feat: add Ellipsis for string

docs/api/packages/strutil.md

@@ -63,6 +63,7 @@ import (
 -   [SubInBetween](#SubInBetween)
 -   [HammingDistance](#HammingDistance)
 -   [Concat](#Concat)
+-   [Ellipsis](#Ellipsis)
 
 <div STYLE="page-break-after: always;"></div>
 
@@ -1563,4 +1564,38 @@ func main() {
 	// Go Language
 	// An apple a day，keeps the doctor away
 }
+```
+
+### <span id="Ellipsis">Ellipsis</span>
+
+<p>将字符串截断到指定长度，并在末尾添加省略号。</p>
+
+<b>函数签名:</b>
+
+```go
+func Ellipsis(str string, length int) string
+```
+
+<b>示例:<span style="float:right;display:inline-block;">[Run]()</span></b>
+
+```go
+import (
+    "fmt"
+    "github.com/duke-git/lancet/v2/strutil"
+)
+
+func main() {
+    result1 := strutil.Ellipsis("hello world", 5)
+    result2 := strutil.Ellipsis("你好，世界!", 2)
+    result3 := strutil.Ellipsis("😀😃😄😁😆", 3)
+
+    fmt.Println(result1)
+    fmt.Println(result2)
+    fmt.Println(result3)
+
+    // Output:
+    // hello...
+    // 你好...
+    // 😀😃😄...
+}
 ```

docs/en/api/packages/strutil.md

@@ -63,6 +63,7 @@ import (
 -   [SubInBetween](#SubInBetween)
 -   [HammingDistance](#HammingDistance)
 -   [Concat](#Concat)
+-   [Ellipsis](#Ellipsis)
 
 <div STYLE="page-break-after: always;"></div>
 
@@ -1100,10 +1101,10 @@ import (
 
 func main() {
     result1 := strutil.IsNotBlank("")
-    result2 := strutil.IsNotBlank("	")
+    result2 := strutil.IsNotBlank("    ")
     result3 := strutil.IsNotBlank("\t\v\f\n")
     result4 := strutil.IsNotBlank(" 中文")
-    result5 := strutil.IsNotBlank(" 	world	")
+    result5 := strutil.IsNotBlank("    world    ")
     
     fmt.Println(result1)
     fmt.Println(result2)
@@ -1553,17 +1554,50 @@ import (
 )
 
 func main() {
+    result1 := strutil.Concat(12, "Hello", " ", "World", "!")
+    result2 := strutil.Concat(11, "Go", " ", "Language")
+    result3 := strutil.Concat(0, "An apple a ", "day，", "keeps the", " doctor away")
+    fmt.Println(result1)
+    fmt.Println(result2)
+    fmt.Println(result3)
 
- 	result1 := strutil.Concat(12, "Hello", " ", "World", "!")
-	result2 := strutil.Concat(11, "Go", " ", "Language")
-	result3 := strutil.Concat(0, "An apple a ", "day，", "keeps the", " doctor away")
-	fmt.Println(result1)
-	fmt.Println(result2)
-	fmt.Println(result3)
+    // Output:
+    // Hello World!
+    // Go Language
+    // An apple a day，keeps the doctor away
+}
+```
 
-	// Output:
-	// Hello World!
-	// Go Language
-	// An apple a day，keeps the doctor away
+### <span id="Ellipsis">Ellipsis</span>
+
+<p>Truncates a string to a specified length and appends an ellipsis.</p>
+
+<b>Signature:</b>
+
+```go
+func Ellipsis(str string, length int) string
+```
+
+<b>Example:<span style="float:right;display:inline-block;">[Run]()</span></b>
+
+```go
+import (
+    "fmt"
+    "github.com/duke-git/lancet/v2/strutil"
+)
+
+func main() {
+    result1 := strutil.Ellipsis("hello world", 5)
+    result2 := strutil.Ellipsis("你好，世界!", 2)
+    result3 := strutil.Ellipsis("😀😃😄😁😆", 3)
+
+    fmt.Println(result1)
+    fmt.Println(result2)
+    fmt.Println(result3)
+
+    // Output:
+    // hello...
+    // 你好...
+    // 😀😃😄...
 }
 ```

strutil/string.go

@@ -621,6 +621,8 @@ func HammingDistance(a, b string) (int, error) {
 // Concat uses the strings.Builder to concatenate the input strings.
 //   - `length` is the expected length of the concatenated string.
 //   - if you are unsure about the length of the string to be concatenated, please pass 0 or a negative number.
+//
+// Play: todo
 func Concat(length int, str ...string) string {
 	if len(str) == 0 {
 		return ""
@@ -638,3 +640,21 @@ func Concat(length int, str ...string) string {
 	}
 	return sb.String()
 }
+
+// Ellipsis truncates a string to a specified length and appends an ellipsis.
+// Play: todo
+func Ellipsis(str string, length int) string {
+	str = strings.TrimSpace(str)
+
+	if length <= 0 {
+		return ""
+	}
+
+	runes := []rune(str)
+
+	if len(runes) <= length {
+		return str
+	}
+
+	return string(runes[:length]) + "..."
+}

strutil/string_example_test.go

@@ -694,3 +694,18 @@ func ExampleConcat() {
 	// Go Language
 	// An apple a day，keeps the doctor away
 }
+
+func ExampleEllipsis() {
+	result1 := Ellipsis("hello world", 5)
+	result2 := Ellipsis("你好，世界!", 2)
+	result3 := Ellipsis("😀😃😄😁😆", 3)
+
+	fmt.Println(result1)
+	fmt.Println(result2)
+	fmt.Println(result3)
+
+	// Output:
+	// hello...
+	// 你好...
+	// 😀😃😄...
+}

strutil/string_test.go

@@ -620,3 +620,27 @@ func TestConcat(t *testing.T) {
 	assert.Equal("你好，世界！", Concat(0, "你好", "，", "", "世界！", ""))
 	assert.Equal("Hello World!", Concat(0, "Hello", " Wo", "r", "ld!", ""))
 }
+
+func TestEllipsis(t *testing.T) {
+	t.Parallel()
+	assert := internal.NewAssert(t, "TestEllipsis")
+
+	tests := []struct {
+		input  string
+		length int
+		want   string
+	}{
+		{"", 0, ""},
+		{"hello world", 0, ""},
+		{"hello world", -1, ""},
+		{"hello world", 5, "hello..."},
+		{"hello world", 11, "hello world"},
+		{"你好，世界!", 2, "你好..."},
+		{"😀😃😄😁😆", 3, "😀😃😄..."},
+		{"This is a test.", 10, "This is a ..."},
+	}
+
+	for _, tt := range tests {
+		assert.Equal(tt.want, Ellipsis(tt.input, tt.length))
+	}
+}