On Thu, Mar 22, 2012 at 11:47 PM, Nathan Rice <nathan.alexander.r...@gmail.com> wrote: > Having one core language with > many DSLs that can interoperate is infinitely better than having many > languages that cannot. A language designed in such a way would also > prevent issues like the Python 2 -> 3 fiasco, because two versions of > a DSL can be separate, and code can reference them independently while > being able to interoperate.
This is either utterly impossible, or already available, depending on your point of view. To have an infinitely-configurable program, you must make its configuration equivalent to writing code. There is already an infinitely-configurable program in Unix: "gcc config.c; ./a.out" takes a simple-format text file called "config.c" and processes it. You want infinite DSLs? Behold! $ ./module1 | ./module2 | ./module3 | ./module4 Each one has a shebang that tells you what they are (Python 2, Python 3, something else entirely). There's a very strict interoperability protocol between the modules - they pass information around through stdout and stdin. You can write any module in any language, and you can rewrite module1 for Python 3 without affecting any other or the invocation sequence. Problems always come when you want to share data between dissimilar modules. There's no single perfect data-transfer protocol that works across all languages. What does it mean to "call a function"? If you truly want this level of flexibility, the best thing to do is to separate sections cleanly. In fact, the pipe system I show above could be used that way, although it's stupidly ugly. Everything going on stdout/stdin has a two-word dispatch envelope with a from and a to, and each module reads a line, and if it's not addressed to it, passes it on to stdout. Responses get sent out with their from and to reversed. All you need is for the last module's stdout to be linked back into the first module's stdin (not sure if you can do that or not - it has the feeling of plugging a power strip into itself), and it'll work perfectly. Add a bit of boilerplate so that the application developers don't see what's happening underneath, and you could pretend that dissimilar languages are able to call into each other. Doesn't mean it's efficient though! TLDR version: Infinite flexibility means you're doing nothing. ChrisA -- http://mail.python.org/mailman/listinfo/python-list
