Re: M4 in python

[Doug McIlroy]

> implementing m4 in python could be expensive effort

The basic architecture of M4 is a simple character-stream processor
that switches sources at macro calls and sinks at macro definitions.
Gnu M4 has become a big program with lots of extra builtins, which
may or may not be useful for particular applications.

As a stream processor, M4 would seem to be a natural candidate for
implementation with Python generators. Unfortunately I don't know
Python well enough to predict whether the frequent stream redirections
can be efficiently done in Python. It's an interesting prospect,
though, to have the basic M4 model built in a framework that was
intended for stream processing.

Doug McIlroy