Patch for strings.c

[Dirk Herrmann <dirk at ida dot ing dot tu-bs dot de>]

Hi!

Getting rid of another call to SCM_NIMP.  (OK, you may call this stupid,
but for me it's a way to look for chances for small improvements whenever 
my time allows.)

In function scm_string_append:
* Replaced call to SCM_NIMP with SCM_NNULLP.
* Added optional type check for rest arguments.
* Always report position of erroneous parameters.
* Minimized some variable scopes.
* Don't use register keyword.

However, unless GUILE_DEBUG is defined, the rest argument is not checked
to be a proper list.  This means, that if GUILE_DEBUG is not defined, 
guile could even crash when a user calls scm_string_append from C and
passes anything but a proper list as a rest argument.

Best regards
Dirk Herrmann


Index: strings.c
===================================================================
RCS file: /cvs/guile/guile/guile-core/libguile/strings.c,v
retrieving revision 1.24
diff -u -p -r1.24 strings.c
--- strings.c   2000/01/18 11:24:03     1.24
+++ strings.c   2000/01/25 18:36:48
@@ -321,31 +321,43 @@ SCM_DEFINE (scm_substring, "substring", 
 }
 #undef FUNC_NAME
 
+
 SCM_DEFINE (scm_string_append, "string-append", 0, 0, 1, 
            (SCM args),
            "")
 #define FUNC_NAME s_scm_string_append
 {
+  unsigned int arg_nr = 0;
+  unsigned long total_length = 0;
   SCM res;
-  register long i = 0;
-  register SCM l, s;
-  register unsigned char *data;
-  for (l = args;SCM_CONSP (l);) {
-    s = SCM_CAR (l);
-    SCM_VALIDATE_ROSTRING (SCM_ARGn,s);
-    i += SCM_ROLENGTH (s);
-    l = SCM_CDR (l);
+  SCM l;
+  unsigned char *data;
+
+#ifdef GUILE_DEBUG
+  if (scm_ilength(args) < 0)
+    SCM_MISC_ERROR("rest arguments do not form a proper list.");
+#endif /* GUILE_DEBUG */
+
+  for (l = args; SCM_NNULLP (l); l = SCM_CDR (l)) {
+    SCM arg;
+
+    ++arg_nr;
+    arg = SCM_CAR (l);
+    SCM_VALIDATE_ROSTRING (arg_nr, arg);
+    total_length += SCM_ROLENGTH (arg);
   }
-  SCM_ASSERT (SCM_NULLP (l), args, SCM_ARGn, FUNC_NAME);
-  res = scm_makstr (i, 0);
+  res = scm_makstr (total_length, 0);
   data = SCM_UCHARS (res);
-  for (l = args;SCM_NIMP (l);l = SCM_CDR (l)) {
-    s = SCM_CAR (l);
-    for (i = 0;i<SCM_ROLENGTH (s);i++) *data++ = SCM_ROUCHARS (s)[i];
+  for (l = args; SCM_NNULLP (l); l = SCM_CDR (l)) {
+    SCM s = SCM_CAR (l);
+    unsigned long pos = 0;
+    for (pos = 0; pos < SCM_ROLENGTH (s); pos++) 
+      *data++ = SCM_ROUCHARS (s)[pos];
   }
   return res;
 }
 #undef FUNC_NAME
+
 
 SCM_DEFINE (scm_make_shared_substring, "make-shared-substring", 1, 2, 0,
            (SCM str, SCM frm, SCM to),