Ubuntu Manpage: happy - the parser generator for Haskell

NAME

       happy - the parser generator for Haskell

SYNOPSIS

       happy [OPTION]... file [OPTION]...

DESCRIPTION

       This manual page documents briefly the happy command.

       This  manual page was written for the Debian GNU/Linux distribution because the original program does not
       have a manual page.  Instead, it has documentation in various other  formats,  including  DVI,  Info  and
       HTML; see below.

       Happy  is  a parser generator system for Haskell.  `HAPPY' is a dyslexic acronym for `A Yacc-like Haskell
       Parser generator'.

       There are two types of grammar files, file.y and file.ly, with the latter observing the  reverse  comment
       bird  track  convention  (i.e.  each code line must begin with `>').  The examples distributed with Happy
       are all of the .ly form.

       Caveat: When using hbc (Chalmers Haskell) the command argument structure is slightly different.  This  is
       because the hbc run time system takes some flags as its own (for setting things like the heap size, etc).
       This problem can be circumvented by adding a single dash (`-') to your command line.  So when using a hbc
       generated version of Happy, the argument structure is:

       happy - [OPTION]... file [OPTION]...

OPTIONS

The programs follow the usual GNU command line syntax, with long options starting with two dashes (`--').
A summary of options is included below. For a complete description, see the other documentation.

-h, --help
Show summary of options.

-v, --version
Print version information on standard output then exit successfully.

-a, --array
Instructs Happy to generate a parser using an array-based shift reduce parser. When used in
conjunction with -g, the arrays will be encoded as strings, resulting in faster parsers. Without
-g, standard Haskell arrays will be used.

-g, --ghc
Instructs Happy to generate a parser that uses GHC-specific extensions to obtain faster code.

-c, --coerce
Use GHC's unsafeCoerce# extension to generate smaller faster parsers. One drawback is that some
type safety is lost, which means that a parser generated with -c may compile fine but crash at
run-time. Be sure to compile your grammar without -c first to ensure it is type-correct.

This option has quite a significant effect on the performance of the resulting parser, but
remember that parsers generated this way can only be compiled by GHC 3.02 and above.

This option may only be used in conjuction with -g.

-d, --debug
Generate a parser that will print debugging information to stderr at run-time, including all the
shifts, reductions, state transitions and token inputs performed by the parser.

This option may only be used in conjuction with -a.

-i [FILE], --info[=FILE]
Directs Happy to produce an info file containing detailed information about the grammar, parser
states, parser actions, and conflicts. Info files are vital during the debugging of grammars.

The filename argument is optional, and if omitted the info file will be written to FILE.info
(where FILE is the input file name with any extension removed).

-o FILE, --outfile=FILE
Specifies the destination of the generated parser module. If omitted, the parser will be placed
in FILE.hs, where FILE is the name of the input file with any extension removed. If FILE is - the
generated parser is sent to the standard output.

-m NAME, --magic-name=NAME
Happy prefixes all the symbols it uses internally with either happy or Happy. To use a different
string, for example if the use of happy is conflicting with one of your own functions, specify the
prefix using the -m option.

-t DIR, --template=DIR
Instructs Happy to use this directory when looking for template files: these files contain the
static code that Happy includes in every generated parser. You shouldn't need to use this option
if Happy is properly configured for your computer.

-l, --glr
Instructs Happy to output a GLR parser instead of an LALR(1) parser.

-k, --decode
Causes the GLR parser to generate code for decoding the parse forest to a list of semantic results
(requires --ghc).

-f, --filter
Causes the GLR parser to filter out nodes which aren't required for the semantic results (an
experimental optimisation, requires --ghc).

FILES

       /usr/share/happy-1.19.5

COPYRIGHT

       Happy Version 1.19.5

       Copyright (c) 1993-1996 Andy Gill, Simon Marlow; (c) 1997-2001 Simon Marlow

AUTHOR

       This manual page was written by Michael Weber <michaelw@debian.org>, for the Debian GNU/Linux system (but
       may be used by others).

Glasgow FP Suite                                   2000-12-23                                           HAPPY(1)