func (i *Iter) SetInput(s []byte) {
	i.bytes = s
	i.str = ""
	i.Reset(0)
}
SetInput resets i to input s.
package colltab
type Iter struct {
	Weighter Weighter
	Elems    []Elem
	N int
	bytes []byte
	str   string
	pEnd  int  
	pNext int  
}
func (i *Iter) Reset(p int) {
	i.Elems = i.Elems[:0]
	i.N = 0
	i.pEnd = p
	i.pNext = p
}
func (i *Iter) Len() int {
	if i.bytes != nil {
		return len(i.bytes)
	}
	return len(i.str)
}
func (i *Iter) Discard() {
	i.Elems = i.Elems[:copy(i.Elems, i.Elems[i.N:])]
	i.N = 0
}
func (i *Iter) End() int {
	return i.pEnd
}