資料來源 : Free On-Line Dictionary of Computing
Yale Haskell
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 {module}s, turn
specific compiler diagnostics on and off and enable and
disable various {optimiser}s. 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 menu}s.
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 instance}s 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 {annotation}s 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}
{module}s) 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:
,
.
(1993-07-14)