Mercurial > hg > xemacs-beta
diff src/fns.c @ 5285:99de5fd48e87
Tighten up Common Lisp compatibility, #'butlast, #'nbutlast, #'tailp, #'ldiff
lisp/ChangeLog addition:
2010-10-14 Aidan Kehoe <kehoea@parhasard.net>
* byte-optimize.el (side-effect-free-fns):
* cl-macs.el (remf, getf):
* cl-extra.el (tailp, cl-set-getf, cl-do-remf):
* cl.el (ldiff, endp):
Tighten up Common Lisp compatibility for #'ldiff, #'endp, #'tailp;
add circularity checking for the first two.
#'cl-set-getf and #'cl-do-remf were Lisp implementations of
#'plist-put and #'plist-remprop; change the names to aliases,
changes the macros that use them to using #'plist-put and
#'plist-remprop directly.
src/ChangeLog addition:
2010-10-14 Aidan Kehoe <kehoea@parhasard.net>
* fns.c (Fnbutlast, Fbutlast):
Tighten up Common Lisp compatibility for these two functions; they
need to operate on dotted lists without erroring.
tests/ChangeLog addition:
2010-10-14 Aidan Kehoe <kehoea@parhasard.net>
* automated/lisp-tests.el (x):
Test #'nbutlast, #'butlast with dotted lists.
Check that #'ldiff and #'tailp don't hang on circular lists; check
that #'tailp returns t with circular lists when that is
appropriate. Test them both with dotted lists.
| author | Aidan Kehoe <kehoea@parhasard.net> |
|---|---|
| date | Thu, 14 Oct 2010 18:50:38 +0100 |
| parents | be436ac36ba4 |
| children | 28651c24b3f8 b9167d522a9a |
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line diff
--- a/src/fns.c Tue Oct 12 21:11:46 2010 +0100 +++ b/src/fns.c Thu Oct 14 18:50:38 2010 +0100 @@ -1570,72 +1570,99 @@ DEFUN ("nbutlast", Fnbutlast, 1, 2, 0, /* Modify LIST to remove the last N (default 1) elements. + If LIST has N or fewer elements, nil is returned and LIST is unmodified. +Otherwise, LIST may be dotted, but not circular. */ (list, n)) { - EMACS_INT int_n; + Elemcount int_n = 1; CHECK_LIST (list); - if (NILP (n)) - int_n = 1; - else + if (!NILP (n)) { CHECK_NATNUM (n); int_n = XINT (n); } - { - Lisp_Object last_cons = list; - - EXTERNAL_LIST_LOOP_1 (list) - { - if (int_n-- < 0) - last_cons = XCDR (last_cons); - } - - if (int_n >= 0) - return Qnil; - - XCDR (last_cons) = Qnil; - return list; - } + if (CONSP (list)) + { + Lisp_Object last_cons = list; + + EXTERNAL_LIST_LOOP_3 (elt, list, tail) + { + if (int_n-- < 0) + { + last_cons = XCDR (last_cons); + } + + if (!CONSP (XCDR (tail))) + { + break; + } + } + + if (int_n >= 0) + { + return Qnil; + } + + XCDR (last_cons) = Qnil; + } + + return list; } DEFUN ("butlast", Fbutlast, 1, 2, 0, /* Return a copy of LIST with the last N (default 1) elements removed. + If LIST has N or fewer elements, nil is returned. +Otherwise, LIST may be dotted, but not circular, and `(butlast LIST 0)' +converts a dotted into a true list. */ (list, n)) { - EMACS_INT int_n; + Lisp_Object retval = Qnil, retval_tail = Qnil; + Elemcount int_n = 1; CHECK_LIST (list); - if (NILP (n)) - int_n = 1; - else + if (!NILP (n)) { CHECK_NATNUM (n); int_n = XINT (n); } - { - Lisp_Object retval = Qnil; - Lisp_Object tail = list; - - EXTERNAL_LIST_LOOP_1 (list) - { - if (--int_n < 0) - { - retval = Fcons (XCAR (tail), retval); - tail = XCDR (tail); - } - } - - return Fnreverse (retval); - } + if (CONSP (list)) + { + Lisp_Object tail = list; + + EXTERNAL_LIST_LOOP_3 (elt, list, list_tail) + { + if (--int_n < 0) + { + if (NILP (retval_tail)) + { + retval = retval_tail = Fcons (XCAR (tail), Qnil); + } + else + { + XSETCDR (retval_tail, Fcons (XCAR (tail), Qnil)); + retval_tail = XCDR (retval_tail); + } + + tail = XCDR (tail); + } + + if (!CONSP (XCDR (list_tail))) + { + break; + } + } + } + + return retval; } DEFUN ("member", Fmember, 2, 2, 0, /*