initial commit

.github/workflows/ci.yaml

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+name: Go package
+
+on:
+  push:
+    tags:        
+      - '*'
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v3
+      - name: Set up Go
+        uses: actions/setup-go@v4
+        with:
+          go-version: '1.20'
+      - name: Build
+        run: go build -v ./...
+      - name: Test
+        run: go test -v ./...

LICENSE

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+MIT License
+
+Copyright (c) 2023 Ville Vesilehto
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.

README.md

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+# go-thespine
+
+The greatest death metal album of all time is "Nespithe" (1993) by Demilich from Kuopio, Finland.
+
+This Go library presents encoding and decoding facilities for the anagrams presented by this album.
+
+## Links
+
+- [Official band website](https://demilich.band/)
+- [How Demilich’s Only Album Became a Death Metal Cult Classic (Bandcamp, 2023)](https://daily.bandcamp.com/features/demilich-nespithe-interview)

go.mod

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+module github.com/thevilledev/go-thespine
+
+go 1.20

thespine.go

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+package thespine
+
+import "strings"
+
+const THE_SIZE = 3
+
+func Decode(s string) string {
+	l := len(s)
+	g := make([]string, 0)
+	gc := l / THE_SIZE
+	if l%THE_SIZE != 0 {
+		gc++
+	}
+	for i := 0; i < gc; i++ {
+		si := l - (i+1)*THE_SIZE
+		ei := l - i*THE_SIZE
+		if si < 0 {
+			si = 0
+		}
+		gs := s[si:ei]
+		g = append(g, gs)
+	}
+	return strings.Join(g, "")
+}
+
+func Encode(s string) string {
+	l := len(s)
+	g := make([]string, 0)
+	gc := l / THE_SIZE
+	if l%THE_SIZE != 0 {
+		gc++
+	}
+	for i := 0; i < gc; i++ {
+		si := i * THE_SIZE
+		ei := (i + 1) * THE_SIZE
+		if ei > l {
+			ei = l
+		}
+		gs := s[si:ei]
+		g = append(g, gs)
+	}
+	for i, j := 0, len(g)-1; i < j; i, j = i+1, j-1 {
+		g[i], g[j] = g[j], g[i]
+	}
+	return strings.Join(g, "")
+}

thespine_test.go

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+package thespine
+
+import "testing"
+
+func Test_EncodeDecode(t *testing.T) {
+	tests := []struct {
+		str  string
+		name string
+		want string
+	}{
+		{
+			str:  "",
+			name: "empty string",
+			want: "",
+		},
+		{
+			str:  "erecshyrinol",
+			name: "the song",
+			want: "nolyricshere",
+		},
+		{
+			str:  "nespithe",
+			name: "the album",
+			want: "thespine",
+		},
+		{
+			str:  "kubernetes",
+			name: "the tech",
+			want: "tesrneubek",
+		},
+	}
+	for _, test := range tests {
+		t.Run(test.name, func(t *testing.T) {
+			got := Decode(test.str)
+			if got != test.want {
+				t.Fatalf("decode got: %s\nwant: %s\n", got, test.want)
+			}
+			got = Encode(test.want)
+			if got != test.str {
+				t.Fatalf("encode got: %s\nwant: %s\n", got, test.str)
+			}
+		})
+	}
+}