[PATCH] Make multiple-values functions substs in 21.4

Hi Vin -- We’ve been running with Jerry’s code below in 21.5 since 2004, and it’s not on the face of it very risky. It is something I need for a 21.5 change I want to make, though, in order for the packages built with 21.4 to continue to not throw random errors with 21.5. The gory details are that I have added C support for multiple values, and if the package byte code tries to call #'values or #'multiple-value-list at runtime (which it does if #'values is implemented as an alias for #'list, for example), it will get inconsistent behaviour with itself on 21.5. If it uses the inline expansion, the functions themselves won’t be called at runtime. Best, Aidan 2009-08-09 Aidan Kehoe <kehoea(a)parhasard.net&gt; * cl.el (values): * cl.el (values-list): * cl.el (multiple-value-list): * cl.el (multiple-value-apply): * cl.el (multiple-value-call): * cl.el (nth-value): Make most of these defsubsts, not aliases, so the byte-code generated doesn't try to call #'values or #'multiple-value-list at runtime; now that these do useful things in 21.5, we need to avoid that if we want to compile code that will work there. --- lisp/cl.el~ 2004-06-22 02:49:47.001000000 +0100 +++ lisp/cl.el 2009-08-09 14:49:06.703125000 +0100 ＠＠ -248,12 +248,41 ＠＠ ;;; simulated. Instead, multiple-value-bind and friends simply expect ;;; the target form to return the values as a list. -(defalias 'values 'list) -(defalias 'values-list 'identity) -(defalias 'multiple-value-list 'identity) -(defalias 'multiple-value-call 'apply) ; only works for one arg -(defalias 'nth-value 'nth) +(defsubst values (&rest values) + "Return multiple values, Common Lisp style. +The arguments of `values' are the values +that the containing function should return." + values) + +(defsubst values-list (list) + "Return multiple values, Common Lisp style, taken from a list. +LIST specifies the list of values +that the containing function should return." + list) +(defsubst multiple-value-list (expression) + "Return a list of the multiple values produced by EXPRESSION. +This handles multiple values in Common Lisp style, but it does not +work right when EXPRESSION calls an ordinary Emacs Lisp function +that returns just one value." + expression) + +(defsubst multiple-value-apply (function expression) + "Evaluate EXPRESSION to get multiple values and apply FUNCTION to them. +This handles multiple values in Common Lisp style, but it does not work +right when EXPRESSION calls an ordinary Emacs Lisp function that returns just +one value." + (apply function expression)) + +(defalias 'multiple-value-call 'apply) ; only works for one arg; not + ; used in any of the packages. + +(defsubst nth-value (n expression) + "Evaluate EXPRESSION to get multiple values and return the Nth one. +This handles multiple values in Common Lisp style, but it does not work +right when EXPRESSION calls an ordinary Emacs Lisp function that returns just +one value." + (nth n expression)) ;;; Macros. -- hi there! -- ¿Dónde estará ahora mi sobrino Yoghurtu Nghe, que tuvo que huir precipitadamente de la aldea por culpa de la escasez de rinocerontes? _______________________________________________ XEmacs-Patches mailing list XEmacs-Patches(a)xemacs.org http://calypso.tux.org/cgi-bin/mailman/listinfo/xemacs-patches