diff --git a/makefile b/makefile
index b02b660..48c29ea 100644
--- a/makefile
+++ b/makefile
@@ -33,10 +33,7 @@ clean:
 
 test:nasal
 	@ ./nasal -e test/ascii-art.nas
-	@ ./nasal -c test/auto_crash.nas
-	@ ./nasal -a -c test/bf.nas
-	@ ./nasal -a -c test/bfconvertor.nas
-	@ ./nasal -d test/bfs.nas
+	@ ./nasal -t -d test/bfs.nas
 	@ ./nasal -t test/bigloop.nas
 	@ ./nasal -t test/bp.nas
 	@ ./nasal -d test/calc.nas
@@ -51,7 +48,6 @@ test:nasal
 	@ ./nasal -t -d test/fib.nas
 	@ ./nasal -e test/filesystem.nas
 	@ ./nasal -d test/hexdump.nas
-	@ ./nasal -c test/httptest.nas
 	@ ./nasal -e test/json.nas
 	@ ./nasal -e test/leetcode1319.nas
 	@ ./nasal -d test/lexer.nas
@@ -63,11 +59,9 @@ test:nasal
 	@ ./nasal -t -d test/md5compare.nas
 	-@ ./nasal -d test/module_test.nas
 	@ ./nasal -e test/nasal_test.nas
-	@ ./nasal test/occupation.nas 2
+	@ ./nasal -t -d test/occupation.nas 2
 	@ ./nasal -t -d test/pi.nas
-	@ ./nasal -c test/ppmgen.nas
 	@ ./nasal -t -d test/prime.nas
-	@ ./nasal -c test/push.nas
 	@ ./nasal -e test/qrcode.nas
 	@ ./nasal -t -d test/quick_sort.nas
 	@ ./nasal -e test/scalar.nas hello world
diff --git a/nasal_codegen.h b/nasal_codegen.h
index 25d189d..a7aa2e7 100644
--- a/nasal_codegen.h
+++ b/nasal_codegen.h
@@ -147,12 +147,11 @@ public:
         u8  op=ins.code.op;
         u32 num=ins.code.num;
         out<<std::hex<<"0x"
-           <<std::setw(6)<<std::setfill('0')<<ins.index<<"      "
+           <<std::setw(6)<<std::setfill('0')<<ins.index<<"     "
            <<std::setw(2)<<std::setfill('0')<<(u32)op<<" "
-           <<std::setw(2)<<std::setfill('0')<<((num>>24)&0xff)<<" "
            <<std::setw(2)<<std::setfill('0')<<((num>>16)&0xff)<<" "
            <<std::setw(2)<<std::setfill('0')<<((num>>8)&0xff)<<" "
-           <<std::setw(2)<<std::setfill('0')<<(num&0xff)<<"      "
+           <<std::setw(2)<<std::setfill('0')<<(num&0xff)<<"     "
            <<opname[op]<<"  "<<std::dec;
         switch(op) {
             case op_addeq: case op_subeq:  case op_muleq: case op_diveq:
diff --git a/nasal_parse.h b/nasal_parse.h
index 0d3963b..79a9691 100644
--- a/nasal_parse.h
+++ b/nasal_parse.h
@@ -836,9 +836,9 @@ ast parse::definition() {
     if (lookahead(tok::var)) {
         match(tok::var);
         switch(toks[ptr].type) {
-            case tok::id:     node.add(id());break;
+            case tok::id: node.add(id());break;
             case tok::lcurve: node.add(outcurve_def());break;
-            default:          die(thisspan,"expected identifier");break;
+            default: die(thisspan,"expected identifier");break;
         }
     } else if (lookahead(tok::lcurve)) {
         node.add(incurve_def());
diff --git a/nasal_vm.h b/nasal_vm.h
index 028fbcd..3fa8cf6 100644
--- a/nasal_vm.h
+++ b/nasal_vm.h
@@ -9,35 +9,39 @@
 
 class vm {
 protected:
+
     /* registers and constants of vm */
-    u32  pc;       // program counter
-    var* localr;   // local scope register
-    var* memr;     // used for mem_call
-    var  funcr;    // function register
-    var  upvalr;   // upvalue register
-    var* canary;   // avoid stackoverflow
-    var* top;      // stack top
+    u32  pc;     // program counter
+    var* localr; // local frame pointer
+    var* memr;   // store address got by memory call
+    var funcr;   // function register
+    var upvalr;  // upvalue register
+    var* canary; // avoid stack overflow, at the top of main stack
+    var* top;    // stack top pointer
 
     /* constants */
-    const f64*    cnum;   // const numbers
-    const string* cstr;   // const symbols
-    std::vector<u32> imm; // immediate number
+    const f64* cnum;      // constant numbers
+    const string* cstr;   // constant symbols and strings
+    std::vector<u32> imm; // immediate number table
     
     /* garbage collector */
-    gc  ngc;
+    gc ngc;
+
     /* main stack */
     var stack[STACK_DEPTH];
 
     /* values used for debugger */
-    const string* files;
-    const opcode* bytecode;
+    const string* files;    // file name list
+    const opcode* bytecode; // bytecode buffer address
 
+    /* vm initializing function */
     void init(
         const std::vector<string>&,
         const std::vector<f64>&,
         const std::vector<opcode>&,
         const std::vector<string>&,
         const std::vector<string>&);
+
     /* debug functions */
     bool verbose;
     void valinfo(var&);
@@ -49,8 +53,10 @@ protected:
     void ustate();
     void detail();
     void die(const string&);
+
     /* vm calculation functions*/
     bool cond(var&);
+
     /* vm operands */
     void o_intg();
     void o_intl();
@@ -139,12 +145,16 @@ protected:
     void o_mcallh();
     void o_ret();
 public:
+
+    /* constructor of vm instance */
     vm():
         pc(0),localr(nullptr),memr(nullptr),funcr(nil),
         upvalr(nil),canary(nullptr),top(stack),
         cnum(nullptr),cstr(nullptr),
         ngc(pc,localr,memr,funcr,upvalr,canary,top,stack),
         files(nullptr),bytecode(nullptr),verbose(false) {}
+
+    /* execution entry */
     void run(
         const codegen&,
         const linker&,
@@ -179,39 +189,38 @@ void vm::init(
 
 void vm::valinfo(var& val) {
     const nas_val* p=val.val.gcobj;
-    std::cout<<"\t";
     switch(val.type) {
-        case vm_none: std::cout<<"| null |";break;
-        case vm_ret:  std::cout<<"| pc   | 0x"<<std::hex
+        case vm_none: std::clog<<"| null |";break;
+        case vm_ret:  std::clog<<"| pc   | 0x"<<std::hex
                                <<val.ret()<<std::dec;break;
-        case vm_addr: std::cout<<"| addr | 0x"<<std::hex
+        case vm_addr: std::clog<<"| addr | 0x"<<std::hex
                                <<(u64)val.addr()<<std::dec;break;
-        case vm_cnt:  std::cout<<"| cnt  | "<<val.cnt();break;
-        case vm_nil:  std::cout<<"| nil  |";break;
-        case vm_num:  std::cout<<"| num  | "<<val.num();break;
-        case vm_str:  std::cout<<"| str  | <0x"<<std::hex<<(u64)p
+        case vm_cnt:  std::clog<<"| cnt  | "<<val.cnt();break;
+        case vm_nil:  std::clog<<"| nil  |";break;
+        case vm_num:  std::clog<<"| num  | "<<val.num();break;
+        case vm_str:  std::clog<<"| str  | <0x"<<std::hex<<(u64)p
                                <<"> "<<rawstr(val.str(),16)<<std::dec;break;
-        case vm_func: std::cout<<"| func | <0x"<<std::hex<<(u64)p
+        case vm_func: std::clog<<"| func | <0x"<<std::hex<<(u64)p
                                <<"> entry:0x"<<val.func().entry
                                <<std::dec;break;
-        case vm_upval:std::cout<<"| upval| <0x"<<std::hex<<(u64)p
+        case vm_upval:std::clog<<"| upval| <0x"<<std::hex<<(u64)p
                                <<std::dec<<"> ["<<val.upval().size
                                <<" val]";break;
-        case vm_vec:  std::cout<<"| vec  | <0x"<<std::hex<<(u64)p
+        case vm_vec:  std::clog<<"| vec  | <0x"<<std::hex<<(u64)p
                                <<std::dec<<"> ["<<val.vec().size()
                                <<" val]";break;
-        case vm_hash: std::cout<<"| hash | <0x"<<std::hex<<(u64)p
+        case vm_hash: std::clog<<"| hash | <0x"<<std::hex<<(u64)p
                                <<std::dec<<"> {"<<val.hash().size()
                                <<" val}";break;
-        case vm_obj:  std::cout<<"| obj  | <0x"<<std::hex<<(u64)p
+        case vm_obj:  std::clog<<"| obj  | <0x"<<std::hex<<(u64)p
                                <<"> obj:0x"<<(u64)val.obj().ptr
                                <<std::dec;break;
-        case vm_co:   std::cout<<"| co   | <0x"<<std::hex<<(u64)p
+        case vm_co:   std::clog<<"| co   | <0x"<<std::hex<<(u64)p
                                <<std::dec<<"> coroutine";break;
-        default:      std::cout<<"| err  | <0x"<<std::hex<<(u64)p
+        default:      std::clog<<"| err  | <0x"<<std::hex<<(u64)p
                                <<std::dec<<"> unknown object";break;
     }
-    std::cout<<"\n";
+    std::clog<<"\n";
 }
 
 void vm::traceback() {
@@ -225,19 +234,19 @@ void vm::traceback() {
         }
     }
     ret.push(pc); // store the position program crashed
-    std::cout<<"trace back ("<<(ngc.stack==stack?"main":"coroutine")<<")\n";
+    std::clog<<"trace back ("<<(ngc.stack==stack?"main":"coroutine")<<")\n";
     for(u32 p=0,same=0,prev=0xffffffff;!ret.empty();prev=p,ret.pop()) {
         if ((p=ret.top())==prev) {
             ++same;
             continue;
         }
         if (same) {
-            std::cout
-            <<"  0x"<<std::hex<<std::setw(8)<<std::setfill('0')
-            <<prev<<std::dec<<"      "<<same<<" same call(s)\n";
+            std::clog
+            <<"  0x"<<std::hex<<std::setw(6)<<std::setfill('0')
+            <<prev<<std::dec<<"     "<<same<<" same call(s)\n";
         }
         same=0;
-        std::cout<<"  "<<codestream(bytecode[p],p,cnum,cstr,files)<<"\n";
+        std::clog<<"  "<<codestream(bytecode[p],p,cnum,cstr,files)<<"\n";
     }
     // the first called place has no same calls
 }
@@ -247,38 +256,40 @@ void vm::stackinfo(const u32 limit=10) {
     const u32 gsize=ngc.stack==stack?bytecode[0].num:0;
     var* t=top;
     var* bottom=ngc.stack+gsize;
-    std::cout<<"vm stack (0x"<<std::hex<<(u64)bottom<<std::dec
-             <<" <sp+"<<gsize<<">, limit "<<limit<<", total "
+    std::clog<<"stack (0x"<<std::hex<<(u64)bottom<<std::dec
+             <<" <+"<<gsize<<">, limit "<<limit<<", total "
              <<(t<bottom? 0:(i64)(t-bottom+1))<<")\n";
     for(u32 i=0;i<limit && t>=bottom;++i,--t) {
-        std::cout<<"  0x"<<std::hex
-                 <<std::setw(8)<<std::setfill('0')
-                 <<(u64)(t-ngc.stack)<<std::dec;
+        std::clog<<"  0x"<<std::hex
+                 <<std::setw(6)<<std::setfill('0')
+                 <<(u64)(t-ngc.stack)<<std::dec
+                 <<"    ";
         valinfo(t[0]);
     }
 }
 
 void vm::reginfo() {
-    std::cout<<"registers ("<<(ngc.cort?"coroutine":"main")<<")\n"<<std::hex
-             <<"  [ pc     ]    | pc   | 0x"<<pc<<"\n"
-             <<"  [ global ]    | addr | 0x"<<(u64)stack<<"\n"
-             <<"  [ localr ]    | addr | 0x"<<(u64)localr<<"\n"
-             <<"  [ memr   ]    | addr | 0x"<<(u64)memr<<"\n"
-             <<"  [ canary ]    | addr | 0x"<<(u64)canary<<"\n"
-             <<"  [ top    ]    | addr | 0x"<<(u64)top<<"\n"
+    std::clog<<"registers ("<<(ngc.cort?"coroutine":"main")<<")\n"<<std::hex
+             <<"  [pc    ]    | pc   | 0x"<<pc<<"\n"
+             <<"  [global]    | addr | 0x"<<(u64)stack<<"\n"
+             <<"  [local ]    | addr | 0x"<<(u64)localr<<"\n"
+             <<"  [memr  ]    | addr | 0x"<<(u64)memr<<"\n"
+             <<"  [canary]    | addr | 0x"<<(u64)canary<<"\n"
+             <<"  [top   ]    | addr | 0x"<<(u64)top<<"\n"
              <<std::dec;
-    std::cout<<"  [ funcr  ]";valinfo(funcr);
-    std::cout<<"  [ upvalr ]";valinfo(upvalr);
+    std::clog<<"  [funcr ]    ";valinfo(funcr);
+    std::clog<<"  [upval ]    ";valinfo(upvalr);
 }
 
 void vm::gstate() {
     if (!bytecode[0].num || stack[0].type==vm_none) { // bytecode[0].op is op_intg
         return;
     }
-    std::cout<<"global (0x"<<std::hex<<(u64)stack<<" <sp+0>)\n"<<std::dec;
+    std::clog<<"global (0x"<<std::hex<<(u64)stack<<" <+0>)\n"<<std::dec;
     for(u32 i=0;i<bytecode[0].num;++i) {
-        std::cout<<"  0x"<<std::hex<<std::setw(8)
-                 <<std::setfill('0')<<i<<std::dec;
+        std::clog<<"  0x"<<std::hex<<std::setw(6)
+                 <<std::setfill('0')<<i<<std::dec
+                 <<"    ";
         valinfo(stack[i]);
     }
 }
@@ -288,11 +299,12 @@ void vm::lstate() {
         return;
     }
     const u32 lsize=funcr.func().lsize;
-    std::cout<<"local (0x"<<std::hex<<(u64)localr
-             <<" <sp+"<<(u64)(localr-ngc.stack)<<">)\n"<<std::dec;
+    std::clog<<"local (0x"<<std::hex<<(u64)localr
+             <<" <+"<<(u64)(localr-ngc.stack)<<">)\n"<<std::dec;
     for(u32 i=0;i<lsize;++i) {
-        std::cout<<"  0x"<<std::hex<<std::setw(8)
-                 <<std::setfill('0')<<i<<std::dec;
+        std::clog<<"  0x"<<std::hex<<std::setw(6)
+                 <<std::setfill('0')<<i<<std::dec
+                 <<"    ";
         valinfo(localr[i]);
     }
 }
@@ -301,14 +313,15 @@ void vm::ustate() {
     if (funcr.type==vm_nil || funcr.func().upval.empty()) {
         return;
     }
-    std::cout<<"upvalue\n";
+    std::clog<<"upvalue\n";
     auto& upval=funcr.func().upval;
     for(u32 i=0;i<upval.size();++i) {
-        std::cout<<"  -> upval["<<i<<"]:\n";
+        std::clog<<"  -> upval["<<i<<"]:\n";
         auto& uv=upval[i].upval();
         for(u32 j=0;j<uv.size;++j) {
-            std::cout<<"     0x"<<std::hex<<std::setw(8)
-                     <<std::setfill('0')<<j<<std::dec;
+            std::clog<<"     0x"<<std::hex<<std::setw(6)
+                     <<std::setfill('0')<<j<<std::dec
+                     <<" ";
             valinfo(uv[j]);
         }
     }
@@ -322,7 +335,7 @@ void vm::detail() {
 }
 
 void vm::die(const string& str) {
-    std::cout<<"[vm] error: "<<str<<"\n";
+    std::cerr<<"[vm] error: "<<str<<"\n";
     traceback();
     stackinfo();
 
diff --git a/test/bfs.nas b/test/bfs.nas
index 97fb818..b210665 100644
--- a/test/bfs.nas
+++ b/test/bfs.nas
@@ -19,7 +19,7 @@ var prt=func(){
     }
     s~='+--------------------+\n';
     print(s);
-    unix.sleep(1/200);
+    unix.sleep(1/800);
 }
 
 var bfs=func(begin,end){
diff --git a/test/coroutine.nas b/test/coroutine.nas
index da42821..20e1732 100644
--- a/test/coroutine.nas
+++ b/test/coroutine.nas
@@ -104,14 +104,14 @@ for(var t=0;t<10;t+=1){
         counter+=1;
         for(var i=0;i<t+1;i+=1)
             coroutine.resume(co);
-        if(counter-int(counter/5000)*5000==0){
+        if(counter-int(counter/1000)*1000==0){
             var rate=counter/2e5;
             print(" ",bar.bar(rate)," ",leftpad(str(int(rate*100)),3),"% | ",str(1e3*int(counter/tm.elapsedMSec()))," tasks/s         \r");
         }
     }
 
     tm.stamp();
-    for(var i=0;i<2e5;i+=1)
+    for(var i=0;i<1e5;i+=1)
         consumer();
     println(" ",bar.bar(1)," 100% | ",str(int(1e3*counter/tm.elapsedMSec()))," tasks/s         ");
 }
\ No newline at end of file
diff --git a/test/datalog.nas b/test/datalog.nas
index 8404d7d..eecf86a 100644
--- a/test/datalog.nas
+++ b/test/datalog.nas
@@ -102,6 +102,6 @@ for(var i=10;i<1e6;i*=10) {
     project(i);
 }
 println("select");
-for(var i=100;i<1e7;i*=10) {
+for(var i=10;i<1e6;i*=10) {
     select(i);
 }
\ No newline at end of file
diff --git a/test/json.nas b/test/json.nas
index 2b6c971..990a255 100644
--- a/test/json.nas
+++ b/test/json.nas
@@ -37,12 +37,14 @@ println(JSON.parse(ss),"\n");
 func {
     var bar=process_bar.high_resolution_bar(30);
     var tmp=[
+        {t0:nil},
         {t1:nil},
         {t2:nil},
         {t3:nil},
         {t4:nil},
         {t5:nil},
-        {t6:nil}
+        {t6:nil},
+        {t7:nil}
     ];
 
     srand();
@@ -50,14 +52,14 @@ func {
         var name=keys(h)[0];
         h[name]=[];
         print("\e[1000D",bar.bar(0));
-        for(var i=0;i<1e3;i+=1) {
+        for(var i=0;i<500;i+=1) {
             append(h[name],{id:i,content:int(rand()*1e7)});
-            print("\e[1000D",bar.bar((i+1)/1e3));
+            print("\e[1000D",bar.bar((i+1)/500));
         }
         print("\e[1000D",bar.bar(1)," executing...\n");
     }
     print("\e[1000D","\e["~str(size(tmp))~"A");
     foreach(var h;JSON.parse(JSON.stringify(tmp))) {
-        println("\e[1000D",bar.bar(1)," done ",keys(h)[0]," ",size(h[keys(h)[0]]),"     ");
+        println("\e[1000D",bar.bar(1)," parse done ",keys(h)[0]," ",size(h[keys(h)[0]]));
     }
 }();
\ No newline at end of file
diff --git a/test/md5compare.nas b/test/md5compare.nas
index a1e4900..115ce51 100644
--- a/test/md5compare.nas
+++ b/test/md5compare.nas
@@ -1,80 +1,66 @@
 import.test.md5;
 import.stl.process_bar;
+import.stl.file;
 srand();
 
-var compare=func(){
+var compare=func() {
     var ch=[
         "0","1","2","3","4","5","6","7","8","9","a","b","c","d","e","f","+",
         "_","*","/","\'","\"",".",",",";",":","<",">","!","@","#","$","%",
         "^","&","*","(",")","-","=","\\","|","[","]","{","}","`"," ","\t","?"
     ];
-    return func(begin,end){
+    return func(begin,end) {
         var byte=0;
         var total=end-begin;
         var timestamp=maketimestamp();
         timestamp.stamp();
         var bar=process_bar.high_resolution_bar(40);
-        for(var i=begin;i<end;i+=1){
+        for(var i=begin;i<end;i+=1) {
             var s="";
-            for(var j=0;j<i;j+=1){
+            for(var j=0;j<i;j+=1) {
                 s~=ch[rand()*size(ch)];
             }
             byte+=size(s);
             var res=md5(s);
-            if(cmp(res,_md5(s))){
+            if(cmp(res,_md5(s))) {
                 die("error: "~str(i));
             }
-            print(" ",bar.bar((i-begin+1)/total)," (",i-begin+1,"/",total,")\t",res," byte: ",int(byte/1024),"k time: ",timestamp.elapsedMSec(),"    \r");
+            if (i-begin-int((i-begin)/4)*4==0) {
+                print(
+                    "\e[1000D ",bar.bar((i-begin+1)/total),
+                    " (",i-begin+1,"/",total,")\t",
+                    res," byte: ",int(byte/1024),"k"
+                );
+            }
         }
+        print(
+            "\e[1000D ",bar.bar((i-begin)/total),
+            " (",i-begin,"/",total,")\t",
+            res," byte: ",int(byte/1024),"k",
+            " time: ",timestamp.elapsedMSec()
+        );
         print("\n");
     };
 }();
 
 var filechecksum=func(){
-    var files=[
-        "./stl/fg_env.nas",         "./stl/file.nas",
-        "./stl/json.nas",           "./stl/lib.nas",
-        "./stl/list.nas",           "./stl/log.nas",
-        "./stl/mat.nas",            "./stl/module.nas",
-        "./stl/padding.nas",        "./stl/process_bar.nas",
-        "./stl/queue.nas",          "./stl/result.nas",
-        "./stl/sort.nas",           "./stl/stack.nas",
-        "./stl/string.nas",
-        "./test/ascii-art.nas",     "./test/auto_crash.nas",
-        "./test/bf.nas",            "./test/bfconvertor.nas",
-        "./test/bfs.nas",           "./test/bigloop.nas",
-        "./test/bp.nas",            "./test/calc.nas",
-        "./test/choice.nas",        "./test/class.nas",
-        "./test/console3D.nas",
-        "./test/coroutine.nas",     "./test/datalog.nas",
-        "./test/diff.nas",          "./test/donuts.nas",
-        "./test/exception.nas",     "./test/fib.nas",
-        "./test/filesystem.nas",    "./test/hexdump.nas",
-        "./test/httptest.nas",      "./test/json.nas",
-        "./test/leetcode1319.nas",  "./test/lexer.nas",
-        "./test/life.nas",          "./test/loop.nas",
-        "./test/mandel.nas",        "./test/mandelbrot.nas",
-        "./test/mcpu.nas",
-        "./test/md5.nas",           "./test/md5compare.nas",
-        "./test/module_test.nas",   "./test/nasal_test.nas",
-        "./test/occupation.nas",    "./test/pi.nas",
-        "./test/ppmgen.nas",        "./test/prime.nas",
-        "./test/qrcode.nas",        "./test/quick_sort.nas",
-        "./test/scalar.nas",        "./test/snake.nas",
-        "./test/tetris.nas",        "./test/trait.nas",
-        "./test/turingmachine.nas", "./test/utf8chk.nas",
-        "./test/watchdog.nas",      "./test/wavecollapse.nas",
-        "./test/word_collector.nas",
-        "./test/ycombinator.nas",   "LICENSE",
-        "main.cpp",                 "makefile",
-        "nasal_ast.h",              "nasal_builtin.h",
-        "nasal_codegen.h",          "nasal_dbg.h",
-        "nasal_err.h",              "nasal_gc.h",
-        "nasal_import.h",           "nasal_lexer.h",
-        "nasal_opt.h",              "nasal_parse.h",
-        "nasal_vm.h",               "nasal.ebnf",
-        "nasal.h",                  "README.md"
-    ];
+    var files=[];
+    foreach(var p;find_all_files_with_extension("./test","nas")) {
+        append(files,"./test/"~p);
+    }
+    foreach(var p;find_all_files_with_extension("./stl","nas")) {
+        append(files,"./stl/"~p);
+    }
+    foreach(var p;find_all_files_with_extension("./module","nas","cpp")) {
+        append(files,"./module/"~p);
+    }
+    foreach(var p;find_all_files_with_extension(".","cpp","h","md")) {
+        append(files,"./"~p);
+    }
+    foreach(var p;find_all_files_with_extension("./doc","md")) {
+        append(files,"./doc/"~p);
+    }
+
     var byte=0;
     var total=size(files);
     var timestamp=maketimestamp();
@@ -87,14 +73,19 @@ var filechecksum=func(){
         if(cmp(res,_md5(f))){
             die("error: "~files[i]);
         }
-        print(" ",bar.bar((i+1)/total)," (",i+1,"/",total,")\t",res," byte: ",int(byte/1024),"k time: ",timestamp.elapsedMSec(),"    \r");
+        print(
+            "\e[1000D ",bar.bar((i+1)/total),
+            " (",i+1,"/",total,")\t",res,
+            " byte: ",int(byte/1024),"k",
+            " time: ",timestamp.elapsedMSec()
+        );
     }
     print("\n");
 }
 
 var randomchecksum=func(){
-    for(var i=0;i<4096;i+=512)
-        compare(i,i+512);
+    for(var i=0;i<2048;i+=256)
+        compare(i,i+256);
 }
 
 if(os.platform()=="windows")
diff --git a/test/quick_sort.nas b/test/quick_sort.nas
index 7afbf6a..1456fe0 100644
--- a/test/quick_sort.nas
+++ b/test/quick_sort.nas
@@ -1,10 +1,15 @@
 import.stl.sort;
+
 var vec=[];
 rand(time(0));
 for(var i=0;i<1e4;i+=1)
     append(vec,int(rand()*1e5));
 sort(vec);
-println(vec);
+for(var i=1;i<1e4;i+=1) {
+    if (vec[i]<vec[i-1]) {
+        die("incorrect sort result");
+    }
+}
 
 var test=func(n){
     var a=[];
@@ -27,6 +32,6 @@ var test=func(n){
     println("[time] ",str(n)," in ",ts.elapsedMSec()/1000," sec (lambda)");
 }
 
-for(var i=1000;i<1e7;i*=10){
+for(var i=1000;i<1e6;i*=10){
     test(i);
 }
\ No newline at end of file