diff --git a/README.md b/README.md
index a091ade..2a00439 100644
--- a/README.md
+++ b/README.md
@@ -21,6 +21,7 @@
 * [__Difference__](#difference-between-andys-and-this-interpreter)
 * [__Trace Back Info__](#trace-back-info)
 * [__Debugger__](#debugger)
+* [__REPL__](#repl)
 
 __Contact us if having great ideas to share!__
 
@@ -613,19 +614,24 @@ that is really inconvenient.
 
 Luckily, we have developed some useful native-functions to help you add modules that created by you.
 
-After 2021/12/3, there are some new functions added to `lib.nas`:
+Functions used to load dynamic libraries are added to `std/dylib.nas`:
 
 ```javascript
-var dylib={
-    dlopen:  func(libname){
-        ...
-    },
-    dlclose: func(lib){return __dlclose;   },
-    dlcall:  func(ptr,args...){return __dlcallv},
-    limitcall: func(arg_size=0){
-        ...
-    }
-};
+var dlopen = func(libname) {
+    ...
+}
+
+var dlclose = func(lib) {
+    ...
+}
+
+var dlcall = func(ptr, args...) {
+    ...
+}
+
+var limitcall = func(arg_size = 0) {
+    ...
+}
 ```
 
 As you could see, these functions are used to load dynamic libraries into the nasal runtime and execute.
@@ -636,21 +642,26 @@ First, write a cpp file that you want to generate the dynamic lib, take the `fib
 ```C++
 // add header file nasal.h to get api
 #include "nasal.h"
-double fibonaci(double x){
-    if(x<=2)
+double fibonaci(double x) {
+    if (x<=2) {
         return x;
+    }
     return fibonaci(x-1)+fibonaci(x-2);
 }
 // module functions' parameter list example
-var fib(var* args,usize size,gc* ngc){
+var fib(var* args, usize size, gc* ngc) {
+    if (!size) {
+        return nas_err("fib", "lack arguments");
+    }
     // the arguments are generated into a vm_vec: args
     // get values from the vector that must be used here
-    var num=args[0];
+    var num = args[0];
     // if you want your function safer, try this
     // nas_err will print the error info on screen
     // and return vm_null for runtime to interrupt
-    if(num.type!=vm_num)
-        return nas_err("extern_fib","\"num\" must be number");
+    if(num.type!=vm_num) {
+        return nas_err("extern_fib", "\"num\" must be number");
+    }
     // ok, you must know that vm_num now is not managed by gc
     // if want to return a gc object, use ngc->alloc(type)
     // usage of gc is the same as adding a native function
@@ -659,9 +670,9 @@ var fib(var* args,usize size,gc* ngc){
 
 // then put function name and address into this table
 // make sure the end of the table is {nullptr,nullptr}
-mod_func func_tbl[]={
-    {"fib",fib},
-    {nullptr,nullptr}
+module_func_info func_tbl[] = {
+    {"fib", fib},
+    {nullptr, nullptr}
 };
 
 // must write this function, this will help nasal to
@@ -669,7 +680,7 @@ mod_func func_tbl[]={
 // the reason why using this way to get function pointer
 // is because `var` has constructors, which is not compatiable in C
 // so "extern "C" var fib" may get compilation warnings
-extern "C" mod_func get(){
+extern "C" module_func_info* get() {
     return func_tbl;
 }
 ```
@@ -693,10 +704,11 @@ Windows(`.dll`):
 Then we write a test nasal file to run this fib function, using `os.platform()` we could write a cross-platform program:
 
 ```javascript
-var dlhandle=dylib.dlopen("libfib."~(os.platform()=="windows"?"dll":"so"));
-var fib=dlhandle.fib;
-for(var i=1;i<30;i+=1)
-    println(dylib.dlcall(fib,i));
+import.std.dylib;
+var dlhandle = dylib.dlopen("libfib."~(os.platform()=="windows"?"dll":"so"));
+var fib = dlhandle.fib;
+for(var i = 1; i<30; i+=1)
+    println(dylib.dlcall(fib, i));
 dylib.dlclose(dlhandle.lib);
 ```
 
@@ -709,11 +721,12 @@ dylib.dlclose(dlhandle.lib);
 `dylib.limitcall` is used to get `dlcall` function that has limited parameter size, this function will prove the performance of your code because it does not use `vm_vec` to store the arguments, instead it uses local scope to store them, so this could avoid frequently garbage collecting. And the code above could also be written like this:
 
 ```javascript
-var dlhandle=dylib.dlopen("libfib."~(os.platform()=="windows"?"dll":"so"));
-var fib=dlhandle.fib;
-var invoke=dylib.limitcall(1); # this means the called function has only one parameter
-for(var i=1;i<30;i+=1)
-    println(invoke(fib,i));
+import.std.dylib;
+var dlhandle = dylib.dlopen("libfib."~(os.platform()=="windows"?"dll":"so"));
+var fib = dlhandle.fib;
+var invoke = dylib.limitcall(1); # this means the called function has only one parameter
+for(var i = 1; i<30; i+=1)
+    println(invoke(fib, i));
 dylib.dlclose(dlhandle.lib);
 ```
 
@@ -998,3 +1011,10 @@ vm stack (0x7fffd0259138 <sp+65>, limit 10, total 7)
 ```
 
 </details>
+
+## REPL
+
+We added experimental repl interpreter in v11.0.
+Use this command to use the repl interpreter:
+
+> nasal -r
diff --git a/doc/README_zh.md b/doc/README_zh.md
index 90ee530..a803ce1 100644
--- a/doc/README_zh.md
+++ b/doc/README_zh.md
@@ -21,6 +21,7 @@
 * [__特殊之处__](#与andy解释器的不同之处)
 * [__堆栈追踪信息__](#堆栈追踪信息)
 * [__调试器__](#调试器)
+* [__交互解释器__](#交互解释器)
 
 __如果有好的意见或建议，欢迎联系我们!__
 
@@ -591,19 +592,24 @@ import("./dirname/dirname/filename.nas");
 如果只有上文中那种方式来添加你自定义的函数到nasal中，这肯定是非常麻烦的。
 因此，我们实现了一组实用的内置函数来帮助你添加你自己创建的模块。
 
-在2021/12/3更新后，我们给`lib.nas`添加了下面的这一批函数:
+用于加载动态库的函数在`std/dylib.nas`中:
 
 ```javascript
-var dylib={
-    dlopen:  func(libname){
-        ...
-    },
-    dlclose: func(lib){return __dlclose;   },
-    dlcall:  func(ptr,args...){return __dlcallv},
-    limitcall: func(arg_size=0){
-        ...
-    }
-};
+var dlopen = func(libname) {
+    ...
+}
+
+var dlclose = func(lib) {
+    ...
+}
+
+var dlcall = func(ptr, args...) {
+    ...
+}
+
+var limitcall = func(arg_size = 0) {
+    ...
+}
 ```
 
 这些函数是用来加载动态库的，这样nasal解释器可以根据用户需求灵活加载动态库来执行。让我们看看这些函数该如何使用。
@@ -613,36 +619,41 @@ var dylib={
 ```C++
 // 这个头文件得加上，因为我们需要拿到nasal的api
 #include "nasal.h"
-double fibonaci(double x){
-    if(x<=2)
+double fibonaci(double x) {
+    if (x<=2) {
         return x;
+    }
     return fibonaci(x-1)+fibonaci(x-2);
 }
 
 // 模块函数的参数列表一律以这个为准
-var fib(var* args,usize size,gc* ngc){
+var fib(var* args, usize size, gc* ngc) {
+    if (!size) {
+        return nas_err("fib", "lack arguments");
+    }
     // 传参会给予一个var指针，指向一个vm_vec的data()
-    var num=args[0];
+    var num = args[0];
     // 如果你想让这个函数有更强的稳定性，那么一定要进行合法性检查
     // nas_err会输出错误信息并返回错误类型让虚拟机终止执行
-    if(num.type!=vm_num)
-        return nas_err("extern_fib","\"num\" must be number");
+    if(num.type!=vm_num) {
+        return nas_err("extern_fib", "\"num\" must be number");
+    }
     // vm_num作为普通的数字类型，不是内存管理的对象，所以无需申请
     // 如果需要返回内存管理的对象，请使用ngc->alloc(type)
     return var::num(fibonaci(num.tonum()));
 }
 
 // 然后将函数名字和函数地址放到一个表里，一定要记住表尾是{nullptr,nullptr}
-mod_func func_tbl[]={
-    {"fib",fib},
-    {nullptr,nullptr}
+module_func_info func_tbl[] = {
+    {"fib", fib},
+    {nullptr, nullptr}
 };
 
 // 必须实现这个函数, 这样nasal可以通过字符串名字获得函数指针
 // 之所以用这种方式来获取函数指针, 是因为`var`是有构造函数的
 // 有构造函数的类型作为返回值, 和C是不兼容的, 这导致
 // 类似 "extern "C" var fib" 的写法会得到编译错误
-extern "C" mod_func get(){
+extern "C" module_func_info* get() {
     return func_tbl;
 }
 ```
@@ -667,10 +678,11 @@ Windows(`.dll`):
 下面例子中`os.platform()`是用来检测当前运行的系统环境的，这样可以实现跨平台:
 
 ```javascript
-var dlhandle=dylib.dlopen("libfib."~(os.platform()=="windows"?"dll":"so"));
-var fib=dlhandle.fib;
-for(var i=1;i<30;i+=1)
-    println(dylib.dlcall(fib,i));
+import.std.dylib;
+var dlhandle = dylib.dlopen("libfib."~(os.platform()=="windows"?"dll":"so"));
+var fib = dlhandle.fib;
+for(var i = 1; i<30; i+=1)
+    println(dylib.dlcall(fib, i));
 dylib.dlclose(dlhandle.lib);
 ```
 
@@ -683,15 +695,16 @@ dylib.dlclose(dlhandle.lib);
 `dylib.limitcall`用于获取使用固定长度传参的 `dlcall` 函数，这种函数可以提高你的程序运行效率，因为它不需要用 `vm_vec` 来存储传入参数，而是使用局部作用域来直接存储，从而避免了频繁调用可能导致的频繁垃圾收集。所以上面展示的代码同样可以这样写：
 
 ```javascript
-var dlhandle=dylib.dlopen("libfib."~(os.platform()=="windows"?"dll":"so"));
-var fib=dlhandle.fib;
-var invoke=dylib.limitcall(1); # this means the called function has only one parameter
-for(var i=1;i<30;i+=1)
-    println(invoke(fib,i));
+import.std.dylib;
+var dlhandle = dylib.dlopen("libfib."~(os.platform()=="windows"?"dll":"so"));
+var fib = dlhandle.fib;
+var invoke = dylib.limitcall(1); # this means the called function has only one parameter
+for(var i = 1; i<30; i+=1)
+    println(invoke(fib, i));
 dylib.dlclose(dlhandle.lib);
 ```
 
-如果接下来你看到了这个运行结果，恭喜你！
+如果得到如下运行结果，恭喜你！
 
 ```bash
 ./nasal a.nas
@@ -963,3 +976,9 @@ vm stack (0x7fffd0259138 <sp+65>, limit 10, total 7)
 ```
 
 </details>
+
+## 交互解释器
+
+v11.0 版本新增了交互式解释器 (REPL)，使用如下命令开启：
+
+> nasal -r
diff --git a/module/fib.cpp b/module/fib.cpp
index 8c0c213..1e81a99 100644
--- a/module/fib.cpp
+++ b/module/fib.cpp
@@ -15,7 +15,7 @@ double fibonaci(double x) {
 
 var fib(var* args, usize size, gc* ngc) {
     if (!size) {
-        return nas_err("fib","lack arguments");
+        return nas_err("fib", "lack arguments");
     }
     var num = args[0];
     return var::num(fibonaci(num.tonum()));
diff --git a/src/nasal_ast.h b/src/nasal_ast.h
index 76ffd6a..73142c1 100644
--- a/src/nasal_ast.h
+++ b/src/nasal_ast.h
@@ -357,7 +357,7 @@ public:
     void set_first(expr* node) {first = node;}
     void add_call(call* node) {calls.push_back(node);}
     expr* get_first() {return first;}
-    std::vector<call*>& get_calls() {return calls;}
+    auto& get_calls() {return calls;}
     void accept(ast_visitor*) override;
 };
 
diff --git a/src/nasal_import.cpp b/src/nasal_import.cpp
index f7390ae..54f6f5d 100644
--- a/src/nasal_import.cpp
+++ b/src/nasal_import.cpp
@@ -297,7 +297,8 @@ definition_expr* linker::generate_module_definition(code_block* block) {
     auto def = new definition_expr(block->get_location());
     def->set_identifier(new identifier(
         block->get_location(),
-        generate_module_name(block->get_location().file)));
+        generate_module_name(block->get_location().file)
+    ));
     
     auto call = new call_expr(block->get_location());
     auto func = new function(block->get_location());
@@ -310,33 +311,44 @@ definition_expr* linker::generate_module_definition(code_block* block) {
     return def;
 }
 
-code_block* linker::load(code_block* root, u16 fileindex) {
+code_block* linker::load(code_block* program_root, u16 fileindex) {
     auto tree = new code_block({0, 0, 0, 0, files[fileindex]});
     // load library, this ast will be linked with root directly
-    // so no namespace is generated
+    // so no extra namespace is generated
     if (!lib_loaded) {
-        auto tmp = import_nasal_lib();
-        link(tree, tmp);
-        delete tmp;
+        auto nasal_lib_code_block = import_nasal_lib();
+        // insert nasal lib code to the back of tree
+        link(tree, nasal_lib_code_block);
+        delete nasal_lib_code_block;
         lib_loaded = true;
     }
+
     // load imported modules
-    for(auto i : root->get_expressions()) {
-        if (!import_check(i)) {
+    for(auto& import_ast_node : program_root->get_expressions()) {
+        if (!import_check(import_ast_node)) {
             break;
         }
-        auto tmp = import_regular_file((call_expr*)i);
-        tree->add_expression(generate_module_definition(tmp));
+        auto module_code_block = import_regular_file((call_expr*)import_ast_node);
+        // after importing the regular file as module, delete this node
+        const auto loc = import_ast_node->get_location();
+        delete import_ast_node;
+        // and replace the node with null_expr node
+        import_ast_node = new null_expr(loc);
+        // then we generate a function warping the code block,
+        // and export the necessary global symbols in this code block
+        // by generate a return statement, with a hashmap return value
+        tree->add_expression(generate_module_definition(module_code_block));
     }
-    // add root to the back of tree
-    link(tree, root);
+
+    // insert program root to the back of tree
+    link(tree, program_root);
     return tree;
 }
 
 const error& linker::link(
     parse& parse, const std::string& self, bool spath = false) {
     show_path = spath;
-    // initializing
+    // initializing file map
     this_file = self;
     files = {self};
     module_load_stack = {self};
diff --git a/src/nasal_misc.cpp b/src/nasal_misc.cpp
index f529db8..374e190 100644
--- a/src/nasal_misc.cpp
+++ b/src/nasal_misc.cpp
@@ -159,7 +159,7 @@ f64 dec2f(const char* str) {
     if (*str) {
         return nan("");
     }
-    return ret*std::pow(10,negative*num_pow);
+    return ret*std::pow(10, negative*num_pow);
 }
 
 f64 str2num(const char* str) {
@@ -226,7 +226,7 @@ std::string rawstr(const std::string& str, const usize maxlen) {
         }
     }
     if (maxlen && ret.length()>maxlen) {
-        ret = ret.substr(0,maxlen)+"...";
+        ret = ret.substr(0, maxlen)+"...";
     }
     return ret;
 }
diff --git a/src/repl.cpp b/src/repl.cpp
index d749c07..2917361 100644
--- a/src/repl.cpp
+++ b/src/repl.cpp
@@ -116,7 +116,9 @@ void repl::execute() {
     runtime.set_allow_repl_output_flag(true);
     std::cout << "[nasal-repl] Initialization complete.\n\n";
 
-    std::cout << "Nasal REPL interpreter(experimental).\n";
+    // finish initialization, output version info
+    std::cout << "Nasal REPL interpreter version " << __nasver;
+    std::cout << " (" << __DATE__ << " " << __TIME__ << ")\n";
     help();
 
     while(true) {
diff --git a/test/scalar.nas b/test/scalar.nas
index eb0b0ea..4d853f7 100644
--- a/test/scalar.nas
+++ b/test/scalar.nas
@@ -233,4 +233,5 @@ for(var a=0;a<16;a+=1) {
     }
 }
 
-print([0, 1, 2]~[3, 4, 5], "\n");
\ No newline at end of file
+print([0, 1, 2]~[3, 4, 5], "\n");
+print(num("4.94065645841246544176568792868e-324"), "\n");
\ No newline at end of file