-Guile NEWS --- history of user-visible changes. 2 Aug 1996 -*- text -*-
-Copyright (C) 1996 Free Software Foundation, Inc.
+Guile NEWS --- history of user-visible changes. -*- text -*-
+Copyright (C) 1996, 1997 Free Software Foundation, Inc.
See the end for copying conditions.
Please send Guile bug reports to bug-guile@prep.ai.mit.edu.
\f
-Guile 1.0b3
+Changes since Guile 1.0 (Sun 5 Jan 1997):
-Changes since Thursday, September 5:
+* Changes to the gh_ interface
+** gh_eval_str() now returns an SCM object which is the result of the
+evaluation
-* Guile now distinguishes between #f and the empty list.
+** gh_scm2str() now copies the Scheme data to a caller-provided C
+array
-This is for compatibility with the IEEE standard, the (possibly)
-upcoming Revised^5 Report on Scheme, and many extant Scheme
-implementations.
+** gh_scm2newstr() now makes a C array, copies the Scheme data to it,
+and returns the array
-Guile used to have #f and '() denote the same object, to make Scheme's
-type system more compatible with Emacs Lisp's. However, the change
-caused too much trouble for Scheme programmers, and we found another
-way to reconcile Emacs Lisp with Scheme that didn't require this.
+** gh_scm2str0() is gone: there is no need to distinguish
+null-terminated from non-null-terminated, since gh_scm2newstr() allows
+the user to interpret the data both ways.
+
+* Changes to documentation
+
+** the $(srcdir)/newdoc hierarchy now contains a new approach to the
+manuals. The approach, recommended by Jim Blandy, is to have: (*) a
+tutorial with the pedagogical style of guile-user, and a non-dry
+reference manual in the style of the most excellent GNU libc reference
+manual: the reference manual should be complete, but at the same time
+it should have an introductory screen for each major topic, which can
+be referenced if the user goes "up" a level in the info documentation.
+
+\f
+Guile 1.0b3
+
+User-visible changes from Thursday, September 5, 1996 until Guile 1.0:
+* Changes to the 'guile' program:
-* You can now use Guile as a shell script interpreter.
+** Guile now loads some new files when it starts up. Guile first
+searches the load path for init.scm, and loads it if found. Then, if
+Guile is not being used to execute a script, and the user's home
+directory contains a file named `.guile', Guile loads that.
+
+** You can now use Guile as a shell script interpreter.
To paraphrase the SCSH manual:
following. Consult the Unix man page for the `exec' system call
for more information.
+Now you can use Guile as an interpreter, using a mechanism which is a
+compatible subset of that provided by SCSH.
+
Guile now recognizes a '-s' command line switch, whose argument is the
name of a file of Scheme code to load. It also treats the two
characters `#!' as the start of a comment, terminated by `!#'. Thus,
end of the line? That is the notation SCSH uses, and although we
don't yet support the other SCSH features that motivate that choice,
we would like to be backward-compatible with any existing Guile
-scripts once we do.
+scripts once we do. Furthermore, if the path to Guile on your system
+is too long for your kernel, you can start the script with this
+horrible hack:
+
+#!/bin/sh
+exec /really/long/path/to/guile -s "$0" ${1+"$@"}
+!#
Note that some very old Unix systems don't support the `#!' syntax.
-* You can now run Guile without installing it.
+** You can now run Guile without installing it.
Previous versions of the interactive Guile interpreter (`guile')
couldn't start up unless Guile's Scheme library had been installed;
export SCHEME_LOAD_PATH=/home/jimb/my-scheme:/home/jimb/guile-1.0b3
-* Guile's header files should no longer conflict with your system's
+
+** Guile's read-eval-print loop no longer prints #<unspecified>
+results. If the user wants to see this, she can evaluate the
+expression (assert-repl-print-unspecified #t), perhaps in her startup
+file.
+
+** Guile no longer shows backtraces by default when an error occurs;
+however, it does display a message saying how to get one, and how to
+request that they be displayed by default. After an error, evaluate
+ (backtrace)
+to see a backtrace, and
+ (debug-enable 'backtrace)
+to see them by default.
+
+
+
+* Changes to Guile Scheme:
+
+** Guile now distinguishes between #f and the empty list.
+
+This is for compatibility with the IEEE standard, the (possibly)
+upcoming Revised^5 Report on Scheme, and many extant Scheme
+implementations.
+
+Guile used to have #f and '() denote the same object, to make Scheme's
+type system more compatible with Emacs Lisp's. However, the change
+caused too much trouble for Scheme programmers, and we found another
+way to reconcile Emacs Lisp with Scheme that didn't require this.
+
+
+** Guile's delq, delv, delete functions, and their destructive
+counterparts, delq!, delv!, and delete!, now remove all matching
+elements from the list, not just the first. This matches the behavior
+of the corresponding Emacs Lisp functions, and (I believe) the Maclisp
+functions which inspired them.
+
+I recognize that this change may break code in subtle ways, but it
+seems best to make the change before the FSF's first Guile release,
+rather than after.
+
+
+** The compiled-library-path function has been deleted from libguile.
+
+** The facilities for loading Scheme source files have changed.
+
+*** The variable %load-path now tells Guile which directories to search
+for Scheme code. Its value is a list of strings, each of which names
+a directory.
+
+*** The variable %load-extensions now tells Guile which extensions to
+try appending to a filename when searching the load path. Its value
+is a list of strings. Its default value is ("" ".scm").
+
+*** (%search-load-path FILENAME) searches the directories listed in the
+value of the %load-path variable for a Scheme file named FILENAME,
+with all the extensions listed in %load-extensions. If it finds a
+match, then it returns its full filename. If FILENAME is absolute, it
+returns it unchanged. Otherwise, it returns #f.
+
+%search-load-path will not return matches that refer to directories.
+
+*** (primitive-load FILENAME :optional CASE-INSENSITIVE-P SHARP)
+uses %seach-load-path to find a file named FILENAME, and loads it if
+it finds it. If it can't read FILENAME for any reason, it throws an
+error.
+
+The arguments CASE-INSENSITIVE-P and SHARP are interpreted as by the
+`read' function.
+
+*** load uses the same searching semantics as primitive-load.
+
+*** The functions %try-load, try-load-with-path, %load, load-with-path,
+basic-try-load-with-path, basic-load-with-path, try-load-module-with-
+path, and load-module-with-path have been deleted. The functions
+above should serve their purposes.
+
+*** If the value of the variable %load-hook is a procedure,
+`primitive-load' applies its value to the name of the file being
+loaded (without the load path directory name prepended). If its value
+is #f, it is ignored. Otherwise, an error occurs.
+
+This is mostly useful for printing load notification messages.
+
+
+** The function `eval!' is no longer accessible from the scheme level.
+We can't allow operations which introduce glocs into the scheme level,
+because Guile's type system can't handle these as data. Use `eval' or
+`read-and-eval!' (see below) as replacement.
+
+** The new function read-and-eval! reads an expression from PORT,
+evaluates it, and returns the result. This is more efficient than
+simply calling `read' and `eval', since it is not necessary to make a
+copy of the expression for the evaluator to munge.
+
+Its optional arguments CASE_INSENSITIVE_P and SHARP are interpreted as
+for the `read' function.
+
+
+** The function `int?' has been removed; its definition was identical
+to that of `integer?'.
+
+** The functions `<?', `<?', `<=?', `=?', `>?', and `>=?'. Code should
+use the R4RS names for these functions.
+
+** The function object-properties no longer returns the hash handle;
+it simply returns the object's property list.
+
+** Many functions have been changed to throw errors, instead of
+returning #f on failure. The point of providing exception handling in
+the language is to simplify the logic of user code, but this is less
+useful if Guile's primitives don't throw exceptions.
+
+** The function `fileno' has been renamed from `%fileno'.
+
+** The function primitive-mode->fdes returns #t or #f now, not 1 or 0.
+
+
+* Changes to Guile's C interface:
+
+** The library's initialization procedure has been simplified.
+scm_boot_guile now has the prototype:
+
+void scm_boot_guile (int ARGC,
+ char **ARGV,
+ void (*main_func) (),
+ void *closure);
+
+scm_boot_guile calls MAIN_FUNC, passing it CLOSURE, ARGC, and ARGV.
+MAIN_FUNC should do all the work of the program (initializing other
+packages, reading user input, etc.) before returning. When MAIN_FUNC
+returns, call exit (0); this function never returns. If you want some
+other exit value, MAIN_FUNC may call exit itself.
+
+scm_boot_guile arranges for program-arguments to return the strings
+given by ARGC and ARGV. If MAIN_FUNC modifies ARGC/ARGV, should call
+scm_set_program_arguments with the final list, so Scheme code will
+know which arguments have been processed.
+
+scm_boot_guile establishes a catch-all catch handler which prints an
+error message and exits the process. This means that Guile exits in a
+coherent way when system errors occur and the user isn't prepared to
+handle it. If the user doesn't like this behavior, they can establish
+their own universal catcher in MAIN_FUNC to shadow this one.
+
+Why must the caller do all the real work from MAIN_FUNC? The garbage
+collector assumes that all local variables of type SCM will be above
+scm_boot_guile's stack frame on the stack. If you try to manipulate
+SCM values after this function returns, it's the luck of the draw
+whether the GC will be able to find the objects you allocate. So,
+scm_boot_guile function exits, rather than returning, to discourage
+people from making that mistake.
+
+The IN, OUT, and ERR arguments were removed; there are other
+convenient ways to override these when desired.
+
+The RESULT argument was deleted; this function should never return.
+
+The BOOT_CMD argument was deleted; the MAIN_FUNC argument is more
+general.
+
+
+** Guile's header files should no longer conflict with your system's
header files.
In order to compile code which #included <libguile.h>, previous
Guile's installation procedure puts libguile.h in $(includedir), and
the rest in $(includedir)/libguile.
-* The compiled-library-path function has been deleted from libguile.
-* A variable and two new functions have been added to libguile:
+** Two new C functions, scm_protect_object and scm_unprotect_object,
+have been added to the Guile library.
-** The variable %load-path now tells Guile which directories to search
-for Scheme code. Its value is a list of strings, each of which names
-a directory.
+scm_protect_object (OBJ) protects OBJ from the garbage collector.
+OBJ will not be freed, even if all other references are dropped,
+until someone does scm_unprotect_object (OBJ). Both functions
+return OBJ.
-** (%search-load-path FILENAME) searches the directories listed in the
-value of the %load-path variable for a Scheme file named FILENAME. If
-it finds a match, then it returns its full filename. Otherwise, it
-returns #f. %search-load-path will not return matches that refer to
-directories.
+Note that calls to scm_protect_object do not nest. You can call
+scm_protect_object any number of times on a given object, and the
+next call to scm_unprotect_object will unprotect it completely.
-** (%try-load-path FILENAME :optional CASE-INSENSITIVE-P SHARP)
-searches the directories listed in %load-path for a file named
-FILENAME, and loads it if it finds it. If it can't read FILENAME for
-any reason, it throws an error.
+Basically, scm_protect_object and scm_unprotect_object just
+maintain a list of references to things. Since the GC knows about
+this list, all objects it mentions stay alive. scm_protect_object
+adds its argument to the list; scm_unprotect_object remove its
+argument from the list.
-The arguments CASE-INSENSITIVE-P and SHARP are interpreted as by the
-%try-load function.
+** scm_eval_0str now returns the value of the last expression
+evaluated.
+
+** The new function scm_read_0str reads an s-expression from a
+null-terminated string, and returns it.
+
+** The new function `scm_stdio_to_port' converts a STDIO file pointer
+to a Scheme port object.
+
+** The new function `scm_set_program_arguments' allows C code to set
+the value teruturned by the Scheme `program-arguments' function.
\f
-This is the beginning of recorded history.
+Older changes:
+
+* Guile no longer includes sophisticated Tcl/Tk support.
+
+The old Tcl/Tk support was unsatisfying to us, because it required the
+user to link against the Tcl library, as well as Tk and Guile. The
+interface was also un-lispy, in that it preserved Tcl/Tk's practice of
+referring to widgets by names, rather than exporting widgets to Scheme
+code as a special datatype.
+
+In the Usenix Tk Developer's Workshop held in July 1996, the Tcl/Tk
+maintainers described some very interesting changes in progress to the
+Tcl/Tk internals, which would facilitate clean interfaces between lone
+Tk and other interpreters --- even for garbage-collected languages
+like Scheme. They expected the new Tk to be publicly available in the
+fall of 1996.
+
+Since it seems that Guile might soon have a new, cleaner interface to
+lone Tk, and that the old Guile/Tk glue code would probably need to be
+completely rewritten, we (Jim Blandy and Richard Stallman) have
+decided not to support the old code. We'll spend the time instead on
+a good interface to the newer Tk, as soon as it is available.
+
+Until then, gtcltk-lib provides trivial, low-maintenance functionality.
\f
Copyright information:
-Copyright (C) 1996 Free Software Foundation, Inc.
+Copyright (C) 1996,1997 Free Software Foundation, Inc.
Permission is granted to anyone to make or distribute verbatim copies
of this document as received, in any medium, provided that the
HCoop / bpt / guile.git / blobdiff