LL(1) parser table

hyperarien@yahoo.com (lee)
5 Jan 2002 01:31:12 -0500

          From comp.compilers
Related articles
LL(1) parser table hyperarien@yahoo.com (2002-01-05)
Re: LL(1) parser table gsc@zip.com.au (Sean Case) (2002-01-07)
Re: LL(1) parser table dr_feriozi@prodigy.net (SLK Parsing) (2002-01-13)
Re: LL(1) parser table kaarthik@cisco.com (Kaarthik) (2002-01-13)
Re: LL(1) parser table kaarthik@cisco.com (Kaarthik) (2002-01-13)
Re: LL(1) parser table hyperarien@yahoo.com (2002-01-14)
| List of all articles for this month |
From: hyperarien@yahoo.com (lee)
Newsgroups: comp.compilers
Date: 5 Jan 2002 01:31:12 -0500
Organization: http://groups.google.com/
Keywords: parse, LL(1), question
Posted-Date: 05 Jan 2002 01:31:12 EST

Hi all,


I am trying construct a LL1 parser table for the following grammar.


S -> E
E -> ++E | E++ | E-E | E/E | id


where symbols have usual meanings.


However in the final table this grammar seems to be ambiguous. I
actually first transformed the above into this disambiguous form.


S -> E
E -> E-T | T
T -> T/F | F
F -> F++ | G
G -> ++E | id


And after that I removed all left-recursions.


S -> E
E -> TE'
E'-> -TE'
E'-> epsilon
T -> FT'
T'-> /FT'
T'-> epsilon
F -> GF'
F'-> ++F'
F'-> epsilon
G -> ++E
G -> id


Still after all this grammar is ambiguous. Because F' FOLLOW set is
{/,-,++,$} and there are two entries for [F',++] comination.


Does this means the above grammar is not suitable for LL1 parsing?


thanks in advance...

Post a followup to this message

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