|LL(1) vs LALR(1) parsers email@example.com (Odd Arild Olsen) (1995-11-04)|
|Re: LL(1) vs LALR(1) parsers firstname.lastname@example.org (Saileshwar Krishnamurthy) (1995-11-09)|
|Re: LL(1) vs LALR(1) parsers email@example.com (Sebastian Schmidt) (1995-11-10)|
|Re: LL(1) vs LALR(1) parsers firstname.lastname@example.org (1995-11-10)|
|Re: LL(1) vs LALR(1) parsers email@example.com (1995-11-14)|
|Re: LL(1) vs LALR(1) parsers firstname.lastname@example.org (steve (s.s.) simmons) (1995-11-15)|
|Re: LL(1) vs LALR(1) parsers email@example.com (Terence John Parr) (1995-11-20)|
|Re: LL(1) vs LALR(1) parsers firstname.lastname@example.org (1995-11-22)|
|Re: LL(1) vs LALR(1) parsers email@example.com (1995-11-24)|
|Re: LL(1) vs LALR(1) parsers firstname.lastname@example.org (1995-11-28)|
|Re: LL(1) vs LALR(1) parsers email@example.com (1995-11-28)|
|[17 later articles]|
|From:||firstname.lastname@example.org (Terence John Parr)|
|Keywords:||LL(1), LALR, parse|
|Organization:||Parr Research Corporation|
|Date:||Tue, 14 Nov 1995 02:10:11 GMT|
Saileshwar Krishnamurthy (email@example.com) wrote:
: They can be parsed perhaps, but the final LL(1) grammar that
: corresponds to the language will probably not be so intuitively
Just thought I'd throw in my 2 cents on LL(1). If I'm building
a recognizer only, LALR(1) clearly wins. The decision is not
so clear when you talk about the debugging, adding actions, etc...
LL(k>1) is actually a nice solution [LALR(k>1) would be nice too].
The syntactic predicates of PCCTS allow arbitrary lookahead
through selective backtracking. Kinda nice. The famous C++
expressions vs declaration ambiguity can be solved via:
stat : (decl)? // if it looks like a declaration, it is
| expr // else it's an expression.
Note that we are smart about this: "a=3;" immediately jumps to
the expr alternative as it's obviously not a declaration.
Please see my upcoming paper with Russell Quong in SIGPLAN Notices
(Jan or Feb 96) called: ``LL and LR Translators Need k>1 Lookahead''.
PS can be had of it now at ftp://ftp.parr-research.com/pub/papers/needlook.ps
Return to the
Search the comp.compilers archives again.