js4vb Javascript Engine w/Debugger and COM

This is a js parser / interpreter in vb6 with x64 number support, COM integration and built in debugging capabilities.

This was built with claude.ai and took about 44 hrs work which is wild for what it is.
Ive already burned through 15 context size limits already.

I am using it in one of my projects and it is stable. I havent had any big problems yet, just some tweaks and small oversights. It should be pretty complete and well tested, but its big, so there will be bugs.

Compiles as a 640k ActiveX dll and has a handful of example projects to show how to use it.

Couple nuances of this engine:
- print is fancy, it can dump arrays and json objects directly
- not case sensitive myVal and myval are the same (dont care actually good)
- function aliases for built in functions is currently unsupported test = alert wont work (works with js declared fx easy fix im sure)
- no regex support (never happening - use a COM object)
- ParseJsonString will look inside string values and auto convert to number including 0x hex, even 64 bit (slightly naughty but perfect for me)
- we use true 64 bit numbers for bigint, not the js spec 53 bit
- COM methods can return native json objects directly to engine: Set myComFunc = json.ParseToCVal(s)
- COM methods can return 64bit numbers directly to engine: Dim v As New CValue: v.LoadNumFromStr(str): Set myComFunc = v
- COM methods can return vb arrays without a problem, auto converted to js array (suck that ms script control)
- can attach js helper functions to COM objects or override COM methods while still able to call real one.
- demo code created on how to sink events, not yet wired into script engine

See the (oldish) readme for the highlights and info below

Dependencies:
- core engine all vb6

- 64 bit numbers requires utypes.dll (open source C std dll)
- COM integration uses dynproxy.dll (open source C std dll - vb CallByName was to limited)
- these dlls are both loaded on demand and included in the git repo

- if you want to use the debugger UI with syntax highlighting you will need scivb2.ocx or sci4vb.ocx -
https://github.com/dzzie/scivb2
https://github.com/dzzie/sci4vb (newer)

Anyway the entire JS core is all regular vb6.

Putting this out under MIT license because we should have all had this forever ago!

I dont really like git, but I made a public repo for this to help everyone track the latest changes. I dont use a dev or release branch so I will try to always keep repo with stable pushs only. That may not be possible if I have to make big changes, but the zip attached below will always be a stable snapshot. It may be a little older as its more work to sync manually.

Public Repo:
https://github.com/dzzie/js4vb

i made a design decision to include full x64 signed number support and break specs with traditional js large number but not quite x64 bs

**Stage 1:**
- Literals (numbers, strings, booleans, null)
- Variables (var)
- Binary operators (+, -, *, /, %, <, >, <=, >=, ==, !=, ===, !==)
- String concatenation

**Stage 2:**
- If/else conditionals
- While/do-while loops
- For loops
- Break/continue
- Logical operators (&&, ||, !)
- Unary operators (!, -, +, ~, typeof, void)
- Update expressions (++, --)

**Stage 3:**
- Functions (declarations & expressions)
- Function calls with parameters
- Return values
- **Closures with captured scope**
- Arrays with indexing
- Objects with properties
- Member access (dot & bracket)
- Recursion

- built in true 64 bit number support with auto promotion and mixing
- Call COM objects from JavaScript
- new ActiveXObject support with UseSafeSubset blocking
- Added JavaScript string API (20+ methods)
- JSON.parse/stringify() - Complete
- Math - all standard methods + constants
- Array - all standard methods
- Array Callback methods: forEach, map, filter, reduce, find, findIndex, some, every
- Error handling (throw/try/catch/finally)
- print can dump objects and arrays like python
- this context supported
- debugger capabilities built in with call stack and variable inspection
- access js objects as COM objects (see below)
- convert copies of js objects to vb variants/scripting.dictionary

Persistent context
AddCode() - build up reusable code
Eval() - evaluate expressions
SetVariable() / GetVariable() - VB6 integration

Global functions:
parseInt (decimal, hex, octal, binary)
parseFloat
isNaN, isFinite, isInteger
encodeURI/decodeURI
encodeURIComponent/decodeURIComponent
escape/unescape
eval
prompt
alert
hex

Very good, very interesting work.
JQuery parsing error

Code:

---

Unexpected token: x10000 at line 755

---

I will try to do more tests.

It's a shame that claude.ai doesn't allow new users.

Very good work keep it up

Ok the debugger with UI is usable now..

btw claude says edit and continue is doable! <-- abandoned see below there be dragons

I will look into the jquery parse error, lots of stuff has been moving around. the version i used for testing is in the /tests folder.

one other idea, this combined with the dynproxy code i posted earlier...it may be possible to wrap javascript objects into a COM wrapper to seamlessly access them. This would give us basically native late bound support for json which could be magical..

Attachment 195459

Quote:

---

Originally Posted by dz32

btw claude says edit and continue is doable!

---

Well this I gotta see ;) Lack of Edit & Continue is the only thing that has kept me away from using an other Language/IDE as a daily driver.

Do you have/keep git repo of this project? It would be entertaining to see history of the progress as its being implemented.

Great work.
A small implementation to add objects to the debugger.

ucJSDebugger

Code:

---

Event AddObject(ByRef inter As CInterpreter)

Public Sub RunScript()
    If m_isRunning Then Exit Sub
   
    m_isRunning = True
    lblStatus.Caption = "Status: Running..."
    UpdateToolbarState
    SetToolBarIcons
  ' lblStatus = "Status: " & IIf(withDebugger, "Debugging...", "Running...")

    Set interp = New CInterpreter
   
    RaiseEvent AddObject(interp)

---

frmDebugger

Code:

---

Private Sub js_AddObject(inter As CInterpreter)
    inter.AddCOMObject "frmDebugger", Me
End Sub

---

Test

Code:

---

console.log(frmDebugger.Caption);
frmDebugger.Caption = "workkkkk";

---

Great work.

a public repo isnt a bad idea, im just doing snapshots for now. cleaner an no in between broken states. Im not fancy enough to use a release branch lol

so I am going to abandon the idea of edit and continue. I do not like what its outputting. it wanted to reparse the entire script fresh, keep the old scope and reset to the current line. I see to many problems. When I asked it about only redoing the specific parts, now were into the problem of the intrepreter being entirely ast based on a nasty nested tree structure. If we were running off of a bytecode it would be much easier i think but thats a whole different design than where we started. (reemit a function bytecode then relink it to others)

right now I am working on "Set next statement" will see how that goes.

The idea of exposing AddObject on the debugger form is a great idea. Justed added it to the debugger demo thanks :)

scintinilla also supports intellisense and tooltips so much more to come still...

I think the reason claude can nail the JS implementation so well is that its a very documented design pattern and language with lots of open source implementations. doing things helping to implement the debug UI or set next statement its messing up a lot.

another bonus of having everything done in vb, we have be able to generate a perfect code navigator and refactoring engine.

this is way beyond what i was initially attempting originally i just wanted an ast parser! but cant pass on making the full implementation now..simply must exist!

after set next statement is decent i am going to try to wrap js objects in that dynamic proxy and see what shakes loose.

edit: finished Set next Statement support in code (didnt implement in debugger UI yet thats later)

If your curious how we got here and why...

MS Script control lacks debugging support and has an old JS engine syntax (1998 - ES3 spec). I wanted better.

I tried to use the IActiveScript debugger interfaces in VB but it was just brutal and never fully worked right.
http://sandsprite.com/CodeStuff/vbAc...incomplete.zip

Ken Foust had his citrus debugger in C++ but it was still beyond me at the time.
http://sandsprite.com/CodeStuff/CitrusDebugger.7z

Next I was playing with the script basic engine which had a debugger interface
and let me play relatively easily.. I tried bolting on some COM integration. But my additions were rough and crashy. if your scripted anything wrong it was fatal. Debugger control worked great though and was converted to use in process callbacks from C to VB. First script debugger success.
https://sandsprite.com/blogs/index.p...=310&year=2014

Next i found duktape which is a nice small C engine with a debugger protocol (4mb complete with ocx):

https://sandsprite.com/tools.php?id=23
https://sandsprite.com/blogs/index.php?uid=11&pid=343

I again bolted on COM integration which was still a little rough. We had to create JS classes and use a resolver in vb
but I have been using it for years. its a little bulky but wrapped well. Again debugger control was converted to use in process callbacks from C to VB. The bad part was JS does not have true x64 number support which kills me for some of the tasks I have to do :(

So...next came py4vb

https://sandsprite.com/tools.php?id=37
https://sandsprite.com/blogs/index.php?uid=11&pid=534

I was able to rip the pywin32 library and compile it right into python and COM access was seamless!
(Thanks Mark!). It also has debugger capabilities.

You can even do this:

Code:

---

Dim tmp(), v
tmp = .Eval("[1+2,2,'a', b'test']") 'array containing 3,2,'a', byte array("test")
For Each v In tmp
    If IsArray(v) Then
        Debug.Print TypeName(v)
    Else
        Debug.Print v
    End If
Next

---

This is awesome, but now your distributing like 30mb. I dont like how you have to implement the debugger
inside the script layer, dont really like python syntax. The COM integration is first class through.

Dealing with the python runtime from the outside..not my favorite..its a mess in there. Also python is
not really designed well for embedding, total second class use of it. I had to hack the main execution loop
to add an abort and you have to override exit() statements in the script layer to prevent scripts from killing
the host process. Lots of hacky thing going on..

Sooo..thats how we end up here. I have wanted this for literally 25 years!

Targets:

- native vb built for embedding
- seamless com support
- debugger
- full ast access
- full control over all the guts
- full native x64 number support

AI made this the right time to create it I guess. Little late to the party! but...is what it is.

Perhaps you can take this approach and let ai generate a C++ Linux basic parser.

Soo...this is working now.. (with dynproxy)

Code:

---

Private Sub Form_Load()

    Dim interp As New CInterpreter
   
    If Not ensureDynProxy() Then
        MsgBox "DynProxy.dll not found"
        Exit Sub
    End If
   
    ' Create a JavaScript object
    interp.Execute "var person = { name: 'John', age: 30, city: 'NYC' };"

    ' Get it as a VB COM object!
    Dim person As Object
    Set person = interp.EvalAsObject("person")

    ' USE IT LIKE A VB OBJECT!
    Debug.Print "Name: " & person.name      ' "John"
    Debug.Print "Age: " & person.age        ' 30
    Debug.Print "City: " & person.city      ' "NYC"

    ' MODIFY IT!
    person.age = 31
    person.Job = "Developer"                ' Add new property!

    ' Read BACK via proxy (not JavaScript!)
    Debug.Print "Age (read via proxy): " & person.age
    Debug.Print "Job (read via proxy): " & person.Job
   
    ' CHECK IT IN JAVASCRIPT!
    interp.AddCode "console.log('interp.AddCode -> Age: ' + person.age);"      ' 31
    interp.AddCode "console.log('interp.AddCode -> Job: ' + person.job);"      ' "Developer"
   
    ' NESTED OBJECTS!
    interp.Execute "var company = { name: 'Acme', address: { city: 'Boston', zip: '02101' } };"
   
    Dim Company As Object
    Set Company = interp.EvalAsObject("company")
   
    Debug.Print "Company: " & Company.name                    ' "Acme"
    Debug.Print "City: " & Company.address.city              ' "Boston"
    Debug.Print "Zip: " & Company.address.Zip                ' "02101"
   
    'MsgBox "FOR THE GLORY! IT WORKS!", vbExclamation
   
    'output:
        'Name: John
        'Age: 30
        'City: NYC
        'Age (read via proxy): 31
        'Job (read via proxy): Developer
        'interp.AddCode -> Age: 31
        'interp.AddCode -> Job: Developer
        'Company: Acme
        'City: Boston
        'Zip: 02101

End Sub

---

and somehow..this works too..

Code:

---

    interp.Execute "function greet(name) { console.log('Hello, ' + name); return 'Hello, ' + name;}"
   
    Dim greet As Object
    Set greet = interp.EvalAsObject("greet")
   
    greet.Invoke "World"       
    Debug.Print "dbg: " & greet.Call("JavaScript") 

Output:
    Hello, World
    Hello, JavaScript
    dbg: Hello, JavaScript

---

Code:

---

    Dim interp As New CInterpreter
    Dim data As Object, items As Variant

    'force latebound case - vb ide sucks here..
    ' maybe trick or firehacker know how to kill case correct in IDE?
    Const user = 1, profile = 1, name = 1, email = 1

    interp.Execute "var data = {" & _
                                "items: [1, 2, 3]," & _
                                "user: {" & _
                                "    profile: {" & _
                                "        name: 'John'," & _
                                "        email: '[email protected]'" & _
                                "    }" & _
                                "}};"

    Set data = interp.EvalAsVariant("data")
    Debug.Print "typename(data) = " & TypeName(data) 'Dictionary
   
    Debug.Print data!user!profile!name  '  John
    Debug.Print data!user!profile!email  '  [email protected]

    items = data("items")
    Debug.Print "typename(items) = " & TypeName(items) 'Variant()
    Debug.Print "items(2) = " & items(2)              'items(2) = 3
    Debug.Print data("items")(2)                      '3
    'Debug.Print data!items(2) 'error object required

---

also added support for this keyword..ok arms shot, weekend over....coding bender complete....

Quote:

---

Originally Posted by dz32

This is a js parser /interpreter in vb6.

It is mostly an experiment to test and see what claude.ai can really do.


I gave this its own blog post here: https://sandsprite.com/blogs/index.p...=575&year=2025

---

twinbasic ide plugin can enhance TbScript functionality, similar to VBSCRIPT and Js-VBForums
https://www.vbforums.com/showthread.php?911390

Someone has written a parser for JS code, and the problem is that it can't perform the parsing of VB code. Microsoft has open sourced the source code for the chakracorejs engine.We are missing the source code for the VBScript parser. The author of another forum topic spent a day making a parser of JS code with ai. If this technology can be used to do VB code parsing, it will run on cross-platform Linux.

If possible, convert the parser directly into assembly code. Create exe or DLL in PE format.
Then we have a js6, IDE

It's just like Vb6, you can type in JS code. Visual form design, and finally directly generate an independent winform program.

In fact, the text box button control is calling the API.

If JavaScript can be called. The windows API, that does that.

We are even allowed to execute JS code, VB6 code, at the same time. VB. Net code, VBS code, assembly code, this is a simple script debugger. Add a simple visual form designer. We have invented a new visualization program called IDE. .
At the end of the day, if it runs on the Linux market, it's a cross-platform IDE and compiler.

As if a parser is the same as a platform independent compiler..

the fun part of this is that we can break standards and make it what we want. couple tweaks so far,

built in alert, prompt, true x64 numbers, print can dump objects and arrays like python, format("my name is {name}") like python and then rolled that into a built in printf

claude offered to add other python nicities like multiple assignments or zip() but I dont want to totally corrupt my js

but the door is wide open for ideas.

I will wrap this into an easy to use dll with simple code examples this weekend. its like 520kb compiled which isnt bad.

ok should be pretty good now. compiling as an ActiveX dll with a bunch of simple examples to test it.

Great job
A file is missing

Code:

---

Class=CReference; analysis\CReference.cls

---

claude.ai is very good, I added small improvements and it worked perfectly, alert, prompt...

keep it up great work

oops I will add that back thanks good catch. There should be an alert and prompt added now here are the global functions

Code:

---

Private Function IsGlobalFunction(funcName As String) As Boolean
    Select Case funcName
        Case "parseInt", "parseFloat", "isNaN", "isFinite", "isInteger", _
            "encodeURIComponent", "decodeURIComponent", "encodeURI", "decodeURI", _
            "escape", "unescape", "eval", "print", "alert", "prompt", "format", _
            "printf", "hex", "Number", "String"
            IsGlobalFunction = True

---

I think something is broken with the console, the messages are not appearing.
The debugger call stack does not work.

Other problem
I get this error when I stop the debugger or close the form.
Variable not set

Code:

---

Sub Abort()
    interp.Abort
End Sub

---

if interp.abort isnt showing up its probably trying to use the old dll, you can open the group project and look at the top of Cinterpreter and ther should be an Abort() function there. If not somethings old. (The new debugger example in examples/5_debugger) try not to mix old and new files as much has changed inside.

Code:

---

Sub Abort()
    m_AbortExec = True
    StopDebug
End Sub

---

Console logging was missing in the debug form, I forgot to add an event handler to raise that event ucJSDebugger add

Code:

---

Private Sub interp_ConsoleLog(ByVal msg As String)
    RaiseEvent output(msg)
End Sub

---

I will have to hunt on the callstack thing that could take a bit more to find I will update later.

ok were back from surgery patient should be healthy..the callstack fix was a little hairy, happened when adding this binding to functions

Quote:

---

Originally Posted by dz32

note: for the x64 support you will need utypes.dll its open source: https://sandsprite.com/tools.php?id=31
i made a design decision to include full x64 signed number support and break specs with traditional js large number but not quite x64 bs

---

vb6_utypes\class_wrappers
cmdUIntTest_Click ERROR:

Code:

---

  Dim a As New UInt
    Dim b As New UInt
   
    List1.Clear
   
    a.use0x = True
    b = a.MAX_SIGNED
    List1.AddItem "start value: (MAX_SIGNED) " & a
    a = a.Add(1)
    List1.AddItem "Max+1 signed = " & a
    List1.AddItem "Max+1 unsigned = " & a.toString(False)
   
    If b.fromString(a.toString(False)) Then
        List1.AddItem "Max+1 signed string transfer = " & b
    Else
        List1.AddItem "string transfer failed..."
    End If

---

I havent updated those tests in a very very long time. Value was supposed to be the class default property but it looks like it got lost somewhere along the way. I think I used the dll in some places so I cant update it right now. You will have to experiment to figure it out sorry dont have time to go back and fix the examples on that one.

The js4vb.zip linked in the sandsprite blog has the utypes.dll & dynproxy.dll versions I am testing against.

DOES IT SUPPORT twinbasic x64 project?

I dont use twin basic. I am not sure of its capabilities if it has 64 bit number support or not. That C dll was built to accept vb types and how they map to C types. It may not make any sense to use that dll in twinbasic or not i have no idea.

Thanks to @dz for the great work, which has given our VB6 better extensions.

Quote:

---

Originally Posted by dz32

I dont use twin basic. I am not sure of its capabilities if it has 64 bit number support or not.

---

TB has LongLong support in 32-bit targets too.

cheers,
</wqw>

I've been working with Claude for a bit, until the limit was reached :o.
I've added the Date functions.
In case you are interested and it saves you a limit.

Code:

---

CParser.cls
Private Function ParseLeftHandSideExpression() As CNode
    Dim expr As CNode
   
    If MatchKeyword("new") Then
        Set expr = ParseNewExpression()
       
        ' ?? ADD: Allow member/call access after 'new'
        ' Ejemplo: new Date().toString()
        Do While match(".") Or match("[") Or match("(")
            If match(".") Then
                Set expr = ParseStaticMember(expr)
            ElseIf match("[") Then
                Set expr = ParseComputedMember(expr)
            ElseIf match("(") Then
                ' Convertir a CallExpression si hay ()
                Dim callNode As New CNode
                callNode.tType = CallExpression_Node
                callNode.LineNumber = expr.LineNumber
                Set callNode.Callee = expr
                Set callNode.Arguments = ParseArguments()
                Set expr = callNode
            End If
        Loop
    Else
        Set expr = ParseCallExpression()
    End If
   
    Set ParseLeftHandSideExpression = expr
End Function

---

CInterpreter.cls
ADD Date to IsGlobalFunction

Code:

---

CallGlobalFunction

Case "Date"
    ' Date() as a function returns string (current date)
    result.vType = vtString
    result.strVal = Format$(Now, "ddd mmm dd yyyy hh:nn:ss")

---

in EvaluateNewExpression ADD: Check for Date constructor

Code:

---

    If Node.Callee.tType = Identifier_Node Then
        If Node.Callee.Name = "Date" Then
            Set result = CreateDateObject(Node.Arguments)
            Set EvaluateNewExpression = result
            Exit Function
        ElseIf Node.Callee.Name = "Error" Then

---

Code:

---

' ? ADD new Function CreateDateObject
Private Function CreateDateObject(args As Collection) As CValue
    Dim result As New CValue
    result.vType = vtObject
    Set result.objectProps = New Collection
    Set result.objectKeys = New Collection
   
    Dim dateVal As Date
   
    ' Determinar la fecha según argumentos
    If args.count = 0 Then
        ' new Date() - fecha actual
        dateVal = Now
    ElseIf args.count = 1 Then
        ' new Date(milliseconds) o new Date(dateString)
        Dim arg As CNode
        Set arg = args(1)
        Dim argVal As CValue
        Set argVal = EvaluateExpression(arg)
       
        If argVal.vType = vtNumber Then
            ' Milliseconds desde epoch (simplificado)
            dateVal = DateAdd("s", argVal.numVal / 1000, #1/1/1970#)
        ElseIf argVal.vType = vtString Then
            ' Parse date string
            On Error Resume Next
            dateVal = CDate(argVal.strVal)
            If Err.Number <> 0 Then
                dateVal = Now  ' Fallback
            End If
            On Error GoTo 0
        Else
            dateVal = Now
        End If
    Else
        ' new Date(year, month, day, hour, min, sec, ms)
        ' Simplificado - solo year, month, day
        Dim yearVal As CValue, monthVal As CValue, dayVal As CValue
       
        Set arg = args(1)
        Set yearVal = EvaluateExpression(arg)
       
        Set arg = args(2)
        Set monthVal = EvaluateExpression(arg)
       
        Dim day As Long
        day = 1
        If args.count >= 3 Then
            Set arg = args(3)
            Set dayVal = EvaluateExpression(arg)
            day = CLng(dayVal.ToNumber())
        End If
       
        dateVal = DateSerial(CLng(yearVal.ToNumber()), _
                            CLng(monthVal.ToNumber()) + 1, _
                            day)
    End If
   
    ' Agregar métodos del Date object
   
    ' toString()
    Dim toStringFunc As New CValue
    toStringFunc.vType = vtfunction
    ' Crear función que retorna la fecha como string
    Dim toStrFn As New CFunction
    toStrFn.Name = "toString"
    Set toStrFn.Body = Nothing  ' Método nativo
    Set toStringFunc.objVal = toStrFn
   
    result.objectProps.Add toStringFunc, "toString"
    result.objectKeys.Add "toString", "toString"
   
    ' getTime() - milliseconds desde epoch
    Dim getTimeFunc As New CValue
    getTimeFunc.vType = vtfunction
    Dim getTimeFn As New CFunction
    getTimeFn.Name = "getTime"
    Set getTimeFn.Body = Nothing
    Set getTimeFunc.objVal = getTimeFn
   
    result.objectProps.Add getTimeFunc, "getTime"
    result.objectKeys.Add "getTime", "getTime"
   
    ' Guardar el valor de fecha internamente
    Dim internalDate As New CValue
    internalDate.vType = vtString
    internalDate.strVal = Format$(dateVal, "ddd mmm dd yyyy hh:nn:ss")
   
    result.objectProps.Add internalDate, "_date"
    result.objectKeys.Add "_date", "_date"
   
    ' Timestamp interno
    Dim timestamp As New CValue
    timestamp.vType = vtNumber
    timestamp.numVal = DateDiff("s", #1/1/1970#, dateVal) * 1000
   
    result.objectProps.Add timestamp, "_timestamp"
    result.objectKeys.Add "_timestamp", "_timestamp"
   
    Set CreateDateObject = result
End Function

---

Code:

---

inEvaluateCall ADD ElseIf Node.Callee.Object.Name = "Date" Then

' After the section of string methods:
If objVal.vType = vtObject Then
    methodName = Node.Callee.prop.Name
   
    ' ? ADD: Check for Date methods
    If IsDateMethod(methodName) Then
        ' Evaluate arguments
        For i = 1 To Node.Arguments.count
            Set arg = Node.Arguments(i)
            argValues.add EvaluateExpression(arg)
        Next
       
        ' Call Date method
        Set result = CallDateMethod(objVal, methodName, argValues)
        depth = depth - 1
        Set EvaluateCall = result
        Exit Function
    End If
   

End If

---

Code:

---

' ? IsDateMethod,CallDateMethod
Private Function IsDateMethod(methodName As String) As Boolean
    Select Case methodName
        Case "toString", "toDateString", "toTimeString", _
            "getTime", "getFullYear", "getMonth", "getDate", _
            "getHours", "getMinutes", "getSeconds", "getMilliseconds"
            IsDateMethod = True
        Case Else
            IsDateMethod = False
    End Select
End Function

Private Function CallDateMethod(dateObj As CValue, methodName As String, args As Collection) As CValue
    Dim result As New CValue
   
    ' Obtener el timestamp interno
    Dim timestampVal As CValue
    Set timestampVal = dateObj.GetProperty("_timestamp")
   
    If timestampVal Is Nothing Then
        result.vType = vtString
        result.strVal = "Invalid Date"
        Set CallDateMethod = result
        Exit Function
    End If
   
    ' Convertr timestamp to Date VB6
    Dim dateVal As Date
    dateVal = DateAdd("s", timestampVal.numVal / 1000, #1/1/1970#)
   
    Select Case methodName
        Case "toString"
            result.vType = vtString
            result.strVal = Format$(dateVal, "ddd mmm dd yyyy hh:nn:ss")
           
        Case "toDateString"
            result.vType = vtString
            result.strVal = Format$(dateVal, "ddd mmm dd yyyy")
           
        Case "toTimeString"
            result.vType = vtString
            result.strVal = Format$(dateVal, "hh:nn:ss")
           
        Case "getTime"
            result.vType = vtNumber
            result.numVal = timestampVal.numVal
           
        Case "getFullYear"
            result.vType = vtNumber
            result.numVal = Year(dateVal)
           
        Case "getMonth"
            result.vType = vtNumber
            result.numVal = Month(dateVal) - 1  ' JavaScript is 0-based
           
        Case "getDate"
            result.vType = vtNumber
            result.numVal = Day(dateVal)
           
        Case "getHours"
            result.vType = vtNumber
            result.numVal = Hour(dateVal)
           
        Case "getMinutes"
            result.vType = vtNumber
            result.numVal = Minute(dateVal)
           
        Case "getSeconds"
            result.vType = vtNumber
            result.numVal = Second(dateVal)
           
        Case "getMilliseconds"
            result.vType = vtNumber
            result.numVal = 0  ' VB6 not have milliseconds
           
        Case Else
            result.vType = vtUndefined
    End Select
   
    Set CallDateMethod = result
End Function

---

TEST

Code:

---

var now = new Date();
print("Current date: " + now.toString());

print("Year: " + now.getFullYear());
print("Month: " + now.getMonth());
print("Day: " + now.getDate());
print("Timestamp: " + now.getTime());

var User= {
    name: "Juan",
    DateRegistred: new Date().toString()
};

print(JSON.stringify(User, null, 2));

var dateStr = new Date().toString();
print("Date in string: " + dateStr);

---

ok I integrated your date handling and ended up making a public github repo so we can track changes easier.

I also added a static handler for Date.now() and a handler in CValue.ToString() so it doesnt show as [object object]

https://github.com/dzzie/js4vb/blob/...eter.cls#L1661
https://github.com/dzzie/js4vb/blob/...CValue.cls#L84

I added credit for the addition in the git commit log, readme.md and in the date.js test. Thanks for the contribution!

https://github.com/dzzie/js4vb/blob/..._basic/date.js

Nothing, it's been more help from claude.ai.
One thing, it wouldn't be good to split the CInterpreter into other modules to avoid overloading it.
For your better understanding.

What's your next step?

Great work.

yes it would make sense to go through CIntrepreter and carve out any helpers which did not depend on internal variables it is quite massive. On the upside that is also nice when dealing with AI as everything is accessible at once. I use a code navigator so it is actually still easy to find things: https://www.vbforums.com/showthread....-Addin-for-vb6

honestly I think the project is complete. there will still be some bugs to root out but I dont want my version to get to fancy. I am primarily developing this for embedding in my apps allowing users to script and control them so I dont want it to bloated or big. The fancier the more room for bugs. I do not need a super complete general purpose js engine. just capable.

I have decided not to include regex support at all. If someone needs regex they can use the activex vbscript object which should operate fine.

my next task is probably to take another run at scivb2.ocx for scintinilla support and redo it to clean it up some more.

this project was more of a helper for my other projects than a project in itself.

Yes, the project meets the basics of javascript, but I liked the idea of ??adding functions.
I plan to also use it in my apps.

I have added setTimeout, setInterval, clearTimeout, clearInterval, sleep
I have decided to go for the simple thing to do and use event queue.

Sorry I don't know how to use github much

Code:

---

'CTimerEvent.cls

Option Explicit

Public ID As Long
Public callback As CValue
Public delay As Long
Public IsInterval As Boolean
Public ExecuteAt As Double
Public IsCancelled As Boolean

---

Code:

---

'CInterpreter.cls

Private m_timerQueue As Collection
Private m_nextTimerID As Long


IsGlobalFunction ADD
          "setTimeout", "setInterval", "clearTimeout", "clearInterval", "sleep"

CallGlobalFunction ADD

        Case "sleep"
            ' sleep(milliseconds) - pausa bloqueante
            If args.Count > 0 Then
                Set arg = args(1)
                Dim ms As Long
                ms = CLng(arg.ToNumber())
               
                If ms > 0 And ms < 60000 Then  ' Máximo 60 segundos
                    Sleep ms
                    DoEvents
                End If
            End If
           
            result.vType = vtUndefined
        Case "setTimeout"
            If args.Count >= 2 Then
                Set arg = args(1)
                If arg.vType = vtfunction Then
                    Dim delayArg As CValue
                    Set delayArg = args(2)
                    ms = CLng(delayArg.ToNumber())
                   
                    result.vType = vtNumber
                    result.numVal = ScheduleTimer(arg, ms, False)
                Else
                    result.vType = vtUndefined
                End If
            Else
                result.vType = vtUndefined
            End If
           
        Case "setInterval"
            If args.Count >= 2 Then
                Set arg = args(1)
                If arg.vType = vtfunction Then
                    Set delayArg = args(2)
                    ms = CLng(delayArg.ToNumber())
                   
                    result.vType = vtNumber
                    result.numVal = ScheduleTimer(arg, ms, True)
                Else
                    result.vType = vtUndefined
                End If
            Else
                result.vType = vtUndefined
            End If
           
        Case "clearTimeout", "clearInterval"
            If args.Count > 0 Then
                Set arg = args(1)
                Dim timerID As Long
                timerID = CLng(arg.ToNumber())
                CancelTimer timerID
            End If
           
            result.vType = vtUndefined
' .......




Private Sub Class_Initialize()
    ' ... source ...
    Set m_timerQueue = New Collection
    m_nextTimerID = 1
End Sub

Private Function ScheduleTimer(callback As CValue, delay As Long, isInterval As Boolean) As Long
    Dim evt As New CTimerEvent
   
    evt.ID = m_nextTimerID
    m_nextTimerID = m_nextTimerID + 1
   
    Set evt.callback = callback
    evt.delay = delay
    evt.IsInterval = isInterval
    evt.ExecuteAt = Timer + (delay / 1000#)
    evt.IsCancelled = False
   
    m_timerQueue.Add evt, "T" & evt.ID
   
    ScheduleTimer = evt.ID
End Function

Private Sub CancelTimer(timerID As Long)
    On Error Resume Next
    Dim evt As CTimerEvent
    Set evt = m_timerQueue("T" & timerID)
   
    If Not evt Is Nothing Then
        evt.IsCancelled = True
    End If
   
    On Error GoTo 0
End Sub

Public Sub ProcessTimers()
    If m_timerQueue.Count = 0 Then Exit Sub
   
    Dim currentTime As Double
    currentTime = Timer
   
    Dim evt As CTimerEvent
    Dim i As Long
   
    For i = m_timerQueue.Count To 1 Step -1
        Set evt = m_timerQueue(i)
       
        If evt.IsCancelled Then
            m_timerQueue.Remove i
        ElseIf currentTime >= evt.ExecuteAt Then
            ' Execute callback
            On Error Resume Next
            If evt.callback.vType = vtfunction Then
                Dim emptyArgs As New Collection
                CallJSFunction evt.callback, emptyArgs
            End If
            On Error GoTo 0
           
            If evt.IsInterval And Not evt.IsCancelled Then
                evt.ExecuteAt = Timer + (evt.delay / 1000#)
            Else
                m_timerQueue.Remove i
            End If
        End If
    Next
End Sub

Public Function HasPendingTimers() As Boolean
    HasPendingTimers = (m_timerQueue.Count > 0)
End Function

---

Code:

---

'modGlobals.bas
Public Declare Sub Sleep Lib "kernel32" (ByVal dwMilliseconds As Long)

---

Code:

---

in vb program

interp.Execute code

Do While interp.HasPendingTimers()
    DoEvents
    interp.ProcessTimers()
    Sleep 10
Loop

---

TEST

Code:

---

// ===== TEST 1: sleep() =====
print("start: " + new Date().toString());
//sleep(2000);  // 2 seg
print("before 2 seg: " + new Date().toString());

// ===== TEST 2: setTimeout (bloqueante) =====
print("after setTimeout");
setTimeout(function() {
    print("after 1 seg");
}, 1000);

// ===== TEST 3: setInterval (con cola) =====
var count = 0;
var intervalID = setInterval(function() {
    count++;
    print("Tick " + count);
   
    if (count >= 5) {
        clearInterval(intervalID);
        print("Interval stopped");
    }
}, 500);
console.log("intervalID:    " + intervalID)

// ===== TEST 4: Callback with closure =====
var message = "hello with closure";
setTimeout(function() {
    print(message);
}, 1000);

// ===== TEST 5: Múltiples timers =====
setTimeout(function() { print("Timer 1 (1 seg)"); }, 1000);
setTimeout(function() { print("Timer 2 (2 seg)"); }, 2000);
setTimeout(function() { print("Timer 3 (500ms)"); }, 500);
print("start Timer 4: " + new Date().toString());
setTimeout(function() {
    print("Timer 4 (5000ms)");
    print("end: " + new Date().toString());
}, 5000);

---

sorry for my way of speaking, I use a translator

those look like good additions. I think others will like them as well. Claude really does a good job of being able to add features it amazes me how well it did building this. Dont forget you can add things with vb classes and AddCOMObject too thats the easiest :)

Weekend additions:

- BugFix: for(;;i+=2) compound assignments had endless loop bug

**New Compound Assignments** - `+=`, `-=`, `*=`, `/=`, `%=`, `&=`, `|=`, `^=`, `<<=`, `>>=`, `>>>=`
**Bitwise Operators** - `&`, `|`, `^` for regular numbers
**Unsigned Right Shift** - `>>>` and `>>>=` for both Number and Int64
**String.fromCharCode()** - Static method for character code conversion
**Function Constructor** - `new Function()` for dynamic function creation
**Case-Sensitive Keywords** - Proper JavaScript keyword handling (Function vs function)
**Int64 Compound Assignment Refactoring** - Unified handling via `EvaluateInt64Arithmetic`
**Basic audit logging with cancel**

**Operator Coverage:**
- All arithmetic, bitwise, logical, comparison operators
- All assignment and compound assignment operators
- All shift operators including unsigned right shift
- Proper Int64/BigInt auto-promotion
- Boundary case handling (no overflows)

random note the COM integration was bruteforcing set obj = callbyname and if the return wasnt an obj, it'd throw an error and then try retVal = callbyname it was horrible, functions getting called twice. Also no more if else cascades based on arg count to CallByName

I ended up having to create a CallByNameEx in C to bypass the slop. downside now dynproxy.dll is required for COM access now

https://github.com/dzzie/js4vb/blob/...proxy.cpp#L751
https://github.com/dzzie/js4vb/blob/...Form1.frm#L108

I will update the zip here when I test it a bit more.

Code:

---

Dim v As Variant, isObj As Boolean, r As Long, args() As Variant
ReDim args(1)
args(0) = "1"
args(1) = "b"
 
'no need for set keyword or multiple callbyname if/else based on arg count
r = CallByNameEx(Me, "getme", DISPATCH_METHOD, args, v, isObj)

Function getme(a As Long, b) As Object
    Set getme = Me
End Function

---

Couple more bonuses, com objects could already return a variant array which would auto translate into a js array,
now com objects can also create js engine native types and return them directly into the javascript engine such as

Code:

---

Function getFunc(IndexVaOrName) 'as CValue of a Json object (or string if we fail!)
    Dim ret As CValue, s As String
    '{'index':483, 'name':'small_sub_421881', 'start':'0x421881', 'end':'0x4218cf', 'size':'78', 'xrefs':'2', 'refqty':'0',  'argsize':'0', 'tailqty':'0', 'labelqty':'0', 'frsize':'0'}
   
    s = ipc.SendCmdRecvText("getfunc:" & IndexVaOrName & ":" & ipc.listenHwnd)
    s = Replace(s, "'", """") 'oopsie
    Set ret = json.ParseToCVal(s)
    If IsObject(ret) Then
        Set getFunc = ret
    Else
        getFunc = s
    End If
   
End Function

then in the engine CallCOMMethod:

  If hr = 0 Then  ' S_OK
        If isObj Then
            If TypeName(resultVar) = "CValue" Then
                'caller is returning a JS engine type
                Set result = resultVar
            Else
                result.vType = vtCOMObject
                Set result.objVal = resultVar
            End If
        Else
            Set result = VariantToCValue(resultVar)
        End If
    Else
        ' Call failed - return undefined
        result.vType = vtUndefined
    End If

---

MSScript control is really bad on these fronts. More is possible with python or duktape, but the cross language barrier means it would require mountains of wrapped functions so I just never did it. When everything is in the same language and we can just use COM objects directly it gets super efficient. Real integration benefits to having everything in the same language!

Very good work.
To be honest, I've burned through Claude's code.
My project has over 14,000 lines of code.
I couldn't stop adding features XD.

Thanks for being an inspiration.

lol i understand completely I have been going through my entire bucket list its amazing what you can get it to kick out.

my only fear is it may turn our brains to jelly and make us very lazy. Actually learning to really really program may die.

Could you update the debugger example to use with your new https://github.com/dzzie/sci4vb

I added a new debugger example using the new sci4vb ocx. I also had to update the sci4vb I forgot to raiseevent keypressed so the F7 etc would work.

edit: ok updated to use the new sci4vb internal breakpoint management and executing line highlighting

https://github.com/dzzie/js4vb/tree/...s/9_dbg_sci4vb

In fact, I suggest that you open source every version, which is better.

Maybe it can be extended to become a node. JS VB version implementation, which supports web sockets and cookies. Session login session management, which becomes a web page background like PHP. Dynamic script
The initial version was smaller and had less code.
Sometimes some people need it. The fewer functions, the better, which is the core function.
Like twinbasic, alas, every day a version is all open. github

If you have time, you can also implement a VB script parser.
Maybe in the project code.When programming, try to make the parts with the same function into a different module..

Your project may go from 6 modules to 30 modules.If there are no duplicate API declarations, you can just merge them into a final module.There is no way to merge this class file.

Each separate set of functions is divided into separate source code files.The main thing is to make it easier for ai to fix it with a smaller context, or to add some functionality.
Otherwise, one module exceeds 30kb. A few thousand lines of code for ai to fix, ah, wastes more money and more time.

I once looked at one person's implementation of the Epe compiler.Just like entering some simple VB6 code, you can generate exe directly. You can parse expressions and make calls to the windowss API.Through the API to create windows, controls, thus achieving a complete window program. Each line of code can then be debugged and compiled into an exe.

For example, if we want to execute VB. Net code on Linux, we need to install a net. It takes 200 megabytes to run.

Vb6 code or VBS is the most difficult thing to execute on Linux.
The three most mature options are. Powershell, VB. Net, Python () can this also execute VB code?
Also gamebas IDE () like VBS
This is an open source project.

YABASIC source code, vc6.0 engineering, classic source code
You have a lot of experience in this area. How to use VB6 itself to implement a basic parser, it should be simpler.
There are a small number of basic parsers implemented in VC + + or other languages. . If you compile it into a DLL, you can also play its role.
But most of us can't modify its source code or add new functions.
It may take months or years.
And you complete a script engine parser in a few days.

One nuance i just noticed, but I am actually ok with...the engine is not case sensitive, so myVal and myval are the same.. just be aware!

also no function aliasing yet. print(typeof alert) //undefined so test = alert doesnt work..
Im actually ok with that too but may need to add it later for compatibility.

im considering adding something like the following...

Code:

---

engine.extend(myComObj, "jsFunc", function() {return 1})

---

it could be useful occasionally to extend COM objects and add js only functions onto them like helper methods or things that are intrinsically easier to do in js, but you want still attached to your main COM object. It actually should be fairly easy to do.

I am consider this because the 64 bit number support in vb is still a bit of a chore and some things are easier done on the js side.

thoughts?

so...it worked. You can do it from JS or from the vb6 host side. you can also override COM methods with it.

https://github.com/dzzie/js4vb/commi...0e128e943ed011

Code:

---

var wsh = new ActiveXObject("WScript.Shell");

// Add a JS helper that uses the actual COM method
wsh.safeExpandEnv = function(varName) {
    var result = this.ExpandEnvironmentStrings("%" + varName + "%");
    if (result === "%" + varName + "%") {
        return "(undefined)";  // Variable doesn't exist
    }
    return result;
};

console.log(wsh.safeExpandEnv("PATH"));  // Returns expanded path or "(undefined)"
form.taco('dude')

---

or from the host side:

Code:

---

    intrep.AddCOMObject "form", Me
    intrep.AttachCOMHelper "form", "taco", "function(cmd){print('its tuesday ' + cmd + '!');}"

---

and a bonus ability to still call the original COM method even if you overrode it with a js function

https://github.com/dzzie/js4vb/commi...d0cdea34b69d98

Code:

---

wsh.Run = function(cmd) {
    console.log("[LOG] " + cmd);
    return this._Run(cmd, 1, true);  // Calls original COM Run
};

wsh.Run("C:\\Windows\\SysWOW64\\notepad.exe")

---

fancy...

It looks very interesting.
I'll work on it.
Good job.

heres a brief discussion on it. its really kind of a parlor trick but was a great addition.

https://sandsprite.com/blogs/index.php?uid=11&pid=583

In other news, I also started playing with a way to forward events to the scripts. It works for vb6 classes and ocx controls, but not for intrinsic vb6 form controls like buttons or textboxes. There would be a way to force it, but Im not getting into it.

It would be kind of amusing to make a form engine and designer so js scripts could popup a windows form and receive events. Its a super bloated feature though for my needs just day dreaming...

https://github.com/dzzie/js4vb/commi...79980aaa74e2c1

so...i have a crazy idea thats kind of fun..i asked claude.ai if he could design a visual from editor like the vb6 ide we all know and love, he kicked out some stuff which i havent tested yet but will be working on.

imagine if we can wire this js engine up to a forms engine with drag and drop form creator with events support.

kind like vb7 but with js syntax, full com support no need for windows api access, just write an activex dll
we can include a basic set of classes in it like a flat fso model and maybe easy curl access.

like autoit with forms. or node with full desktop access and forms.

it would be single thread and interpreted, and specifically built for common end user rad tasks not enterprise software or trying to do everything,
just for standard pc users. what was vb6 strongest suit.

just a fun twist on an old thought...

I like how the slop piles up :-))

Btw, wondering how can this perform reasonably if everything is a giant CValue in current implementation?

Code:

---

Public vType As ValueType
Public numVal As Double
Public strVal As String
Public boolVal As Boolean
Public objVal As Object
Public int64Val As Currency
Public arrayVal As Collection
Public objectProps As Collection
Public objectKeys As Collection

---

cheers,
</wqw>

the slop is a piling!

dunno, dont care, just playing :)

python guts are abhorrant, i have zero shame

basically i needed this engine for my own scripting tool with specific needs thats been evolving for like 20 yrs.

ive always been curious about how to write a drag drop form designer.

no mistakes, failed and dirty experiments are fine

might as well toss them all into a bowl and see what we get. I am in the fa2fo phase lol

ironically even at peak slop 0 fore thought levels we would be smaller and tighter than python and .net

What a coincidence, I'm also working in js4vb, he wants to connect.
With my node system or workflow.
It's still very early, but a lot of the behind-the-scenes work is done.
As always, delighted to see your work.

https://imgur.com/a/IqLIgsy

Attachment 195635

Best regards

very neat reminds me of a plc programming model i saw once. :)

Another thing I was wondering is if it's feasable for LLMs to translate C codebase (like Micro QuickJS) to VB6?

Obviously there are language features not available in VB6 so a lot of "creativity" has to be used to achieve this.

cheers,
</wqw>

that would be an interesting experiment to try. Id probably start the test with some largish C function without bit shifting and see where how its base translations hold up.

With a multifile source, you would have to get most or all of it into the context at once. or at least the relevant parts for conversion run X.
context length limits are the tricky part. If it doesnt have a function in context, it will silently make assumptions about what it does and how it operates without asking.
This can probable be overcome with strict prompting.

Building this project, and the sci4vb project it was helpful that it was building from scratch and had a large corpus of similar projects. It knew the design patterns
and its own inclinations and guesses about how previous contexts had done things played over. I caught it guessing, but its guessed names were very close to what had
actually used in the previous context.

Switching contexts was a little tricky, I had to reload it to give it a snapshot, but i couldnt overload or refill it or the usable context window would get very short. In the classview addin i added a right click feature to copy all public prototypes for all files in a project. This way i could stuff all of the class interfaces, public methods, and properties into the context in a condensed format without implementation bulk.

pointers and string parsing nuances would probably the thing to check for the conversion. It would be worth a shot, bug generation could be intractable.

I think it could kick out massive boiler plate to wrap a C library functions quickly. Claude was not rock solid on vb declare mechanics / C data passing. It would need specific rules in a strict prompt to help it out and guide it away from some of its tendencies. Ironically it did amazing at knowing the COM interface rules and passing data through COM methods. It also had a quirk always trying to Dim as new in a loop and expecting a new object each time vrs set x = new, had lots of bugs there. I think the weaknesses could be fixed through proper preemptive prompting.

I have been thinking about writing a doc on what i found so far about how to work across context limits and what tools I developed as I went to make it easier to integrate with. Like the classview addin i also added right click options to replace the entire source file (with unix to dos built in) or to replace specific functions from clipboard (with unix to dos) or goto line number. Since the vb6 iDE isnt integrated with AI tools directly its meat bag relay the whole way. Also you will see very heavy debug out messages in teh code so i can paste runlogs into the ai and it can see whats happening for hairy bugs.

Its very interesting what its capable of pumping out and mapping its strengths/weaknesses.

I would probably start with a hand written AGENTS.md which explains what to use and what not to use in VB6. Something like a crash course on VB6 and/or coding conventions like generating and using FUNC_NAME and MODULE_NAME consts etc.

It might be helpful to first let LLM generate GUIDLINES.md which will contain an overview of the project -- list of output binaries with list of classes and with functions and/or some high-level strategies how to approach conversion.

cheers,
</wqw>

thats smart. Id think id also want to figure out how to break it into testable units. convert it by blocks of functionality which I could individually test heavily. of course for that you would need to understand the original design first.

probably something like helper functions, then ast parsing, then intrepreter. building with a template.

instrumentating a copy of the c source first with lots of debug output on a known input that you could compare later might be valuable.

but also i created this whole thing in like 50 hours from scratch. it knew what to do. so the question is are its translation skills faster than its raw green field creation skills.

I have no data on that.

here is claudes take on the question:

prompt: (note: its internal hour estimates are always way off on the high side)
so we implemented a js engine from scratch in vb6 in about 50 hours. Do you think that it would have been faster to get you to translate a c js engine: https://github.com/bellard/mquickjs


response:

Honestly? I don't think the translation route would have been faster, and the end result would likely have been worse. Here's my thinking:

**The C-to-VB6 translation problem is brutal:**
- QuickJS (even mquickjs) relies heavily on NaN-boxing with tagged pointers - packing type information into IEEE 754 NaN bits. Translating that to VB6's Variant system would be a complete redesign, not a translation.
- Pointer arithmetic everywhere. Every `p++` and `*ptr` needs rethinking in VB6 terms.
- The GC model (refcounting + cycle detection) would need fundamental changes for VB6's COM-based lifetime management.

**Even mquickjs is substantial** - probably 10-15k lines of dense, optimized C. I'd estimate 80-120 hours of translation work with constant back-and-forth debugging subtle issues like signed/unsigned conversions, integer overflow semantics, struct packing differences.

**The bigger issue: you'd end up debugging code you didn't write**, in a paradigm that fights VB6 at every turn. With the from-scratch approach, you understand every line and it uses VB6 idioms naturally - Variants, Collections, COM integration, the bidirectional object wrapping.

**Feature mismatch too** - QuickJS has a bytecode compiler, full ES2020 compliance, tons of stuff you don't need. What you *do* need - deep COM integration, WMI automation support, the VB6 object synchronization - isn't in QuickJS anyway.

The 50 hours got you a tailored tool. Translation would've given you a Frankenstein fighting its host language.

Sounds like it understands it’s not as simple as VB6 to C translation. Nice!

I finally got around to do a blog post on AI coding tips and tricks: https://sandsprite.com/blogs/index.p...=584&year=2026

Very good article.
Claude has been a huge help to me on huge projects.
What I don't like is that I have to repeat everything so many times.
After a while, he starts inventing functions and variables.
And I'm already getting lazy :p.
sounds interesting drag and drop form designer w/ event sinks? VB7 with a js heart.
Best regards