alias operators: '<<' same as '<+', '>>' same as '+>'. Insert and append operation optimized with linked lists

kern/linked-list.go

@@ -0,0 +1,273 @@
+// simple-list project slist.go
+package kern
+
+import (
+	"fmt"
+)
+
+type ListNode struct {
+	data any
+	next *ListNode
+}
+
+func (node *ListNode) Next() *ListNode {
+	return node.next
+}
+
+func (self *ListNode) Data() any {
+	return self.data
+}
+
+type LinkedList struct {
+	count uint32
+	first *ListNode
+	last  *ListNode
+}
+
+func NewLinkedList() (list *LinkedList) {
+	list = &LinkedList{0, nil, nil}
+	return
+}
+
+func (ls *LinkedList) Len() uint32 {
+	return ls.count
+}
+
+func (ls *LinkedList) Empty() bool {
+	return ls.count == 0
+}
+
+func (ls *LinkedList) PushFront(data any) *ListNode {
+	ls.first = &ListNode{data, ls.first}
+	if ls.last == nil {
+		ls.last = ls.first
+	}
+	ls.count++
+	return ls.first
+}
+
+func (ls *LinkedList) SeqPushFront(data any) (result *LinkedList) {
+	switch seq := data.(type) {
+	case Iterator:
+		result = ls.IterPushFront(seq)
+	default:
+		ls.PushFront(data)
+		result = ls
+	}
+	return
+}
+
+func (ls *LinkedList) IterPushFront(it Iterator) *LinkedList {
+	for item, err1 := it.Next(); err1 == nil; item, err1 = it.Next() {
+		ls.PushFront(item)
+	}
+	return ls
+}
+
+func (ls *LinkedList) PushBack(data any) (node *ListNode) {
+	node = &ListNode{data, nil}
+	if ls.last != nil {
+		ls.last.next = node
+	}
+	ls.last = node
+	if ls.first == nil {
+		ls.first = node
+	}
+	ls.count++
+	return
+}
+
+func (ls *LinkedList) SeqPushBack(data any) (result *LinkedList) {
+	switch seq := data.(type) {
+	case Iterator:
+		result = ls.IterPushBack(seq)
+	default:
+		ls.PushBack(data)
+		result = ls
+	}
+	return
+}
+
+func (ls *LinkedList) IterPushBack(it Iterator) *LinkedList {
+	for item, err1 := it.Next(); err1 == nil; item, err1 = it.Next() {
+		ls.PushBack(item)
+	}
+	return ls
+}
+
+func (ls *LinkedList) FirstNode() *ListNode {
+	return ls.first
+}
+
+func (ls *LinkedList) First() (data any, err error) {
+	if ls.first != nil {
+		data = ls.first.data
+	} else {
+		err = errorListEmpty()
+	}
+	return
+}
+
+func (ls *LinkedList) LastNode() *ListNode {
+	return ls.last
+}
+
+func (ls *LinkedList) Last() (data interface{}, err error) {
+	if ls.last != nil {
+		data = ls.last.data
+	} else {
+		err = errorListEmpty()
+	}
+	return
+}
+
+func (ls *LinkedList) NodeAt(index uint32) (node *ListNode, err error) {
+	if ls.count == 0 {
+		err = errorListEmpty()
+	} else if index > ls.count {
+		err = errorOutOfRange()
+	} else if index == ls.count-1 {
+		node = ls.last
+	} else {
+		current := ls.first
+		for pos := uint32(0); pos < index; pos++ {
+			current = current.next
+		}
+		node = current
+	}
+	return
+}
+
+func (ls *LinkedList) At(index uint32) (data interface{}, err error) {
+	node, err := ls.NodeAt(index)
+	if err == nil {
+		data = node.data
+	}
+	return
+}
+
+func (ls *LinkedList) Insert(index uint32, data interface{}) *ListNode {
+	var prev *ListNode
+
+	prev = nil
+	current := ls.first
+	for pos := uint32(0); current != nil && pos < index; pos++ {
+		prev = current
+		current = current.next
+	}
+
+	node := &ListNode{data, current}
+
+	if prev != nil {
+		prev.next = node
+	}
+
+	if ls.first == current {
+		ls.first = node
+	}
+	if node.next == nil {
+		ls.last = node
+	}
+	ls.count++
+	return node
+}
+
+func (ls *LinkedList) PushBackStringArray(items []string) {
+	for _, v := range items {
+		ls.PushBack(v)
+	}
+}
+
+// type TraverseOperator func(index uint32, elem interface{}, userData interface{}) (err error)
+
+// func (self *LinkedList) Traverse(op TraverseOperator, user_data interface{}) (err error) {
+// 	index := uint32(0)
+// 	for current := self.first; current != nil; current = current.next {
+// 		err = op(index, current.data, user_data)
+// 		if err != nil {
+// 			break
+// 		}
+// 		index++
+// 	}
+// 	return
+// }
+
+// func (self *LinkedList) Traverse2(observer Observer, abortOnError bool) (err error) {
+// 	index := uint32(0)
+// 	for current := self.first; current != nil; current = current.next {
+// 		err = observer.Observe(current, index)
+// 		if err != nil && abortOnError {
+// 			break
+// 		}
+// 		index++
+// 	}
+// 	return
+// }
+
+type EqualFunc func(current, target any) bool
+
+func (ls *LinkedList) FindFirst(eqFunc EqualFunc, targetData any) (targetNode *ListNode) {
+	for current := ls.first; current != nil && targetNode == nil; current = current.next {
+		if eqFunc(current.data, targetData) {
+			targetNode = current
+		}
+	}
+	return
+}
+
+func (ls *LinkedList) FindNext(eqFunc EqualFunc, startNode *ListNode) (targetNode *ListNode) {
+	if startNode != nil {
+		for current := startNode.next; current != nil && targetNode == nil; current = current.next {
+			if eqFunc(current.data, startNode.Data()) {
+				targetNode = current
+			}
+		}
+	}
+	return
+}
+
+// type DataFeeder func(user_data interface{}) interface{}
+// type NodeObserver func(node *ListNode, index uint32, userData interface{})
+
+// func (self *LinkedList) FeedTail(feeder DataFeeder, feederUserData interface{}, observer NodeObserver, observerUserData interface{}) (count uint32) {
+// 	count = 0
+// 	for item := feeder(feederUserData); item != nil; item = feeder(feederUserData) {
+// 		// fmt.Println("Item", count, item)
+// 		node := self.PushBack(item)
+// 		if observer != nil {
+// 			observer(node, count, observerUserData)
+// 		}
+// 		count++
+// 	}
+// 	return
+// }
+
+// func (self *LinkedList) FeedTail2(feeder Feeder, observer Observer, abortOnError bool) (count uint32, err error) {
+// 	count = 0
+// 	// item := feeder.Next()
+// 	for item, err1 := feeder.Next(); item != nil; item, err1 = feeder.Next() {
+// 		if err1 != nil {
+// 			if err == nil {
+// 				err = err1
+// 			}
+// 			if abortOnError {
+// 				break
+// 			}
+// 		}
+// 		// fmt.Println("Item", count, item)
+// 		node := self.PushBack(item)
+// 		if observer != nil {
+// 			observer.Observe(node, count)
+// 		}
+// 		count++
+// 	}
+// 	return
+// }
+
+func errorListEmpty() error {
+	return fmt.Errorf("List is empty")
+}
+
+func errorOutOfRange() error {
+	return fmt.Errorf("Out of range")
+}