+void
+Output_def::set_variable (SCM sym, SCM val)
+{
+ scm_module_define (scope_, sym, val);
+}
+
+LY_DEFINE (ly_paper_lookup, "ly:output-def-lookup",
+ 2, 0, 0, (SCM pap, SCM sym),
+ "Lookup @var{sym} in @var{pap}. "
+ "Return the value or @code{'()} if undefined.")
+{
+ Output_def *op = unsmob_output_def (pap);
+ SCM_ASSERT_TYPE (op, pap, SCM_ARG1, __FUNCTION__, "Output_def");
+ SCM_ASSERT_TYPE (ly_c_symbol_p (sym), sym, SCM_ARG2, __FUNCTION__, "symbol");
+
+ return op->lookup_variable (sym);
+}
+
+LY_DEFINE (ly_output_def_scope, "ly:output-def-scope",
+ 1, 0,0, (SCM def),
+ "Get the variable scope inside @var{def}.")
+{
+ Output_def *op = unsmob_output_def (def);
+ SCM_ASSERT_TYPE (op, def, SCM_ARG1, __FUNCTION__, "Output definition");
+ return op->scope_;
+}
+
+
+LY_DEFINE (ly_output_def_parent, "ly:output-def-parent",
+ 1, 0, 0, (SCM def),
+ "Get the parent output-def of @var{def}.")
+{
+ Output_def *op = unsmob_output_def (def);
+ SCM_ASSERT_TYPE (op, def, SCM_ARG1, __FUNCTION__, "Output definition");
+ return op->parent_ ? op->parent_->self_scm () : SCM_EOL;
+}
+
+
+LY_DEFINE (ly_output_def_clone, "ly:output-def-clone",
+ 1, 0, 0, (SCM def),
+ "Clone @var{def}.")
+{
+ Output_def *op = unsmob_output_def (def);
+ SCM_ASSERT_TYPE (op, def, SCM_ARG1, __FUNCTION__, "Output definition");
+ SCM s = op->clone ()->self_scm ();
+ scm_gc_unprotect_object (s);
+ return s;
+}
+
+LY_DEFINE(ly_output_description, "ly:output-description",
+ 1,0,0,
+ (SCM output_def),
+ "Return the description of translators in @var{output-def}.")
+{
+ Output_def *id = unsmob_output_def (output_def);
+
+ SCM al =ly_module_to_alist (id->scope_);
+
+ SCM l = SCM_EOL;
+ for (SCM s = al ; ly_c_pair_p (s); s = ly_cdr (s))