package main
-// Stack is a simple implementation of a LIFO stack
+// Stack is a simple implementation of a LIFO stack for text events
type Stack struct {
- top *Element
- size int
+ Top *Element
+ Size int
}
// An Element which is stored in the Stack
type Element struct {
- value interface{} // All types satisfy the empty interface, so we can store anything here.
- next *Element
+ Value *TextEvent
+ Next *Element
}
// Len returns the stack's length
func (s *Stack) Len() int {
- return s.size
+ return s.Size
}
// Push a new element onto the stack
-func (s *Stack) Push(value interface{}) {
- s.top = &Element{value, s.top}
- s.size++
+func (s *Stack) Push(value *TextEvent) {
+ s.Top = &Element{value, s.Top}
+ s.Size++
}
// Pop removes the top element from the stack and returns its value
// If the stack is empty, return nil
-func (s *Stack) Pop() (value interface{}) {
- if s.size > 0 {
- value, s.top = s.top.value, s.top.next
- s.size--
+func (s *Stack) Pop() (value *TextEvent) {
+ if s.Size > 0 {
+ value, s.Top = s.Top.Value, s.Top.Next
+ s.Size--
return
}
return nil
}
// Peek returns the top element of the stack without removing it
-func (s *Stack) Peek() interface{} {
- if s.size > 0 {
- return s.top.value
+func (s *Stack) Peek() *TextEvent {
+ if s.Size > 0 {
+ return s.Top.Value
}
return nil
}