parser.yy: simplify intermediate structure of music_list

diff --git a/lily/parser.yy b/lily/parser.yy
index 2a4032e4bf65ba3faa46f047454d3b0949b16a23..27b158cc536ca24c15a3f145c699fd02f0d9fe68 100644 (file)
--- a/lily/parser.yy
+++ b/lily/parser.yy
@@ -928,25 +928,14 @@ tempo_event:
        ;
 
 /*
-The representation of a  list is the
-
-  (LIST . LAST-CONS)
-
- to have efficient append.  */
+The representation of a  list is reversed to have efficient append.  */
 
 music_list:
        /* empty */ {
-               $$ = scm_cons (SCM_EOL, SCM_EOL);
+               $$ = SCM_EOL;
        }
        | music_list music {
-               SCM s = $$;
-               SCM c = scm_cons ($2, SCM_EOL);
-
-               if (scm_is_pair (scm_cdr (s)))
-                       scm_set_cdr_x (scm_cdr (s), c); /* append */
-               else
-                       scm_set_car_x (s, c); /* set first cons */
-               scm_set_cdr_x (s, c);  /* remember last cell */
+               $$ = scm_cons ($2, $1);
        }
        | music_list embedded_scm {
 
@@ -955,15 +944,8 @@ music_list:
                Music *m = MY_MAKE_MUSIC("Music", @$);
                // ugh. code dup
                m->set_property ("error-found", SCM_BOOL_T);
-               SCM s = $$;
-               SCM c = scm_cons (m->self_scm (), SCM_EOL);
+               $$ = scm_cons (m->self_scm (), $1);
                m->unprotect (); /* UGH */
-
-               if (scm_is_pair (scm_cdr (s)))
-                       scm_set_cdr_x (scm_cdr (s), c); /* append */
-               else
-                       scm_set_car_x (s, c); /* set first cons */
-               scm_set_cdr_x (s, c);  /* remember last cell */
        }
        ;
 
@@ -978,7 +960,7 @@ alternative_music:
                $$ = SCM_EOL;
        }
        | ALTERNATIVE '{' music_list '}' {
-               $$ = scm_car ($3);
+               $$ = scm_reverse_x ($3, SCM_EOL);
        }
        ;
 
@@ -992,19 +974,19 @@ repeated_music:
 
 sequential_music:
        SEQUENTIAL '{' music_list '}'           {
-               $$ = MAKE_SYNTAX ("sequential-music", @$, scm_car ($3));
+               $$ = MAKE_SYNTAX ("sequential-music", @$, scm_reverse_x ($3, SCM_EOL));
        }
        | '{' music_list '}'            {
-               $$ = MAKE_SYNTAX ("sequential-music", @$, scm_car ($2));
+               $$ = MAKE_SYNTAX ("sequential-music", @$, scm_reverse_x ($2, SCM_EOL));
        }
        ;
 
 simultaneous_music:
        SIMULTANEOUS '{' music_list '}'{
-               $$ = MAKE_SYNTAX ("simultaneous-music", @$, scm_car ($3));
+               $$ = MAKE_SYNTAX ("simultaneous-music", @$, scm_reverse_x ($3, SCM_EOL));
        }
        | DOUBLE_ANGLE_OPEN music_list DOUBLE_ANGLE_CLOSE       {
-               $$ = MAKE_SYNTAX ("simultaneous-music", @$, scm_car ($2));
+               $$ = MAKE_SYNTAX ("simultaneous-music", @$, scm_reverse_x ($2, SCM_EOL));
        }
        ;