Support full Common Lisp multiple values in C. lisp/ChangeLog 2009-08-11 Aidan Kehoe <kehoea@parhasard.net> * bytecomp.el : Update this file to support full C-level multiple values. This involves: -- Four new bytecodes, and special compiler functions to compile multiple-value-call, multiple-value-list-internal, values, values-list, and, since it now needs to pass back multiple values and is a special form, throw. -- There's a new compiler variable, byte-compile-checks-on-load, which is a list of forms that are evaluated at the very start of a file, with an error thrown if any of them give nil. -- The header is now inserted *after* compilation, giving a chance for the compilation process to influence what those checks are. There is still a check done before compilation for non-ASCII characters, to try to turn off dynamic docstrings if appopriate, in `byte-compile-maybe-reset-coding'. Space is reserved for checks; comments describing the version of the byte compiler generating the file are inserted if space remains for them. * bytecomp.el (byte-compile-version): Update this, we're a newer version of the byte compiler. * byte-optimize.el (byte-optimize-funcall): Correct a comment. * bytecomp.el (byte-compile-lapcode): Discard the arg with byte-multiple-value-call. * bytecomp.el (byte-compile-checks-and-comments-space): New variable, describe how many octets to reserve for checks at the start of byte-compiled files. * cl-compat.el: Remove the fake multiple-value implementation. Have the functions that use it use the real multiple-value implementation instead. * cl-macs.el (cl-block-wrapper, cl-block-throw): Revise the byte-compile properties of these symbols to work now we've made throw into a special form; keep the byte-compile properties as anonymous lambdas, since we don't have docstrings for them. * cl-macs.el (multiple-value-bind, multiple-value-setq) (multiple-value-list, nth-value): Update these functions to work with the C support for multiple values. * cl-macs.el (values): Modify the setf handler for this to call #'multiple-value-list-internal appropriately. * cl-macs.el (cl-setf-do-store): If the store form is a cons, treat it specially as wrapping the store value. * cl.el (cl-block-wrapper): Make this an alias of #'and, not #'identity, since it needs to pass back multiple values. * cl.el (multiple-value-apply): We no longer support this, mark it obsolete. * lisp-mode.el (eval-interactive-verbose): Remove a useless space in the docstring. * lisp-mode.el (eval-interactive): Update this function and its docstring. It now passes back a list, basically wrapping any eval calls with multiple-value-list. This allows multiple values to be printed by default in *scratch*. * lisp-mode.el (prin1-list-as-multiple-values): New function, printing a list as multiple values in the manner of Bruno Haible's clisp, separating each entry with " ;\n". * lisp-mode.el (eval-last-sexp): Call #'prin1-list-as-multiple-values on the return value of #'eval-interactive. * lisp-mode.el (eval-defun): Call #'prin1-list-as-multiple-values on the return value of #'eval-interactive. * mouse.el (mouse-eval-sexp): Deal with lists corresponding to multiple values from #'eval-interactive. Call #'cl-prettyprint, which is always available, instead of sometimes calling #'pprint and sometimes falling back to prin1. * obsolete.el (obsolete-throw): New function, called from eval.c when #'funcall encounters an attempt to call #'throw (now a special form) as a function. Only needed for compatibility with 21.4 byte-code. man/ChangeLog addition: 2009-08-11 Aidan Kehoe <kehoea@parhasard.net> * cl.texi (Organization): Remove references to the obsolete multiple-value emulating code. src/ChangeLog addition: 2009-08-11 Aidan Kehoe <kehoea@parhasard.net> * bytecode.c (enum Opcode /* Byte codes */): Add four new bytecodes, to deal with multiple values. (POP_WITH_MULTIPLE_VALUES): New macro. (POP): Modify this macro to ignore multiple values. (DISCARD_PRESERVING_MULTIPLE_VALUES): New macro. (DISCARD): Modify this macro to ignore multiple values. (TOP_WITH_MULTIPLE_VALUES): New macro. (TOP_ADDRESS): New macro. (TOP): Modify this macro to ignore multiple values. (TOP_LVALUE): New macro. (Bcall): Ignore multiple values where appropriate. (Breturn): Pass back multiple values. (Bdup): Preserve multiple values. Use TOP_LVALUE with most bytecodes that assign anything to anything. (Bbind_multiple_value_limits, Bmultiple_value_call, Bmultiple_value_list_internal, Bthrow): Implement the new bytecodes. (Bgotoifnilelsepop, Bgotoifnonnilelsepop, BRgotoifnilelsepop, BRgotoifnonnilelsepop): Discard any multiple values. * callint.c (Fcall_interactively): Ignore multiple values when calling #'eval, in two places. * device-x.c (x_IO_error_handler): * macros.c (pop_kbd_macro_event): * eval.c (Fsignal): * eval.c (flagged_a_squirmer): Call throw_or_bomb_out, not Fthrow, now that the latter is a special form. * eval.c: Make Qthrow, Qobsolete_throw available as symbols. Provide multiple_value_current_limit, multiple-values-limit (the latter as specified by Common Lisp. * eval.c (For): Ignore multiple values when comparing with Qnil, but pass any multiple values back for the last arg. * eval.c (Fand): Ditto. * eval.c (Fif): Ignore multiple values when examining the result of the condition. * eval.c (Fcond): Ignore multiple values when comparing what the clauses give, but pass them back if a clause gave non-nil. * eval.c (Fprog2): Never pass back multiple values. * eval.c (FletX, Flet): Ignore multiple when evaluating what exactly symbols should be bound to. * eval.c (Fwhile): Ignore multiple values when evaluating the test. * eval.c (Fsetq, Fdefvar, Fdefconst): Ignore multiple values. * eval.c (Fthrow): Declare this as a special form; ignore multiple values for TAG, preserve them for VALUE. * eval.c (throw_or_bomb_out): Make this available to other files, now Fthrow is a special form. * eval.c (Feval): Ignore multiple values when calling a compiled function, a non-special-form subr, or a lambda expression. * eval.c (Ffuncall): If we attempt to call #'throw (now a special form) as a function, don't error, call #'obsolete-throw instead. * eval.c (make_multiple_value, multiple_value_aset) (multiple_value_aref, print_multiple_value, mark_multiple_value) (size_multiple_value): Implement the multiple_value type. Add a long comment describing our implementation. * eval.c (bind_multiple_value_limits): New function, used by the bytecode and by #'multiple-value-call, #'multiple-value-list-internal. * eval.c (multiple_value_call): New function, used by the bytecode and #'multiple-value-call. * eval.c (Fmultiple_value_call): New special form. * eval.c (multiple_value_list_internal): New function, used by the byte code and #'multiple-value-list-internal. * eval.c (Fmultiple_value_list_internal, Fmultiple_value_prog1): New special forms. * eval.c (Fvalues, Fvalues_list): New Lisp functions. * eval.c (values2): New function, for C code returning multiple values. * eval.c (syms_of_eval): Make our new Lisp functions and symbols available. * eval.c (multiple-values-limit): Make this available to Lisp. * event-msw.c (dde_eval_string): * event-stream.c (execute_help_form): * glade.c (connector): * glyphs-widget.c (glyph_instantiator_to_glyph): * glyphs.c (evaluate_xpm_color_symbols): * gui-x.c (wv_set_evalable_slot, button_item_to_widget_value): * gui.c (gui_item_value, gui_item_display_flush_left): * lread.c (check_if_suppressed): * menubar-gtk.c (menu_convert, menu_descriptor_to_widget_1): * menubar-msw.c (populate_menu_add_item): * print.c (Fwith_output_to_temp_buffer): * symbols.c (Fsetq_default): Ignore multiple values when calling Feval. * symeval.h: Add the header declarations necessary for the multiple-values implementation. * inline.c: #include symeval.h, now that it has some inline functions. * lisp.h: Update Fthrow's declaration. Make throw_or_bomb_out available to all files. * lrecord.h (enum lrecord_type): Add the multiple_value type here.

--- a/man/cl.texi	Sun Aug 16 14:58:57 2009 +0100
+++ b/man/cl.texi	Sun Aug 16 20:55:49 2009 +0100
@@ -249,9 +249,8 @@
 There is another file, @file{cl-compat.el}, which defines some
 routines from the older @file{cl.el} package that are no longer
 present in the new package.  This includes internal routines
-like @code{setelt} and @code{zip-lists}, deprecated features
-like @code{defkeyword}, and an emulation of the old-style
-multiple-values feature.  @xref{Old CL Compatibility}.
+like @code{setelt} and @code{zip-lists}, and deprecated features
+like @code{defkeyword}.  @xref{Old CL Compatibility}.
 
 @node Installation, Naming Conventions, Organization, Overview
 @section Installation
@@ -5345,14 +5344,6 @@
 The @code{loop} macro is complete except that @code{loop-finish}
 and type specifiers are unimplemented.
 
-The multiple-value return facility treats lists as multiple
-values, since Emacs Lisp cannot support multiple return values
-directly.  The macros will be compatible with Common Lisp if
-@code{values} or @code{values-list} is always used to return to
-a @code{multiple-value-bind} or other multiple-value receiver;
-if @code{values} is used without @code{multiple-value-@dots{}}
-or vice-versa the effect will be different from Common Lisp.
-
 Many Common Lisp declarations are ignored, and others match
 the Common Lisp standard in concept but not in detail.  For
 example, local @code{special} declarations, which are purely
@@ -5377,14 +5368,6 @@
 Following is a list of all known incompatibilities between this package
 and the older Quiroz @file{cl.el} package.
 
-This package's emulation of multiple return values in functions is
-incompatible with that of the older package.  That package attempted
-to come as close as possible to true Common Lisp multiple return
-values; unfortunately, it could not be 100% reliable and so was prone
-to occasional surprises if used freely.  This package uses a simpler
-method, namely replacing multiple values with lists of values, which
-is more predictable though more noticeably different from Common Lisp.
-
 The @code{defkeyword} form and @code{keywordp} function are not
 implemented in this package.
 
@@ -5449,19 +5432,6 @@
 use the more natural keyword argument processing offered by
 @code{defun*}.
 
-Multiple return values are treated differently by the two
-Common Lisp packages.  The old package's method was more
-compatible with true Common Lisp, though it used heuristics
-that caused it to report spurious multiple return values in
-certain cases.  The @code{cl-compat} package defines a set
-of multiple-value macros that are compatible with the old
-CL package; again, they are heuristic in nature, but they
-are guaranteed to work in any case where the old package's
-macros worked.  To avoid name collision with the ``official''
-multiple-value facilities, the ones in @code{cl-compat} have
-capitalized names:  @code{Values}, @code{Values-list},
-@code{Multiple-value-bind}, etc.
-
 The functions @code{cl-floor}, @code{cl-ceiling}, @code{cl-truncate},
 and @code{cl-round} are defined by @code{cl-compat} to use the
 old-style multiple-value mechanism, just as they did in the old