Changing type function to not blow up on nil, which makes a lot of code

simpler. A pseudo type code is introduced called NIL with value 0.

* lib.h (enum type): New enumeration value, NIL.
(type): Function accepts object nil and maps it to code NIL.

* eval.c (dwim_loc, op_dwim): test for nil obj and goto hack is gone,
just handle NIL in the switch.

* gc.c (make_obj, mark): Handle new NIL type code in switch.

* hash.c (equal_hash): Handle NIL in the switch instead of nil test.

* lib.c (code2type): Map new NIL type code to null.
(typeof, typecheck): Code simplified.
(class_check, car): Move nil test into switch.
(eql, equal, consp, bignump, stringp, lazy_stringp,
symbolp, functionp, vectorp, cobjp): Simplified.
(length, sub, ref, refset, replace, obj_print, obj_pprint): Handle NIL
in switch instead of nil test.  goto hack removed from refset.

* match.c (do_match_line, do_output_line): switch condition simplified.

* regex.c (regexp): Simplified.
(regex_nfa): Assert condition simplified.

1 files changed, 2 insertions, 2 deletions

diff --git a/match.c b/match.c
index f381dcd4..cad32714 100644
--- a/match.c
+++ b/match.c
@@ -1112,7 +1112,7 @@ static val do_match_line(match_line_ctx *c, val completely)
     debug_check(elem, c->bindings, c->dataline, c->data_lineno,
                 c->pos, c->base);
 
-    switch (elem ? type(elem) : 0) {
+    switch (type(elem)) {
     case CONS: /* directive */
       {
         val directive = first(elem);
@@ -1583,7 +1583,7 @@ static void do_output_line(val bindings, val specline, val filter, val out)
   for (; specline; specline = rest(specline)) {
     val elem = first(specline);
 
-    switch (elem ? type(elem) : 0) {
+    switch (type(elem)) {
     case CONS:
       {
         val directive = first(elem);