaluate(item)

	// the spec defines this functin to ONLY operate on numeric values
	// all other types result in NULL
	if err != nil {
		switch err := err.(type) {
		case *dparval.Undefined:
			// undefined returns null
			return dparval.NewValue(nil), nil
		default:
			// any other error return to caller
			return nil, err
		}
	}

	if av.Type() == dparval.NUMBER {
		avalue := av.Value()
		switch avalue := avalue.(type) {
		case float64:
			return dparval.NewValue(math.Ceil(avalue)), nil
		}
	}

	return dparval.NewValue(nil), nil
}

func (this *OrOperator) Evaluate(item *dparval.Value) (*dparval.Value, error) {
	var rv interface{}
	var re error
	rv = false
	re = nil
	for _, operand := range this.Operands {
		operandVal, err := operand.Evaluate(item)
		if err != nil {
			switch err := err.(type) {
			case *dparval.Undefined:
				rv = nil
				re = err
				continue
			default:
				// any other error should be returned to caller
				return nil, err
			}
		}
		// now interpret the evaluated value in a boolean context
		operandValVal := operandVal.Value()
		operandBoolVal := ValueInBooleanContext(operandValVal)
		if operandBoolVal == true {
			return dparval.NewValue(true), nil
		} else if operandBoolVal == nil && rv == false {
			rv = operandBoolVal
			re = nil
		}
		// if operandBoolVal is true, do nothing
		// rv starts as true, and should never change back to true
	}
	if re != nil {
		return nil, re
	}
	return dparval.NewValue(rv), re
}

func init() {
	doc := dparval.NewValue(map[string]interface{}{
		"name": "mike",
		"children": []interface{}{
			map[string]interface{}{
				"name": "bob",
			},
			map[string]interface{}{
				"name": "dan",
			},
		},
	})
	doc.SetAttachment("meta", map[string]interface{}{"id": "1"})
	joinerTestData = append(joinerTestData, doc)

	doc = dparval.NewValue(map[string]interface{}{
		"name": "dustin",
		"children": []interface{}{
			map[string]interface{}{
				"name": "mary",
			},
			map[string]interface{}{
				"name": "jane",
			},
		},
	})
	doc.SetAttachment("meta", map[string]interface{}{"id": "2"})
	joinerTestData = append(joinerTestData, doc)
}

func (vi *viewIndex) ValueCount() (int64, query.Error) {
	indexItemChannel := make(catalog.EntryChannel)
	indexWarnChannel := make(query.ErrorChannel)
	indexErrorChannel := make(query.ErrorChannel)

	go vi.ScanRange(catalog.LookupValue{dparval.NewValue(nil)}, catalog.LookupValue{dparval.NewValue(nil)}, catalog.Both, 0, indexItemChannel, indexWarnChannel, indexErrorChannel)

	var err query.Error
	nullCount := int64(0)
	ok := true
	for ok {
		select {
		case _, ok = <-indexItemChannel:
			if ok {
				nullCount += 1
			}
		case _, ok = <-indexWarnChannel:
			// ignore warnings here
		case err, ok = <-indexErrorChannel:
			if err != nil {
				return 0, err
			}
		}
	}

	totalCount, err := ViewTotalRows(vi.bucket.cbbucket, vi.DDocName(), vi.ViewName(), map[string]interface{}{})
	if err != nil {
		return 0, err
	}

	return totalCount - nullCount, nil

}

func (this *FunctionCallLength) Evaluate(item *dparval.Value) (*dparval.Value, error) {
	// first evaluate the argument
	av, err := this.Operands[0].Expr.Evaluate(item)

	// the spec does not define it to operate on missing, so return null
	if err != nil {
		switch err := err.(type) {
		case *dparval.Undefined:
			// undefined returns null
			return dparval.NewValue(nil), nil
		default:
			// any other error return to caller
			return nil, err
		}
	}

	// return the length only if the operand is a string
	if av.Type() == dparval.STRING {
		avalue := av.Value()
		switch avalue := avalue.(type) {
		case string:
			return dparval.NewValue(float64(len(avalue))), nil
		}
	}
	return dparval.NewValue(nil), nil
}

func (this *FunctionCallStrToMillis) Evaluate(item *dparval.Value) (*dparval.Value, error) {
	av, err := this.Operands[0].Expr.Evaluate(item)

	if err != nil {
		switch err := err.(type) {
		case *dparval.Undefined:
			// undefined returns null
			return dparval.NewValue(nil), nil
		default:
			// any other error return to caller
			return nil, err
		}
	}

	val := av.Value()

	switch val := val.(type) {
	case string:
		t, err := strToTime(val)
		if err != nil {
			return nil, fmt.Errorf("Date not in a recognized format.")
		}
		return dparval.NewValue(timeToMillis(t)), nil
	default:
		return dparval.NewValue(nil), nil
	}
}

func (this *FunctionCallMin) UpdateAggregate(group *dparval.Value, item *dparval.Value) error {
	aggregate_key := this.Key()
	currentVal, err := aggregateValue(group, aggregate_key)
	if err != nil {
		return fmt.Errorf("group defaults not set correctly")
	}

	if this.Operands[0].Expr != nil {
		val, err := this.Operands[0].Expr.Evaluate(item)
		val, err = eliminateNullMissing(val, err)
		if err != nil {
			return err
		}
		if val != nil {

			nextVal := val.Value()
			currVal := currentVal.Value()

			if currVal == nil {
				// any value is greater than nil (we eliminated null/mising already)
				setAggregateValue(group, aggregate_key, dparval.NewValue(nextVal))
			} else {
				// check to see
				comp := CollateJSON(nextVal, currVal)
				if comp < 0 {
					setAggregateValue(group, aggregate_key, dparval.NewValue(nextVal))
				}
			}
		}
	}
	return nil
}

func (this *CollectionAnyOperator) Evaluate(item *dparval.Value) (*dparval.Value, error) {
	// first evaluate the over
	ov, err := this.Over.Evaluate(item)
	if err != nil {
		switch err := err.(type) {
		case *dparval.Undefined:
			// spec says return false
			return dparval.NewValue(false), nil
		default:
			// any other error should be returned to caller
			return nil, err
		}
	}

	// see if we're dealing with an array
	if ov.Type() == dparval.ARRAY {
		// by accessing the array contents this way
		// we avoid parsing it
		ok := true
		index := 0
		for ok {
			inner, err := ov.Index(index)
			index = index + 1
			if err != nil {
				switch err := err.(type) {
				case *dparval.Undefined:
					ok = false
				default:
					return nil, err
				}
			} else {
				// duplicate the existing context
				innerContext := item.Duplicate()
				// add this object named as the alias
				innerContext.SetPath(this.As, inner)
				// now evaluate the condition in this new context
				innerResult, err := this.Condition.Evaluate(innerContext)
				if err != nil {
					switch err := err.(type) {
					case *dparval.Undefined:
						// this is not true, keep trying
						continue
					default:
						// any other error should be returned to caller
						return nil, err
					}
				}
				innerResultVal := innerResult.Value()
				// check to see if this value is true
				innerBoolResult := ValueInBooleanContext(innerResultVal)
				if innerBoolResult == true {
					return dparval.NewValue(true), nil
				}
			}
		}
		return dparval.NewValue(false), nil
	}
	return dparval.NewValue(false), nil
}

func (this *FunctionCallMax) DefaultAggregate(group *dparval.Value) error {
	aggregate_key := this.Key()
	currentVal, err := aggregateValue(group, aggregate_key)
	if err != nil {
		currentVal = dparval.NewValue(nil)
		// store this, so that even if all values are eliminated we return null
		setAggregateValue(group, aggregate_key, dparval.NewValue(currentVal))
	}
	return nil
}

func (this *FunctionCallSplit) Evaluate(item *dparval.Value) (*dparval.Value, error) {
	// first evaluate the arguments
	av, err := this.Operands[0].Expr.Evaluate(item)

	if err != nil {
		switch err := err.(type) {
		case *dparval.Undefined:
			// undefined returns null
			return dparval.NewValue(nil), nil
		default:
			// any other error return to caller
			return nil, err
		}

		// FIXME warn if arguments were wrong type?
		if av.Type() != dparval.STRING {
			return dparval.NewValue(nil), nil
		}
	}

	var sep *dparval.Value = nil
	if len(this.Operands) > 1 {
		sep, err = this.Operands[1].Expr.Evaluate(item)
		if err != nil {
			switch err := err.(type) {
			case *dparval.Undefined:
				// undefined returns null
				return dparval.NewValue(nil), nil
			default:
				// any other error return to caller
				return nil, err
			}
		}

		// FIXME warn if arguments were wrong type?
		if sep.Type() != dparval.STRING {
			return dparval.NewValue(nil), nil
		}
	}

	var sa []string
	if sep != nil {
		sa = strings.Split(av.Value().(string),
			sep.Value().(string))
	} else {
		sa = strings.Fields(av.Value().(string))
	}

	rv := make([]interface{}, len(sa))
	for i, s := range sa {
		rv[i] = s
	}

	return dparval.NewValue(rv), nil
}

func (this *InOperator) Evaluate(context *dparval.Value) (*dparval.Value, error) {

	false_result := dparval.NewValue(false)
	true_result := dparval.NewValue(true)

	lv, err := this.Left.Evaluate(context)
	if err != nil {
		return nil, err
	}

	rv, err := this.Right.Evaluate(context)
	if err != nil {
		return nil, err
	}

	lvalue := lv.Value()
	if rv.Type() == dparval.ARRAY {
		ok := true
		index := 0
		for ok {
			inner, err := rv.Index(index)
			index = index + 1
			if err != nil {
				switch err := err.(type) {
				case *dparval.Undefined:
					ok = false
				default:
					return nil, err
				}
			} else {
				if lv.Type() != inner.Type() {
					continue
				} else {
					iv := inner.Value()
					switch lvalue := lvalue.(type) {
					case string:
						if lvalue == iv {
							return true_result, nil
						}
					default:
						if reflect.DeepEqual(lvalue, iv) == true {
							return true_result, nil
						}
					}
				}
			}
		}
	}

	return false_result, nil
}

// sum and avg have same elimination rules, test them together
func TestSumAndAvg(t *testing.T) {

	dataset := dparval.ValueCollection{
		dparval.NewValue(map[string]interface{}{
			"name":  "marty",
			"score": 20.0,
		}),
		dparval.NewValue(map[string]interface{}{
			"name":  "gerald",
			"score": nil,
		}),
		dparval.NewValue(map[string]interface{}{
			"name": "steve",
		}),
		dparval.NewValue(map[string]interface{}{
			"name":  "siri",
			"score": "thirty",
		}),
		dparval.NewValue(map[string]interface{}{
			"name":  "deep",
			"score": 10.0,
		}),
		dparval.NewValue(map[string]interface{}{
			"name":  "ketaki",
			"score": "false",
		}),
		dparval.NewValue(map[string]interface{}{
			"name":  "pratap",
			"score": []interface{}{5.5},
		}),
		dparval.NewValue(map[string]interface{}{
			"name":  "karen",
			"score": map[string]interface{}{"score": 5.5},
		}),
	}

	tests := AggregateTestSet{
		// test expression (eliminiates null and missing)
		{
			NewFunctionCall("SUM", FunctionArgExpressionList{NewFunctionArgExpression(NewProperty("score"))}),
			dparval.NewValue(30.0),
		},
		{
			NewFunctionCall("AVG", FunctionArgExpressionList{NewFunctionArgExpression(NewProperty("score"))}),
			dparval.NewValue(15.0),
		},
	}

	tests.Run(t, dataset)

}

func init() {
	doc := dparval.NewValue(map[string]interface{}{"name": "mike", "age": 100.0})
	doc.SetAttachment("meta", map[string]interface{}{"id": "1"})
	testData = append(testData, doc)

	doc = dparval.NewValue(map[string]interface{}{"name": "dustin"})
	doc.SetAttachment("meta", map[string]interface{}{"id": "1"})
	testData = append(testData, doc)

	doc = dparval.NewValue(map[string]interface{}{"name": "bob", "age": nil})
	doc.SetAttachment("meta", map[string]interface{}{"id": "1"})
	testData = append(testData, doc)

	doc = dparval.NewValue(map[string]interface{}{"name": "marty", "age": 99.0})
	doc.SetAttachment("meta", map[string]interface{}{"id": "1"})
	testData = append(testData, doc)

	doc = dparval.NewValue(map[string]interface{}{"name": "steve", "age": 200.0})
	doc.SetAttachment("meta", map[string]interface{}{"id": "2"})
	testData = append(testData, doc)

	doc = dparval.NewValue(map[string]interface{}{"name": "gerald", "age": 175.0})
	doc.SetAttachment("meta", map[string]interface{}{"id": "3"})
	testData = append(testData, doc)

	doc = dparval.NewValue(map[string]interface{}{"name": "siri", "age": 74.0})
	doc.SetAttachment("meta", map[string]interface{}{"id": "4"})
	testData = append(testData, doc)

	doc = dparval.NewValue(map[string]interface{}{"name": "ali", "age": 100.0})
	doc.SetAttachment("meta", map[string]interface{}{"id": "1"})
	testData = append(testData, doc)
}