v0.0.65

cryptext/aes.go

@@ -0,0 +1,47 @@
+package cryptext
+
+import (
+	"crypto/aes"
+	"crypto/cipher"
+	"crypto/rand"
+	"encoding/base64"
+	"errors"
+	"io"
+)
+
+// https://stackoverflow.com/a/18819040/1761622
+
+func EncryptAES(key, text []byte) ([]byte, error) {
+	block, err := aes.NewCipher(key)
+	if err != nil {
+		return nil, err
+	}
+	b := base64.StdEncoding.EncodeToString(text)
+	ciphertext := make([]byte, aes.BlockSize+len(b))
+	iv := ciphertext[:aes.BlockSize]
+	if _, err := io.ReadFull(rand.Reader, iv); err != nil {
+		return nil, err
+	}
+	cfb := cipher.NewCFBEncrypter(block, iv)
+	cfb.XORKeyStream(ciphertext[aes.BlockSize:], []byte(b))
+	return ciphertext, nil
+}
+
+func DecryptAES(key, text []byte) ([]byte, error) {
+	block, err := aes.NewCipher(key)
+	if err != nil {
+		return nil, err
+	}
+	if len(text) < aes.BlockSize {
+		return nil, errors.New("ciphertext too short")
+	}
+	iv := text[:aes.BlockSize]
+	text = text[aes.BlockSize:]
+	cfb := cipher.NewCFBDecrypter(block, iv)
+	cfb.XORKeyStream(text, text)
+	data, err := base64.StdEncoding.DecodeString(string(text))
+	if err != nil {
+		return nil, err
+	}
+	return data, nil
+}

dataext/stack.go

@@ -105,3 +105,12 @@ func (s *Stack[T]) Length() int {
 
 	return len(s.data)
 }
+
+func (s *Stack[T]) Empty() bool {
+	if s.lock != nil {
+		s.lock.Lock()
+		defer s.lock.Unlock()
+	}
+
+	return len(s.data) == 0
+}

langext/sort.go

@@ -37,3 +37,21 @@ func IsSliceSorted[T any](arr []T, less func(v1, v2 T) bool) bool {
 		return less(arr[i1], arr[i2])
 	})
 }
+
+func SortBy[TElem any, TSel OrderedConstraint](arr []TElem, selector func(v TElem) TSel) {
+	sort.Slice(arr, func(i1, i2 int) bool {
+		return selector(arr[i1]) < selector(arr[i2])
+	})
+}
+
+func SortByStable[TElem any, TSel OrderedConstraint](arr []TElem, selector func(v TElem) TSel) {
+	sort.SliceStable(arr, func(i1, i2 int) bool {
+		return selector(arr[i1]) < selector(arr[i2])
+	})
+}
+
+func IsSortedBy[TElem any, TSel OrderedConstraint](arr []TElem, selector func(v TElem) TSel) {
+	sort.SliceStable(arr, func(i1, i2 int) bool {
+		return selector(arr[i1]) < selector(arr[i2])
+	})
+}