[antlr-interest] Fixed field

[Brian Lavender]

Hello empty antlr echo chambers. Is there anybody out there?

I figured out that if I create a lexer rule to match the newline, that it will match rather than
putting it in the parser rule. Now, it only seems to parse the first bill that it finds. When I test
it in the antlr works, it parses both entries from input. Any ideas?


grammar Agenda;

agenda	:	bill+;
bill	:	title author NL { System.out.println("All " + $bill.text + "\n"); }
;
title 	:	LTR LTR LTR LTR LTR LTR LTR LTR LTR LTR LTR LTR LTR LTR LTR { System.out.println("Title " + $title.text + "\n"); };
author	:	LTR LTR LTR LTR LTR LTR LTR LTR LTR { System.out.println("Author " + $author.text + "\n"); };
	

LTR  :   ('a'..'z'|'A'..'Z' | ' ' | '1'..'9') ;
NL	:	('\n'|'\r');


import org.antlr.runtime.*;

public class Test {
    public static void main(String[] args) throws Exception {
        ANTLRInputStream input = new ANTLRInputStream(System.in);
        AgendaLexer lexer = new AgendaLexer(input);
        CommonTokenStream tokens = new CommonTokenStream(lexer);
        AgendaParser parser = new AgendaParser(tokens);
        parser.agenda();
    }
}

Sample input


construct bill frank burn
eazememnt bill billy bob





On Thu, Jul 29, 2010 at 06:07:40PM -0700, Brian Lavender wrote:
> Well, it looks like my attempt isn't so feeble, but I can't seem to get the input to 
> match on the newline. Do I need to do something different? 
> 
> 
> grammar Agenda;
> 
> agenda	:	bill+;
> bill	:	title author '\n' { System.out.println($bill.text); }
> ;
> author	:	LTR LTR LTR LTR LTR LTR LTR LTR LTR { System.out.println($author.text); };
> title 	:	LTR LTR LTR LTR LTR LTR LTR LTR LTR LTR LTR LTR LTR LTR LTR { System.out.println($title.text); };	
> 
> LTR  :   ('a'..'z'|'A'..'Z' | ' ' | '1'..'9') ;
> 
> Input is the following.
> Bill to allow eBill Joy  
> Bill to preventFrank Dist
>   
> 
> 
> 
> On Mon, Jul 26, 2010 at 08:27:41PM -0700, Brian Lavender wrote:
> > What's the best way to get the words out of a fixed field file? Say the title
> > is in the first 20 columns, and then the author is in the next 20?
> > 
> > Below is a feeble attempt that will get four letters, but I would like to ignore
> > any whitespace that occurs after the last letter before the end column. 
> > 
> > brian
> > 
> > 
> > grammar Foo;
> > 
> > title	:	LTR LTR LTR LTR '\n'{System.out.println($title.text);};
> > 
> > LTR 	:	('a'..'z'|'A'..'Z');
> > 
> > -- 
> > Brian Lavender
> > http://www.brie.com/brian/
> > 
> > "There are two ways of constructing a software design. One way is to
> > make it so simple that there are obviously no deficiencies. And the other
> > way is to make it so complicated that there are no obvious deficiencies."
> > 
> > Professor C. A. R. Hoare
> > The 1980 Turing award lecture
> > 
> > List: http://www.antlr.org/mailman/listinfo/antlr-interest
> > Unsubscribe: http://www.antlr.org/mailman/options/antlr-interest/your-email-address
> 
> -- 
> Brian Lavender
> http://www.brie.com/brian/
> 
> "There are two ways of constructing a software design. One way is to
> make it so simple that there are obviously no deficiencies. And the other
> way is to make it so complicated that there are no obvious deficiencies."
> 
> Professor C. A. R. Hoare
> The 1980 Turing award lecture
> 
> List: http://www.antlr.org/mailman/listinfo/antlr-interest
> Unsubscribe: http://www.antlr.org/mailman/options/antlr-interest/your-email-address

-- 
Brian Lavender
http://www.brie.com/brian/

"There are two ways of constructing a software design. One way is to
make it so simple that there are obviously no deficiencies. And the other
way is to make it so complicated that there are no obvious deficiencies."

Professor C. A. R. Hoare
The 1980 Turing award lecture