Difference between revisions of "2008 Jython"

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(Abstract)
(Abstract)
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<br/><br/>This talk assumes that the audience is familiar with EBNF and recursive descent parsers, however, no previous experience with ANTLR or Python is assumed.
 
<br/><br/>This talk assumes that the audience is familiar with EBNF and recursive descent parsers, however, no previous experience with ANTLR or Python is assumed.
  
http://wiki.jvmlangsummit.com/pdf/TBD
+
http://wiki.jvmlangsummit.com/pdf/29_Wierzbicki_jython.pdf
  
 
=== Author Bio ===
 
=== Author Bio ===

Revision as of 08:50, 26 September 2008

Parsing with ANTLR 3.1

Frank Wierzbicki - Sun

Project
http://www.jython.org

Abstract

NOTE: This talk was switched to a talk on Jython internals

Talk Abstract
Writing a basic recursive descent parser by hand is actually a pretty straight-forward task. However, when the parser grows to cover error handling, language specific semantic peculiarities, and other real world concerns that must be covered in a production-ready language, a parser can become difficult to read and maintain. This is where Terrance Parr's ANTLR (ANother Tool for Language Recognition) really helps. ANTLR is essentially a tool that allows you to write a parser as an executable EBNF (Extended BackusÐNaur Form) with embeddable actions. Another way to say it is that ANTLR provides a domain specific language for writing parsers.

Over the last year I have worked extensively with ANTLR 3.0 and then 3.1 to write a new parser for Jython 2.5. In this talk I will discuss the various techniques that I was able to use to make a correct parser for Jython that is reasonably readable. I will also discuss the way Python exposes its internal AST (abstract syntax tree) and how I was able to use this property to empirically prove to a reasonable level of confidence that Jython's AST is the same as the C Implementation of Python's AST.

Some of the topics that will be discussed:
* Basic parsing with ANTLR 3.1
* AST generation and rewriting
* Heterogeneous node specification syntax
* How significant indents (part of Python) are parsed in Jython with ANTLR
* Error handling
* Visualizing grammars with ANTLRWorks



This talk assumes that the audience is familiar with EBNF and recursive descent parsers, however, no previous experience with ANTLR or Python is assumed.

http://wiki.jvmlangsummit.com/pdf/29_Wierzbicki_jython.pdf

Author Bio

Frank Wierzbicki is the Jython Project Lead. He is employed by Sun Microsystems where he works on Jython full-time. He has been a Java and a Python developer for over ten years. Frank has a B.S. in Biochemistry from Old Dominion University and an All-But-Dissertation in Neuroscience from Baylor College of Medicine.

Key Issues for Discussion (cooperative)

(please expand cooperatively) Talk:Jython