greater than infinity

NQ-NQP’s Status:

• A fairly well defined grammar for parsing nqp exists. It generates AST nodes for most of the grammar, but not all of the grammar.
  • In the future, it would be useful for AST optimizations, like constant folding
• Code generation supports integers and subs, but it does not yet support other data types like floats, strings, bools, or anything else like regular expressions.
  • Built in basic types should eventually include:
    • Packages
    • Subs
    • Classes
    • Roles
    • Arrays
    • Hashes
    • Ints
    • Nums
    • Strings
    • Bools
• Execution of code generated works.
  • Debugging is surprisingly easy with the gdb, but I will have to see how hard it is in the future. I know that if I start working with a JIT it becomes increasingly difficult to view whats being run on the processor.
• A limited number of binary ops, like add and subtract are working.
• The VM supports method calls, but the code does not currently generate code properly.

Lessons learned:

• LLVM is neat but advanced and complicated
• Grammars are fun, we should do more of those
  • Having a way of defining a grammar is difficult though currently, in C there is yacc/bison but that is a bit limited compared to other systems.
• Grammars are hard, parsing is not easy
  • Tokenizers and Lexers are difficult if you want to contextually call things based off of where they should be in your grammar
• Focusing on construction a real “Compiler” is probably a mistake. Start small, an ast that you can walk and execute each step of the way is better for learning than building a code generation system. Code generation is useful but hard, and can be deferred until later.

Things I would do different if I could start over:

• Focus on the grammar, and making an executable AST rather than translating the AST into code.
• If there was a VM out there I could link to for a runtime, I have not found an easy to use one. It would be nice to have because then I could of focused more on other parts of the language, but VM support is not that hard, just lots of typing.

This entry was posted on Tuesday, May 4th, 2010 at 2:03 am and is filed under NQP. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.