add lifetime exercise2

data/1.rust初阶/1.预备知识/1.rust简介/helloworld.json

 {
-    "type": "code_options",
-    "author": "幻灰龙",
-    "source": "helloworld.md",
-    "notebook_enable": true
+  "type": "code_options",
+  "author": "huanhuilong",
+  "source": "helloworld.md",
+  "notebook_enable": true,
+  "exercise_id": "6ee394e414ff4ca88dbd9e4bf0cee33d"
 }
\ No newline at end of file

data/1.rust初阶/1.预备知识/1.rust简介/historyofrust.json

 {
-    "type": "code_options",
-    "author": "maozhonggui",
-    "source": "historyofrust.md",
-    "notebook_enable": true
+  "type": "code_options",
+  "author": "maozhonggui",
+  "source": "historyofrust.md",
+  "notebook_enable": true,
+  "exercise_id": "7e6ebda86d1e44b7974f719f08c24c7e"
 }
\ No newline at end of file

data/2.rust中阶/2.生命周期/1.函数生命周期/config.json

+{
+  "node_id": "rust-7f73462bc1d54b52891a4c2fc84f2a19",
+  "keywords": [],
+  "children": [],
+  "export": [
+    "lifetime.json"
+  ]
+}
\ No newline at end of file

data/2.rust中阶/2.生命周期/1.函数生命周期/lifetime.json

+{
+  "type": "code_options",
+  "author": "huanhuilong",
+  "source": "lifetime.md",
+  "notebook_enable": false,
+  "exercise_id": "526a3ad38c9a4f38af213e5d243c0e9e"
+}
\ No newline at end of file

data/2.rust中阶/2.生命周期/lifetime.md → data/2.rust中阶/2.生命周期/1.函数生命周期/lifetime.md

-# Rust 函数的生命周期
+# Rust 函数的生命周期(I)
 
 选出以下Rust代码中，生命周期错误的选项
 

data/2.rust中阶/2.生命周期/2.结构体生命周期/config.json

+{
+  "node_id": "rust-f7b9ef1329c745959fb1ca56061b4ae5",
+  "keywords": [],
+  "children": [],
+  "export": [
+    "lifetime_struct.json"
+  ]
+}
\ No newline at end of file

data/2.rust中阶/2.生命周期/2.结构体生命周期/lifetime_struct.json

+{
+  "type": "code_options",
+  "author": "huanhuilong",
+  "source": "lifetime_struct.md",
+  "notebook_enable": false,
+  "exercise_id": "64a2ddc560a54f588e62e5730883df38"
+}
\ No newline at end of file

data/2.rust中阶/2.生命周期/2.结构体生命周期/lifetime_struct.md

+# 结构体里的生命周期(I)
+
+以下对Rust结构体生命周期使用中，正确的代码是哪一项？
+
+## 答案
+
+```rust
+struct Piece<'a>{
+  slice:&'a [u8] // 表明slice是来自外部对象的一个借用，'a只是一个生命周期形参
+}
+ 
+ 
+// Piece的定义里面，'a 表示vec的生命周期，
+// 下面的例子调用，vec的生命周期至少应该大于等于piece的生命周期
+// 简单说vec存活的作用域应该大于等于piece的存活作用域
+fn test(){
+  let vec = Vec::<u8>::new();
+  let piece = Piece{slice: vec.as_slice()}; 
+}
+```
+
+## 选项
+
+### 结构体内含有的引用变量，函数返回后，生命周期就结束了
+
+```rust
+struct Piece<'a>{
+  slice:&'a [u8] // 表明slice是来自外部对象的一个借用，'a只是一个生命周期形参
+}
+
+fn test_2()->Piece{
+  let vec = Vec::<u8>::new();
+  let piece = Piece{slice: vec.as_slice()}; 
+  piece // compile error: ^^^^^ returns a value referencing data owned by the current function
+}
+```
+
+### expected named lifetime parameter
+
+```rust
+struct Piece{
+  slice:& [u8] // 表明slice是来自外部对象的一个借用，'a只是一个生命周期形参
+}
+ 
+ 
+// Piece的定义里面，'a 表示vec的生命周期，
+// 下面的例子调用，vec的生命周期至少应该大于等于piece的生命周期
+// 简单说vec存活的作用域应该大于等于piece的存活作用域
+fn test(){
+  let vec = Vec::<u8>::new();
+  let piece = Piece{slice: vec.as_slice()}; 
+}
+```
+
+### 结构体内持有的变量应该在构建的时候存活
+
+```rust
+struct Piece<'a>{
+  slice:&'a [u8] // 表明slice是来自外部对象的一个借用，'a只是一个生命周期形参
+}
+
+fn test(){
+    let vec
+    {
+        vec = Vec::<u8>::new();
+    }
+    let piece = Piece{slice: vec.as_slice()}; 
+}
+```

data/2.rust中阶/2.生命周期/config.json

 {
   "node_id": "rust-d38898d251df42d49f5f367f077ede55",
-  "keywords": [],
-  "children":[],
-  "export": [
-    "lifetime.json"
-  ]
+  "keywords": []
 }
\ No newline at end of file

data/2.rust中阶/2.生命周期/lifetime.json

-{
-    "type": "code_options",
-    "author": "huanhuilong",
-    "source": "lifetime.md",
-    "notebook_enable": false
-}
\ No newline at end of file

data/tree.json

@@ -330,7 +330,22 @@
               "生命周期": {
                 "node_id": "rust-d38898d251df42d49f5f367f077ede55",
                 "keywords": [],
-                "children": []
+                "children": [
+                  {
+                    "函数生命周期": {
+                      "node_id": "rust-7f73462bc1d54b52891a4c2fc84f2a19",
+                      "keywords": [],
+                      "children": []
+                    }
+                  },
+                  {
+                    "结构体生命周期": {
+                      "node_id": "rust-f7b9ef1329c745959fb1ca56061b4ae5",
+                      "keywords": [],
+                      "children": []
+                    }
+                  }
+                ]
               }
             },
             {

src/tree.py

@@ -71,10 +71,6 @@ def check_export(base, cfg):
     return flag
 
 
-def gen_node_id():
-    return "oceanbase-" + uuid.uuid4().hex
-
-
 class TreeWalker:
     def __init__(self, root, tree_name, title=None, log=None):
         self.name = tree_name
@@ -107,7 +103,7 @@ class TreeWalker:
                 for index, section_node in enumerate(chapter_node["children"]):
                     section_title = list(section_node.keys())[0]
                     full_path = os.path.join(
-                        chapter_path, f"{index}.{section_title}")
+                        chapter_path, f"{index+1}.{section_title}")
                     if os.path.isdir(full_path):
                         self.ensure_exercises(full_path)
 
@@ -123,7 +119,8 @@ class TreeWalker:
             level_path = os.path.join(self.root, level)
             num, config = self.load_level_node(level_path)
             levels.append((num, config))
-        levels.sort(key=lambda item: item[0])
+
+        levels = self.resort_children(self.root, levels)
         root_node["children"] = [item[1] for item in levels]
         return root_node
 
@@ -149,7 +146,7 @@ class TreeWalker:
                 num, chapter = self.load_chapter_node(full_name)
                 chapters.append((num, chapter))
 
-        chapters.sort(key=lambda item: item[0])
+        chapters = self.resort_children(base, chapters)
         level_node["children"] = [item[1] for item in chapters]
         return level_node
 
@@ -161,10 +158,21 @@ class TreeWalker:
                 num, section = self.load_section_node(full_name)
                 sections.append((num, section))
 
-        sections.sort(key=lambda item: item[0])
+        sections = self.resort_children(base, sections)
         chapter_node["children"] = [item[1] for item in sections]
         return chapter_node
 
+    def resort_children(self, base, children):
+        children.sort(key=lambda item: item[0])
+        for index, [number, element] in enumerate(children):
+            title = list(element.keys())[0]
+            origin = os.path.join(base, f"{number}.{title}")
+            posted = os.path.join(base, f"{index+1}.{title}")
+            if origin != posted:
+                self.logger.info(f"rename [{origin}] to [{posted}]")
+            os.rename(origin, posted)
+        return children
+
     def ensure_chapters(self):
         for subdir in os.listdir(self.root):
             self.ensure_level_config(subdir)
@@ -285,4 +293,4 @@ class TreeWalker:
             exercise = load_json(full_name)
             if "exercise_id" not in exercise:
                 exercise["exercise_id"] = uuid.uuid4().hex
-                dump_json(full_name, exercise)
+                dump_json(full_name, exercise, True, True)