v4

CHANGELOG

@@ -1,3 +1,10 @@
+v4.0.0, released 2025-01-06
+    * support both 32 and 64 bases
+    * added Convert command between bases
+
+v2.0.0, released 2024-09-20 
+    * move to base 62
+
 v1.0.2, released 2024-08-08 
     * support negative values
 

README.md

@@ -2,10 +2,22 @@
 
 [![Build Status](https://drone.arns.lt/api/badges/zordsdavini/abcex/status.svg)](https://drone.arns.lt/zordsdavini/abcex)
 
-Computing system based on the number 62
+Computing system based on the number 62 or 36
+
+## Usage
+
+`Encode(int, int) -> string` - convert number into string based on given base.
+
+`Decode(string, int) -> int` - convert from encoded string into number based on given base.
+
+`Convert(string, int, int) -> string` - convert encoded string from one base to another.
 
 ## History
 
 **Version 1** - based on 32: number and case insensitive letters
 
-**Version 2** - based on 62: number and case sensitive letters
+**Version 2** - failed release
+
+**Version 3** - based on 62: number and case sensitive letters
+
+**Version 4** - support both versions, based on 62 and 32

abcex.go

@@ -5,7 +5,15 @@ import (
 	"math"
 )
 
-var decToAbcex = map[int]string{
+var decToAbcex36 = map[int]string{
+	0: "0", 1: "1", 2: "2", 3: "3", 4: "4", 5: "5", 6: "6", 7: "7",
+	8: "8", 9: "9", 10: "a", 11: "b", 12: "c", 13: "d", 14: "e",
+	15: "f", 16: "g", 17: "h", 18: "i", 19: "j", 20: "k", 21: "l",
+	22: "m", 23: "n", 24: "o", 25: "p", 26: "q", 27: "r", 28: "s",
+	29: "t", 30: "u", 31: "v", 32: "w", 33: "x", 34: "y", 35: "z",
+}
+
+var decToAbcex62 = map[int]string{
 	0: "0", 1: "1", 2: "2", 3: "3", 4: "4", 5: "5", 6: "6", 7: "7",
 	8: "8", 9: "9", 10: "A", 11: "B", 12: "C", 13: "D", 14: "E",
 	15: "F", 16: "G", 17: "H", 18: "I", 19: "J", 20: "K", 21: "L",
@@ -17,7 +25,20 @@ var decToAbcex = map[int]string{
 	57: "v", 58: "w", 59: "x", 60: "y", 61: "z",
 }
 
-var abcexToDec = flipMap()
+var (
+	BASE36 int = 36
+	BASE62 int = 62
+)
+
+func getDict(base int) map[int]string {
+	if base == 36 {
+		return decToAbcex36
+	} else if base == 62 {
+		return decToAbcex62
+	}
+
+	panic("Invalid base")
+}
 
 func reverse(s string) string {
 	runes := []rune(s)
@@ -27,16 +48,16 @@ func reverse(s string) string {
 	return string(runes)
 }
 
-func flipMap() map[string]int {
+func flipMap(dict map[int]string) map[string]int {
 	flipped := make(map[string]int)
-	for i, val := range decToAbcex {
+	for i, val := range dict {
 		flipped[val] = i
 	}
 
 	return flipped
 }
 
-func Encode(number int64) string {
+func Encode(number int64, base int) string {
 	if number == 0 {
 		return "0"
 	}
@@ -49,8 +70,8 @@ func Encode(number int64) string {
 	}
 
 	for number > 0 {
-		result = fmt.Sprintf("%s%s", decToAbcex[int(number%62)], result)
-		number /= 62
+		result = fmt.Sprintf("%s%s", getDict(base)[int(number%int64(base))], result)
+		number /= int64(base)
 	}
 
 	if negative {
@@ -60,9 +81,10 @@ func Encode(number int64) string {
 	return result
 }
 
-func Decode(str string) int64 {
+func Decode(str string, base int) int64 {
 	var result int64
 	result = 0
+	abcexToDec := flipMap(getDict(base))
 	negative := false
 	if string(str[0]) == "-" {
 		negative = true
@@ -72,7 +94,7 @@ func Decode(str string) int64 {
 	str = reverse(str)
 
 	for i, c := range str {
-		result = int64(math.Pow(62, float64(i)))*int64(abcexToDec[string(c)]) + result
+		result = int64(math.Pow(float64(base), float64(i)))*int64(abcexToDec[string(c)]) + result
 	}
 
 	if negative {
@@ -81,3 +103,7 @@ func Decode(str string) int64 {
 
 	return result
 }
+
+func Convert(str string, fromBase int, toBase int) string {
+	return Encode(Decode(str, fromBase), toBase)
+}

abcex_test.go

@@ -4,34 +4,52 @@ import (
 	"testing"
 )
 
+func TestConvert(t *testing.T) {
+	if Convert("9ix", BASE36, BASE62) != "3D7" {
+		t.Fatal("Failed conversion")
+	}
+}
+
+func TestEncode36(t *testing.T) {
+	if Encode(12345, BASE36) != "9ix" {
+		t.Fatal("Failed encoding")
+	}
+}
+
+func TestDecode36(t *testing.T) {
+	if Decode("9ix", BASE36) != 12345 {
+		t.Fatal("Failed decoding")
+	}
+}
+
 func TestEncode(t *testing.T) {
-	if Encode(12345) != "3D7" {
+	if Encode(12345, BASE62) != "3D7" {
 		t.Fatal("Failed encoding")
 	}
 }
 
 func TestDecode(t *testing.T) {
-	if Decode("3D7") != 12345 {
+	if Decode("3D7", BASE62) != 12345 {
 		t.Fatal("Failed decoding")
 	}
 }
 
 func TestZero(t *testing.T) {
-	if Encode(0) != "0" {
+	if Encode(0, BASE62) != "0" {
 		t.Fatal("Failed zero encoding")
 	}
 
-	if Decode("0") != 0 {
+	if Decode("0", BASE62) != 0 {
 		t.Fatal("Failed zero decoding")
 	}
 }
 
 func TestNegative(t *testing.T) {
-	if Encode(-20) != "-K" {
-		t.Fatal("Failed negative encoding:", Encode(-20))
+	if Encode(-20, BASE62) != "-K" {
+		t.Fatal("Failed negative encoding:", Encode(-20, BASE62))
 	}
 
-	if Decode("-ab") != -2269 {
-		t.Fatal("Failed negative decoding", Decode("-ab"))
+	if Decode("-ab", BASE62) != -2269 {
+		t.Fatal("Failed negative decoding", Decode("-ab", BASE62))
 	}
 }

go.mod

@@ -1,3 +1,3 @@
-module g.arns.lt/zordsdavini/abcex
+module g.arns.lt/zordsdavini/abcex/v4
 
 go 1.16