Frown is an LALR(k) parser generator for Haskell 98 written in
Haskell 98.
The work on Frown started as an experiment in generating genuinely
functional LR parsers. The first version was written within three
days—yes, Haskell is a wonderful language for rapid prototyping.
Since then Frown has gone through several cycles of reorganization
and rewriting. It also grew considerably: dozens of features were
added, examples were conceived and tested, and this manual was
written. In the end, Frown has become a useable tool. I hope you
will find it useful, too.
1.1 Obtaining and installing Frown
Obtaining Frown
The parser generator is available from
http://www.informatik.uni-bonn.de/~ralf/frown.
The bundle includes the sources and the complete documentation (dvi,
ps, PDF, and HTML).
Requirements
You should be able to build Frown with every Haskell 98-compliant
compiler. You have to use a not too ancient compiler as there have
been some changes to the Haskell language in Sep. 2001 (GHC 5.02 and
later versions will do).
The Haskell interpreter Hugs 98 is needed for running the testsuite.
Various tools are required to generate the documentation from scratch:
lhs2TeX, LATEX, functional , HEVEA and HACHA. Note, however, that
the bundle already includes the complete documentation.
Installation
Unzip and untar the bundle. This creates a directory called Frown.
Enter this directory.
| ralf> tar xzf frown.tar.gz |
| ralf> cd Frown
|
The documentation resides in the directory Manual; example grammars
can be found in Examples and Manual/Examples (the files ending in
.g and .lg).
You can install Frown using either traditional makefiles or Cabal.
Using makefiles
Optionally, edit the Makefile to specify destinations for the binary
and the documentation (this information is only used by make install). Now, you can trigger
which compiles Frown generating an executable called frown (to use
Frown you only need this executable). Optionally, continue with
to install the executable and the documentation.
For reference, here is a list of possible targets:
-
make
Compiles Frown generating an executable called frown (to use Frown
you only need this executable).
- make install
Compiles Frown and installs the executable and the documentation.
- make test
Runs the testsuite.1
- make man
Generates the documentation in various formats (dvi, ps, PDF, and
HTML).
- make clean
Removes some temporary files.
- make distclean
Removes all files except the ones that are included in the distribution.
Using Cabal
Alternatively, you can build Frown using Cabal (version 1.1.3 or
later), Haskell's Common Architecture for Building Applications and
Libraries.
For a global install, type:
| ralf/Frown> runhaskell Setup.hs configure --ghc |
| ralf/Frown> runhaskell Setup.hs build |
| ralf/Frown> runhaskell Setup.hs install
|
If you want to install Frown locally, use (you may wish to replace
$HOME by a directory of your choice):
| ralf/Frown> runhaskell Setup.hs configure --ghc --prefix=$HOME |
| ralf/Frown> runhaskell Setup.hs build |
| ralf/Frown> runhaskell Setup.hs install --user
|
Usage
The call
displays the various options. For more information consult this
manual.
1.2 Reporting bugs
Bug reports should be send to Ralf Hinze (ralf@cs.uni-bonn.de).
The report should include all information necessary to reproduce the
bug: the compiler used to compile Frown, the grammar source file (and
possibly auxiliary Haskell source files), and the command-line
invocation of Frown.
Suggestions for improvements or request for features should also be
sent to the above address.
1.3 License
Frown is distributed under the GNU general public licence
(version 2).
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% %
% Frown --- An LALR(k) parser generator for Haskell 98 %
% Copyright (C) 2001-2005 Ralf Hinze %
% %
% This program is free software; you can redistribute it and/or modify %
% it under the terms of the GNU General Public License (version 2) as %
% published by the Free Software Foundation. %
% %
% This program is distributed in the hope that it will be useful, %
% but WITHOUT ANY WARRANTY; without even the implied warranty of %
% MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the %
% GNU General Public License for more details. %
% %
% You should have received a copy of the GNU General Public License %
% along with this program; see the file COPYING. If not, write to %
% the Free Software Foundation, Inc., 59 Temple Place - Suite 330, %
% Boston, MA 02111-1307, USA. %
% %
% Contact information %
% Email: Ralf Hinze <ralf@cs.uni-bonn.de> %
% Homepage: http://www.informatik.uni-bonn.de/~ralf/ %
% Paper mail: Dr. Ralf Hinze %
% Institut für Informatik III %
% Universität Bonn %
% Römerstraße 164 %
% 53117 Bonn, Germany %
% %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
1.4 Credits
Frown wouldn't have seen the light of day without the work of Ross
Paterson and Doaitse Swierstra. Ross invoked my interest in LR parsing
and he devised the --code=stackless and --code=gvstack output
formats. Doaitse invented the --code=standard format, which was
historically the first format Frown supported.
A big thank you goes to Andres Löh and Ross Paterson for various bug
reports and suggestions for improvement.
- 1
- There are some known problems. The
format code=stackless behaves differently for Loop.g (the
generated parser is less strict than the standard one). Also,
Empty.g does not work yet. Finally, error reports may differ for
different formats and for optimized and unoptimized versions (as some
parsers perform additional reductions before an error is
reported).