[VBA/VB6] COM prototyping and monkey patching without dlls

[n013]

For those who daily struggle against the limitations imposed by VBA/VB6 regarding class inheritance, polymorphism, and advanced methods for arrays and objects, as well as for those who have found areas of code that could be handled more elegantly and concisely with more expressive syntax, and for those who have dreamed of safely modifying the behavior of certain DLLs at runtime without code injection or enforced memory protection, today I present the Advanced Scripting Framework (ASF), an abstract runtime layer that even includes its own independent regular expression engine.

Below is an example of what is possible to achieve in a limited language like VBA.

    // prototypes.vas
    export prototype.COM.Range addStyle(color) {
        this.Interior.Color = color;
    };
    
    export prototype.COM.Worksheet highlight(rng, color) {
        rng.addStyle(color);
    };
    
    // main_prototype.vas
    scwd(wd);
    import { Range_addStyle, Worksheet_highlight } from './prototypes.vas';
    // Prototypes are live immediately after import
    let ws = $1.ActiveSheet;
    let rng = ws.Range('J1:L3');
    rng.addStyle(65535);          // yellow
    ws.highlight(rng, 255);       // red
    return rng.Interior.Color

Here is the driving VBA code:

    Private Sub module_system_prototype_imports()
        Dim result As Long
        Dim wd As String
        Dim eng As New ASF
        wd = ThisWorkbook.path
        With eng
            .AppAccess = True
            .InjectVariable "wd", wd
            result = CLng(.Execute(wd & "\main_prototype.vas", ThisWorkbook))
        End With
        'Expected: 255
    End Sub

And here is the execution trace:

    === Runtime Log ===
    RUN Program: 
    CALL: ActiveSheet() -> <Worksheet>
    CALL: range('J1:L3') -> <Range>
    CALL: addstyle(65535) -> 
    CALL: __PROTOTYPE_RANGE_ADDSTYLE(65535) -> 
    CALL: Interior() -> <Interior>
    CALL: highlight(<Range>, 255) -> 
    CALL: __PROTOTYPE_WORKSHEET_HIGHLIGHT(<Range>, 255) -> 
    CALL: addstyle(255) -> 
    CALL: __PROTOTYPE_RANGE_ADDSTYLE(255) -> 
    CALL: Interior() -> <Interior>
    CALL: Interior() -> <Interior>
    CALL: Color() -> 255
    CALL: @anon() -> 255

ASF comes with 233 Ruberduck tests and its regex engine has over 190 tests. Community testing is now welcome!