Move pkg out from advent-of-code-2020

== Reason

December is coming and I'm very confident I'll just `cp` the `pkg` directory
over or importing from the 2020 directory. Both of them are pretty bad, so to
avoid this, I'll just create a common, shared library for my AoC solutions.

Author: yitsushi

.github/workflows/quality-check.yaml

@@ -0,0 +1,71 @@
+name: Quality Check
+
+on:
+  push:
+  pull_request:
+
+jobs:
+  test:
+    name: Test and coverage
+    runs-on: ubuntu-latest
+    steps:
+      - name: Set up Go 1.x
+        uses: actions/setup-go@v2
+        with:
+          go-version: ^1.17
+        id: go
+
+      - name: Checkout code
+        uses: actions/checkout@v2
+
+      - name: Get dependencies
+        run: |
+          go get -v -t -d ./...
+
+      - name: go test
+        run: go test -v -covermode=count -coverprofile=coverage.out ./...
+
+      - name: Convert coverage.out to coverage.lcov
+        uses: jandelgado/[email protected]
+
+      - name: Coveralls
+        uses: coverallsapp/github-action@master
+        with:
+          github-token: ${{ secrets.GITHUB_TOKEN }}
+          path-to-lcov: coverage.lcov
+
+  vet:
+    name: go vet and lint
+    runs-on: ubuntu-latest
+    steps:
+      - name: Set up Go 1.x
+        uses: actions/setup-go@v2
+        with:
+          go-version: ^1.17
+        id: go
+
+      - name: Checkout code
+        uses: actions/checkout@v2
+
+      - name: Get dependencies
+        run: |
+          go get -v -t -d ./...
+          go get -u golang.org/x/lint/golint
+
+      - name: go vet
+        run: go vet ./...
+
+      - name: go lint
+        run: golint -set_exit_status ./...
+
+  golangci:
+    name: golangci lint check
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@v2
+
+      - name: golangci-lint
+        uses: golangci/golangci-lint-action@v2
+        with:
+          version: v1.43.0

.golangci.yml

@@ -0,0 +1,56 @@
+run:
+    timeout: 10m
+    tests: false
+    allow-parallel-runners: true
+
+linters-settings:
+  staticcheck:
+    go: "1.17"
+  stylecheck:
+    go: "1.17"
+  cyclop:
+    skip-tests: true
+  misspell:
+    locale: GB
+  goimports:
+    local-prefixes: github.com/yitsushi/go-aoc
+  govet:
+    check-shadowing: true
+  nolintlint:
+    allow-leading-space: false
+    allow-unused: false
+    require-explanation: true
+    require-specific: false
+  varnamelen:
+    ignore-names:
+    - err
+    - idx
+
+issues:
+  max-same-issues: 0
+  max-issues-per-linter: 0
+  exclude-rules:
+  - text: "github.com/yitsushi/go-aoc/"
+    linters:
+    - wrapcheck
+  - text: "https://"
+    linters:
+    - lll
+  - path: _test\.go
+    linters:
+    - goerr113
+    - gocyclo
+    - errcheck
+    - gosec
+    - dupl
+    - funlen
+    - testpackage
+
+linters:
+  enable-all: true
+  disable:
+  - golint     # deprecated
+  - interfacer # deprecated
+  - ireturn
+  - maligned   # deprecated
+  - scopelint  # deprecated

bullshit/drop.go

@@ -0,0 +1,16 @@
+package bullshit
+
+// DropErrorBoolean drops the error and returns with the boolean value only.
+func DropErrorBoolean(value bool, err error) bool {
+	return value
+}
+
+// DropErrorInt64 drops the error and returns with the Int64 value only.
+func DropErrorInt64(value int64, err error) int64 {
+	return value
+}
+
+// DropErrorUint64 drops the error and returns with the Uint64 value only.
+func DropErrorUint64(value uint64, err error) uint64 {
+	return value
+}

bullshit/drop_test.go

@@ -0,0 +1,26 @@
+package bullshit_test
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/yitsushi/go-aoc/bullshit"
+	"github.com/yitsushi/go-aoc/puzzle"
+)
+
+func TestDropErrorBoolean(t *testing.T) {
+	assert.True(t, bullshit.DropErrorBoolean(true, puzzle.NoInputError{}))
+	assert.False(t, bullshit.DropErrorBoolean(false, puzzle.NoInputError{}))
+	assert.True(t, bullshit.DropErrorBoolean(true, nil))
+	assert.False(t, bullshit.DropErrorBoolean(false, nil))
+}
+
+func TestDropErrorInt64(t *testing.T) {
+	assert.Equal(t, int64(78), bullshit.DropErrorInt64(78, puzzle.NoInputError{}))
+	assert.Equal(t, int64(99), bullshit.DropErrorInt64(99, nil))
+}
+
+func TestDropErrorUint64(t *testing.T) {
+	assert.Equal(t, uint64(78), bullshit.DropErrorUint64(78, puzzle.NoInputError{}))
+	assert.Equal(t, uint64(99), bullshit.DropErrorUint64(99, nil))
+}

debug/io.go

@@ -0,0 +1,11 @@
+package debug
+
+import (
+	"bufio"
+	"os"
+)
+
+// WaitForKeypress a simple debugger tool. It waits for a keypress.
+func WaitForKeypress() {
+	_, _ = bufio.NewReader(os.Stdin).ReadBytes('\n')
+}

generic/hashable.go

@@ -0,0 +1,6 @@
+package generic
+
+// Hashable object. The hash can be used for cache.
+type Hashable interface {
+	Hash() interface{}
+}

generic/queue.go

@@ -0,0 +1,64 @@
+package generic
+
+import (
+	"sync"
+)
+
+// Queue is a simple queue with unique items.
+type Queue struct {
+	queue    []Hashable
+	keyCache map[interface{}]bool
+	lock     sync.RWMutex
+}
+
+// NewQueue create a new Queue.
+func NewQueue() Queue {
+	return Queue{
+		queue:    []Hashable{},
+		keyCache: map[interface{}]bool{},
+		lock:     sync.RWMutex{},
+	}
+}
+
+// Push items into the queue.
+// The queue contains only unique items.
+func (q *Queue) Push(items ...Hashable) {
+	q.lock.Lock()
+	defer q.lock.Unlock()
+
+	for _, item := range items {
+		if v, found := q.keyCache[item.Hash()]; found && v {
+			continue
+		}
+
+		q.keyCache[item.Hash()] = true
+		q.queue = append(q.queue, item)
+	}
+}
+
+// Pull an item from the Queue.
+func (q *Queue) Pull() Hashable {
+	if len(q.queue) > 0 {
+		q.lock.Lock()
+		defer q.lock.Unlock()
+
+		item := q.queue[0]
+		q.queue = q.queue[1:]
+
+		q.keyCache[item.Hash()] = false
+
+		return item
+	}
+
+	return nil
+}
+
+// Size of the queue.
+func (q *Queue) Size() int {
+	return len(q.queue)
+}
+
+// Empty or not?
+func (q *Queue) Empty() bool {
+	return q.Size() == 0
+}

go.mod

@@ -0,0 +1,17 @@
+module github.com/yitsushi/go-aoc
+
+go 1.17
+
+require (
+	github.com/sirupsen/logrus v1.8.1
+	github.com/stretchr/testify v1.6.1
+)
+
+require (
+	github.com/davecgh/go-spew v1.1.1 // indirect
+	github.com/niemeyer/pretty v0.0.0-20200227124842-a10e7caefd8e // indirect
+	github.com/pmezard/go-difflib v1.0.0 // indirect
+	golang.org/x/sys v0.0.0-20201024132449-ef9fd89ba245 // indirect
+	gopkg.in/check.v1 v1.0.0-20200902074654-038fdea0a05b // indirect
+	gopkg.in/yaml.v3 v3.0.0-20200313102051-9f266ea9e77c // indirect
+)

go.sum

@@ -0,0 +1,24 @@
+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/kr/pty v1.1.1/go.mod h1:pFQYn66WHrOpPYNljwOMqo10TkYh1fy3cYio2l3bCsQ=
+github.com/kr/text v0.1.0 h1:45sCR5RtlFHMR4UwH9sdQ5TC8v0qDQCHnXt+kaKSTVE=
+github.com/kr/text v0.1.0/go.mod h1:4Jbv+DJW3UT/LiOwJeYQe1efqtUx/iVham/4vfdArNI=
+github.com/niemeyer/pretty v0.0.0-20200227124842-a10e7caefd8e h1:fD57ERR4JtEqsWbfPhv4DMiApHyliiK5xCTNVSPiaAs=
+github.com/niemeyer/pretty v0.0.0-20200227124842-a10e7caefd8e/go.mod h1:zD1mROLANZcx1PVRCS0qkT7pwLkGfwJo4zjcN/Tysno=
+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/sirupsen/logrus v1.8.1 h1:dJKuHgqk1NNQlqoA6BTlM1Wf9DOH3NBjQyu0h9+AZZE=
+github.com/sirupsen/logrus v1.8.1/go.mod h1:yWOB1SBYBC5VeMP7gHvWumXLIWorT60ONWic61uBYv0=
+github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
+github.com/stretchr/testify v1.2.2/go.mod h1:a8OnRcib4nhh0OaRAV+Yts87kKdq0PP7pXfy6kDkUVs=
+github.com/stretchr/testify v1.6.1 h1:hDPOHmpOpP40lSULcqw7IrRb/u7w6RpDC9399XyoNd0=
+github.com/stretchr/testify v1.6.1/go.mod h1:6Fq8oRcR53rry900zMqJjRRixrwX3KX962/h/Wwjteg=
+golang.org/x/sys v0.0.0-20191026070338-33540a1f6037/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
+golang.org/x/sys v0.0.0-20201024132449-ef9fd89ba245 h1:GGQcbpn3KsnwsPvzzr1mDsTriyvGNKi9eo2lG3N8YdM=
+golang.org/x/sys v0.0.0-20201024132449-ef9fd89ba245/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
+gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
+gopkg.in/check.v1 v1.0.0-20200902074654-038fdea0a05b h1:QRR6H1YWRnHb4Y/HeNFCTJLFVxaq6wH4YuVdsUOr75U=
+gopkg.in/check.v1 v1.0.0-20200902074654-038fdea0a05b/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
+gopkg.in/yaml.v3 v3.0.0-20200313102051-9f266ea9e77c h1:dUUwHk2QECo/6vqA44rthZ8ie2QXMNeKRTHCNY2nXvo=
+gopkg.in/yaml.v3 v3.0.0-20200313102051-9f266ea9e77c/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=

math/const.go

@@ -0,0 +1,5 @@
+package math
+
+import "math"
+
+const rad = math.Pi / 180

math/division.go

@@ -0,0 +1,6 @@
+package math
+
+// DivMod is a simple div and mod together.
+func DivMod(numerator, denominator int64) (int64, int64) {
+	return numerator / denominator, numerator % denominator
+}

math/division_test.go

@@ -0,0 +1,49 @@
+package math_test
+
+import (
+	"testing"
+
+	"github.com/yitsushi/go-aoc/math"
+)
+
+func TestDivMod(t *testing.T) {
+	type args struct {
+		numerator   int64
+		denominator int64
+	}
+
+	tests := []struct {
+		name      string
+		args      args
+		quotient  int64
+		remainder int64
+	}{
+		{
+			name:      "9 divmod 3",
+			args:      args{numerator: 9, denominator: 3},
+			quotient:  3,
+			remainder: 0,
+		},
+		{
+			name:      "9 divmod 4",
+			args:      args{numerator: 9, denominator: 4},
+			quotient:  2,
+			remainder: 1,
+		},
+		{
+			name:      "9 divmod 13",
+			args:      args{numerator: 9, denominator: 13},
+			quotient:  0,
+			remainder: 9,
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			q, r := math.DivMod(tt.args.numerator, tt.args.denominator)
+			if q != tt.quotient || r != tt.remainder {
+				t.Errorf("DivMod() got = (%v, %v), want (%v, %v)", q, r, tt.quotient, tt.remainder)
+			}
+		})
+	}
+}