VBScript in JavaScript

This is an attempt to write a VBScript parser in JS. The output is also JavaScript.

It's far from compelete, but it does compile the .vbs files.

View the live demo: kastner.github.com/vbscript_in_js/

How

Here's what's worked for me... YMMV:

• use node v0.6.2 or higher
• use npm (curl http://npmjs.org/install.sh | sh)
• install jison: npm install jison -g
• compile and run: jison vbs4.jison && node run.js test3.vbs

What

VBScript -> JS compiler, using the amazing jison project.

This is my first time playing with a formal language definition. It's not pretty ;)

Why

I suggested that someone port their old, giant IE6 only application to modern browsers by simply, "writing a VBScript interpreter in JS". That got me thinking about how hard it would be (hint: I vastly underestimated the complexity).

This project is the result of me hacking around with that idea for the past few days here and there.

When

Seriously, calling this abandon-ware is being kind. This is a hack, pure-and-simple. If someone wanted to run with it, be my guest, but don't expect it to do anything useful in it's current state.

In a Perfect World

This wouldn't even be needed, since VBScript would never have been used in client browsers. Baring that, here's what I imagine this project would look like if it had some attention given to it:

• a standard lib of VBScript functions (like inStr - most likely in JS)
• a way to automatically run in modern browsers
  • auto-detection and parsing of <script language='VBScript'> tags (much like CoffeeScript)
  • auto DOM manipulation / access (foo_onClick, etc.)
  • inline handlers working somehow?

Example

given this VBScript input:

Set oOldSort = Nothing

Sub ChangeSort(oSortField, oField)
  If TypeName(oOldSort) = "HTMLSpanElement" Then
    oOldSort.className = "smallestblack"
  End If

  If oSortField Is Nothing Then
    frmSearch.Sort.value = ""
  Else
    oSortField.className = "smallestred"
    Set oOldSort = oSortField
    If oField.Name = "LocType" Then
      frmSearch.Sort.value = "Type"
    Else
      frmSearch.Sort.value = oField.Name
    End If
  End If
End Sub

this is the javascript that is produced:

(function () {
  oOldSort = null;
  function ChangeSort (oSortField, oField) {
    if (TypeName(oOldSort) = "HTMLSpanElement") {
      oOldSort.className = "smallestblack";
    }
    if (oSortField == null) {
      frmSearch.Sort.value = "";
    } else {
      oSortField.className = "smallestred";
      oOldSort = oSortField;
      if (oField.Name = "LocType") {
        frmSearch.Sort.value = "Type";
      } else {
        frmSearch.Sort.value = oField.Name;
      }
    }
  }
})();