Mitchell McMullen Paul Nguyen SWAN

Python written entirely in C#. Can access all.NET libraries and Silverlight. Created by the same guy as Jython. No design documentation or developer’s guide for source code =(

IronPySwan Added Oracle Database Connectivity. Embedded SQL commands/queries. Allows arbitrary python expressions within SQL commands/queries. (Using back ticks)

Overview

Tokenizer Breaks up the source code into tokens. IronPython uses a mostly hand-written tokenizer and parser. Some token recognition code is auto-generated. MAKECONNECT INSERT _________________ ______________

Parser Identifies tokens as they come in. Implements the Python (BNF) grammar directly. Constructs the Python AST.

MSAstNode Declaration This is where a statement/expression is turned into a node fit for the AST. The statement/expression’s Reduce() method is called, which returns a simpler node. Typically, reduce() links to implementation code.

AstMethods Big collection of Method signatures, used for reflection/indirection to PythonOps. Connection Statement (Nonquery) Expression (Query) AstMethods

PythonOps Pretty much another layer of indirection, and a repository for some helper functions. Connection Statement (Nonquery) Expression (Query)

Runtime Behavior This is the implementation-ey kind of stuff. In the end, this is where the heavy lifting for each method call is located. We have one class, PySwanSqlRunner, which houses the connection and passes the final SQL strings on to the database. These methods are executed by the interpreter.

PySwanSqlRunner Connection Statement (Nonquery) Expression (Query)

Stuff That Still Really Needs Work Error handling is pretty primitive. No RDF. (Sorry, Dr. Cannata!!) SQL must be well-formed.

Programming Language Terms Terminal/Nonterminal (Tokenizer.cs). Abstract Syntax Tree (Parser.cs). Parse tree is implicitly built. (Parser.cs) Python.g BNF is implemented directly (Parser.cs Some SQL involved.

Demonstration Hope you enjoy!

Questions?