Re: yacc for Pascal, was Why LL(1) Parsers do not support left recursion?

Hans-Peter Diettrich <DrDiettrich1@aol.com>
29 Jul 2006 19:37:26 -0400

          From comp.compilers

Related articles
Re: Why LL(1) Parsers do not support left recursion? DrDiettrich1@aol.com (Hans-Peter Diettrich) (2006-07-22)
Re: Why LL(1) Parsers do not support left recursion? wyrmwif@tsoft.org (SM Ryan) (2006-07-23)
Re: Why LL(1) Parsers do not support left recursion? DrDiettrich1@aol.com (Hans-Peter Diettrich) (2006-07-25)
Re: Why LL(1) Parsers do not support left recursion? ajonospam@andrew.cmu.edu (Arthur J. O'Dwyer) (2006-07-25)
Re: Why LL(1) Parsers do not support left recursion? DrDiettrich1@aol.com (Hans-Peter Diettrich) (2006-07-28)
Re: Why LL(1) Parsers do not support left recursion? ajo@andrew.cmu.edu (Arthur J. O'Dwyer) (2006-07-29)
Re: yacc for Pascal, was Why LL(1) Parsers do not support left recursi DrDiettrich1@aol.com (Hans-Peter Diettrich) (2006-07-29)
Re: yacc for Pascal, was Why LL(1) Parsers do not support left recursi cfc@shell01.TheWorld.com (Chris F Clark) (2006-07-29)
Re: yacc for Pascal, was Why LL(1) Parsers do not support left recursi DrDiettrich1@aol.com (Hans-Peter Diettrich) (2006-07-31)
Re: yacc for Pascal, was Why LL(1) Parsers do not support left recursi DrDiettrich1@aol.com (Hans-Peter Diettrich) (2006-08-03)
| List of all articles for this month |

From: Hans-Peter Diettrich <DrDiettrich1@aol.com>
Newsgroups: comp.compilers
Date: 29 Jul 2006 19:37:26 -0400
Organization: Compilers Central
References: 06-07-059 06-07-065 06-07-071 06-07-083 06-07-095 06-07-099
Keywords: yacc, Pascal
Posted-Date: 29 Jul 2006 19:37:26 EDT

Arthur J. O'Dwyer schrieb:


> [then, on debugging yacc-alike parser generators...]
[...]
> Which I guess brings us back to "why are yacc-alikes so hard to
> use?", which is code for "why are yacc-alikes targeted at system hackers
> instead of normal people?", which practically answers itself: hackers
> wrote yacc in the first place, and yacc is mainly used by hardcore
> programmers who are going to spend a lot of time debugging anyway. :)


You mean, I simply should use a different tool?
Sounds good, but can you recommend me any one, usable to create an
parser in e.g. Pascal?


I really don't insist in a tool, written in Pascal, but it should at
least allow to output the parser tables and code (including the
semantical actions) in any appropriate language.


My dream were a tool which reads in a grammar, possibly in precompiled
form, and then interprets some input according to that grammar. It would
be sufficient, in the first place, if the engine would create an parse
tree, which then could be inspected and evaluated without language
restrictions. Furthermore it were nice to have hooks, so that parts of
the final parse tree can be processed, and possibly discarded, as
appropriate for the actual application.


    > (And you're still better off than if the tools didn't exist at all,
right?)


Well, yes and no. Yes, I'm happy if I don't have to write an parser
generator myself, but no, I'm not really happy with a possibly
unreliable tool. We spend so much time in discussing and constructing
"safe" (unambiguous...) grammars, and in the next step we should rely on
unsafe tools?


> </software-engineering metadiscussion>


DoDi



Post a followup to this message

Return to the comp.compilers page.
Search the comp.compilers archives again.