Stack in Golang

Introduction

A simple stack can be implemented in GO using

1. container/list package
2. slice

A stack will have below operations:

1. Push
2. Pop
3. Front
4. Size
5. Empty

List Implementation

package main
import (
"container/list"
"fmt"
)
type customStack struct {
stack *list.List
}
func (c *customStack) Push(value string) {
c.stack.PushFront(value)
}
func (c *customStack) Pop() error {
if c.stack.Len() > 0 {
ele := c.stack.Front()
c.stack.Remove(ele)
}
return fmt.Errorf("Pop Error: Stack is empty")
}
func (c *customStack) Front() (string, error) {
if c.stack.Len() > 0 {
if val, ok := c.stack.Front().Value.(string); ok {
return val, nil
}
return "", fmt.Errorf("Peep Error: Stack Datatype is incorrect")
}
return "", fmt.Errorf("Peep Error: Stack is empty")
}
func (c *customStack) Size() int {
return c.stack.Len()
}
func (c *customStack) Empty() bool {
return c.stack.Len() == 0
}
func main() {
customStack := &customStack{
stack: list.New(),
}
fmt.Printf("Push: A\n")
customStack.Push("A")
fmt.Printf("Push: B\n")
customStack.Push("B")
fmt.Printf("Size: %d\n", customStack.Size())
for customStack.Size() > 0 {
frontVal, _ := customStack.Front()
fmt.Printf("Front: %s\n", frontVal)
fmt.Printf("Pop: %s\n", frontVal)
customStack.Pop()
}
fmt.Printf("Size: %d\n", customStack.Size())
}

Output:

Push: A
Push: B
Size: 2
Front: B
Pop: B
Front: A
Pop: A
Size: 0

Slice Implementation

package main
import (
"fmt"
"sync"
)
type customStack struct {
stack []string
lock sync.RWMutex
}
func (c *customStack) Push(name string) {
c.lock.Lock()
defer c.lock.Unlock()
c.stack = append(c.stack, name)
}
func (c *customStack) Pop() error {
len := len(c.stack)
if len > 0 {
c.lock.Lock()
defer c.lock.Unlock()
c.stack = c.stack[:len-1]
return nil
}
return fmt.Errorf("Pop Error: Stack is empty")
}
func (c *customStack) Front() (string, error) {
len := len(c.stack)
if len > 0 {
c.lock.Lock()
defer c.lock.Unlock()
return c.stack[len-1], nil
}
return "", fmt.Errorf("Peep Error: Stack is empty")
}
func (c *customStack) Size() int {
return len(c.stack)
}
func (c *customStack) Empty() bool {
return len(c.stack) == 0
}
func main() {
customStack := &customStack{
stack: make([]string, 0),
}
fmt.Printf("Push: A\n")
customStack.Push("A")
fmt.Printf("Push: B\n")
customStack.Push("B")
fmt.Printf("Size: %d\n", customStack.Size())
for customStack.Size() > 0 {
frontVal, _ := customStack.Front()
fmt.Printf("Front: %s\n", frontVal)
fmt.Printf("Pop: %s\n", frontVal)
customStack.Pop()
}
fmt.Printf("Size: %d\n", customStack.Size())
}

Output:

Push: A
Push: B
Size: 2
Front: B
Pop: B
Front: A
Pop: A
Size: 0