> So you can't make an internal DSL like this that uses Python's built- > in grammar. You'd have to hack the parser or settle for an external > preprocessor.
This time it is really hard for me but I begin accepting the fact that I will have to build an external DSL. I experimented some weeks ago with ANTLR and the tools work fine but I do not like the extra effort to learn and maintain the extra tooling. I think that in the beginning the DSL language will have to change a very often as new features are added. To implement a standardized rock solid language like SQL ANTLR might be the perfect tool but to develop something from scratch that will be expanded interactively a internal DSL has huge benefits. Please not that I really like ANTLR. It is just the first tool I used for this task and I want to double check if other tools fit better to my needs. I will look into Ply and Pyparsing over the next weeks unless someone points out that there is some special tool that makes growing a new "fast evolving" language as easy as building an internal DSL. Maybe this is all overkill and there is a hacking ruby-style DSLs with regular expressions recipe out there? So far I could not find one. > However, the gist of it seems to be that you want to be able to write > files in your DSL that can be imported just like a regular Python > module. Yes, that can be done. > > See PEP 302, Import Hooks: > > http://www.python.org/dev/peps/pep-0302/ > > Python's standard importer looks for files with *.py, *.pyc, *.pyd, or > *.so extensions. You could write an importer that looks for *.dsl > files, and, instead of loading it as a Python file, invokes your DSL > parser. This is really helpful. Thanks for giving me directions. Mark -- http://mail.python.org/mailman/listinfo/python-list
