Re: [HACKERS] Re: Hand written parsers

2001-04-15 Thread Bruce Guenter
On Fri, Apr 13, 2001 at 03:12:57AM -0400, Tom Lane wrote: > I have some interest in proposals to switch to a better parser-generator > tool than yacc ... There are tools to produce efficient top-down parsers as well. Those doing such parsers "by hand" may be interested in looking at PCCTS (http:

Re: [HACKERS] Re: Hand written parsers

2001-04-13 Thread Tom Lane
[EMAIL PROTECTED] (Nathan Myers) writes: > Yacc and yacc-like programs are most useful when the target grammar (or > your understanding of it) is not very stable. With Yacc you can make > sweeping changes much more easily; big changes can be a lot of work in > a hand-coded parser. And, in fac

Re: [HACKERS] Re: Hand written parsers

2001-04-12 Thread Nathan Myers
On Wed, Apr 11, 2001 at 10:44:59PM -0700, Ian Lance Taylor wrote: > Mark Butler <[EMAIL PROTECTED]> writes: > > ... > > The advantages of using a hand written recursive descent parser lie in > > 1) ease of implementing grammar changes > > 2) ease of debugging > > 3) ability to handle unusual case

Re: [HACKERS] Re: Hand written parsers

2001-04-11 Thread Ian Lance Taylor
Mark Butler <[EMAIL PROTECTED]> writes: > Bruce Momjian wrote: > > > Interesting. What advantages would there be? > > As any one who has ever attempted to build a C++ parser using Yacc or Bison > can attest, it is very difficult to get an LALR based parser to correctly > parse a sophisticated

[HACKERS] Re: Hand written parsers

2001-04-11 Thread Mark Butler
Bruce Momjian wrote: > Interesting. What advantages would there be? As any one who has ever attempted to build a C++ parser using Yacc or Bison can attest, it is very difficult to get an LALR based parser to correctly parse a sophisticated grammar. The advantages of using a hand written recurs