1// Copyright (c) 2015, Emir Pasic. All rights reserved.
2// Use of this source code is governed by a BSD-style
3// license that can be found in the LICENSE file.
4
5package treebidimap
6
7import (
8	"github.com/emirpasic/gods/containers"
9	rbt "github.com/emirpasic/gods/trees/redblacktree"
10)
11
12func assertIteratorImplementation() {
13	var _ containers.ReverseIteratorWithKey = (*Iterator)(nil)
14}
15
16// Iterator holding the iterator's state
17type Iterator struct {
18	iterator rbt.Iterator
19}
20
21// Iterator returns a stateful iterator whose elements are key/value pairs.
22func (m *Map) Iterator() Iterator {
23	return Iterator{iterator: m.forwardMap.Iterator()}
24}
25
26// Next moves the iterator to the next element and returns true if there was a next element in the container.
27// If Next() returns true, then next element's key and value can be retrieved by Key() and Value().
28// If Next() was called for the first time, then it will point the iterator to the first element if it exists.
29// Modifies the state of the iterator.
30func (iterator *Iterator) Next() bool {
31	return iterator.iterator.Next()
32}
33
34// Prev moves the iterator to the previous element and returns true if there was a previous element in the container.
35// If Prev() returns true, then previous element's key and value can be retrieved by Key() and Value().
36// Modifies the state of the iterator.
37func (iterator *Iterator) Prev() bool {
38	return iterator.iterator.Prev()
39}
40
41// Value returns the current element's value.
42// Does not modify the state of the iterator.
43func (iterator *Iterator) Value() interface{} {
44	return iterator.iterator.Value().(*data).value
45}
46
47// Key returns the current element's key.
48// Does not modify the state of the iterator.
49func (iterator *Iterator) Key() interface{} {
50	return iterator.iterator.Key()
51}
52
53// Begin resets the iterator to its initial state (one-before-first)
54// Call Next() to fetch the first element if any.
55func (iterator *Iterator) Begin() {
56	iterator.iterator.Begin()
57}
58
59// End moves the iterator past the last element (one-past-the-end).
60// Call Prev() to fetch the last element if any.
61func (iterator *Iterator) End() {
62	iterator.iterator.End()
63}
64
65// First moves the iterator to the first element and returns true if there was a first element in the container.
66// If First() returns true, then first element's key and value can be retrieved by Key() and Value().
67// Modifies the state of the iterator
68func (iterator *Iterator) First() bool {
69	return iterator.iterator.First()
70}
71
72// Last moves the iterator to the last element and returns true if there was a last element in the container.
73// If Last() returns true, then last element's key and value can be retrieved by Key() and Value().
74// Modifies the state of the iterator.
75func (iterator *Iterator) Last() bool {
76	return iterator.iterator.Last()
77}
78