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-rwxr-xr-xlibgo/go/container/list/list.go211
-rwxr-xr-xlibgo/go/container/list/list_test.go209
2 files changed, 420 insertions, 0 deletions
diff --git a/libgo/go/container/list/list.go b/libgo/go/container/list/list.go
new file mode 100755
index 000000000..c1ebcddaa
--- /dev/null
+++ b/libgo/go/container/list/list.go
@@ -0,0 +1,211 @@
+// Copyright 2009 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// The list package implements a doubly linked list.
+//
+// To iterate over a list (where l is a *List):
+// for e := l.Front(); e != nil; e = e.Next() {
+// // do something with e.Value
+// }
+//
+package list
+
+// Element is an element in the linked list.
+type Element struct {
+ // Next and previous pointers in the doubly-linked list of elements.
+ // The front of the list has prev = nil, and the back has next = nil.
+ next, prev *Element
+
+ // The list to which this element belongs.
+ list *List
+
+ // The contents of this list element.
+ Value interface{}
+}
+
+// Next returns the next list element or nil.
+func (e *Element) Next() *Element { return e.next }
+
+// Prev returns the previous list element or nil.
+func (e *Element) Prev() *Element { return e.prev }
+
+// List represents a doubly linked list.
+// The zero value for List is an empty list ready to use.
+type List struct {
+ front, back *Element
+ len int
+}
+
+// Init initializes or clears a List.
+func (l *List) Init() *List {
+ l.front = nil
+ l.back = nil
+ l.len = 0
+ return l
+}
+
+// New returns an initialized list.
+func New() *List { return new(List) }
+
+// Front returns the first element in the list.
+func (l *List) Front() *Element { return l.front }
+
+// Back returns the last element in the list.
+func (l *List) Back() *Element { return l.back }
+
+// Remove removes the element from the list
+// and returns its Value.
+func (l *List) Remove(e *Element) interface{} {
+ l.remove(e)
+ e.list = nil // do what remove does not
+ return e.Value
+}
+
+// remove the element from the list, but do not clear the Element's list field.
+// This is so that other List methods may use remove when relocating Elements
+// without needing to restore the list field.
+func (l *List) remove(e *Element) {
+ if e.list != l {
+ return
+ }
+ if e.prev == nil {
+ l.front = e.next
+ } else {
+ e.prev.next = e.next
+ }
+ if e.next == nil {
+ l.back = e.prev
+ } else {
+ e.next.prev = e.prev
+ }
+
+ e.prev = nil
+ e.next = nil
+ l.len--
+}
+
+func (l *List) insertBefore(e *Element, mark *Element) {
+ if mark.prev == nil {
+ // new front of the list
+ l.front = e
+ } else {
+ mark.prev.next = e
+ }
+ e.prev = mark.prev
+ mark.prev = e
+ e.next = mark
+ l.len++
+}
+
+func (l *List) insertAfter(e *Element, mark *Element) {
+ if mark.next == nil {
+ // new back of the list
+ l.back = e
+ } else {
+ mark.next.prev = e
+ }
+ e.next = mark.next
+ mark.next = e
+ e.prev = mark
+ l.len++
+}
+
+func (l *List) insertFront(e *Element) {
+ if l.front == nil {
+ // empty list
+ l.front, l.back = e, e
+ e.prev, e.next = nil, nil
+ l.len = 1
+ return
+ }
+ l.insertBefore(e, l.front)
+}
+
+func (l *List) insertBack(e *Element) {
+ if l.back == nil {
+ // empty list
+ l.front, l.back = e, e
+ e.prev, e.next = nil, nil
+ l.len = 1
+ return
+ }
+ l.insertAfter(e, l.back)
+}
+
+// PushFront inserts the value at the front of the list and returns a new Element containing the value.
+func (l *List) PushFront(value interface{}) *Element {
+ e := &Element{nil, nil, l, value}
+ l.insertFront(e)
+ return e
+}
+
+// PushBack inserts the value at the back of the list and returns a new Element containing the value.
+func (l *List) PushBack(value interface{}) *Element {
+ e := &Element{nil, nil, l, value}
+ l.insertBack(e)
+ return e
+}
+
+// InsertBefore inserts the value immediately before mark and returns a new Element containing the value.
+func (l *List) InsertBefore(value interface{}, mark *Element) *Element {
+ if mark.list != l {
+ return nil
+ }
+ e := &Element{nil, nil, l, value}
+ l.insertBefore(e, mark)
+ return e
+}
+
+// InsertAfter inserts the value immediately after mark and returns a new Element containing the value.
+func (l *List) InsertAfter(value interface{}, mark *Element) *Element {
+ if mark.list != l {
+ return nil
+ }
+ e := &Element{nil, nil, l, value}
+ l.insertAfter(e, mark)
+ return e
+}
+
+// MoveToFront moves the element to the front of the list.
+func (l *List) MoveToFront(e *Element) {
+ if e.list != l || l.front == e {
+ return
+ }
+ l.remove(e)
+ l.insertFront(e)
+}
+
+// MoveToBack moves the element to the back of the list.
+func (l *List) MoveToBack(e *Element) {
+ if e.list != l || l.back == e {
+ return
+ }
+ l.remove(e)
+ l.insertBack(e)
+}
+
+// Len returns the number of elements in the list.
+func (l *List) Len() int { return l.len }
+
+// PushBackList inserts each element of ol at the back of the list.
+func (l *List) PushBackList(ol *List) {
+ last := ol.Back()
+ for e := ol.Front(); e != nil; e = e.Next() {
+ l.PushBack(e.Value)
+ if e == last {
+ break
+ }
+ }
+}
+
+// PushFrontList inserts each element of ol at the front of the list. The ordering of the passed list is preserved.
+func (l *List) PushFrontList(ol *List) {
+ first := ol.Front()
+ for e := ol.Back(); e != nil; e = e.Prev() {
+ l.PushFront(e.Value)
+ if e == first {
+ break
+ }
+ }
+}
diff --git a/libgo/go/container/list/list_test.go b/libgo/go/container/list/list_test.go
new file mode 100755
index 000000000..1d44ff84e
--- /dev/null
+++ b/libgo/go/container/list/list_test.go
@@ -0,0 +1,209 @@
+// Copyright 2009 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package list
+
+import (
+ "testing"
+)
+
+func checkListPointers(t *testing.T, l *List, es []*Element) {
+ if len(es) == 0 {
+ if l.front != nil || l.back != nil {
+ t.Errorf("l.front/l.back = %v/%v should be nil/nil", l.front, l.back)
+ }
+ return
+ }
+
+ if l.front != es[0] {
+ t.Errorf("l.front = %v, want %v", l.front, es[0])
+ }
+ if last := es[len(es)-1]; l.back != last {
+ t.Errorf("l.back = %v, want %v", l.back, last)
+ }
+
+ for i, e := range es {
+ var e_prev, e_next *Element = nil, nil
+ if i > 0 {
+ e_prev = es[i-1]
+ }
+ if i < len(es)-1 {
+ e_next = es[i+1]
+ }
+ if e.prev != e_prev {
+ t.Errorf("elt #%d (%v) has prev=%v, want %v", i, e, e.prev, e_prev)
+ }
+ if e.next != e_next {
+ t.Errorf("elt #%d (%v) has next=%v, want %v", i, e, e.next, e_next)
+ }
+ }
+}
+
+func checkListLen(t *testing.T, l *List, n int) {
+ if an := l.Len(); an != n {
+ t.Errorf("l.Len() = %d, want %d", an, n)
+ }
+}
+
+func TestList(t *testing.T) {
+ l := New()
+ checkListPointers(t, l, []*Element{})
+ checkListLen(t, l, 0)
+
+ // Single element list
+ e := l.PushFront("a")
+ checkListLen(t, l, 1)
+ checkListPointers(t, l, []*Element{e})
+ l.MoveToFront(e)
+ checkListPointers(t, l, []*Element{e})
+ l.MoveToBack(e)
+ checkListPointers(t, l, []*Element{e})
+ checkListLen(t, l, 1)
+ l.Remove(e)
+ checkListPointers(t, l, []*Element{})
+ checkListLen(t, l, 0)
+
+ // Bigger list
+ e2 := l.PushFront(2)
+ e1 := l.PushFront(1)
+ e3 := l.PushBack(3)
+ e4 := l.PushBack("banana")
+ checkListPointers(t, l, []*Element{e1, e2, e3, e4})
+ checkListLen(t, l, 4)
+
+ l.Remove(e2)
+ checkListPointers(t, l, []*Element{e1, e3, e4})
+ checkListLen(t, l, 3)
+
+ l.MoveToFront(e3) // move from middle
+ checkListPointers(t, l, []*Element{e3, e1, e4})
+
+ l.MoveToFront(e1)
+ l.MoveToBack(e3) // move from middle
+ checkListPointers(t, l, []*Element{e1, e4, e3})
+
+ l.MoveToFront(e3) // move from back
+ checkListPointers(t, l, []*Element{e3, e1, e4})
+ l.MoveToFront(e3) // should be no-op
+ checkListPointers(t, l, []*Element{e3, e1, e4})
+
+ l.MoveToBack(e3) // move from front
+ checkListPointers(t, l, []*Element{e1, e4, e3})
+ l.MoveToBack(e3) // should be no-op
+ checkListPointers(t, l, []*Element{e1, e4, e3})
+
+ e2 = l.InsertBefore(2, e1) // insert before front
+ checkListPointers(t, l, []*Element{e2, e1, e4, e3})
+ l.Remove(e2)
+ e2 = l.InsertBefore(2, e4) // insert before middle
+ checkListPointers(t, l, []*Element{e1, e2, e4, e3})
+ l.Remove(e2)
+ e2 = l.InsertBefore(2, e3) // insert before back
+ checkListPointers(t, l, []*Element{e1, e4, e2, e3})
+ l.Remove(e2)
+
+ e2 = l.InsertAfter(2, e1) // insert after front
+ checkListPointers(t, l, []*Element{e1, e2, e4, e3})
+ l.Remove(e2)
+ e2 = l.InsertAfter(2, e4) // insert after middle
+ checkListPointers(t, l, []*Element{e1, e4, e2, e3})
+ l.Remove(e2)
+ e2 = l.InsertAfter(2, e3) // insert after back
+ checkListPointers(t, l, []*Element{e1, e4, e3, e2})
+ l.Remove(e2)
+
+ // Check standard iteration.
+ sum := 0
+ for e := l.Front(); e != nil; e = e.Next() {
+ if i, ok := e.Value.(int); ok {
+ sum += i
+ }
+ }
+ if sum != 4 {
+ t.Errorf("sum over l.Iter() = %d, want 4", sum)
+ }
+
+ // Clear all elements by iterating
+ var next *Element
+ for e := l.Front(); e != nil; e = next {
+ next = e.Next()
+ l.Remove(e)
+ }
+ checkListPointers(t, l, []*Element{})
+ checkListLen(t, l, 0)
+}
+
+func checkList(t *testing.T, l *List, es []interface{}) {
+ if l.Len() != len(es) {
+ t.Errorf("list has len=%v, want %v", l.Len(), len(es))
+ return
+ }
+ i := 0
+ for e := l.Front(); e != nil; e = e.Next() {
+ le := e.Value.(int)
+ if le != es[i] {
+ t.Errorf("elt #%d has value=%v, want %v", i, le, es[i])
+ }
+ i++
+ }
+}
+
+func TestExtending(t *testing.T) {
+ l1 := New()
+ l2 := New()
+
+ l1.PushBack(1)
+ l1.PushBack(2)
+ l1.PushBack(3)
+
+ l2.PushBack(4)
+ l2.PushBack(5)
+
+ l3 := New()
+ l3.PushBackList(l1)
+ checkList(t, l3, []interface{}{1, 2, 3})
+ l3.PushBackList(l2)
+ checkList(t, l3, []interface{}{1, 2, 3, 4, 5})
+
+ l3 = New()
+ l3.PushFrontList(l2)
+ checkList(t, l3, []interface{}{4, 5})
+ l3.PushFrontList(l1)
+ checkList(t, l3, []interface{}{1, 2, 3, 4, 5})
+
+ checkList(t, l1, []interface{}{1, 2, 3})
+ checkList(t, l2, []interface{}{4, 5})
+
+ l3 = New()
+ l3.PushBackList(l1)
+ checkList(t, l3, []interface{}{1, 2, 3})
+ l3.PushBackList(l3)
+ checkList(t, l3, []interface{}{1, 2, 3, 1, 2, 3})
+
+ l3 = New()
+ l3.PushFrontList(l1)
+ checkList(t, l3, []interface{}{1, 2, 3})
+ l3.PushFrontList(l3)
+ checkList(t, l3, []interface{}{1, 2, 3, 1, 2, 3})
+
+ l3 = New()
+ l1.PushBackList(l3)
+ checkList(t, l1, []interface{}{1, 2, 3})
+ l1.PushFrontList(l3)
+ checkList(t, l1, []interface{}{1, 2, 3})
+}
+
+func TestRemove(t *testing.T) {
+ l := New()
+ e1 := l.PushBack(1)
+ e2 := l.PushBack(2)
+ checkListPointers(t, l, []*Element{e1, e2})
+ e := l.Front()
+ l.Remove(e)
+ checkListPointers(t, l, []*Element{e2})
+ checkListLen(t, l, 1)
+ l.Remove(e)
+ checkListPointers(t, l, []*Element{e2})
+ checkListLen(t, l, 1)
+}