Example of a script parser and interpreter

I showed not long ago a basis of how to parse a script using the abstract tree format.
I've been busy to make an interpreter and reseached some examples i found floating on the internet.

I must admit im not a user friendly coder and i also admit my code might not be well written as desired by some of you (*cough* ident), however this is the best i think i can produce to show you a way to create a script interpreter done in vb.net.

My script supports the following types:

• String
• Integer
• Float
• Boolean
• Collection (list)
• Stream
• Function
• Delegate
• Null

Exposing external modules and custom functions

I found a suitable idea from John Leitch (Link)

Code:

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<ScriptFunction("Path", ValueType.Function, False, False)> _
Public Shared Function AssemblyAbsolutePath(Name As String) As String
      Return Path.Combine(Helpers.AssemblyDirectory, Name)
End Function

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Once the evaluater has located the class that you want to utilize in your script it archives all the methods to a delegate class, this class acts as middle men that invokes it.
Some of those are global functions and some are an extension to a type.
Those are set on the global scope of the script like "__string.name", once you would call a member function of a string type then it would invoke that static method.

http://i.imgur.com/QxxwGJE.png

The creation of a static method he wrote was as followed (and a bit modified by my needs)

Code:

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Public Shared Function CreateDelegate(Method As MethodInfo) As System.[Delegate]
            If (Method IsNot Nothing) AndAlso (Method.IsStatic) AndAlso (Not Method.IsGenericMethod) Then
                Dim ExprParams() As LinqExpressions.ParameterExpression = Method.GetParameters().Select(Function(p) LinqExpressions.Expression.Parameter(p.ParameterType, p.Name)).ToArray()
                Dim ExprCall As LinqExpressions.MethodCallExpression = LinqExpressions.Expression.Call(Nothing, Method, ExprParams)
                Return LinqExpressions.Expression.Lambda(ExprCall, ExprParams).Compile()
            End If
            Throw New Exception(String.Format(My.Settings.InvalidFunctionForDelegate, Method.ToString))
End Function

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Serializing scripts

Further on i was aimed to use the google's approach for serializing, called proto-buf.
Simply because my idea later on is that i want to send scripts from a remote location to a client.
And protobuf produces very small binary footprints, a script of 300 bytes would result in 400 bytes.

Example of using a query and file stream usage script wise:

http://i.imgur.com/lBacnel.png


Well i guess you just need to download the source and see how you can utilize it for your own desire.

Any suggestions or qeustions, feel free to bombard this thread ;)

Nameco Source: Attachment 125747 (repacked, all binaries removed)

- Barret

Oh darn it, just realized i posted this in the general vb.net instead of Codebank -.- im so sorry...

Quote:

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Originally Posted by TheBarret

Oh darn it, just realized i posted this in the general vb.net instead of Codebank -.- im so sorry...

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Not to mention contains multiple exe files that is not allowed on this forum ;)

Quote:

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Originally Posted by ident

Not to mention contains multiple exe files that is not allowed on this forum ;)

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I thought i removed all the binary except the proto-buf library. Hmmz im sorry folks , scan it anyway :S

Repacked the zip , i double checked it no binaries are in there.