Re: GLR ambiguity

[Alessandro Di Marco]

Hans Aberg <address@hidden> writes:

   On 16 Jun 2007, at 08:15, Paul Hilfinger wrote:

   >
   >> On 14 Jun 2007, at 12:48, Alessandro Di Marco wrote:
   >> I was trying to create a GLR grammar for natural languages
   >> ...when I stuck on the
   >> following s/r ambiguity.
   >
   >> text:
   >>     /* empty */
   >>   | text sentence
   >>   ;
   >>
   >> sentence:
   >>     WORD EOL
   >>   | DOUBLEQ WORD EOL
   >>   | DOUBLEQ WORD EOL DOUBLEQ
   >>   ;

   > GLR does not resolve grammar conflicts statically.  Bison will
   > continue to report conflicts, and these reports really don't tell you
   > much.  Since natural languages ARE ambiguous, what you must use GLR
   > for is to gather the possible interpretations.  That is the purpose of
   > %merge, which allows you, on encountering two different parses of the
   > same phrase, to collect the interpretations (syntax trees, or
   > whatever semantic values you are using) and return this collection
   > (represented however you choose) as the value of the ambiguous
   > construct.  %merge also allows you to reject some interpretations on
   > context-sensitive grounds.  When I say "allows you" I don't mean that
   > it provides specific facilities to do any of this, but rather that it
   > gives a parser structure that allows YOU to write the necessary  actions.

   We did not get to know how much of actual language process that was  
intended -
   perhaps the intent was only to filter out quotations?!

Well, IMO it would be a good starting point... (did you know that the ladies'
market is managed by the Kowloon neighborhoods' people? :-)

   But it would sure be interesting if somebody took up the quest of  doing a
   natural language grammar. There is, in fact, a Flex/Bison  grammar for the
   constructed language lojban, which is made not not be  ambiguous:
     http://www.lojban.org/tiki/tiki-index.php?page=Home+Page&bl
   It might give inputs on how to do it for natural languages.

Thanx!

Bye,
Alessandro

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