44 lines
835 B
Go
44 lines
835 B
Go
package main
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// Stack is a simple implementation of a LIFO stack for text events
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type Stack struct {
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Top *Element
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Size int
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}
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// An Element which is stored in the Stack
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type Element struct {
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Value *TextEvent
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Next *Element
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}
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// Len returns the stack's length
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func (s *Stack) Len() int {
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return s.Size
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}
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// Push a new element onto the stack
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func (s *Stack) Push(value *TextEvent) {
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s.Top = &Element{value, s.Top}
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s.Size++
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}
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// Pop removes the top element from the stack and returns its value
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// If the stack is empty, return nil
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func (s *Stack) Pop() (value *TextEvent) {
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if s.Size > 0 {
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value, s.Top = s.Top.Value, s.Top.Next
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s.Size--
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return
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}
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return nil
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}
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// Peek returns the top element of the stack without removing it
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func (s *Stack) Peek() *TextEvent {
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if s.Size > 0 {
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return s.Top.Value
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}
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return nil
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}
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