Guile NEWS --- history of user-visible changes. -*- text -*-
-Copyright (C) 1996, 1997 Free Software Foundation, Inc.
+Copyright (C) 1996, 1997, 1998 Free Software Foundation, Inc.
See the end for copying conditions.
-Please send Guile bug reports to bug-guile@prep.ai.mit.edu.
+Please send Guile bug reports to bug-guile@gnu.org.
\f
-Changes since Guile 1.2:
+Changes in Guile 1.3 (released Monday, October 19, 1998):
* Changes to the distribution
+** We renamed the SCHEME_LOAD_PATH environment variable to GUILE_LOAD_PATH.
+To avoid conflicts, programs should name environment variables after
+themselves, except when there's a common practice establishing some
+other convention.
+
+For now, Guile supports both GUILE_LOAD_PATH and SCHEME_LOAD_PATH,
+giving the former precedence, and printing a warning message if the
+latter is set. Guile 1.4 will not recognize SCHEME_LOAD_PATH at all.
+
+** The header files related to multi-byte characters have been removed.
+They were: libguile/extchrs.h and libguile/mbstrings.h. Any C code
+which referred to these explicitly will probably need to be rewritten,
+since the support for the variant string types has been removed; see
+below.
+
+** The header files append.h and sequences.h have been removed. These
+files implemented non-R4RS operations which would encourage
+non-portable programming style and less easy-to-read code.
+
* Changes to the stand-alone interpreter
+** New procedures have been added to implement a "batch mode":
+
+*** Function: batch-mode?
+
+ Returns a boolean indicating whether the interpreter is in batch
+ mode.
+
+*** Function: set-batch-mode?! ARG
+
+ If ARG is true, switches the interpreter to batch mode. The `#f'
+ case has not been implemented.
+
+** Guile now provides full command-line editing, when run interactively.
+To use this feature, you must have the readline library installed.
+The Guile build process will notice it, and automatically include
+support for it.
+
+The readline library is available via anonymous FTP from any GNU
+mirror site; the canonical location is "ftp://prep.ai.mit.edu/pub/gnu".
+
+** the-last-stack is now a fluid.
+
* Changes to the procedure for linking libguile with your programs
+** You can now use the `guile-config' utility to build programs that use Guile.
+
+Guile now includes a command-line utility called `guile-config', which
+can provide information about how to compile and link programs that
+use Guile.
+
+*** `guile-config compile' prints any C compiler flags needed to use Guile.
+You should include this command's output on the command line you use
+to compile C or C++ code that #includes the Guile header files. It's
+usually just a `-I' flag to help the compiler find the Guile headers.
+
+
+*** `guile-config link' prints any linker flags necessary to link with Guile.
+
+This command writes to its standard output a list of flags which you
+must pass to the linker to link your code against the Guile library.
+The flags include '-lguile' itself, any other libraries the Guile
+library depends upon, and any `-L' flags needed to help the linker
+find those libraries.
+
+For example, here is a Makefile rule that builds a program named 'foo'
+from the object files ${FOO_OBJECTS}, and links them against Guile:
+
+ foo: ${FOO_OBJECTS}
+ ${CC} ${CFLAGS} ${FOO_OBJECTS} `guile-config link` -o foo
+
+Previous Guile releases recommended that you use autoconf to detect
+which of a predefined set of libraries were present on your system.
+It is more robust to use `guile-config', since it records exactly which
+libraries the installed Guile library requires.
+
+This was originally called `build-guile', but was renamed to
+`guile-config' before Guile 1.3 was released, to be consistent with
+the analogous script for the GTK+ GUI toolkit, which is called
+`gtk-config'.
+
+
+** Use the GUILE_FLAGS macro in your configure.in file to find Guile.
+
+If you are using the GNU autoconf package to configure your program,
+you can use the GUILE_FLAGS autoconf macro to call `guile-config'
+(described above) and gather the necessary values for use in your
+Makefiles.
+
+The GUILE_FLAGS macro expands to configure script code which runs the
+`guile-config' script, to find out where Guile's header files and
+libraries are installed. It sets two variables, marked for
+substitution, as by AC_SUBST.
+
+ GUILE_CFLAGS --- flags to pass to a C or C++ compiler to build
+ code that uses Guile header files. This is almost always just a
+ -I flag.
+
+ GUILE_LDFLAGS --- flags to pass to the linker to link a
+ program against Guile. This includes `-lguile' for the Guile
+ library itself, any libraries that Guile itself requires (like
+ -lqthreads), and so on. It may also include a -L flag to tell the
+ compiler where to find the libraries.
+
+GUILE_FLAGS is defined in the file guile.m4, in the top-level
+directory of the Guile distribution. You can copy it into your
+package's aclocal.m4 file, and then use it in your configure.in file.
+
+If you are using the `aclocal' program, distributed with GNU automake,
+to maintain your aclocal.m4 file, the Guile installation process
+installs guile.m4 where aclocal will find it. All you need to do is
+use GUILE_FLAGS in your configure.in file, and then run `aclocal';
+this will copy the definition of GUILE_FLAGS into your aclocal.m4
+file.
+
+
* Changes to Scheme functions and syntax
+** Multi-byte strings have been removed, as have multi-byte and wide
+ports. We felt that these were the wrong approach to
+internationalization support.
+
+** New function: readline [PROMPT]
+Read a line from the terminal, and allow the user to edit it,
+prompting with PROMPT. READLINE provides a large set of Emacs-like
+editing commands, lets the user recall previously typed lines, and
+works on almost every kind of terminal, including dumb terminals.
+
+READLINE assumes that the cursor is at the beginning of the line when
+it is invoked. Thus, you can't print a prompt yourself, and then call
+READLINE; you need to package up your prompt as a string, pass it to
+the function, and let READLINE print the prompt itself. This is
+because READLINE needs to know the prompt's screen width.
+
+For Guile to provide this function, you must have the readline
+library, version 2.1 or later, installed on your system. Readline is
+available via anonymous FTP from prep.ai.mit.edu in pub/gnu, or from
+any GNU mirror site.
+
+See also ADD-HISTORY function.
+
+** New function: add-history STRING
+Add STRING as the most recent line in the history used by the READLINE
+command. READLINE does not add lines to the history itself; you must
+call ADD-HISTORY to make previous input available to the user.
+
+** The behavior of the read-line function has changed.
+
+This function now uses standard C library functions to read the line,
+for speed. This means that it doesn not respect the value of
+scm-line-incrementors; it assumes that lines are delimited with
+#\newline.
+
+(Note that this is read-line, the function that reads a line of text
+from a port, not readline, the function that reads a line from a
+terminal, providing full editing capabilities.)
+
+** New module (ice-9 getopt-gnu-style): Parse command-line arguments.
+
+This module provides some simple argument parsing. It exports one
+function:
+
+Function: getopt-gnu-style ARG-LS
+ Parse a list of program arguments into an alist of option
+ descriptions.
+
+ Each item in the list of program arguments is examined to see if
+ it meets the syntax of a GNU long-named option. An argument like
+ `--MUMBLE' produces an element of the form (MUMBLE . #t) in the
+ returned alist, where MUMBLE is a keyword object with the same
+ name as the argument. An argument like `--MUMBLE=FROB' produces
+ an element of the form (MUMBLE . FROB), where FROB is a string.
+
+ As a special case, the returned alist also contains a pair whose
+ car is the symbol `rest'. The cdr of this pair is a list
+ containing all the items in the argument list that are not options
+ of the form mentioned above.
+
+ The argument `--' is treated specially: all items in the argument
+ list appearing after such an argument are not examined, and are
+ returned in the special `rest' list.
+
+ This function does not parse normal single-character switches.
+ You will need to parse them out of the `rest' list yourself.
+
+** The read syntax for byte vectors and short vectors has changed.
+
+Instead of #bytes(...), write #y(...).
+
+Instead of #short(...), write #h(...).
+
+This may seem nutty, but, like the other uniform vectors, byte vectors
+and short vectors want to have the same print and read syntax (and,
+more basic, want to have read syntax!). Changing the read syntax to
+use multiple characters after the hash sign breaks with the
+conventions used in R5RS and the conventions used for the other
+uniform vectors. It also introduces complexity in the current reader,
+both on the C and Scheme levels. (The Right solution is probably to
+change the syntax and prototypes for uniform vectors entirely.)
+
+
+** The new module (ice-9 session) provides useful interactive functions.
+
+*** New procedure: (apropos REGEXP OPTION ...)
+
+Display a list of top-level variables whose names match REGEXP, and
+the modules they are imported from. Each OPTION should be one of the
+following symbols:
+
+ value --- Show the value of each matching variable.
+ shadow --- Show bindings shadowed by subsequently imported modules.
+ full --- Same as both `shadow' and `value'.
+
+For example:
+
+ guile> (apropos "trace" 'full)
+ debug: trace #<procedure trace args>
+ debug: untrace #<procedure untrace args>
+ the-scm-module: display-backtrace #<compiled-closure #<primitive-procedure gsubr-apply>>
+ the-scm-module: before-backtrace-hook ()
+ the-scm-module: backtrace #<primitive-procedure backtrace>
+ the-scm-module: after-backtrace-hook ()
+ the-scm-module: has-shown-backtrace-hint? #f
+ guile>
+
+** There are new functions and syntax for working with macros.
+
+Guile implements macros as a special object type. Any variable whose
+top-level binding is a macro object acts as a macro. The macro object
+specifies how the expression should be transformed before evaluation.
+
+*** Macro objects now print in a reasonable way, resembling procedures.
+
+*** New function: (macro? OBJ)
+True iff OBJ is a macro object.
+
+*** New function: (primitive-macro? OBJ)
+Like (macro? OBJ), but true only if OBJ is one of the Guile primitive
+macro transformers, implemented in eval.c rather than Scheme code.
+
+*** New function: (macro-type OBJ)
+Return a value indicating what kind of macro OBJ is. Possible return
+values are:
+
+ The symbol `syntax' --- a macro created by procedure->syntax.
+ The symbol `macro' --- a macro created by procedure->macro.
+ The symbol `macro!' --- a macro created by procedure->memoizing-macro.
+ The boolean #f --- if OBJ is not a macro object.
+
+*** New function: (macro-name MACRO)
+Return the name of the macro object MACRO's procedure, as returned by
+procedure-name.
+
+*** New function: (macro-transformer MACRO)
+Return the transformer procedure for MACRO.
+
+*** New syntax: (use-syntax MODULE ... TRANSFORMER)
+
+Specify a new macro expander to use in the current module. Each
+MODULE is a module name, with the same meaning as in the `use-modules'
+form; each named module's exported bindings are added to the current
+top-level environment. TRANSFORMER is an expression evaluated in the
+resulting environment which must yield a procedure to use as the
+module's eval transformer: every expression evaluated in this module
+is passed to this function, and the result passed to the Guile
+interpreter.
+
+*** macro-eval! is removed. Use local-eval instead.
+
+** Some magic has been added to the printer to better handle user
+written printing routines (like record printers, closure printers).
+
+The problem is that these user written routines must have access to
+the current `print-state' to be able to handle fancy things like
+detection of circular references. These print-states have to be
+passed to the builtin printing routines (display, write, etc) to
+properly continue the print chain.
+
+We didn't want to change all existing print code so that it
+explicitly passes thru a print state in addition to a port. Instead,
+we extented the possible values that the builtin printing routines
+accept as a `port'. In addition to a normal port, they now also take
+a pair of a normal port and a print-state. Printing will go to the
+port and the print-state will be used to control the detection of
+circular references, etc. If the builtin function does not care for a
+print-state, it is simply ignored.
+
+User written callbacks are now called with such a pair as their
+`port', but because every function now accepts this pair as a PORT
+argument, you don't have to worry about that. In fact, it is probably
+safest to not check for these pairs.
+
+However, it is sometimes necessary to continue a print chain on a
+different port, for example to get a intermediate string
+representation of the printed value, mangle that string somehow, and
+then to finally print the mangled string. Use the new function
+
+ inherit-print-state OLD-PORT NEW-PORT
+
+for this. It constructs a new `port' that prints to NEW-PORT but
+inherits the print-state of OLD-PORT.
+
+** struct-vtable-offset renamed to vtable-offset-user
+
+** New constants: vtable-index-layout, vtable-index-vtable, vtable-index-printer
+
+** There is now a fourth (optional) argument to make-vtable-vtable and
+ make-struct when constructing new types (vtables). This argument
+ initializes field vtable-index-printer of the vtable.
+
** The detection of circular references has been extended to structs.
That is, a structure that -- in the process of being printed -- prints
itself does not lead to infinite recursion.
fluids are not special variables but ordinary objects. FLUID
should evaluate to a fluid.
-* Changes to system call interfaces:
+** Changes to system call interfaces:
-** close-port, close-input-port and close-output-port now return a
+*** close-port, close-input-port and close-output-port now return a
boolean instead of an `unspecified' object. #t means that the port
was successfully closed, while #f means it was already closed. It is
also now possible for these procedures to raise an exception if an
error occurs (some errors from write can be delayed until close.)
-** the first argument to chmod, fcntl, ftell and fseek can now be a
+*** the first argument to chmod, fcntl, ftell and fseek can now be a
file descriptor.
-** the third argument to fcntl is now optional.
+*** the third argument to fcntl is now optional.
-** the first argument to chown can now be a file descriptor or a port.
+*** the first argument to chown can now be a file descriptor or a port.
-** the argument to stat can now be a port.
+*** the argument to stat can now be a port.
-** The following new procedures have been added (most use scsh
+*** The following new procedures have been added (most use scsh
interfaces):
-** close PORT/FD
-Similar to close-port, but also works on file descriptors. A side
-effect of closing a file descriptor is that any ports using that file
-descriptor are moved to a different file descriptor and have
-their revealed counts set to zero.
-
-The next five procedures perform a dup2 system call, if NEWFD (an
-integer) is supplied, otherwise a dup. The file descriptor to be
-duplicated can be supplied as an integer or wrapped in a port. The
+*** procedure: close PORT/FD
+ Similar to close-port (*note close-port: Closing Ports.), but also
+ works on file descriptors. A side effect of closing a file
+ descriptor is that any ports using that file descriptor are moved
+ to a different file descriptor and have their revealed counts set
+ to zero.
+
+*** procedure: port->fdes PORT
+ Returns the integer file descriptor underlying PORT. As a side
+ effect the revealed count of PORT is incremented.
+
+*** procedure: fdes->ports FDES
+ Returns a list of existing ports which have FDES as an underlying
+ file descriptor, without changing their revealed counts.
+
+*** procedure: fdes->inport FDES
+ Returns an existing input port which has FDES as its underlying
+ file descriptor, if one exists, and increments its revealed count.
+ Otherwise, returns a new input port with a revealed count of 1.
+
+*** procedure: fdes->outport FDES
+ Returns an existing output port which has FDES as its underlying
+ file descriptor, if one exists, and increments its revealed count.
+ Otherwise, returns a new output port with a revealed count of 1.
+
+ The next group of procedures perform a `dup2' system call, if NEWFD
+(an integer) is supplied, otherwise a `dup'. The file descriptor to be
+duplicated can be supplied as an integer or contained in a port. The
type of value returned varies depending on which procedure is used.
-All procedures also have the side effect when performing dup2 that any
-ports using NEWFD are moved to a different file descriptor and have
+ All procedures also have the side effect when performing `dup2' that
+any ports using NEWFD are moved to a different file descriptor and have
their revealed counts set to zero.
-** dup->fdes PORT/FD [NEWFD]
-Returns an integer file descriptor.
+*** procedure: dup->fdes PORT/FD [NEWFD]
+ Returns an integer file descriptor.
-** dup->inport PORT/FD [NEWFD]
-Returns a new input port using the new file descriptor.
+*** procedure: dup->inport PORT/FD [NEWFD]
+ Returns a new input port using the new file descriptor.
-** dup->outport PORT/FD [NEWFD]
-Returns a new output port using the new file descriptor.
+*** procedure: dup->outport PORT/FD [NEWFD]
+ Returns a new output port using the new file descriptor.
-** dup PORT/FD [NEWFD]
-Returns a new port if PORT/FD is a port, with the same mode as the
-supplied port, otherwise returns an integer file descriptor.
+*** procedure: dup PORT/FD [NEWFD]
+ Returns a new port if PORT/FD is a port, with the same mode as the
+ supplied port, otherwise returns an integer file descriptor.
-** dup->port PORT/FD MODE [NEWFD]
-Returns a new port using the new file descriptor. MODE supplies a
-mode string for the port (as for `open-file').
+*** procedure: dup->port PORT/FD MODE [NEWFD]
+ Returns a new port using the new file descriptor. MODE supplies a
+ mode string for the port (*note open-file: File Ports.).
-** port->fdes PORT
-Returns the integer file descriptor underlying PORT. As a
-side effect the revealed count of PORT is incremented.
+*** procedure: setenv NAME VALUE
+ Modifies the environment of the current process, which is also the
+ default environment inherited by child processes.
-** fdes->inport FDES
-Returns an existing input port which has FDES as its underlying file
-descriptor, if one exists, and increments its revealed count.
-Otherwise, returns a new input port with a revealed count of 1.
+ If VALUE is `#f', then NAME is removed from the environment.
+ Otherwise, the string NAME=VALUE is added to the environment,
+ replacing any existing string with name matching NAME.
-** fdes->outport FDES
-Returns an existing output port which has FDES as its underlying file
-descriptor, if one exists, and increments its revealed count.
-Otherwise, returns a new output port with a revealed count of 1.
-
-** setenv NAME VALUE
-If VALUE is `#f', removes NAME from the environment. Otherwise
-adds the string NAME=VALUE to the environment, replacing any previous
-value for NAME.
+ The return value is unspecified.
-** truncate-file OBJ SIZE
+*** procedure: truncate-file OBJ SIZE
Truncates the file referred to by OBJ to at most SIZE bytes. OBJ
can be a string containing a file name or an integer file
descriptor or port open for output on the file. The underlying
The return value is unspecified.
-** setvbuf PORT MODE [SIZE]
+*** procedure: setvbuf PORT MODE [SIZE]
Set the buffering mode for PORT. MODE can be:
`_IONBF'
non-buffered
size. Procedures e.g., *Note open-file: File Ports, which accept a
mode string allow `0' to be added to request an unbuffered port.
-** fsync PORT/FD
+*** procedure: fsync PORT/FD
Copies any unwritten data for the specified output file descriptor
to disk. If PORT/FD is a port, its buffer is flushed before the
underlying file descriptor is fsync'd. The return value is
unspecified.
-** open-fdes PATH FLAGS [MODES]
+*** procedure: open-fdes PATH FLAGS [MODES]
Similar to `open' but returns a file descriptor instead of a port.
-** procedure: execle PATH ENV [ARG] ...
+*** procedure: execle PATH ENV [ARG] ...
Similar to `execl', but the environment of the new process is
specified by ENV, which must be a list of strings as returned by
the `environ' procedure.
call, but we call it `execle' because of its Scheme calling
interface.
-** procedure: primitive-exit [STATUS]
+*** procedure: strerror ERRNO
+ Returns the Unix error message corresponding to ERRNO, an integer.
+
+*** procedure: primitive-exit [STATUS]
Terminate the current process without unwinding the Scheme stack.
This is would typically be useful after a fork. The exit status
is STATUS if supplied, otherwise zero.
-** procedure: times
+*** procedure: times
Returns an object with information about real and processor time.
The following procedures accept such an object as an argument and
return a selected component:
Similarly, the CPU times units used by the system on behalf of
terminated child processes.
+** Removed: list-length
+** Removed: list-append, list-append!
+** Removed: list-reverse, list-reverse!
+
+** array-map renamed to array-map!
+
+** serial-array-map renamed to serial-array-map!
+
+** catch doesn't take #f as first argument any longer
+
+Previously, it was possible to pass #f instead of a key to `catch'.
+That would cause `catch' to pass a jump buffer object to the procedure
+passed as second argument. The procedure could then use this jump
+buffer objekt as an argument to throw.
+
+This mechanism has been removed since its utility doesn't motivate the
+extra complexity it introduces.
+
+** The `#/' notation for lists now provokes a warning message from Guile.
+This syntax will be removed from Guile in the near future.
+
+To disable the warning message, set the GUILE_HUSH environment
+variable to any non-empty value.
+
+** The newline character now prints as `#\newline', following the
+normal Scheme notation, not `#\nl'.
+
* Changes to the gh_ interface
+** The gh_enter function now takes care of loading the Guile startup files.
+gh_enter works by calling scm_boot_guile; see the remarks below.
+
+** Function: void gh_write (SCM x)
+
+Write the printed representation of the scheme object x to the current
+output port. Corresponds to the scheme level `write'.
+
+** gh_list_length renamed to gh_length.
+
+** vector handling routines
+
+Several major changes. In particular, gh_vector() now resembles
+(vector ...) (with a caveat -- see manual), and gh_make_vector() now
+exists and behaves like (make-vector ...). gh_vset() and gh_vref()
+have been renamed gh_vector_set_x() and gh_vector_ref(). Some missing
+vector-related gh_ functions have been implemented.
+
+** pair and list routines
+
+Implemented several of the R4RS pair and list functions that were
+missing.
+
+** gh_scm2doubles, gh_doubles2scm, gh_doubles2dvect
+
+New function. Converts double arrays back and forth between Scheme
+and C.
+
* Changes to the scm_ interface
+** The function scm_boot_guile now takes care of loading the startup files.
+
+Guile's primary initialization function, scm_boot_guile, now takes
+care of loading `boot-9.scm', in the `ice-9' module, to initialize
+Guile, define the module system, and put together some standard
+bindings. It also loads `init.scm', which is intended to hold
+site-specific initialization code.
+
+Since Guile cannot operate properly until boot-9.scm is loaded, there
+is no reason to separate loading boot-9.scm from Guile's other
+initialization processes.
+
+This job used to be done by scm_compile_shell_switches, which didn't
+make much sense; in particular, it meant that people using Guile for
+non-shell-like applications had to jump through hoops to get Guile
+initialized properly.
+
+** The function scm_compile_shell_switches no longer loads the startup files.
+Now, Guile always loads the startup files, whenever it is initialized;
+see the notes above for scm_boot_guile and scm_load_startup_files.
+
+** Function: scm_load_startup_files
+This new function takes care of loading Guile's initialization file
+(`boot-9.scm'), and the site initialization file, `init.scm'. Since
+this is always called by the Guile initialization process, it's
+probably not too useful to call this yourself, but it's there anyway.
+
+** The semantics of smob marking have changed slightly.
+
+The smob marking function (the `mark' member of the scm_smobfuns
+structure) is no longer responsible for setting the mark bit on the
+smob. The generic smob handling code in the garbage collector will
+set this bit. The mark function need only ensure that any other
+objects the smob refers to get marked.
+
+Note that this change means that the smob's GC8MARK bit is typically
+already set upon entry to the mark function. Thus, marking functions
+which look like this:
+
+ {
+ if (SCM_GC8MARKP (ptr))
+ return SCM_BOOL_F;
+ SCM_SETGC8MARK (ptr);
+ ... mark objects to which the smob refers ...
+ }
+
+are now incorrect, since they will return early, and fail to mark any
+other objects the smob refers to. Some code in the Guile library used
+to work this way.
+
+** The semantics of the I/O port functions in scm_ptobfuns have changed.
+
+If you have implemented your own I/O port type, by writing the
+functions required by the scm_ptobfuns and then calling scm_newptob,
+you will need to change your functions slightly.
+
+The functions in a scm_ptobfuns structure now expect the port itself
+as their argument; they used to expect the `stream' member of the
+port's scm_port_table structure. This allows functions in an
+scm_ptobfuns structure to easily access the port's cell (and any flags
+it its CAR), and the port's scm_port_table structure.
+
+Guile now passes the I/O port itself as the `port' argument in the
+following scm_ptobfuns functions:
+
+ int (*free) (SCM port);
+ int (*fputc) (int, SCM port);
+ int (*fputs) (char *, SCM port);
+ scm_sizet (*fwrite) SCM_P ((char *ptr,
+ scm_sizet size,
+ scm_sizet nitems,
+ SCM port));
+ int (*fflush) (SCM port);
+ int (*fgetc) (SCM port);
+ int (*fclose) (SCM port);
+
+The interfaces to the `mark', `print', `equalp', and `fgets' methods
+are unchanged.
+
+If you have existing code which defines its own port types, it is easy
+to convert your code to the new interface; simply apply SCM_STREAM to
+the port argument to yield the value you code used to expect.
+
+Note that since both the port and the stream have the same type in the
+C code --- they are both SCM values --- the C compiler will not remind
+you if you forget to update your scm_ptobfuns functions.
+
+
+** Function: int scm_internal_select (int fds,
+ SELECT_TYPE *rfds,
+ SELECT_TYPE *wfds,
+ SELECT_TYPE *efds,
+ struct timeval *timeout);
+
+This is a replacement for the `select' function provided by the OS.
+It enables I/O blocking and sleeping to happen for one cooperative
+thread without blocking other threads. It also avoids busy-loops in
+these situations. It is intended that all I/O blocking and sleeping
+will finally go through this function. Currently, this function is
+only available on systems providing `gettimeofday' and `select'.
+
+** Function: SCM scm_internal_stack_catch (SCM tag,
+ scm_catch_body_t body,
+ void *body_data,
+ scm_catch_handler_t handler,
+ void *handler_data)
+
+A new sibling to the other two C level `catch' functions
+scm_internal_catch and scm_internal_lazy_catch. Use it if you want
+the stack to be saved automatically into the variable `the-last-stack'
+(scm_the_last_stack_var) on error. This is necessary if you want to
+use advanced error reporting, such as calling scm_display_error and
+scm_display_backtrace. (They both take a stack object as argument.)
+
+** Function: SCM scm_spawn_thread (scm_catch_body_t body,
+ void *body_data,
+ scm_catch_handler_t handler,
+ void *handler_data)
+
+Spawns a new thread. It does a job similar to
+scm_call_with_new_thread but takes arguments more suitable when
+spawning threads from application C code.
+
+** The hook scm_error_callback has been removed. It was originally
+intended as a way for the user to install his own error handler. But
+that method works badly since it intervenes between throw and catch,
+thereby changing the semantics of expressions like (catch #t ...).
+The correct way to do it is to use one of the C level catch functions
+in throw.c: scm_internal_catch/lazy_catch/stack_catch.
+
+** Removed functions:
+
+scm_obj_length, scm_list_length, scm_list_append, scm_list_append_x,
+scm_list_reverse, scm_list_reverse_x
+
+** New macros: SCM_LISTn where n is one of the integers 0-9.
+
+These can be used for pretty list creation from C. The idea is taken
+from Erick Gallesio's STk.
+
+** scm_array_map renamed to scm_array_map_x
+
+** mbstrings are now removed
+
+This means that the type codes scm_tc7_mb_string and
+scm_tc7_mb_substring has been removed.
+
+** scm_gen_putc, scm_gen_puts, scm_gen_write, and scm_gen_getc have changed.
+
+Since we no longer support multi-byte strings, these I/O functions
+have been simplified, and renamed. Here are their old names, and
+their new names and arguments:
+
+scm_gen_putc -> void scm_putc (int c, SCM port);
+scm_gen_puts -> void scm_puts (char *s, SCM port);
+scm_gen_write -> void scm_lfwrite (char *ptr, scm_sizet size, SCM port);
+scm_gen_getc -> void scm_getc (SCM port);
+
+
+** The macros SCM_TYP7D and SCM_TYP7SD has been removed.
+
+** The macro SCM_TYP7S has taken the role of the old SCM_TYP7D
+
+SCM_TYP7S now masks away the bit which distinguishes substrings from
+strings.
+
+** scm_catch_body_t: Backward incompatible change!
+
+Body functions to scm_internal_catch and friends do not any longer
+take a second argument. This is because it is no longer possible to
+pass a #f arg to catch.
+
+** Calls to scm_protect_object and scm_unprotect now nest properly.
+
+The function scm_protect_object protects its argument from being freed
+by the garbage collector. scm_unprotect_object removes that
+protection.
+
+These functions now nest properly. That is, for every object O, there
+is a counter which scm_protect_object(O) increments and
+scm_unprotect_object(O) decrements, if the counter is greater than
+zero. Every object's counter is zero when it is first created. If an
+object's counter is greater than zero, the garbage collector will not
+reclaim its storage.
+
+This allows you to use scm_protect_object in your code without
+worrying that some other function you call will call
+scm_unprotect_object, and allow it to be freed. Assuming that the
+functions you call are well-behaved, and unprotect only those objects
+they protect, you can follow the same rule and have confidence that
+objects will be freed only at appropriate times.
+
\f
Changes in Guile 1.2 (released Tuesday, June 24 1997):
To use the scm_shell function, first initialize any guile modules
linked into your application, and then call scm_shell with the values
-of ARGC and ARGV your `main' function received. scm_shell will adding
+of ARGC and ARGV your `main' function received. scm_shell will add
any SCSH-style meta-arguments from the top of the script file to the
argument vector, and then process the command-line arguments. This
generally means loading a script file or starting up an interactive
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.
+the value returned by the Scheme `program-arguments' function.
\f
Older changes:
HCoop / bpt / guile.git / blobdiff