Snowflake

Snowflake is licensed under the Apache 2.0 licence.

Snowflake is actually two projects in one, each of which are described below.

Part I: The Library

The library facilitates the creation of PEG-based recursive-descent parsers at runtime.

Quick Links:

• Download the library as a precompiled jar file.
• Browse the library's source-code.
• View the Javadoc documentation for the library.
• View unit-test coverage statistics.

Part II: The Graphical Grammar Editor (a.k.a. The Snowflake GUI)

The grammar editor provides you the ability to interactively develop PEG grammars. Specifically, upon entering a grammar and some input, you can immediately view the resulting parse-tree in browsable form.

Quick Links:

• Quick Demonstration (Only 10 Slides)
• Cheat Sheet
• Download the grammar editor as a single precompiled ready-to-run jar file.

Part III: Downloadable Grammars

• Simple Demonstration
• Simple Phone Book
• Prefix Notation Calculator
• Infix Notation Calculator

Part IV: Downloadable Projects - These projects include executable example programs. Note: You need to download the entire zip file. (Click File->Download)

• Simple Phone Book
• Prefix Notation Calculator
• Infix Notation Calculator

Part V: Here are some other resources and links that may help you.

• Parsing Expression Grammars: An Example Driven Introduction
• Wikipedia: Parsing Expression Grammars
• The Packrat Parsing and Parsing Expression Grammars Page
• The Grammar of Snowflake Grammars