= Using jhc =

Installation of jhc involves building the jhc binary, placing it somewhere you
can execute it and putting the libraries somewhere.

=== Building jhc ===

building jhc requires the most recent version of DrIFT 2.2.1 or better, which
can be gotten at http://repetae.net/john/computer/haskell/DrIFT/, GHC 6.6,
happy, Perl, and having darcs will help keep updated with the newest version
and submit patches.

==== Getting the source ====

Because jhc uses subrepositories, you need to use multiple darcs commands to
pull everything needed to build jhc.

  darcs get http://repetae.net/john/repos/jhc
  cd jhc
  darcs get http://repetae.net/john/repos/Doc
  cd lib
  darcs get http://darcs.haskell.org/packages/haskell98/
  darcs get http://darcs.haskell.org/packages/QuickCheck/

The binary and zlib packages also need to be installed.

  http://hackage.haskell.org/cgi-bin/hackage-scripts/package/binary/
  http://hackage.haskell.org/cgi-bin/hackage-scripts/package/zlib/

==== making it ====

Assuming you have ghc 6.6, happy, and DrIFT installed, you may now run GNU
make by typing 'gmake' or just 'make' depending on your system and get a
binary 'jhc' out if nothing went wrong.

Installation is done with 'gmake install' or for a custom installation
prefix 'gmake install PREFIX=/foo/bar'. This will install jhc and jhci
in ${PREFIX}/bin and base libraries in ${PREFIX}/lib, from where they
are automatically included when needed.

=== Installing the libraries - the old way ====

The jhc libraries will be in the 'lib' directory. these may be installed
anywhere or left in place but the directory where they are installed *must be
writable by the user of jhc* otherwise the compiler cannot create its
intermediate files.

Set the environment variable JHCPATH to the location of the library wherever
you put it, or pass -i<dir> to jhc every time you call it so it can find the
standard libraries.

The first time you compile something, jhc will automatically create an
optimized version of the standard libraries in 'ho' files next to their source
code. This is why the library needs to be somewhere writable. Another effect
being the first time you run jhc, it will take much longer than future runs.


=== Running jhc ===

jhc always runs in a mode similar to 'ghc --make' and will find all
dependencies automatically. just run jhc on your file containing the Main module.

  jhc -v Main.hs

it is HIGHLY HIGHLY recommended you pass the '-v' flag to jhc. jhc takes a very
long time to compile programs and without feedback you won't know if there is a
problem. Much of the debugging output contains Unicode characters, it helps if
your terminal is UTF8.

While compiling, jhc will drop 'ho' files alongside your source code to speed
up future compilation. feel free to delete these if you want to. There are
various options for controlling the writing and reading of these ho files.

=== Environment Variables ===

jhc understands the following environment variables

 JHCPATH - path to search for haskell source files, seperated by colons.

 JHCLIBPATH - path to search for jhc library files

==== Options ====

general options

<include text `/home/john/bin/jhc --help 2>&1`>

things to pass to -d

<include text `/home/john/bin/jhc -dhelp  2>&1`>

things to pass to -f

<include text `/home/john/bin/jhc -fhelp 2>&1 `>

----

http://repetae.net/john/computer/jhc