[Python-Dev] Re: PEP 269 will live again.

Samuele Pedroni pedroni@inf.ethz.ch
Tue, 13 Aug 2002 19:41:43 +0200

>Note that Jeremy has a new Python compiler package (Lib/python/ in the
>Python 2.3 CVS tree), which currently uses parse trees as produced by
>the old 'parser' module as input, and then restructures them into more
>abstract syntax trees.  This compiler is easily retargetable to other
>input and output structures though -- I believe Finn Bock already has
>a Jython version of it.  I don't know what it generates, I doubt it
>generates CPython bytecode, maybe it generates Java source or JVM
>assembler; I believe it takes the same parse tree that Jython uses as

yup, it is more than a prototype,
the compilers in the current Jython CVS are based on that.

>I think it would be useful if you use the same form of abstract syntax
>trees as Jeremy's parser uses (not the parser module output, but the
>restructured abstract syntax trees); I think they are quite flexible
>and useful.

Yup and the point of the exercise is to make possible for
the future versions of PyChecker etc to work with Jython too.

>If you don't want to do this, you'll have to motivate why your
>alternative is better, and also show how Jeremy's compiler package can
>be easily adapted to use your form of parse trees.

yes ideally it should output a superset of that, or something with
small changes that can be easely backported to the above effort in
Jython, otherwise is a kind of step backward:

when first proposed the PEP would have been a furher blessing
for the awful parser module output format,

now the efforts of Jeremy and Finn have moved a bit both
Python and Jython away from that and on a parallel track.