DRAFT PROPOSAL: Meta-compiler for non-java code to run on the java virtual machine

[Anders Björklund]

Hi all,

I propose to implement
     A meta-compiler for non-java code to run on the java virtual machine.

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1.0 Specifics
      A system consisting of:

      A representation of class files with utility methods to translate 
to and
      from the internal binary representation. This representation could 
also
      be used outside of the compiler for other binary formats.

      An instrumentation to manipulate the internal bytearrays of the
      representation, shielding users of the system from implementation
      details.

      Bytecode needed in the compilation stage would be created with most
      code calling a language-type library written in java. That way most
      parts of a language implementation can be made using java, with just
      some minor parts as bytecode from the language developer.

      I belive such a system would decrease the time it would take to
      implement a new language on the jvm. Performance would be lower, but
      once the new language is up and running, focus can turn to changing
      those non performing sections into bytecode, all the time having a
      working language.

      Operations could be mapped to a specific command class defined in
      the language-type library. Eventually the library may be discarded 
once
      the entire new language has been properly implemented as bytecode.

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2.0 Goals
      To simplify the creation and manipulation of binary files - in 
particular the
      java class format.

      To simplify the migration of one or more computer languages to the 
java
      platform.

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3.0 Status
      I already have the binary parsing and the resulting representation
      working as a graph of objects.

      When it comes to parsing source code, I have previously created the
      lexer/parser "HiLexed" (available from SourceForge under GPL 2).
      Using HiLexed I am able to map most computer languages using a
       format similar to Backus Naur, into callbacks to the would-be 
compiler.

      The binary representation is functional and I can look at classfiles
      accessing bytecode in separate methods, read the constant pool and
      look at access modifiers of fields etc.

      The representation graph can be saved into a classfile again after
      manipulation.

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4.0 Complete implementation
       As evaluation of my proposal, I suggest to build an 
implementation of a
       small new language running on the jvm.

       This language would be extendable, supporting reading from the
       keyboard, loops, some operation on collected input as well as writing
       the results back to the console.

(Submitter: Anders Bjorklund__AT__sajtopia.se)