yale haskell

Yale Haskell

   <language> A fully integrated {Haskell} programming
   environment.  It provides tightly coupled interactive editing,
   {incremental compilation} and dynamic execution of Haskell
   programs.  Two major modes of compilation, correspond to
   {Lisp}'s traditional "interpreted" and "compiled" modes.
   Compiled and interpreted modules may be freely mixed in any
   combination.

   Yale Haskell is run using either a command-line interface or
   as an {inferior process} running under the {Emacs} editor.
   Using the Emacs interface, simple two-keystroke commands
   evaluate expressions, run dialogues, compile {modules}, turn
   specific compiler diagnostics on and off and enable and
   disable various {optimisers}.  Commands may be queued up
   arbitrarily, thus allowing, for example, a compilation to be
   running in the background as the editing of a source file
   continues in Emacs in the foreground.

   A "scratch pad" may be automatically created for any module.
   Such a pad is a logical extension of the module, in which
   additional function and value definitions may be added, but
   whose evaluation does not result in recompilation of the
   module.

   A tutorial on Haskell is also provided in the Emacs
   environment.  A {Macintosh} version of Yale Haskell includes
   its own integrated programming environment, complete with an
   Emacs-like editor and {pull-down menus}.

   Yale Haskell is a complete implementation of the Haskell
   language, but also contains a number of extensions, including:

   (1) Instead of stream based I/O, a {monadic I/O} system is
   used.  Although similar to what will be part of the new
   {Haskell 1.3} report, the I/O system will change yet again
   when 1.3 becomes official.

   (2) Haskell programs can call both {Lisp} and {C} functions
   using a flexible foreign function interface.

   (3) Yale Haskell includes a {dynamic typing} system.  Dynamic
   typing has been used to implement {derived instances} in a
   user extensible manner.

   (4) A number of small Haskell 1.3 changes have been added,
   including {polymorphic recursion} and the use of @_@ in an
   expression to denote {bottom}.  Although the 1.3 report is not
   yet complete, these changes will almost certainly be part of
   the new report.

   (5) A complete Haskell level {X Window System} interface,
   based on {CLX}.

   (6) A number of {annotations} are available for controlling
   the optimiser, including those for specifying both function
   and data constructor {strict}ness properties, "{inlining}"
   functions, and specialising {over-loaded} functions.  Many
   standard {prelude} functions have been specialised for better
   performance using these annotations.

   (7) {Separate compilation} (including {mutually recursive}
   {modules}) is supported using a notion of a UNIT file, which
   is a kind of localised {makefile} that tells the compiler
   about compiler options and logical dependencies amongst
   program files.

   (8) Yale Haskell supports both standard and "{literate}"
   Haskell syntax.

   Performance of Yale Haskell's compiled code has been improved
   considerably over previous releases.  Although still not as
   good as the Glasgow ({GHC}) and Chalmers ({HBC}) compilers,
   the flexibility afforded by the features described earlier
   makes Yale Haskell a good choice for large systems
   development.  For some idea of performance, Hartel's latest
   "Nuc" benchmark runs at about the same speed under both Yale
   Haskell and hbc.  (Our experiments suggest, however, that Yale
   Haskell's compiled code is on average about 3 times slower
   than hbc.)

   Binaries are provided for {Sun}/{SPARC} and {Macintosh}, but
   it is possible to build the system on virtually any system
   that runs one of a number of {Common Lisp} implementations:
   {CMU Common Lisp}, {Lucid Common Lisp}, {Allegro Common Lisp}
   or {Harlequin LispWorks}.  {akcl}, {gcl} and {CLisp} do not
   have adaquate performance for our compiler.  The current
   version is 2.1.

   Yale (ftp://nebula.cs.yale.edu/pub/haskell/yale).
   (128.36.13.1).  UK
   (ftp://ftp.dcs.glasgow.ac.uk/pub/haskell/yale/).  Sweden
   (ftp://ftp.cs.chalmers.se/pub/haskell/yale/).  E-mail:
   <[email protected]>,
   <[email protected]>.

   (1993-07-14)