caseq, caseql, casequal: improvement in expansion.

* eval.c (me_case): When a list of case keys is one
element long, reduce it to an atom. Then a simple
equality is applied whether the item is equal
to the key, rather than whether it is a member
of a list containing that one key.
This helps with the (t) case which is mandatory,
since t is ruled out as a key.

1 files changed, 3 insertions, 0 deletions

diff --git a/eval.c b/eval.c
index 31938f56..3f904e21 100644
--- a/eval.c
+++ b/eval.c
@@ -3665,6 +3665,9 @@ static val me_case(val form, val menv)
     if (keys == t)
       eval_error(form_orig, lit("~s: symbol t used as key"), casesym, nao);
 
+    if (consp(keys) && !cdr(keys))
+      keys = car(keys);
+
     if (star) {
       if (atom(keys))
         keys = eval(keys, nil, form);