T a dialect of Scheme

[James Philbin <philbin-jim@YALE.ARPA>]

                   The T Programming Language



T is a superset of Scheme developed at Yale University.  T's extensions
to Scheme include:

    multiple return values - a very efficient implementation,
    objects - a simple and efficient object system,
    debugger and inspector,
    locales - first class environments,
    macros - a syntax system,
    unwind-protect,
    dynamic binding,
    structures - efficient and integrated into the object system,
    tables - a generalize package
    pools, weak pointers, and weak tables.

Although the default environment is the T programming language (a Scheme
dialect based on the Revised Report on Scheme), an environment comforming
to the Revised^3 Report on Scheme is also available.  T is intended for
use in education, systems programming, AI programming, and for programming
language design and development.  The system and compiler are written almost
entirely in T.

A new version of T (version 3.0) was released in January 1987.  This system
includes both an interpreter and a highly optimizing native code compiler
(described in a paper by Kranz et al. in the Proceedings of the 1986 SIGPLAN
Compiler Construction Conference) that compiles closures efficiently.  This
compiler produces code that is competitive with the best C and Pascal
compilers.  The following benchmarks from "Performance and Evaluation of
Lisp Systems" by Gabrial were run on a Sun 3/160 in the most optimized
mode of the compiler.

    tak        .22      rdiv2      .76      fprint    1.80
    puzzle    2.40      destru     .98      fread     3.08
    triangle 79.18      deriv     2.44      tprint    1.46
    idiv2      .50      dderiv    3.02

T is available via Internet FTP.  Telnet to PREP.AI.MIT.EDU and log
in as user scheme, password scheme.  The login shell is an FTP program.
Send one or more of the following files:

    /t/readme.tar.Z
    /t/hp.tar.Z       executable image for HP-UX
    /t/sun.tar.Z      executable image for SUN
    /t/aegis.tar.Z    executable image for Apollo Domain
    /t/vax_unix.tar.Z executable image for VAX running 4.2BSD, 4.2BSD or Ultrix
    /t/sources.tar.Z  source code for compiler and runtime system

If you can't get T this way, try to get it from someone who has it, or,
Yale will mail you a tape for $200 (outside US $250).

For more information contact Linda Abelli or Chris Hatchell at:

              T Project
              Yale University Dept. of Computer Science
              PO Box 2158 Yale Station
              New Haven, CT 06520
              Email: t-project@yale.edu,
                     decvax!yale!t-project.uucp, or
                     tproj@YALECS.BITNET
              Phone: (203) 432-2381
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