This is scheme.info, produced by makeinfo version 4.6 from scheme.texinfo. This file documents the installation and use of UMB Scheme. Copyright (C) 1988, 1996 William R Campbell. Permission is granted to make and distribute verbatim copies of this manual provided the copyright notice and this permission notice are preserved on all copies. Permission is granted to copy and distribute modified versions of this manual under the conditions for verbatim copying, provided also that the section entitled "GNU General Public License" is included exactly as in the original, and provided that the entire resulting derived work is distributed under the terms of a permission notice identical to this one. Permission is granted to copy and distribute translations of this manual into another language, under the above conditions for modified versions, except that the section entitled "GNU General Public License" and this permission notice may be included in translations approved by the Free Software Foundation instead of in the original English.  File: scheme.info, Node: Top, Next: Copying, Prev: Files, Up: (DIR) Introduction ************ This manual documents how to install and use UMB Scheme as well as its new features and incompatibilities, and how to report bugs. * Menu: * Copying:: GNU General Public License says how you can copy and share GNU CC. * Why:: Why we implemented UMB Scheme. * What:: What's supported by UMB Scheme. * Performance:: Remarks on performance. * Contributors:: People who have contributed to UMB Scheme. * Installation:: How to compile and install UMB Scheme. * Use:: How to use UMB Scheme. * Bugs:: How to report bugs (if you want them fixed). * Files:: Distribution files.  File: scheme.info, Node: Copying, Next: Why, Prev: Top, Up: Top GNU GENERAL PUBLIC LICENSE ************************** Version 1, February 1989 Copyright (C) 1989 Free Software Foundation, Inc. 675 Mass Ave, Cambridge, MA 02139, USA Everyone is permitted to copy and distribute verbatim copies of this license document, but changing it is not allowed. Preamble ======== The license agreements of most software companies try to keep users at the mercy of those companies. By contrast, our General Public License is intended to guarantee your freedom to share and change free software--to make sure the software is free for all its users. The General Public License applies to the Free Software Foundation's software and to any other program whose authors commit to using it. You can use it for your programs, too. When we speak of free software, we are referring to freedom, not price. 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IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW OR AGREED TO IN WRITING WILL ANY COPYRIGHT HOLDER, OR ANY OTHER PARTY WHO MAY MODIFY AND/OR REDISTRIBUTE THE PROGRAM AS PERMITTED ABOVE, BE LIABLE TO YOU FOR DAMAGES, INCLUDING ANY GENERAL, SPECIAL, INCIDENTAL OR CONSEQUENTIAL DAMAGES ARISING OUT OF THE USE OR INABILITY TO USE THE PROGRAM (INCLUDING BUT NOT LIMITED TO LOSS OF DATA OR DATA BEING RENDERED INACCURATE OR LOSSES SUSTAINED BY YOU OR THIRD PARTIES OR A FAILURE OF THE PROGRAM TO OPERATE WITH ANY OTHER PROGRAMS), EVEN IF SUCH HOLDER OR OTHER PARTY HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES. END OF TERMS AND CONDITIONS  File: scheme.info, Node: Why, Next: What, Prev: Copying, Up: Top Why We Implemented UMB Scheme ***************************** Our reasons form implementing yet another version of Scheme are the following: 1. We use Scheme for modeling the operational semantics of programming languages in our undergraduate languages course. We wanted a Scheme system that was easily ported to the various architectures on campus and that gave reasonable run-time performance. 2. We wanted to produce a relatively large piece if code as an example of good program organization for our undergraduate and graduate software engineering students. 3. We wanted to involve students in all phases of the implementation effort, including initial development, testing, extensions, and performance tuning. 4. We wanted to illustrate that object-oriented design might successfully be applied to programs written in vanilla programming languages such as C. Although this effort was meant as an exercise in design and programming, we have ended up with what we think to be a rather nice interpreter. It runs relatively fast (performance comparisons with MIT Scheme are made below) and we (as well as others not involved in development) have found the code very easy to maintain and extend.  File: scheme.info, Node: What, Next: Performance, Prev: Why, Up: Top What's Supported by UMB Scheme ****************************** UMB Scheme is an implementation of the language described in the IEEE STANDARD FOR THE SCHEME PROGRAMMING LANGUAGE (December, 1990). It also supports R4RS (with the help of the Scheme Portable Library (Aubrey Jaffrey) for high level macros. All syntax, variables and procedures are implemented. Integers are implemented as fixnums and bignums, rationals as pairs of integers, (inexact) reals as double-precision floats, and (inexact) complex numbers as pairs of double-precision floats. For information on what additional functionality is supported, see the man page (scheme.1). The following files are loaded in order at startup: If the variable SCHEME_INIT is set in the user's environment by executing setenv SCHEME_INIT file then file is loaded. If SCHEME_INIT is not set and if a file .SCHEME exists in the user's home directory then it is loaded. The files named as optional arguments are loaded from left to right.  File: scheme.info, Node: Performance, Next: Contributors, Prev: What, Up: Top Remarks on Performance ********************** So far as speed is concerned, UMB Scheme loses to MIT's C Scheme in pure evaluation but performs significantly better than C Scheme when it comes to compile-load-and-go. For example, consider the following TAK benchmark code from Richard P Gabriel, PERFORMANCE AND EVALUATION OF LISP SYSTEMS, MIT Press, 1985. ; tak ; function-call-heavy; test of function call and recursion (define (tak x y z) (if (not (< y x)) z (tak (tak (- x 1) y z) (tak (- y 1) z x) (tak (- z 1) x y)))) (tak 18 12 6) On a Sun 3/140, C Scheme gets through this in 75 seconds while UMB Scheme takes 98 seconds; in this instance C Scheme runs faster. But consider a definition-heavy file of code such as the following. (define (fac x) (if (= x 0) 1 (* x (fac (- x 1))) )) (fac 5) (define (fac x) (if (= x 0) 1 (* x (fac (- x 1))) )) (fac 5) (define (fac x) (if (= x 0) 1 (* x (fac (- x 1))) )) (fac 5) ;; ... 1000 copies To get through these 1000 definitions of (and calls to) FAC, C Scheme takes 432 seconds but UMB Scheme takes only 19 seconds; in this instance UMB Scheme runs 22 times faster than C Scheme. Therefore, UMB Scheme appears to do much better in a heavy compile-load-and-go environment (such as one would find in an undergraduate languages course) than in raw computation. Space is more difficult to address when comparing Scheme systems since it depends on one's choice for a heap size. UMB Scheme's load module has a size of 216K bytes; C Scheme's load module is 279K bytes. As they are currently configured, UMB Scheme runs in a 1600K region as compared to C Scheme's 3944K (as measured by top(1) on Unix). UMB Scheme's storage allocator begins with a small (200K byte) heap and increases heap size as necessary (and as permitted by the operating system) at garbage collection time.  File: scheme.info, Node: Contributors, Next: Installation, Prev: Performance, Up: Top Contributors to UMB Scheme ************************** * The interpreter is based on the Explicit-Control Evaluator described in the textbook: Harold Abelson and Gerald Jay Sussman, STRUCTURE AND INTERPRETATION OF COMPUTER PROGRAMS, MIT Press, Cambridge, Massachusetts, 1985. * Bill Campbell was the primary author and project manager. * The idea of organizing the control of the interpreter around objects comes from Richard Schooler. * Karl Berry and Kathy Hargreaves helped with the initial programming. * Bill McCabe coded some performance improvements, particularly lexical variable addressing. * Mary Glaser, Tim Holt, Long Nguyen and Thang Quoc Tran worked on numbers. * Ira Gerstein and Jeyashree Sivasubram help bring UMB Scheme up to R4RS standard. * Barbara Dixey, Susan Quina and Bela Sohoni coded some additional performance improvements, handling varying numbers of arguments to functions in C. * John Tam rewrote the macro facility for supporting defmacro and for interfacing to the Scheme Portable Library. * Many undergraduate students at UMB wrote test programs and offered suggestions for improvement.  File: scheme.info, Node: Installation, Next: Use, Prev: Contributors, Up: Top Compiling and Installing UMB Scheme *********************************** UMB Scheme has been installed successfully using both CC and GCC (the Gnu C compiler) on the following machines and operating systems: * Sun 3 and Sun 4 running Unix. * Sun 386i running Sun Unix 4.0.1. * DEC Vax 11/750 running Unix 4.3 BSD. * DEC Decstation 5000 running Ultrix. UMB Scheme was written so as to be easily ported to other systems. Some modifications may be required. To install UMB Scheme one of the systems listed above, simply go into the distribution directory and do the following. 1. Carefully read the file portable.h file. Any minor modifications will want to be made here. Of particular importance are ALIGNMENT, NEGATIVE_ADDRESSES and the definition for Intergral_Pointer; see portable.h for details. 2. Compile UMB Scheme using the `Makefile' provided. If you have the Gnu C Compiler, GCC, then simply type make or, make CC=gcc Otherwise, to use CC, type make CC=cc CFLAGS=-O This will compile all necessary source files and create the executable file `scheme'. 3. Install the executable file in some public bin, e.g. cp scheme /usr/local/bin/scheme 4. Install the UMB Scheme STANDARD PRELUDE in the public library. mkdir /usr/local/lib/scheme cp prelude.scheme /usr/local/lib/scheme This pathname is wired into UMB Scheme. If necessary, you can change the definition of `STANDARD_PRELUDE_FILENAME' in the source file `steering.c'. 5. Install the SLIB directory. cp -r slib /usr/local/lib # not in /scheme cp SLIB-for-umb-scheme.init /usr/local/lib/scheme The standard prelude, `prelude.scheme', assumes that the start up file `SLIB-for-umb_scheme.init' is here; if you put it somewhere else, modify `prelude.scheme' accordingly. If you do not wish to use SLIB, then comment out the load near the end of `prelude.scheme'. 6. Copy the manual page to the appropriate directory, e.g. cp scheme.l /usr/spool/man/man1 Some shops maintain a separate `manl' directory for local manual pages; consult your local system administrator. That should do it!  File: scheme.info, Node: Use, Next: Bugs, Prev: Installation, Up: Top Using UMB Scheme **************** Invoking UMB Scheme is straightforward; simply type scheme [names of any scheme files to be loaded] To get out of UMB Scheme type `Control-D'. See the man pages (scheme.l) for details.  File: scheme.info, Node: Bugs, Next: Files, Prev: Use, Up: Top What To Do About Bugs ********************* UMB Scheme has been used by many undergraduate students and several bugs have been exposed and repaired. No doubt, bugs remain. The author would appreciate hearing about any bugs found (and any fixes made). Send reports to bill@cs.umb.edu or, by postal service, to Bill Campbell Department of Mathematics and Computer Science University of Massachusetts at Boston Harbor Campus Boston, MA 02125 617-287-6449  File: scheme.info, Node: Files, Next: Top, Prev: Bugs, Up: Top Distribution files ****************** Distribution Files for UMB Scheme Version 1.1 README This list of files. scheme.texinfo UMB Scheme Release Notes. Makefile For compiling UMB Scheme. prelude.scheme The Scheme prelude, primitives loaded at start. scheme.l UMB Scheme manual page (in man(1) format). Source files: portable.h Portability considerations. steering.c UMB Scheme steering -- including main(). steering.h debug.c Debugger steering and debug primitives. debug.h architecture.c Registers, stacks, heap, name handling. architecture.h object.c Scheme objects. object.h io.c Read, display, print, file handling. io.h compiler.c Compiler: Expression -> Graph. compiler.h eval.c Eval(). eval.h primitive.c (Non-numeric) primitives implemented in C. primitive.h number.c Number primitives. number.h bignum.c Bignum (integers of arbitrary magnitude). bignum.h complex.c Complex number support. complex.h fixnum.c Fixnum (smaller integers) support. fixnum.h real.c Real number (C double) support. real.h rational.c NB: rationals not yet implemented (skeletons). rational.h See the Release Notes (scheme.texinfo) for installation.  Tag Table: Node: Top1066 Node: Copying1801 Node: Why12404 Node: What13741 Node: Performance14844 Node: Contributors16909 Node: Installation18224 Node: Use20616 Node: Bugs20928 Node: Files21509  End Tag Table