feat: add FindAllOccurrences

docs/api/packages/strutil.md

@@ -69,6 +69,7 @@ import (
 -   [TemplateReplace](#TemplateReplace)
 -   [RegexMatchAllGroups](#RegexMatchAllGroups)
 -   [ExtractContent](#ExtractContent)
+-   [FindAllOccurrences](#FindAllOccurrences)
 
 
 <div STYLE="page-break-after: always;"></div>
@@ -1708,7 +1709,7 @@ func main() {
 func RegexMatchAllGroups(pattern, str string) [][]string
 ```
 
-<b>示例:<span style="float:right;display:inline-block;">[Run](https://go.dev/play/p/JZiu0RXpgN-)</span></b>
+<b>示例:<span style="float:right;display:inline-block;">[运行](https://go.dev/play/p/JZiu0RXpgN-)</span></b>
 
 ```go
 import (
@@ -1741,7 +1742,7 @@ func main() {
 func ExtractContent(s, start, end string) []string
 ```
 
-<b>示例:<span style="float:right;display:inline-block;">[Run](https://go.dev/play/p/Ay9UIk7Rum9)</span></b>
+<b>示例:<span style="float:right;display:inline-block;">[运行](https://go.dev/play/p/Ay9UIk7Rum9)</span></b>
 
 ```go
 import (
@@ -1760,3 +1761,31 @@ func main() {
     // [content1 content2 content1]
 }
 ```
+
+### <span id="FindAllOccurrences">FindAllOccurrences</span>
+
+<p>返回子字符串在字符串中所有出现的位置。</p>
+
+<b>函数签名:</b>
+
+```go
+func FindAllOccurrences(str, substr string) []int
+```
+
+<b>示例:<span style="float:right;display:inline-block;">[运行](todo)</span></b>
+
+```go
+import (
+    "fmt"
+    "github.com/duke-git/lancet/v2/strutil"
+)
+
+func main() {
+    result := strutil.FindAllOccurrences("ababab", "ab")
+
+    fmt.Println(result)
+
+    // Output:
+    // [0 2 4]
+}
+```

docs/en/api/packages/strutil.md

@@ -68,7 +68,8 @@ import (
 -   [Rotate](#Rotate)
 -   [TemplateReplace](#TemplateReplace)
 -   [RegexMatchAllGroups](#RegexMatchAllGroups)
--   [ExtractContent](#RegexMatchAllGroups)
+-   [ExtractContent](#ExtractContent)
+-   [FindAllOccurrences](#FindAllOccurrences)
 
 
 <div STYLE="page-break-after: always;"></div>
@@ -1762,3 +1763,31 @@ func main() {
     // [content1 content2 content1]
 }
 ```
+
+### <span id="FindAllOccurrences">FindAllOccurrences</span>
+
+<p>Returns the positions of all occurrences of a substring in a string.</p>
+
+<b>Signature:</b>
+
+```go
+func FindAllOccurrences(str, substr string) []int
+```
+
+<b>Example:<span style="float:right;display:inline-block;">[Run](todo)</span></b>
+
+```go
+import (
+    "fmt"
+    "github.com/duke-git/lancet/v2/strutil"
+)
+
+func main() {
+    result := strutil.FindAllOccurrences("ababab", "ab")
+
+    fmt.Println(result)
+
+    // Output:
+    // [0 2 4]
+}
+```

strutil/string.go

@@ -738,14 +738,14 @@ func RegexMatchAllGroups(pattern, str string) [][]string {
 
 // ExtractContent extracts the content between the start and end strings in the source string.
 // Play: https://go.dev/play/p/Ay9UIk7Rum9
-func ExtractContent(s, start, end string) []string {
+func ExtractContent(str, start, end string) []string {
 	result := []string{}
 
 	for {
-		if _, after, ok := strings.Cut(s, start); ok {
+		if _, after, ok := strings.Cut(str, start); ok {
 			if before, _, ok := strings.Cut(after, end); ok {
 				result = append(result, before)
-				s = after
+				str = after
 			} else {
 				break
 			}
@@ -756,3 +756,20 @@ func ExtractContent(s, start, end string) []string {
 
 	return result
 }
+
+// FindAllOccurrences returns the positions of all occurrences of a substring in a string.
+// Play: todo
+func FindAllOccurrences(str, substr string) []int {
+	var positions []int
+
+	for i := 0; i < len(str); {
+		index := strings.Index(str[i:], substr)
+		if index == -1 {
+			break
+		}
+		positions = append(positions, i+index)
+		i += index + 1
+	}
+
+	return positions
+}

strutil/string_example_test.go

@@ -763,5 +763,13 @@ func ExampleExtractContent() {
 
 	// Output:
 	// [content1 content2 content1]
-
+}
+
+func ExampleFindAllOccurrences() {
+	result := FindAllOccurrences("ababab", "ab")
+
+	fmt.Println(result)
+
+	// Output:
+	// [0 2 4]
 }

strutil/string_test.go

@@ -937,3 +937,32 @@ func TestExtractContent(t *testing.T) {
 		})
 	}
 }
+
+func TestFindAllOccurrences(t *testing.T) {
+	t.Parallel()
+
+	assert := internal.NewAssert(t, "TestFindAllOccurrences")
+
+	var empty []int
+	tests := []struct {
+		input    string
+		substr   string
+		expected []int
+	}{
+		{"", "", empty},
+		{"", "a", empty},
+		{"a", "", []int{0}},
+		{"a", "a", []int{0}},
+		{"aa", "a", []int{0, 1}},
+		{"ababab", "ab", []int{0, 2, 4}},
+		{"ababab", "ba", []int{1, 3}},
+		{"ababab", "c", empty},
+		{"ababab", "ababab", []int{0}},
+		{"ababab", "abababc", empty},
+		{"ababab", "abababa", empty},
+	}
+
+	for _, tt := range tests {
+		assert.Equal(tt.expected, FindAllOccurrences(tt.input, tt.substr))
+	}
+}