| // 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 := 0; i < len(es); i++ { |
| e := es[i]; |
| 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 := range l.Iter() { |
| if i, ok := e.(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); |
| } |