Chameleon

The Chameleon home page has moved to here (new version available).

Jeremy Wazny's PhD Type inference and type error diagnosis for Hindley/Milner with Extensions (ps.gz) summarizes our work on inference and type error reporting.

Version from July 2005

• source (see README how to build)
• examples are under the test directory
• chameleon --just-infer-types --dont-import-implicit filename.ch typechecks the program text in filename.ch
• in the current version the type error reporting mode is switched off (see here for earlier versions)
• in the near future we will provide a complete back-end

Chameleon is a Haskell-style language which implements the ideas described in a ``A Theory of Overloading''. Publications and talks related to Chameleon can be found here .

• Latest release: linux executable (should run under any linux system as long as you can run ghc6). We plan to release the source code soon (next week or so). Note that you'll also need to include Prelude.ch in your Chameleon directory.
  

• Improved Type Inference and Lexically Scoped Annotations
  For details, consult Improved Inference for Checking Type Annotations
• Improving Type Error Diagnosis
• Beyond Functional Dependencies. For details, consult Sound and Decidable Type Inference for Functional Dependencies
• Translation of Chameleon to (plain) Haskell
• Mixing Haskell and Chameleon overloading

• Existentially Quantified Type Classes (to be updated soon)
  • linux executable
    Also requires the Prelude.ch file. The "exists" version will eventually subsume the version above. However, we're still fixing some bugs here and there. But, the examples below will work. Note that the "exists" version only works in the -d mode at the moment.
  • Examples: ex1.ch,ex2.ch, append.ch, append2.ch, mkt.ch

• A Haskell Programmer's Guide to Chameleon
  Examples: eqordC.ch , erk-foo-bar.ch , eval.ch , hasempty.ch , lexical-poly-rec.ch , pq.ch, pq2.ch , prefix.ch , record.ch , show.ch , zip.ch
• The Chameleon Type Debugger (Tool Demonstration)
  The examples from the paper: plot.hs , realprog.ch . stack.hs, normalize.hs, merge.hs, reverse.hs, collect.ch, div.ch
  * Currently, you need to write :explain (sum) ((Num [*]) => *) rather than :explain sum (Num [*]=>*)
  * You will need the interface file for the Haskell 98 Standard Prelude . See A Haskell Programmer's Guide to Chameleon for details.

Papers:

Check out the publication page.

The Chameleon Team

• Andreas Rossberg
• Peter J. Stuckey
• Martin Sulzmann
• Jeremy Wazny