path: root/README

This directory contains the distribution of scm4e6.  Scm conforms to
Revised^4 Report on the Algorithmic Language Scheme and the IEEE P1178
specification.  Scm runs under VMS, MS-DOS, OS2, MacOS, Amiga,
Atari-ST, NOS/VE, Unix and similar systems.

This file consists mainly of excerpts from "scm.info", the result of
compiling (with makeinfo) "scm.texi" to `info' form.  In case of
conflicts with "scm.info", consult "scm.info".

The author can be reached at <jaffer@ai.mit.edu>

			       MANIFEST

  `README' is this file.  It contains a MANIFEST, INSTALLATION
	INSTRUCTIONS, hints for EDITING SCHEME CODE, and a TROUBLE
	SHOOTING GUIDE.
  `COPYING' details the LACK OF WARRANTY for scm and the conditions
	for distributing scm.
  `scm.1' is the unix style man page in nroff format.
  `scm.doc' is the text man page generated from scm.1.
  `QUICKREF' is a Quick Reference card for IEEE and R4RS.
  `scm.texi' details feature support and enhancements to Scheme and
	contains a SCHEME BIBLIOGRAPHY.
  `ChangeLog' documents changes to the scm.

  `r4rstest.scm' is Scheme code which tests conformance with Scheme
	specifications.
  `example.scm' is Scheme code from Revised^4 Report on the
	Algorithmic Language Scheme which uses inexact numbers.
  `pi.scm' is Scheme code for computing digits of pi [type (pi 100 5)]
	which can be used to test the performance of scm against
	compiled C code [cc -o pi pi.c;time pi 100 5].
  `pi.c' is C code for computing digits of pi.
  `bench.scm' is Scheme code for computing and recording speed of
	"pi.scm".

  `Makefile' is for building scmlit using the `make' program.
  `build.scm' creates a database and program for compiling and linking
	new SCM executables, libraries, and dlls.
  `build.bat' invokes build.scm on MS-DOS platforms.
  `setjump.mar' provides setjmp and longjmp which do not use $unwind
	utility on VMS.
  `setjump.s' provides setjmp and longjmp for the Cray YMP.

  `Init.scm' is Scheme initialization code.
  `Transcen.scm' has Scheme code for inexact builtin procedures.
  `Link.scm' has Scheme code for compiling and dynamic linking.
  `scmfig.h' is a C include file containing system dependent definitions.
  `patchlvl.h is the patchlevel of this release.
  `continue.c' code for continuations.
  `continue.h' data types and external functions for continuations.
  `setjump.h' is an include file dealing with continuations, stacks,
	and memory allocation.
  `scm.h' has the data type and external definitions of scm.

  `scm.c' has the top level and interrupt code.
  `findexec.c' has code to find the executable file.
  `time.c' has functions dealing with time.
  `repl.c' has error, read-eval-print loop, read, write and load code.
  `scl.c' has the code for utility functions which are not part of the
	IEEE Scheme spec or which are required for non-integer
	arithmetic.
  `eval.c' has the evaluator, apply, map, and foreach.
  `sys.c' has the code for opening and closing files, storage
	allocation and garbage collection.
  `rope.c' has C interface functions.
  `subr.c' has all the rest of functions.
  `sc2.c' has code for procedures from R2RS and R3RS not in R4RS.
  `dynl.c' has c code for dynamically loading object files.
  `unif.c' has code for uniform vectors.
  `rgx.c' has code for string regular expression match.
  `crs.c' has code for interactive terminal control.
  `split.scm' sets up CURSCM (SCM with crs.c) so that input, output,
	and diagnostic output are each directed to separate windows.
  `edline.c' Gnu readline input editing
	(get ftp.sys.toronto.edu:/pub/rc/editline.shar).
  `Iedline.scm' Gnu readline input editing.
  `record.c' has code for proposed "Record" user definable datatypes.
  `gsubr.c' has make_gsubr for arbitrary (< 11) arguments to C functions.

  `ioext.c' has code for system calls in common between PC compilers and unix.
  `posix.c' has code for posix library interface.
  `unix.c' has code for non-posix system calls on unix systems.
  `socket.c' has code for socket interface.

				 SLIB

[SLIB] is a portable Scheme library meant to provide compatibility and
utility functions for all standard Scheme implementations.  Although
SLIB is not *neccessary* to run SCM, I strongly suggest you obtain and
install it.  Bug reports about running SCM without SLIB have very low
priority.  SLIB is available from the same sites as SCM:

   * ftp-swiss.ai.mit.edu:pub/scm/slib2a6.tar.gz
   * prep.ai.mit.edu:pub/gnu/jacal/slib2a6.tar.gz
   * ftp.maths.tcd.ie:pub/bosullvn/jacal/slib2a6.tar.gz
   * ftp.cs.indiana.edu:/pub/scheme-repository/imp/slib2a6.tar.gz

Unpack SLIB (`tar xzf slib2a6.tar.gz' or `unzip -ao slib2a6.zip') in an
appropriate directory for your system; both `tar' and `unzip' will
create the directory `slib'.

Then create a file `require.scm' in the SCM "implementation-vicinity"
(this is the same directory as where the file `Init.scm' is installed).
`require.scm' should have the contents:

     (define (library-vicinity) "/usr/local/lib/slib/")
     (load (in-vicinity (library-vicinity) "require"))

where the pathname string `/usr/local/lib/slib/' is to be replaced by
the pathname into which you installed SLIB.  Absolute pathnames are
recommended here; if you use a relative pathname, SLIB can get confused
when the working directory is changed (*note chmod: I/O-Extensions.).
The way to specify a relative pathname is to append it to the
implementation-vicinity, which is absolute:

     (define library-vicinity
       (let ((lv (string-append (implementation-vicinity) "../slib/")))
         (lambda () lv)))
     (load (in-vicinity (library-vicinity) "require"))

Alternatively, you can set the (shell) environment variable
`SCHEME_LIBRARY_PATH' to the pathname of the SLIB directory (*note
SCHEME_LIBRARY_PATH: SCM Variables.).  If set, the environment variable
overrides `require.scm'.  Again, absolute pathnames are recommended.

			      MAKING SCM

  The SCM distribution has "Makefile" which contains rules for making
"scmlit", a "bare-bones" version of SCM sufficient for running
`build.scm'.  `build.scm' is used to compile (or create scripts to
compile) full featured versions.

  Makefiles are not portable to the majority of platforms.  If
`Makefile' works for you, good; If not, I don't want to hear about it.
If you need to compile SCM without build.scm, there are several ways to
proceed:

   * Use SCM on a different platform to run `build.scm' to create a
     script to build SCM;

   * Use another implementation of Scheme to run `build.scm' to create a
     script to build SCM;

   * Create your own script or `Makefile'.

   * Buy a SCM executable from jaffer@ai.mit.edu.  See the end of
     `ANNOUNCE' in the distribution for details.

   * Use scmconfig (From: bos@scrg.cs.tcd.ie):

     Build and install scripts using GNU "autoconf" are available from
     `scmconfig4e6.tar.gz' in the distribution directories.  See
     `README.unix' in `scmconfig4e6.tar.gz' for further instructions.

		  Making SCM with Think C 4.0 or 4.1

Note: These instructions need to be uptdated for scm4e6.  If Think C
can be called using system(), then SCM can be built using build.scm.

  Edit Scmfig.H to set desired options and IMPLINIT.
  from Yasuaki Honda // honda@csl.SONY.co.jp:
  Make a project and add source files repl.c, time.c, scm.c, subr.c,
  sys.c, eval.c, scl.c, sc2.c, and unif.c to it.
  Add libraries MacTraps, unix, ANSI to the project.
  The project should be segmented in the following way:
    ----------
    repl.c
    scm.c
    subr.c
    sys.c
    sc2.c
    unif.c
    time.c
    ----------
    MacTraps
    unix
    ----------
    ANSI
    ----------
    eval.c
    ----------
    scl.c
    ----------
  Choose 'Set Project Type' from 'Project' menu.
    Choose Application from radio buttons.
    Set Partition size to 600K. (The default 384K is not enough).

			 EDITING SCHEME CODE

Gnu Emacs:
     Editing of Scheme code is supported by emacs.  Buffers holding
     files ending in .scm are automatically put into scheme-mode.

     If your Emacs can run a process in a buffer you can use the Emacs
     command `M-x run-scheme' with SCM.  However, the run-scheme
     (`xscheme.el') which comes included with Gnu Emacs 18 will work
     only with MIT Cscheme.  If you are using Emacs 18, get the emacs
     packages:

        * ftp-swiss.ai.mit.edu:/pub/scheme-editor-packages/cmuscheme.el

        * ftp-swiss.ai.mit.edu:/pub/scheme-editor-packages/comint.el

     These files are already standard in Emacs 19.

     If your Emacs can not run a process in a buffer, see "under other
     systems" below.

Epsilon (MS-DOS):
     There is lisp (and scheme) mode available by use of the package
     `LISP.E'.  It offers several different indentation formats.  With
     this package, buffers holding files ending in `.L', `.LSP', `.S',
     and `.SCM' (my modification) are automatically put into lisp-mode.

     It is possible to run a process in a buffer under Epsilon.  With
     Epsilon 5.0 the command line options `-e512 -m0' are neccessary to
     manage RAM properly.  It has been reported that when compiling SCM
     with Turbo C, you need to `#define NOSETBUF' for proper operation
     in a process buffer with Epsilon 5.0.

     One can also call out to an editor from SCM if RAM is at a
     premium; See "under other systems" below.

other systems:
     Define the environment variable `EDITOR' to be the name of the
     editing program you use.  The SCM procedure `(ed arg1 ...)' will
     invoke your editor and return to SCM when you exit the editor.  The
     following definition is convenient:

          (define (e) (ed "work.scm") (load "work.scm"))

     Typing `(e)' will invoke the editor with the file of interest.
     After editing, the modified file will be loaded.

			   TROUBLE SHOOTING

Reported problems and solutions are grouped under "Compiling",
"Linking", "Running", and "Testing".  If you don't find your problem
listed here, you can send a bug report to <jaffer@ai.mit.edu>.  The
bug report should include:

 * The version of SCM (printed when SCM is invoked with no arguments).

 * The type of computer you are using.

 * The name and version of your computer's operating system.

 * The values of the environment variables SCM_INIT_PATH and
   SCHEME_LIBRARY_PATH.

 * The name and version of your C compiler.

 * If you are using an executable from a distribution, the name,
   vendor, and date of that distribution.  In this case,
   corresponding with the vendor is recommended.


		Compiling:

FILE	ERROR or WARNING			HOW TO FIX

*.c	include file not found			Correct status of
						STDC_HEADERS

						fix #include statement
						or add #define for
						system type to scmfig.h

scm.c	assignment between incompatible types	change SIGRETTYPE in scm.c

time.c	CLK_TCK redefined			incompatablility
						between <stdlib.h> and
						<sys/types.h>.  remove
						STDC_HEADERS in scmfig.h

						edit <sys/types.h> to
						remove incompatability.

sys.c	statement not reached			ignore
	constant in conditional expression	ignore

sys.c: `???' undeclared, outside of functions	#undef STDC_HEADERS
						in scmfig.h

scl.c	syntax error				define system type in
						scmfig.h and scl.c (softtype)

		Linking:

ERROR or WARNING			HOW TO FIX

_sin etc. missing.			uncomment LIBS in makefile

		Running:

PROBLEM					HOW TO FIX

Opening message and then machine	Change memory model option
crashes.				to C compiler (or makefile).

					Make sure sizet definition is
					correct in scmfig.h

					Reduce size of HEAP_SEG_SIZE
					in setjump.h

Input hangs				#define NOSETBUF

ERROR: heap: need larger initial	Need to increase the initial
					heap allocation using
					-a<kbytes> or INIT_HEAP_SIZE.

ERROR: Could not allocate ...		Check sizet definition.

					Get more memory.

					Don't try to run as subproccess

... in scmfig.h and recompile scm	Do it and recompile files.

ERROR: Init.scm not found		Assign correct IMPLINIT in
					makefile or scmfig.h or
					define environment variable
					SCM_INIT_PATH to be the full
					pathname of Init.scm (see
					INSTALLATION instructions).

WARNING: require.scm not found		define environment variable
					SCHEME_LIBRARY_PATH to be the
					full pathname of the scheme
					library SLIB or change
					library-vicinity in Init.scm
					to point to library or remove.
					See section SLIB above.

					Make sure library-vicinity has
					a trailing file separator
					(like / or \).

		Testing: (load "r4rstest.scm") or (load "pi.scm") (pi 100 5)

Runs some and then machine crashes.	See above under machine
					crashes.

Runs some and then ERROR: ...		Remove optimization option
(after a GC has happened)		to C compiler and recompile.

					#define SHORT_ALIGN in scmfig.h

Some symbol names print incorrectly.	Change memory model option
					to C compiler (or makefile).

					Check that HEAP_SEG_SIZE fits
					within sizet.

					Increase size of HEAP_SEG_SIZE
					(or INIT_HEAP_SIZE if it is
					smaller than HEAP_SEG_SIZE).

ERROR: Rogue pointer in Heap.		See above under machine
					crashes.

Newlines don't appear correctly in	Check file mode (define OPEN_...
output files.				in Init.scm

Spaces or control characters appear	Check character defines in
in symbol names				scmfig.h

Negative numbers turn positive.		Check SRS in scmfig.h

VMS: Couldn't unwind stack		#define CHEAP_CONTIUATIONS
VAX: botched longjmp			in scmfig.h

Sparc(SUN-4) heap is growing out of control:

	You are experiencing a GC problem peculiar to the Sparc.  The
	problem is that SCM doesn't know how to clear register
	windows.  Every location which is not reused still gets marked
	at GC time.  This causes lots of stuff which should be
	collected to not be.  This will be a problem with any
	"conservative" GC until we find what instruction will clear
	the register windows.  This problem is exacerbated by using
	lots of call-with-current-continuations.