diff --git a/std/csv.nas b/std/csv.nas
index bf2e54a..94800a9 100644
--- a/std/csv.nas
+++ b/std/csv.nas
@@ -1,16 +1,16 @@
 # lib csv.nas
 # ValKmjolnir 2022/10/15
-var read_csv=func(path,delimeter=",",endline="\n"){
-    var context=io.readfile(path);
-    context=split(endline,context);
+var read = func(path, delimeter=",", endline="\n"){
+    var context = io.readfile(path);
+    context = split(endline, context);
     forindex(var i;context){
-        context[i]=split(delimeter,context[i]);
+        context[i] = split(delimeter,context[i]);
     }
     if(size(context)<=1){
         die("incorrect csv file <"~path~">: "~size(context)~" line(s).");
     }
     return {
-        property:context[0],
-        data:context[1:]
+        property: context[0],
+        data: context[1:]
     };
 }
\ No newline at end of file
diff --git a/std/file.nas b/std/file.nas
index 7824c3e..4159561 100644
--- a/std/file.nas
+++ b/std/file.nas
@@ -1,78 +1,85 @@
 # lib file.nas
 # ValKmjolnir 2022/3/6
-var file={
-    SEEK_SET:io.SEEK_SET,
-    SEEK_CUR:io.SEEK_CUR,
-    SEEK_END:io.SEEK_END,
-    new: func(filename,mode="r"){
-        if(!io.exists(filename))
-            return nil;
-        var fd=io.open(filename,mode);
-        return {
-            close:  func(){io.close(fd);},
-            read:   func(len){
-                var buf=mut("");
-                io.read(fd,buf,len);
-                return buf;
-            },
-            write:  func(str){return io.write(fd,str);},
-            seek:   func(pos,whence){return io.seek(fd,pos,whence);},
-            tell:   func(){return io.tell(fd);},
-            readln: func(){return io.readln(fd);},
-            stat:   func(){return io.stat(filename);},
-            eof:    func(){return io.eof(fd);}
-        };
-    }
-};
 
-var find_all_files_with_extension=func(path,extensions...){
-    var in_vec=func(ext){
-        foreach(var i;extensions){
-            if(ext==i){
+var SEEK_SET = io.SEEK_SET;
+
+var SEEK_CUR = io.SEEK_CUR;
+
+var SEEK_END = io.SEEK_END;
+
+
+var new = func(filename, mode="r"){
+    if (!io.exists(filename)) {
+        return nil;
+    }
+    var fd = io.open(filename, mode);
+    return {
+        close:  func() {io.close(fd);},
+        read:   func(len) {
+            var buf = mut("");
+            io.read(fd, buf, len);
+            return buf;
+        },
+        write:  func(str) {return io.write(fd, str);},
+        seek:   func(pos, whence) {return io.seek(fd, pos, whence);},
+        tell:   func() {return io.tell(fd);},
+        readln: func() {return io.readln(fd);},
+        stat:   func() {return io.stat(filename);},
+        eof:    func() {return io.eof(fd);}
+    };
+}
+
+var find_all_files_with_extension = func(path, extensions...){
+    var in_vec = func(ext) {
+        foreach(var i;extensions) {
+            if (ext==i){
                 return 1;
             }
         }
         return 0;
     }
-    var res=[];
+    var res = [];
     foreach(var f;find_all_files(path)){
-        var tmp=split('.',f);
-        if(size(tmp)>1 and in_vec(tmp[-1])){
-            append(res,f);
+        var tmp = split('.', f);
+        if (size(tmp)>1 and in_vec(tmp[-1])) {
+            append(res, f);
         }
     }
     return res;
 }
 
-var find_all_files=func(path){
-    if(!io.exists(path))
+var find_all_files = func(path){
+    if (!io.exists(path)) {
         return [];
-    var dd=unix.opendir(path);
-    var res=[];
-    while(var n=unix.readdir(dd))
-        if(unix.isfile(path~"/"~n))
-            append(res,n);
+    }
+    var dd = unix.opendir(path);
+    var res = [];
+    while(var n = unix.readdir(dd))
+        if(unix.isfile(path~"/"~n)) {
+            append(res, n);
+        }
     unix.closedir(dd);
     return res;
 }
 
-var recursive_find_files=func(path){
-    if(!io.exists(path))
+var recursive_find_files = func(path) {
+    if (!io.exists(path)) {
         return nil;
-    var dd=unix.opendir(path);
-    var res={
-        dir:path,
-        files:[]
+    }
+    var dd = unix.opendir(path);
+    var res = {
+        dir: path,
+        files: []
     };
-    while(var n=unix.readdir(dd)){
-        if(unix.isfile(path~"/"~n)){
+    while(var n = unix.readdir(dd)) {
+        if (unix.isfile(path~"/"~n)) {
             append(res.files,n);
-        }elsif(unix.isdir(path~"/"~n) and n!="." and n!=".."){
-            var tmp=recursive_find_files(path~"/"~n);
-            if(tmp!=nil)
+        } elsif (unix.isdir(path~"/"~n) and n!="." and n!="..") {
+            var tmp = recursive_find_files(path~"/"~n);
+            if (tmp!=nil) {
                 append(res.files,tmp);
+            }
         }
-
     }
     unix.closedir(dd);
     return res;
diff --git a/std/json.nas b/std/json.nas
index 145ca01..e2ff68a 100644
--- a/std/json.nas
+++ b/std/json.nas
@@ -1,59 +1,59 @@
 # lib json.nas
 # 2021 ValKmjolnir
-var JSON=func() {
 
-    var (
-        j_eof,
-        j_lbrace,
-        j_rbrace,
-        j_lbrkt,
-        j_rbrkt,
-        j_comma,
-        j_colon,
-        j_str,
-        j_num,
-        j_id
-    )=(0,1,2,3,4,5,6,7,8,9);
-    var j_content=[
-        "eof",
-        "`{`",
-        "`}`",
-        "`[`",
-        "`]`",
-        "`,`",
-        "`:`",
-        "string",
-        "number",
-        "identifier"
-    ];
+var (
+    _j_eof, _j_lbrace, _j_rbrace, _j_lbrkt, _j_rbrkt,
+    _j_comma, _j_colon, _j_str, _j_num, _j_id
+) = (0, 1, 2, 3, 4, 5, 6, 7, 8, 9);
 
-    var text='';
-    var line=1;
-    var text_size=0;
-    var ptr=0;
-    var token={content:'',type:''};
+var _j_content = [
+    "eof",
+    "`{`",
+    "`}`",
+    "`[`",
+    "`]`",
+    "`,`",
+    "`:`",
+    "string",
+    "number",
+    "identifier"
+];
 
-    var init=func() {
-        text='';
-        line=1;
-        text_size=0;
-        ptr=0;
-        token={content:'',type:''};
+var JSON = func() {
+
+    var text = "";
+    var line = 1;
+    var text_size = 0;
+    var ptr = 0;
+    var token = {
+        content: "",
+        type: ""
+    };
+
+    var init = func() {
+        text = "";
+        line = 1;
+        text_size = 0;
+        ptr = 0;
+        token = {
+            content: "",
+            type: ""
+        };
     }
 
-    var isnum=func(c) {
+    var isnum = func(c) {
         return '0'<=c and c<='9';
     }
 
-    var isid=func(c) {
-        var tmp=c[0];
+    var isid = func(c) {
+        var tmp = c[0];
         return ('a'[0]<=tmp and tmp<='z'[0]) or
-        ('A'[0]<=tmp and tmp<='Z'[0]) or
-        c=='_';
+            ('A'[0]<=tmp and tmp<='Z'[0]) or
+            c=='_';
     }
 
-    var check=func() {
-        var c=char(text[ptr]);
+    var check = func() {
+        var c = char(text[ptr]);
         return (
             c=='{' or c=='}' or
             c=='[' or c==']' or
@@ -63,151 +63,152 @@ var JSON=func() {
         );
     }
 
-    var get=func(str) {
+    var get = func(str) {
         init();
-        if(!size(str)) {
+        if (!size(str)) {
             println("JSON.parse: empty string");
-            str="[]";
+            str = "[]";
         }
-        text=str;
-        text_size=size(text);
+        text = str;
+        text_size = size(text);
         return;
     }
 
-    var next=func() {
+    var next = func() {
         while(ptr<text_size and !check()) {
-            if(char(text[ptr])=='\n')
-                line+=1;
-            ptr+=1;
+            if (char(text[ptr])=='\n') {
+                line += 1;
+            }
+            ptr += 1;
         }
         if(ptr>=text_size) {
-            token.content="eof";
-            token.type=j_eof;
+            token.content = "eof";
+            token.type = _j_eof;
             return;
         }
         
-        var c=char(text[ptr]);
-        if(c=='{') {
-            token.content='{';
-            token.type=j_lbrace;
-        } elsif(c=='}') {
-            token.content='}';
-            token.type=j_rbrace;
-        } elsif(c=='[') {
-            token.content='[';
-            token.type=j_lbrkt;
-        } elsif(c==']') {
-            token.content=']';
-            token.type=j_rbrkt;
-        } elsif(c==',') {
-            token.content=',';
-            token.type=j_comma;
-        } elsif(c==':') {
-            token.content=':';
-            token.type=j_colon;
-        } elsif(c=='\"' or c=='\'') {
-            var strbegin=c;
-            var s="";
-            ptr+=1;
+        var c = char(text[ptr]);
+        if (c=='{') {
+            token.content = '{';
+            token.type = _j_lbrace;
+        } elsif (c=='}') {
+            token.content = '}';
+            token.type = _j_rbrace;
+        } elsif (c=='[') {
+            token.content = '[';
+            token.type = _j_lbrkt;
+        } elsif (c==']') {
+            token.content = ']';
+            token.type = _j_rbrkt;
+        } elsif (c==',') {
+            token.content = ',';
+            token.type = _j_comma;
+        } elsif (c==':') {
+            token.content = ':';
+            token.type = _j_colon;
+        } elsif (c=='\"' or c=='\'') {
+            var strbegin = c;
+            var s = "";
+            ptr += 1;
             while(ptr<text_size and char(text[ptr])!=strbegin) {
-                s~=char(text[ptr]);
-                ptr+=1;
-                if(char(text[ptr-1])=="\\" and ptr<text_size) {
-                    s~=char(text[ptr]);
-                    ptr+=1;
+                s ~= char(text[ptr]);
+                ptr += 1;
+                if (char(text[ptr-1])=="\\" and ptr<text_size) {
+                    s ~= char(text[ptr]);
+                    ptr += 1;
                 }
             }
             token.content=s;
-            token.type=j_str;
-        } elsif(isnum(c)) {
-            var s=c;
-            ptr+=1;
+            token.type=_j_str;
+        } elsif (isnum(c)) {
+            var s = c;
+            ptr += 1;
             while(ptr<text_size and ((isnum(char(text[ptr])) or char(text[ptr])=='.'))) {
-                s~=char(text[ptr]);
-                ptr+=1;
+                s ~= char(text[ptr]);
+                ptr += 1;
             }
-            ptr-=1;
-            token.content=num(s);
-            token.type=j_num;
-        } elsif(isid(c)) {
-            var s=c;
-            ptr+=1;
+            ptr -= 1;
+            token.content = num(s);
+            token.type = _j_num;
+        } elsif (isid(c)) {
+            var s = c;
+            ptr += 1;
             while(ptr<text_size and (isid(char(text[ptr])) or isnum(char(text[ptr])))) {
-                s~=char(text[ptr]);
-                ptr+=1;
+                s ~= char(text[ptr]);
+                ptr += 1;
             }
-            ptr-=1;
-            token.content=s;
-            token.type=j_id;
+            ptr -= 1;
+            token.content = s;
+            token.type = _j_id;
         }
-        ptr+=1;
+        ptr += 1;
         return;
     }
 
-    var match=func(type) {
+    var match = func(type) {
         if(token.type!=type)
-            println("JSON.parse: line ",line,": expect ",j_content[type]," but get `",token.content,"`.");
+            println("JSON.parse: line ",line,": expect ",_j_content[type]," but get `",token.content,"`.");
         next();
         return;
     }
 
-    var member=func(hash) {
-        var name=token.content;
-        if(token.type==j_rbrace) {
+    var member = func(hash) {
+        var name = token.content;
+        if(token.type==_j_rbrace) {
             return;
         }
-        if(token.type==j_str) {
-            match(j_str);
+        if(token.type==_j_str) {
+            match(_j_str);
         } else {
-            match(j_id);
+            match(_j_id);
         }
-        match(j_colon);
-        if(token.type==j_lbrace) {
-            hash[name]=hash_gen();
-        } elsif(token.type==j_lbrkt) {
-            hash[name]=vec_gen();
-        } elsif(token.type==j_str or token.type==j_num) {
-            hash[name]=token.content;
+        match(_j_colon);
+        if(token.type==_j_lbrace) {
+            hash[name] = hash_gen();
+        } elsif(token.type==_j_lbrkt) {
+            hash[name] = vec_gen();
+        } elsif(token.type==_j_str or token.type==_j_num) {
+            hash[name] = token.content;
             next();
         }
         return;
     }
 
-    var hash_gen=func() {
-        var hash={};
-        match(j_lbrace);
+    var hash_gen = func() {
+        var hash = {};
+        match(_j_lbrace);
         member(hash);
-        while(token.type==j_comma) {
-            match(j_comma);
+        while(token.type==_j_comma) {
+            match(_j_comma);
             member(hash);
         }
-        match(j_rbrace);
+        match(_j_rbrace);
         return hash;
     }
 
-    var vec_gen=func() {
-        var vec=[];
-        match(j_lbrkt);
-        if(token.type==j_lbrace) {
-            append(vec,hash_gen());
-        } elsif(token.type==j_lbrkt) {
-            append(vec,vec_gen());
-        } elsif(token.type==j_str or token.type==j_num) {
-            append(vec,token.content);
+    var vec_gen = func() {
+        var vec = [];
+        match(_j_lbrkt);
+        if(token.type==_j_lbrace) {
+            append(vec, hash_gen());
+        } elsif(token.type==_j_lbrkt) {
+            append(vec, vec_gen());
+        } elsif(token.type==_j_str or token.type==_j_num) {
+            append(vec, token.content);
             next();
         }
-        while(token.type==j_comma) {
-            match(j_comma);
-            if(token.type==j_lbrace) {
-                append(vec,hash_gen());
-            } elsif(token.type==j_lbrkt) {
-                append(vec,vec_gen());
-            } elsif(token.type==j_str or token.type==j_num) {
-                append(vec,token.content);
+        while(token.type==_j_comma) {
+            match(_j_comma);
+            if(token.type==_j_lbrace) {
+                append(vec, hash_gen());
+            } elsif(token.type==_j_lbrkt) {
+                append(vec, vec_gen());
+            } elsif(token.type==_j_str or token.type==_j_num) {
+                append(vec, token.content);
                 next();
             }
         }
-        match(j_rbrkt);
+        match(_j_rbrkt);
         return vec;
     }
 
@@ -220,10 +221,10 @@ var JSON=func() {
             get(str);
             next();
 
-            if(token.type==j_lbrkt) {
-                var res=vec_gen();
+            if (token.type==_j_lbrkt) {
+                var res = vec_gen();
             } else {
-                var res=hash_gen();
+                var res = hash_gen();
             }
 
             init();
@@ -232,55 +233,55 @@ var JSON=func() {
     };
 }();
 
-JSON.stringify=func(object) {
+JSON.stringify = func(object) {
     if(typeof(object)!="hash" and typeof(object)!="vec") {
         println("JSON.stringify: must use hashmap or vector");
         return "[]";
     }
 
-    var s="";
-    var gen=func(elem) {
-        var t=typeof(elem);
+    var s = "";
+    var gen = func(elem) {
+        var t = typeof(elem);
         if(t=="num") {
-            s~=str(elem);
+            s ~= str(elem);
         } elsif(t=="str") {
-            s~='"'~elem~'"';
+            s ~= '"'~elem~'"';
         } elsif(t=="vec") {
             vgen(elem);
         } elsif(t=="hash") {
             hgen(elem);
         } else {
-            s~='"undefined"';
+            s ~= '"undefined"';
         }
     }
 
-    var vgen=func(v) {
-        s~="[";
-        var vsize=size(v);
-        for(var i=0;i<vsize;i+=1) {
+    var vgen = func(v) {
+        s ~= "[";
+        var vsize = size(v);
+        for(var i = 0; i<vsize; i += 1) {
             gen(v[i]);
-            if(i!=vsize-1) {
+            if (i!=vsize-1) {
                 s~=",";
             }
         }
-        s~="]";
+        s ~= "]";
     }
 
-    var hgen=func(h) {
-        s~="{";
-        var k=keys(h);
-        var vsize=size(k);
-        for(var i=0;i<vsize;i+=1) {
-            s~=k[i]~":";
+    var hgen = func(h) {
+        s ~= "{";
+        var k = keys(h);
+        var vsize = size(k);
+        for(var i = 0; i<vsize; i += 1) {
+            s ~= k[i]~":";
             gen(h[k[i]]);
-            if(i!=vsize-1) {
-                s~=",";
+            if (i!=vsize-1) {
+                s ~= ",";
             }
         }
-        s~="}";
+        s ~= "}";
     }
 
-    if(typeof(object)=="vec") {
+    if (typeof(object)=="vec") {
         vgen(object);
     } else {
         hgen(object);
diff --git a/std/padding.nas b/std/padding.nas
index b327470..f008ec8 100644
--- a/std/padding.nas
+++ b/std/padding.nas
@@ -1,20 +1,24 @@
 # padding.nas
 # ValKmjolnir 2022/9/4
 
-var leftpad=func(s,len,char=" "){
-    if(typeof(s)=="num")
-        s=str(s);
-    var strlen=size(s);
-    for(var i=strlen;i<len;i+=1)
-        s=char~s;
+var leftpad = func(s, len, char=" ") {
+    if (typeof(s)=="num") {
+        s = str(s);
+    }
+    var strlen = size(s);
+    for(var i = strlen; i<len; i += 1) {
+        s = char~s;
+    }
     return s;
 }
 
-var rightpad=func(s,len,char=" "){
-    if(typeof(s)=="num")
-        s=str(s);
-    var strlen=size(s);
-    for(var i=strlen;i<len;i+=1)
-        s~=char;
+var rightpad = func(s, len, char=" ") {
+    if (typeof(s)=="num") {
+        s = str(s);
+    }
+    var strlen = size(s);
+    for(var i = strlen; i<len; i += 1) {
+        s ~= char;
+    }
     return s;
 }
\ No newline at end of file
diff --git a/std/string.nas b/std/string.nas
index 5aefb90..81da2fa 100644
--- a/std/string.nas
+++ b/std/string.nas
@@ -1,10 +1,10 @@
 # string.nas
 # ValKmjolnir 2022/10/5
 
-var join=func(sep, vec){
+var join = func(sep, vec){
     var len = size(vec);
     var res = "";
-    for(var i = 0; i<len; i+=1) {
+    for(var i = 0; i<len; i += 1) {
         res ~= vec[i];
         res ~= (i==len-1? "":sep);
     }