OT: Ultimate Language Syntax Cleanness Comparison
pyth at devel.trillke.net
Mon Feb 10 12:50:59 CET 2003
Jeremy Fincher wrote:
> holger krekel <pyth at devel.trillke.net> wrote in message news:<mailman.1044706941.23586.python-list at python.org>...
> > please show me the snippet how to parse a perl snippet without evaluating it.
> > I am really interested and we even posted to the perl-porters list at
> > the time.
> Check out the root level directory of an unpacked Perl 5.8.0
> distribution. You'll find two files there, bytecode.pl and perly.y.
> Perly.y is the yacc parser for Perl. At the beginning you'll see the
> list of tokens it parses code into (those lines begin with %token.)
> Then look at the end of bytecode.pl. It's a perl script that details
> the bytecodes that Perl is compiled into; you'll note that the set of
> parser tokens is most definitely *not* the set of bytecodes. Thus,
> there exists some transformation elsewhere in the Perl code that turns
> the abstract syntax tree created by perly.y into the bytecode later
> interpreted. Thus, Perl is parsed separately from being evaluated.
Then it should be easy enough to come up with a mini-snippet
that gives me the parse tree, right? I don't think that the
mentioned files help me much with it. Sites like
or a thread on perl monks
suggests it's extremely difficult.
If so can you send the snippet which parses *any* perl script?
If your deduction above is true, then it should be easy.
As said before someone who is doing perl for ages (and hacking
at the core) looked for a *whole day* trying to come up with
a *sane* way to parse perl scripts. We could eventually parse
some files but often enough our perl-interpreter got seriously
Has this changed with 5.8?
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