core: Add member.

* src/lib.c (member): New function.
* module/mes/scm.mes (member): Remove.

module/mes/scm.mes

@@ -126,11 +126,6 @@
 
 (define memv memq)
 
-(define (member x lst)
-  (if (null? lst) #f
-      (if (equal? x (car lst)) lst
-          (member x (cdr lst)))))
-
 
 ;;; Lists
 (define (make-list n . x)

src/lib.c

@@ -312,3 +312,21 @@ equal2_p (SCM a, SCM b)
     }
   return eq_p (a, b);
 }
+
+SCM
+member (SCM x, SCM a)
+{
+  switch (TYPE (x))
+    {
+    case TCHAR:
+    case TNUMBER:
+    case TKEYWORD:
+    case TSYMBOL:
+    case TSPECIAL:
+      return memq (x, a);
+    default:
+      while (a != cell_nil && equal2_p (x, CAR (a)) != cell_t)
+        a = CDR (a);
+    }
+  return a != cell_nil ? a : cell_f;
+}