+
+String
+print_scm_val (SCM val)
+{
+ String realval = ly_scm2string (ly_write2scm (val));
+ if (realval.length_i () > 200)
+ realval = realval.left_str (100) + "\n :\n :\n" + realval.right_str (100);
+
+ return realval;
+}
+
+bool
+type_check_assignment (SCM sym, SCM val, SCM type_symbol)
+{
+ bool ok = true;
+
+ /*
+ Always succeeds.
+
+
+ TODO: should remove #f from allowed vals?
+ */
+ if (val == SCM_EOL || val == SCM_BOOL_F)
+ return ok;
+
+
+ SCM type_p = SCM_EOL;
+
+ if (gh_symbol_p (sym))
+ type_p = scm_object_property (sym, type_symbol);
+
+ if (type_p != SCM_EOL && !gh_procedure_p (type_p))
+ {
+ warning (_f ("Can't find property type-check for `%s' (%s). Perhaps you made a typing error? Doing assignment anyway.",
+ ly_symbol2string (sym).ch_C (),
+ ly_symbol2string (type_symbol).ch_C ()
+
+ ));
+ }
+ else
+ {
+ if (val != SCM_EOL
+ && gh_procedure_p (type_p)
+ && gh_call1 (type_p, val) == SCM_BOOL_F)
+ {
+ SCM errport = scm_current_error_port ();
+ ok = false;
+ SCM typefunc = scm_primitive_eval (ly_symbol2scm ("type-name"));
+ SCM type_name = gh_call1 (typefunc, type_p);
+
+
+ scm_puts (_f ("Type check for `%s' failed; value `%s' must be of type `%s'",
+ ly_symbol2string (sym).ch_C (),
+ print_scm_val (val),
+ ly_scm2string (type_name).ch_C ()).ch_C (),
+ errport);
+ scm_puts ("\n", errport);
+ }
+ }
+ return ok;
+}
+
+
+/* some SCM abbrevs
+
+ zijn deze nou handig?
+ zijn ze er al in scheme, maar heten ze anders? */
+
+
+/* Remove doubles from (sorted) list */
+SCM
+ly_unique (SCM list)
+{
+ SCM unique = SCM_EOL;
+ for (SCM i = list; gh_pair_p (i); i = ly_cdr (i))
+ {
+ if (!gh_pair_p (ly_cdr (i))
+ || !gh_equal_p (ly_car (i), ly_cadr (i)))
+ unique = gh_cons (ly_car (i), unique);
+ }
+ return scm_reverse_x (unique, SCM_EOL);
+}
+
+/* tail add */
+SCM
+ly_snoc (SCM s, SCM list)
+{
+ return gh_append2 (list, scm_list_n (s, SCM_UNDEFINED));
+}
+
+
+/* Split list at member s, removing s.
+ Return (BEFORE . AFTER) */
+SCM
+ly_split_list (SCM s, SCM list)
+{
+ SCM before = SCM_EOL;
+ SCM after = list;
+ for (; gh_pair_p (after);)
+ {
+ SCM i = ly_car (after);
+ after = ly_cdr (after);
+ if (gh_equal_p (i, s))
+ break;
+ before = gh_cons (i, before);
+ }
+ return gh_cons ( scm_reverse_x (before, SCM_EOL), after);
+
+}
+