Newbie: Does an LR(k) parser compute the FIRST set?

"Ulrich Frank" <franku@fmi.uni-passau.de>
12 Feb 2006 11:02:34 -0500

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Related articles
Newbie: Does an LR(k) parser compute the FIRST set? franku@fmi.uni-passau.de (Ulrich Frank) (2006-02-12)
Re: Newbie: Does an LR(k) parser compute the FIRST set? schmitz@i3s.unice.fr (Sylvain Schmitz) (2006-02-14)
Newbie: Does an LR(k) parser compute the FIRST set? egagnon@sablevm.org (Etienne Gagnon) (2006-02-14)
Re: Newbie: Does an LR(k) parser compute the FIRST set? franku@fmi.uni-passau.de (Ulrich Frank) (2006-02-14)
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From: "Ulrich Frank" <franku@fmi.uni-passau.de>
Newsgroups: comp.compilers
Date: 12 Feb 2006 11:02:34 -0500
Organization: http://groups.google.com
Keywords: parse, yacc
Posted-Date: 12 Feb 2006 11:02:34 EST

Hello NG,


I'm a newbie in compiler building and have general problems.
- Does a LR-Parser also compute the FIRST and FOLLOW sets like a
LL-Parser?


- Especially in practical aspects: if so, can I get access to the FIRST
set in an (LA)LR Parser like JavaCUP or SableCC?


- What are examples for LR-Parser generators (LL-Parser generators I
found are ANTLR and JavaCC, LALR are JavaCUP and SableCC)?


So far I used ANTLR for generating a grammar. I've chosen ANTLR
because I need to analyse the FIRST set. Now I've read that LR-Parsers
are much more efficient and faster then LL-Parsers, so I want to
change but I don't know if I can access the FIRST set in an
(LA)LR-Parser like JavaCUP and I haven't read anything towards
this. So can you help me. Thanks,


Uli
[Yes, LR parsers need first and follow sets. The most popular LALR parser
generators are yacc and bison, though recent versions of bison are moving
to GLR parsing. -John]



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