Method valueVarAggregation

query/query.go:1262–1377

(doneVars map[string]varValue, path []*SubGraph,
	parent *SubGraph)

}

func (sg *SubGraph) valueVarAggregation(doneVars map[string]varValue, path []*SubGraph,
	parent *SubGraph) error {
	if !sg.IsInternal() && !sg.IsGroupBy() && !sg.Params.IsEmpty {
		return nil
	}

	// Aggregation function won't be present at root.
	if sg.Params.IsEmpty && parent == nil {
		return nil
	}

	switch {
	case sg.IsGroupBy():
		if err := sg.processGroupBy(doneVars, path); err != nil {
			return err
		}
	case sg.SrcFunc != nil && !parent.IsGroupBy() && isAggregatorFn(sg.SrcFunc.Name):
		// Aggregate the value over level.
		mp, err := evalLevelAgg(doneVars, sg, parent)
		if err != nil {
			return err
		}
		if sg.Params.Var != "" {
			it := doneVars[sg.Params.Var]
			it.Vals = mp
			doneVars[sg.Params.Var] = it
		}
		sg.Params.UidToVal = mp
	case sg.MathExp != nil:
		// Preprocess to bring all variables to the same level.
		err := sg.transformVars(doneVars, path)
		if err != nil {
			return err
		}

		err = evalMathTree(sg.MathExp)
		if err != nil {
			return err
		}

		switch {
		case sg.MathExp.Val.Len() != 0:
			it := doneVars[sg.Params.Var]
			var isInt, isFloat bool
			err := sg.MathExp.Val.Iterate(func(k uint64, v types.Val) error {
				if v.Tid == types.FloatID {
					isFloat = true
				}
				if v.Tid == types.IntID {
					isInt = true
				}
				return nil
			})
			if err != nil {
				return err
			}
			if isInt && isFloat {
				err := sg.MathExp.Val.Iterate(func(k uint64, v types.Val) error {