Edison: A Library of Efficient Data Structures 
(Haskell Version 1.1)
December 20, 1999

This release updates Edison from Haskell 1.4 to Haskell 98,
and removes most of the GHC specific code.  Edison should now
run under both GHC and Hugs (at least).  Note that Edison is
still not fully Haskell 98 compliant because of the use of
multi-parameter type classes and the occasional use of
GHC/Hugs libraries such as Bits.

See docs/users.{dvi,ps} for more extensive documentation.  Basic
instructions for using Edison with GHC or Hugs are included below.
See the User's Guide for more discussion about portability.

In its current state, Edison is still mostly a framework.  That is, I
provide signatures, but not yet very many implementations.  I intend
to populate this framework over time, adding a new module every few
weeks.  Thus, the library is extremely unstable in the sense that I
will continually be modifying existing data structures and adding new
ones.  However, I hope that the signatures will remain fairly stable
over time, making these changes to the implementations mostly
transparent to users of the library.

If you wish to request a particular data structure or volunteer to
provide an implementation, or if you have any other comments or
suggestions, send me email at cdo@cs.columbia.edu.

Chris Okasaki


USING EDISON WITH GHC
---------------------

To begin using Edison with GHC, first run
    make depend
    make all
I recommend using GHC 4.04 or higher (I used GHC 4.04 for testing).

To compile a file Foo.hs that uses Edison, type something like
    ghc -c -fglasgow-exts -iEDHOME/Import Foo.hs
where EDHOME should be replaced with the correct path
to the Edison home directory.  To compile and link, type something
like
    ghc -fglasgow-exts -iEDHOME/Import -LEDHOME/Lib -ledison Foo.hs


USING EDISON WITH HUGS
----------------------

To use Edison under Hugs, simply add the Edison directories
to the Hugs search path, as in
    hugs -98 -PEDHOME:EDHOME/Seq:EDHOME/Coll:EDHOME/Assoc: Foo.hs
where EDHOME should be replaced with the correct path
to the Edison home directory.  I do this by aliasing "ehugs"
to "hugs -98 -PEDHOME:EDHOME/Seq:EDHOME/Coll:EDHOME/Assoc:"
and then typing
    ehugs Foo.hs

There is a problem with this approach in that the built-in
Hugs libraries already contain a Sequence module, which is
now being shadowed by Edison's Sequence module.  It is unlikely
that any of your code depends on this built-in module directly,
but it may depend on it indirectly through the HugsLibs module.
Here is the easiest way to fix the problem.

  1. Go the the .../share/hugs/lib/hugs directory.
  2. Rename Sequence.hs to HugsSequence.hs.
  3. Edit HugsSequence.hs, replacing the line
         module Sequence(
     with
         module HugsSequence(
  4. Edit HugsLibs.hs, replacing the line
         import Sequence
     with
         import HugsSequence

These directions were tested under the November 1999 release
of Hugs.  It is likely that the next release of Hugs will
rename or eliminate the built-in Sequence module.