v0.0.295 added generic base-conversion algorithm

goextVersion.go

@@ -1,5 +1,5 @@
 package goext
 
-const GoextVersion = "0.0.294"
+const GoextVersion = "0.0.295"
 
-const GoextVersionTimestamp = "2023-10-31T22:58:28+0100"
+const GoextVersionTimestamp = "2023-11-01T00:23:17+0100"

langext/baseAny.go

@@ -0,0 +1,178 @@
+package langext
+
+import (
+	"crypto/rand"
+	"errors"
+	"math"
+	"math/big"
+)
+
+type AnyBaseConverter struct {
+	base    uint64
+	charset []rune
+}
+
+func NewAnyBaseConverter(cs string) AnyBaseConverter {
+	rcs := []rune(cs)
+	return AnyBaseConverter{
+		base:    uint64(len(rcs)),
+		charset: rcs,
+	}
+}
+
+func (bc AnyBaseConverter) Rand(rlen int) string {
+	biBase := big.NewInt(int64(bc.base))
+
+	randMax := big.NewInt(math.MaxInt64)
+
+	r := ""
+
+	for i := 0; i < rlen; i++ {
+		v, err := rand.Int(rand.Reader, randMax)
+		if err != nil {
+			panic(err)
+		}
+
+		r += string(bc.charset[v.Mod(v, biBase).Int64()])
+	}
+
+	return r
+}
+
+func (bc AnyBaseConverter) EncodeUInt64(num uint64) string {
+	if num == 0 {
+		return "0"
+	}
+
+	b := ""
+
+	// loop as long the num is bigger than zero
+	for num > 0 {
+		r := num % bc.base
+
+		num -= r
+		num /= base62Base
+
+		b += string(bc.charset[int(r)])
+	}
+
+	return b
+}
+
+func (bc AnyBaseConverter) DecodeUInt64(str string) (uint64, error) {
+	if str == "" {
+		return 0, errors.New("empty string")
+	}
+
+	result := uint64(0)
+
+	for _, v := range str {
+		result *= base62Base
+
+		pos := ArrFirstIndex(bc.charset, v)
+		if pos == -1 {
+			return 0, errors.New("invalid character: " + string(v))
+		}
+
+		result += uint64(pos)
+	}
+
+	return result, nil
+}
+
+func (bc AnyBaseConverter) Encode(src []byte) string {
+	value := new(big.Int)
+	value.SetBytes(src)
+	return bc.EncodeBigInt(value)
+}
+
+func (bc AnyBaseConverter) EncodeBigInt(src *big.Int) string {
+	value := new(big.Int)
+	value.Set(src)
+
+	isneg := value.Sign() < 0
+
+	answer := ""
+
+	if isneg {
+		value.Neg(value)
+	}
+
+	biBase := big.NewInt(int64(bc.base))
+
+	rem := new(big.Int)
+
+	for value.Sign() > 0 {
+		value.QuoRem(value, biBase, rem)
+		answer = string(bc.charset[rem.Int64()]) + answer
+	}
+
+	if isneg {
+		return "-" + answer
+	} else {
+		return answer
+	}
+}
+
+func (bc AnyBaseConverter) Decode(src string) ([]byte, error) {
+	value, err := bc.DecodeToBigInt(src)
+	if err != nil {
+		return nil, err
+	}
+	return value.Bytes(), nil
+}
+
+func (bc AnyBaseConverter) DecodeToBigInt(_src string) (*big.Int, error) {
+	result := new(big.Int)
+	result.SetInt64(0)
+
+	src := []rune(_src)
+
+	if len(src) == 0 {
+		return nil, errors.New("string is empty")
+	}
+	if bc.base < 2 {
+		return nil, errors.New("not enough digits")
+	}
+
+	i := 0
+
+	sign := new(big.Int)
+	sign.SetInt64(1)
+	if src[i] == '+' {
+		i++
+	} else if src[i] == '-' {
+		i++
+		sign.SetInt64(-1)
+	}
+
+	if i >= len(src) {
+		return nil, errors.New("no digits in input")
+	}
+
+	biBase := big.NewInt(int64(bc.base))
+
+	oldResult := new(big.Int)
+
+	for ; i < len(src); i++ {
+		n := ArrFirstIndex(bc.charset, src[i])
+		if n < 0 {
+			return nil, errors.New("invalid characters in input")
+		}
+
+		oldResult.Set(result)
+
+		result.Mul(result, biBase)
+		result.Add(result, big.NewInt(int64(n)))
+
+		if result.Cmp(oldResult) < 0 {
+			return nil, errors.New("overflow")
+		}
+	}
+
+	if sign.Cmp(big.NewInt(0)) < 0 {
+		result.Neg(result)
+	}
+
+	return result, nil
+}

langext/baseAny_test.go

@@ -0,0 +1,80 @@
+package langext
+
+import (
+	"gogs.mikescher.com/BlackForestBytes/goext/tst"
+	"testing"
+)
+
+func _anyEncStr(bc AnyBaseConverter, v string) string {
+	vr := bc.Encode([]byte(v))
+	return vr
+}
+
+func _anyDecStr(bc AnyBaseConverter, v string) string {
+	vr, err := bc.Decode(v)
+	if err != nil {
+		panic(err)
+	}
+	return string(vr)
+}
+
+func TestAnyBase58DefaultEncoding(t *testing.T) {
+	tst.AssertEqual(t, _anyEncStr(NewAnyBaseConverter("123456789ABCDEFGHJKLMNPQRSTUVWXYZabcdefghijkmnopqrstuvwxyz"), "Hello"), "9Ajdvzr")
+	tst.AssertEqual(t, _anyEncStr(NewAnyBaseConverter("123456789ABCDEFGHJKLMNPQRSTUVWXYZabcdefghijkmnopqrstuvwxyz"), "If debugging is the process of removing software bugs, then programming must be the process of putting them in."), "48638SMcJuah5okqPx4kCVf5d8QAdgbdNf28g7ReY13prUENNbMyssjq5GjsrJHF5zeZfqs4uJMUJHr7VbrU4XBUZ2Fw9DVtqtn9N1eXucEWSEZahXV6w4ysGSWqGdpeYTJf1MdDzTg8vfcQViifJjZX")
+}
+
+func TestAnyBase58DefaultDecoding(t *testing.T) {
+	tst.AssertEqual(t, _anyDecStr(NewAnyBaseConverter("123456789ABCDEFGHJKLMNPQRSTUVWXYZabcdefghijkmnopqrstuvwxyz"), "9Ajdvzr"), "Hello")
+	tst.AssertEqual(t, _anyDecStr(NewAnyBaseConverter("123456789ABCDEFGHJKLMNPQRSTUVWXYZabcdefghijkmnopqrstuvwxyz"), "48638SMcJuah5okqPx4kCVf5d8QAdgbdNf28g7ReY13prUENNbMyssjq5GjsrJHF5zeZfqs4uJMUJHr7VbrU4XBUZ2Fw9DVtqtn9N1eXucEWSEZahXV6w4ysGSWqGdpeYTJf1MdDzTg8vfcQViifJjZX"), "If debugging is the process of removing software bugs, then programming must be the process of putting them in.")
+}
+
+func TestAnyBaseDecode(t *testing.T) {
+
+	const (
+		Binary  = "01"
+		Decimal = "0123456789"
+		Hex     = "0123456789ABCDEF"
+		DNA     = "ACGT"
+		Base32  = "ABCDEFGHIJKLMNOPQRSTUVWXYZ234567"
+		Base58  = "123456789ABCDEFGHJKLMNPQRSTUVWXYZabcdefghijkmnopqrstuvwxyz"
+		Base62  = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz"
+		Base64  = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/"
+		Base256 = "🚀🪐☄🛰🌌🌑🌒🌓🌔🌕🌖🌗🌘🌍🌏🌎🐉☀💻🖥💾💿😂❤😍🤣😊🙏💕😭😘👍😅👏😁🔥🥰💔💖💙😢🤔😆🙄💪😉☺👌🤗💜😔😎😇🌹🤦🎉💞✌✨🤷😱😌🌸🙌😋💗💚😏💛🙂💓🤩😄😀🖤😃💯🙈👇🎶😒🤭❣😜💋👀😪😑💥🙋😞😩😡🤪👊🥳😥🤤👉💃😳✋😚😝😴🌟😬🙃🍀🌷😻😓⭐✅🥺🌈😈🤘💦✔😣🏃💐☹🎊💘😠☝😕🌺🎂🌻😐🖕💝🙊😹🗣💫💀👑🎵🤞😛🔴😤🌼😫⚽🤙☕🏆🤫👈😮🙆🍻🍃🐶💁😲🌿🧡🎁⚡🌞🎈❌✊👋😰🤨😶🤝🚶💰🍓💢🤟🙁🚨💨🤬✈🎀🍺🤓😙💟🌱😖👶🥴▶➡❓💎💸⬇😨🌚🦋😷🕺⚠🙅😟😵👎🤲🤠🤧📌🔵💅🧐🐾🍒😗🤑🌊🤯🐷☎💧😯💆👆🎤🙇🍑❄🌴💣🐸💌📍🥀🤢👅💡💩👐📸👻🤐🤮🎼🥵🚩🍎🍊👼💍📣🥂"
+	)
+
+	type TestDef struct {
+		FromCS  string
+		FromVal string
+		ToCS    string
+		ToVal   string
+	}
+
+	defs := []TestDef{
+		{Binary, "10100101011100000101010", Decimal, "5421098"},
+		{Decimal, "5421098", DNA, "CCAGGTGAAGGG"},
+		{Decimal, "5421098", DNA, "CCAGGTGAAGGG"},
+		{Decimal, "80085", Base256, "🪐💞🔵"},
+		{Hex, "48656C6C6C20576F526C5421", Base64, "SGVsbGwgV29SbFQh"},
+		{Base64, "SGVsbGw/gV29SbF+Qh", Base32, "CIMVWGY3B7QFO32SNRPZBB"},
+		{Base64, "SGVsbGw/gV29SbF+Qh", Base58, "2fUsGKQUcgQcwSqpvy6"},
+		{Base64, "SGVsbGw/gV29SbF+Qh", Base62, "V34nvybdQ3m3RHk9Sr"},
+	}
+
+	for _, def := range defs {
+
+		d1 := NewAnyBaseConverter(def.FromCS)
+		d2 := NewAnyBaseConverter(def.ToCS)
+
+		v1 := tst.Must(d1.Decode(def.FromVal))(t)
+		v2 := tst.Must(d2.Decode(def.ToVal))(t)
+
+		tst.AssertArrayEqual(t, v1, v2)
+
+		str2 := d2.Encode(v1)
+		tst.AssertEqual(t, str2, def.ToVal)
+
+		str1 := d1.Encode(v2)
+		tst.AssertEqual(t, str1, def.FromVal)
+
+	}
+}

tst/assertions.go

@@ -14,6 +14,20 @@ func AssertEqual[T comparable](t *testing.T, actual T, expected T) {
 	}
 }
 
+func AssertArrayEqual[T comparable](t *testing.T, actual []T, expected []T) {
+	t.Helper()
+	if len(actual) != len(expected) {
+		t.Errorf("values differ: Actual: '%v', Expected: '%v' (len %d <> %d)", actual, expected, len(actual), len(expected))
+		return
+	}
+	for i := 0; i < len(actual); i++ {
+		if actual[i] != expected[i] {
+			t.Errorf("values differ: Actual: '%v', Expected: '%v' (at index %d)", actual, expected, i)
+			return
+		}
+	}
+}
+
 func AssertNotEqual[T comparable](t *testing.T, actual T, expected T) {
 	t.Helper()
 	if actual == expected {