func (e IndexExp) ProcessVar(p VarProcessor) {
	p.ProcessIndexExpVar(e)
}
ProcessVar uses the given VarProcessor to process the receiver.
package ast
type IndexExp struct {
	Location
	Coll ExpNode
	Idx  ExpNode
}
var _ Var = IndexExp{}
func NewIndexExp(coll ExpNode, idx ExpNode) IndexExp {
	return IndexExp{
		Location: MergeLocations(coll, idx),  
		Coll:     coll,
		Idx:      idx,
	}
}
func (e IndexExp) ProcessExp(p ExpProcessor) {
	p.ProcessIndexExp(e)
}