[antlr-interest] Free Text mixed with rules

[victor panizza]

Hi Loring,

Could you point me to an example??

Thanks in advance!!!

On Tue, Jun 17, 2008 at 7:49 PM, Loring Craymer <lgcraymer at yahoo.com> wrote:

>  If you want to recover text in its original format, you might as well use
> the start and stop markers on the first and last tokens of the "text"
> sequence from the input stream (ANTLR 3 keeps the text input stream in
> memory).  At the same time, you are probably best off in going ahead and
> including an expression grammar in your parser to handle what you are
> calling "free text"--otherwise, you will have to deal with nested
> conditionals in your lexer, and that gets very messy.  You can repackage the
> "text" segments in the output AST as a replacement for the nodes matched by
> the expression grammar.
>
> --Loring
>
>
> ----- Original Message ----
> From: victor panizza <victor.panizza at gmail.com>
> To: antlr-interest at antlr.org
> Sent: Tuesday, June 17, 2008 5:17:29 PM
> Subject: [antlr-interest] Free Text mixed with rules
>
> Hello All,
>
> I have the follow issue:
>
> I'm trying to develop a Parse Grammar and a Tree Parse for read PL/SQL
> scripts and translate it to DB2 SQL PL. Now, there're many diferences
> beetwen thems and this diferences are defined by the rules and some
> literals, but there're many things in common like the IF LOGICAL_OPERATION
> THEN END IF;
>
> My Idea is create a Node in the tree (using a token like FREE_TEXT) where I
> can put each segment of free text like the above and later walk the tree and
> get this free text in the same order on they were recongnized. For example:
>
> IF (LAST_DAY(PDATE)!=PDATE) THEN
>   PDATEAUX := ADD_MONTHS(PDATE, PMONTHS);
>   RETURN ADD_MONTHS(PDATE, PMONTHS);
> END IF;
>
> In text tree representation:
>
> (ROOT
>           (FREE_TEXT "IF (LAST_DAY(PDATE)!=PDATE) THEN")
>           (ASSING "PDATEAUX := PDATE;")
>           (FREE_TEXT "RETURN ADD_MONTHS(PDATE, PMONTHS);")
>            (FREE_TEXT "END IF;);")
> )
>
>
> Any idea, thanks in advance!!!!
>
> --
> Saludos,
> Victor Panizza
>
>


-- 
Saludos,
Victor Panizza
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