Scripting Language [VB]

[TheMinistered]

This is the watered down framework for a scripting language:

clsInstruction:

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Public Enum Instruction
   END_SCRIPT = 0
   NO_OPCODE
End Enum

Private menumInstruction As Instruction

Public Property Get Instruction() As Instruction
   Instruction = menumInstruction
End Property
Public Property Let Instruction(ByVal Instruction As Instruction)
   menumInstruction = Instruction
End Property


clsScript:

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Private mcolInstructionList As Collection

Private Sub Class_Initialize()
   Set mcolInstructionList = New Collection
End Sub

Public Function Add(ByVal Instruction As Instruction) As clsInstruction
   Dim objNewMember As clsInstruction
   Set objNewMember = New clsInstruction


   objNewMember.Instruction = Instruction
   mcolInstructionList.Add objNewMember

   Set Add = objNewMember
   Set objNewMember = Nothing
End Function

Public Property Get Item(ByVal vntIndexKey As Variant) As clsInstruction
 Set Item = mcolInstructionList(vntIndexKey)
End Property

Public Property Get Count() As Long
   Count = mcolInstructionList.Count
End Property

Public Sub Remove(ByVal vntIndexKey As Variant)
   mcolInstructionList.Remove vntIndexKey
End Sub

Public Property Get NewEnum() As IUnknown
   Set NewEnum = mcolInstructionList.[_NewEnum]
End Property

Private Sub Class_Terminate()
   Set mcolInstructionList = Nothing
End Sub


clsVirtualMachine:

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Private mcolScriptList As Collection

Private Sub Class_Initialize()
   Set mcolScriptList = New Collection
End Sub

Public Sub Add(ByVal Script As clsScript, ByVal strKey As String)
   If (LenB(strKey) = 0) Then
       mcolScriptList.Add Script
   Else
       mcolScriptList.Add Script, strKey
   End If
End Sub

Public Sub ExecuteScript(ByVal strKey As String)
   Dim Script As clsScript
   Dim Instruction As clsInstruction
   Dim Counter As Long
   
   Set Script = mcolScriptList.Item(strKey)
   
   Do
       Counter = Counter + 1
       Set Instruction = Script.Item(Counter)
       
       Select Case Instruction.Instruction
           Case NO_OPCODE
               'Do Nothing
       End Select
       
   Loop While Instruction.Instruction <> END_SCRIPT
End Sub

Public Property Get Item(ByVal vntIndexKey As Variant) As clsInstruction
 Set Item = mcolScriptList(vntIndexKey)
End Property

Public Property Get Count() As Long
   Count = mcolScriptList.Count
End Property

Public Sub Remove(ByVal vntIndexKey As Variant)
   mcolScriptList.Remove vntIndexKey
End Sub

Public Property Get NewEnum() As IUnknown
   Set NewEnum = mcolScriptList.[_NewEnum]
End Property

Private Sub Class_Terminate()
   Set mcolScriptList = Nothing
End Sub


Example of Use:

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   Dim Instruction As clsInstruction
   Dim Script As clsScript
   Dim VirtualMachine As clsVirtualMachine
   
   Set Instruction = New clsInstruction
       Instruction.Instruction = NO_OPCODE
       
   Set Script = New clsScript
       Script.Add Instruction.Instruction
       'OR
       Script.Add NO_OPCODE
       Script.Add END_SCRIPT
       
   Set VirtualMachine = New clsVirtualMachine
       VirtualMachine.Add Script, ObjPtr(Script) 'ObjPtr(x) should always be unique
       
       VirtualMachine.ExecuteScript ObjPtr(Script)