parser.yy: Use precedences to remove REPEAT/ALTERNATIVE shift/reduce problem

diff --git a/lily/parser.yy b/lily/parser.yy
index df3cd1a58486806ff4e95be24ee83bb718733df0..3a966f13cf31912141f3479554359333a17c31ef 100644 (file)
--- a/lily/parser.yy
+++ b/lily/parser.yy
@@ -40,13 +40,14 @@
 deleting them.  Let's hope that a stack overflow doesnt trigger a move
 of the parse stack onto the heap. */
 
-%left PREC_TOP
-%left ADDLYRICS
 %left PREC_BOT
+%nonassoc REPEAT
+%nonassoc ALTERNATIVE
+%left ADDLYRICS
+%left PREC_TOP
 
-%expect 1
 
-/* One shift/reduce problem
+/* The above precedences tackle the shift/reduce problem
 
 1.  \repeat
        \repeat .. \alternative
@@ -327,6 +328,7 @@ If we give names, Bison complains.
 /* Music */
 %type <scm> composite_music
 %type <scm> grouped_music_list
+%type <scm> braced_music_list
 %type <scm> closed_music
 %type <scm> music
 %type <scm> prefix_composite_music
@@ -364,7 +366,6 @@ If we give names, Bison complains.
 %type <outputdef> output_def
 %type <outputdef> paper_block
 
-%type <scm> alternative_music
 %type <scm> generic_prefix_music_scm
 %type <scm> music_list
 %type <scm> absolute_pitch
@@ -996,41 +997,43 @@ music_list:
        }
        ;
 
+braced_music_list:
+       '{' music_list '}'
+       {
+               $$ = scm_reverse_x ($2, SCM_EOL);
+       }
+       ;
+
 music:
        simple_music
        | composite_music
        | MUSIC_IDENTIFIER
        ;
 
-alternative_music:
-       /* empty */ {
-               $$ = SCM_EOL;
-       }
-       | ALTERNATIVE '{' music_list '}' {
-               $$ = scm_reverse_x ($3, SCM_EOL);
-       }
-       ;
-
 
 repeated_music:
-       REPEAT simple_string unsigned_number music alternative_music
+       REPEAT simple_string unsigned_number music
+       {
+               $$ = MAKE_SYNTAX ("repeat", @$, $2, $3, $4, SCM_EOL);
+       }
+       | REPEAT simple_string unsigned_number music ALTERNATIVE braced_music_list
        {
-               $$ = MAKE_SYNTAX ("repeat", @$, $2, $3, $4, $5);
+               $$ = MAKE_SYNTAX ("repeat", @$, $2, $3, $4, $6);
        }
        ;
 
 sequential_music:
-       SEQUENTIAL '{' music_list '}'           {
-               $$ = MAKE_SYNTAX ("sequential-music", @$, scm_reverse_x ($3, SCM_EOL));
+       SEQUENTIAL braced_music_list {
+               $$ = MAKE_SYNTAX ("sequential-music", @$, $2);
        }
-       | '{' music_list '}'            {
-               $$ = MAKE_SYNTAX ("sequential-music", @$, scm_reverse_x ($2, SCM_EOL));
+       | braced_music_list {
+               $$ = MAKE_SYNTAX ("sequential-music", @$, $1);
        }
        ;
 
 simultaneous_music:
-       SIMULTANEOUS '{' music_list '}'{
-               $$ = MAKE_SYNTAX ("simultaneous-music", @$, scm_reverse_x ($3, SCM_EOL));
+       SIMULTANEOUS braced_music_list {
+               $$ = MAKE_SYNTAX ("simultaneous-music", @$, $2);
        }
        | DOUBLE_ANGLE_OPEN music_list DOUBLE_ANGLE_CLOSE       {
                $$ = MAKE_SYNTAX ("simultaneous-music", @$, scm_reverse_x ($2, SCM_EOL));