51 lines
1.0 KiB
Go
51 lines
1.0 KiB
Go
/*
|
|
Package "iterator"
|
|
*/
|
|
package iterator
|
|
|
|
import "fmt"
|
|
|
|
// An iterator over slices.
|
|
type Iterator[T any] struct {
|
|
data []T
|
|
index int
|
|
}
|
|
|
|
// Create a new iterator, over a set of items.
|
|
func New[T any](items []T) Iterator[T] {
|
|
return Iterator[T]{data: items, index: 0}
|
|
}
|
|
|
|
// Returns the current position of the iterator.
|
|
func (i Iterator[T]) Index() int {
|
|
return i.index
|
|
}
|
|
|
|
// Returns true if the iterator has no more items to iterate over.
|
|
func (i Iterator[T]) IsDone() bool {
|
|
return i.index == len(i.data)
|
|
}
|
|
|
|
// Gets the next item in the slice, if one exists. Returns an error if there
|
|
// isn't one.
|
|
func (i Iterator[T]) Peek() (T, error) {
|
|
var null T
|
|
|
|
if i.IsDone() {
|
|
return null, fmt.Errorf("iterator is exhausted")
|
|
}
|
|
|
|
return i.data[i.index], nil
|
|
}
|
|
|
|
// Moves the iterator pointer to the next item. Returns the current item. Fails
|
|
// if there are no more items to iterate over.
|
|
func (i *Iterator[T]) Next() (T, error) {
|
|
if val, err := i.Peek(); err != nil {
|
|
return val, err
|
|
} else {
|
|
i.index++
|
|
return val, nil
|
|
}
|
|
}
|