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Re: RE : problem with lexer.dat


The Lexer and Parser classes expect the lexer.dat and parser.dat files
to be respectively in the same directory as the Lexer.class and
Parser.class files (be it on the file system, or in a .jar file).

So, assuming your grammar is in the directory c:\mygrammar, you
would do as follows:

...> C:
C:\...> cd \mygrammar
C:\mygrammar> java -jar ...[path-to-jar]...\sablecc.jar littlegrammar.sablecc
[sablecc output]
C:\mygrammar> edit Main.java
...[create the Main class of your little compiler]...
C:\mygrammar> javac Main.java
C:\mygrammar> edit sampleinput.txt
...[create some input file to test your compiler]...
C:\mygrammar> java Main sampleinput.txt

This should work without complaining about missing or corrupted .dat files. (In my experience, I have not heard of corrupted .dat files other than though bad usage of source-control systems like CVS [if you forget to disable keywords/end-of-line conversion]).

If this works, then look for the .dat files in the subdorectories.  If you
package your compiler, you put leave these files in the same *relative*
pathes, otherwise the lexer & parser classes won't find them.

Have fun!


Pascal AUDANT wrote:
Re everybody,Kevin ... (thank you for the response! )
I didn't really 'install' sablecc... I just use it by calling it with
java -jar ...

I tried once to install it using Ant but it doesn't work. In fact I
can't even install Ant:
I am using Win XP and it doesn't recognise the command 'build' when I
try it from console. (In the manual they say to install Ant for Windows
by using the build command :

build -Ddist.dir=<directory_to_contain_Ant_distribution> dist

but when I try it windows says it doesn't know a command 'build'

Can somebody help me here pls ?
Thank you !

-----Message d'origine----- De : owner-sablecc-list@sable.mcgill.ca [mailto:owner-sablecc-list@sable.mcgill.ca] De la part de Agbakpem Kevin Komivi Envoyé : 7 septembre, 2003 16:07 À : Pascal AUDANT Cc : sablecc-list@sable.mcgill.ca Objet : Re: problem with lexer.dat

Pascal AUDANT wrote:

Greetings everyone,

Btw, thanx alot for your help AND patience.

I have now constructed my min grammar file which goes like :

Package test;


a = 'a';

b = 'b';


s = a s [second]:a |

{alternative_two} b;

I generated all my classes and I implemented them in a main class …

However when I try to run the program I obtain the following error from the lexer.java class :

"The file \"lexer.dat\" is either missing or corrupted."

To make sure that the lexer.dat file is not missing I have put it in C: and change the code to :

new BufferedInputStream(


However I still obtain the same error msg (The error occurs as soon as

lexer tries to read the lexer.dat file in int length = s.readInt();

As always your help is really appreciated


Hi Pascal, All,

As mentioned by the SableCC error message, i think that your problem is related to corruption of the file lexer.dat.
You do not need to move this file.
What you can do is :
first, re-build SableCC(ant clean; ant jar).
then, generate the classes for your grammar by running SableCC. Before that, make sure to remove old generated files if necessary.

I hope this can help you,



Etienne M. Gagnon, Ph.D.             http://www.info.uqam.ca/~egagnon/
SableVM:                                       http://www.sablevm.org/
SableCC:                                       http://www.sablecc.org/