init

.gitignore

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+.idea

LICENSE

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+Copyright 2023 Evan Burkey <dev@fputs.com>
+
+Permission to use, copy, modify, and distribute this software for any
+purpose with or without fee is hereby granted, provided that the above
+copyright notice and this permission notice appear in all copies.
+
+THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.

README.md

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+# stack
+
+A super simple stack implementation using generics

go.mod

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+module stack
+
+go 1.20
+
+require github.com/stretchr/testify v1.8.4
+
+require (
+	github.com/davecgh/go-spew v1.1.1 // indirect
+	github.com/pmezard/go-difflib v1.0.0 // indirect
+	github.com/stretchr/objx v0.5.0 // indirect
+	gopkg.in/yaml.v3 v3.0.1 // indirect
+)

go.sum

@@ -0,0 +1,18 @@
+github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
+github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
+github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
+github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
+github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
+github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
+github.com/stretchr/objx v0.4.0/go.mod h1:YvHI0jy2hoMjB+UWwv71VJQ9isScKT/TqJzVSSt89Yw=
+github.com/stretchr/objx v0.5.0 h1:1zr/of2m5FGMsad5YfcqgdqdWrIhu+EBEJRhR1U7z/c=
+github.com/stretchr/objx v0.5.0/go.mod h1:Yh+to48EsGEfYuaHDzXPcE3xhTkx73EhmCGUpEOglKo=
+github.com/stretchr/testify v1.7.1/go.mod h1:6Fq8oRcR53rry900zMqJjRRixrwX3KX962/h/Wwjteg=
+github.com/stretchr/testify v1.8.0/go.mod h1:yNjHg4UonilssWZ8iaSj1OCr/vHnekPRkoO+kdMU+MU=
+github.com/stretchr/testify v1.8.4 h1:CcVxjf3Q8PM0mHUKJCdn+eZZtm5yQwehR5yeSVQQcUk=
+github.com/stretchr/testify v1.8.4/go.mod h1:sz/lmYIOXD/1dqDmKjjqLyZ2RngseejIcXlSw2iwfAo=
+gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405 h1:yhCVgyC4o1eVCa2tZl7eS0r+SDo693bJlVdllGtEeKM=
+gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
+gopkg.in/yaml.v3 v3.0.0-20200313102051-9f266ea9e77c/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=
+gopkg.in/yaml.v3 v3.0.1 h1:fxVm/GzAzEWqLHuvctI91KS9hhNmmWOoWu0XTYJS7CA=
+gopkg.in/yaml.v3 v3.0.1/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=

stack.go

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+package stack
+
+import "fmt"
+
+type Stack[T any] struct {
+	arr  []T
+	size int
+}
+
+func NewStack[T any]() *Stack[T] {
+	return &Stack[T]{
+		arr:  make([]T, 0),
+		size: 0,
+	}
+}
+
+func (s *Stack[T]) Clear() {
+	s.arr = make([]T, 0)
+	s.size = 0
+}
+
+func (s *Stack[T]) Size() int {
+	return s.size
+}
+
+func (s *Stack[T]) Pop() (*T, error) {
+	if s.size == 0 {
+		return nil, fmt.Errorf("tried to pop empty stack")
+	}
+	t := s.arr[s.size-1]
+	s.arr = s.arr[:s.size-1]
+	s.size--
+	return &t, nil
+}
+
+func (s *Stack[T]) Push(t T) {
+	s.arr = append(s.arr, t)
+	s.size++
+}
+
+func (s *Stack[T]) Peek() T {
+	t := s.arr[s.size-1]
+	return t
+}
+
+func (s *Stack[T]) PeekPtr() *T {
+	return &(s.arr[s.size-1])
+}

stack_test.go

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+package stack
+
+import (
+	"github.com/stretchr/testify/assert"
+	"testing"
+)
+
+func TestNewStack(t *testing.T) {
+	s := NewStack[int]()
+	assert.NotNil(t, s)
+}
+
+func TestStackPush(t *testing.T) {
+	s := NewStack[int]()
+	s.Push(2)
+	s.Push(10)
+
+	assert.Equal(t, s.Peek(), 10)
+	assert.Equal(t, *s.PeekPtr(), 10)
+}
+
+func TestStackPop(t *testing.T) {
+	s := NewStack[int]()
+	s.Push(2)
+	s.Push(10)
+
+	x, err := s.Pop()
+	assert.NotNil(t, x)
+	assert.NoError(t, err)
+	assert.Equal(t, *x, 10)
+}
+
+func TestStackPopEmpty(t *testing.T) {
+	s := NewStack[int]()
+	x, err := s.Pop()
+	assert.Error(t, err)
+	assert.Nil(t, x)
+}
+
+func TestStackClear(t *testing.T) {
+	s := NewStack[int]()
+	s.Push(10)
+	s.Push(11)
+	assert.Equal(t, s.Size(), 2)
+	s.Clear()
+	assert.Equal(t, s.Size(), 0)
+}
+
+func TestStackComplete(t *testing.T) {
+	s := NewStack[int]()
+	s.Push(1)
+	s.Push(2)
+	s.Push(3)
+
+	assert.Equal(t, s.Size(), 3)
+	x := s.Peek()
+	assert.Equal(t, 3, x)
+
+	y := s.PeekPtr()
+	assert.NotNil(t, y)
+	assert.Equal(t, 3, *y)
+
+	z, err := s.Pop()
+	assert.NoError(t, err)
+	assert.Equal(t, *z, 3)
+	assert.Equal(t, s.Peek(), 2)
+	assert.Equal(t, s.Size(), 2)
+
+	s.Clear()
+	assert.Equal(t, s.Size(), 0)
+}