README for asdlGen version 2.0-beta

Daniel C. Wang

This is beta release asdlGen. Many of the internals have been significantly reworked, and most of the major internal interfaces have been documented. There have been also several significant changes to various backends, and a different compilation model for the generated code.

In the past asdlGen assumed the existence of several support libraries that it would link with the source code produced by it. This made installing asdlGen quiet a non-trivial task. In the new model asdlGen will by default emit all the necessary source code needed to compile the world, rather than assuming the existence of asdlGen specific libraries. The C code still requires libcii.a which is included verbatim but not built in the current distribution.

There's still work to do, most importantly documenting many of the new features and providing some good examples. The old user manual is out of date but it's better then nothing.

Also, asdlGen is designed to make inter-language operation easier. It may not exploit or produce the most idiomatic code for a given language, advice on how to improve the code for a given language will be appreciated.

% ./configure --prefix=<install-prefix>
% make all

Major Changes/Features include

• Support for SML97, Haskell98, OCaml-2.0, Java, C++, C, and Icon.
• Reworked command line handling and command line options. asdlGen --help is now much more informative.
• asdlGen can optionally output dependency information for make or language appropriate build system.
• Reworked pretty printing for all the backends to produce more readable code.
• Currently dropped support for pickle pretty-printer, it will be reincarnated some time in the future.
• Java and C++ backends now use generic/templated arrays to implement sequence and option types.
• Experimental support for preservation of sharing and XML.
• SML97, Haskell98, and Ocaml-2.0 supports an "s-expression" ASCII picklers. Useful for debugging.
• Ability for users to define there own primitive types.
• New syntax for importing modules

  ---

  module T (imports VeryLongModuleName alias M) {
   foo = (M.t)
  }
  

  ---

• Better name mangling schemes.
• Support for user defined primitives. Rather than hard coding information about user primitive types into asdlGen primitives are now extensible. In particular the old primitive types of int, string, identifier. Are implemented by pre-appending the following declaration to all inputs

  ---

  primitive module StdPrims {
   int string identifier
  }
  

  ---

  asdlGen tacks this on to any set of input files to remain compatible with existing code. Users, can add their own primitive types by simply including there own primitive module declaration. See std-types.asdl for an example that defines a richer set fix width integer and word types, for various languages.
• Support for an unnamed "Toplevel" module. Allowing one to generate less verbose code for pedagogical purposes. See toplevel.asdl for an example usage.

1. COPYRIGHT

2. Installation