From bd47120c2a2f83f19a45abebf78b45d1af780519 Mon Sep 17 00:00:00 2001
From: David Kastrup <dak@gnu.org>
Date: Sun, 24 Jul 2011 22:02:51 +0200
Subject: [PATCH] parser.yy: rearrange to allow more lenient use of music
 arguments for music functions.

---
 lily/parser.yy | 80 ++++++++++++++++++--------------------------------
 1 file changed, 29 insertions(+), 51 deletions(-)

diff --git a/lily/parser.yy b/lily/parser.yy
index 6c45e59507..9c1e38db41 100644
--- a/lily/parser.yy
+++ b/lily/parser.yy
@@ -328,6 +328,7 @@ If we give names, Bison complains.
 %type <scm> composite_music
 %type <scm> grouped_music_list
 %type <scm> closed_music
+%type <scm> open_music
 %type <scm> music
 %type <scm> prefix_composite_music
 %type <scm> repeated_music
@@ -391,9 +392,8 @@ If we give names, Bison complains.
 %type <scm> full_markup_list
 %type <scm> function_scm_argument
 %type <scm> function_arglist
-%type <scm> function_arglist_music_last
-%type <scm> function_arglist_nonmusic_last
-%type <scm> function_arglist_nonmusic
+%type <scm> closed_function_arglist
+%type <scm> open_function_arglist
 %type <scm> identifier_init
 %type <scm> lilypond_header
 %type <scm> lilypond_header_body
@@ -413,7 +413,6 @@ If we give names, Bison complains.
 %type <scm> mode_changing_head
 %type <scm> mode_changing_head_with_context
 %type <scm> multiplied_duration
-%type <scm> music_function_identifier_musicless_prefix
 %type <scm> music_function_event
 %type <scm> music_function_chord_body
 %type <scm> new_chord
@@ -968,6 +967,7 @@ music_list:
 music:
 	simple_music
 	| composite_music
+	| MUSIC_IDENTIFIER
 	;
 
 alternative_music:
@@ -1007,7 +1007,6 @@ simultaneous_music:
 
 simple_music:
 	event_chord
-	| MUSIC_IDENTIFIER
 	| music_property_def
 	| context_change
 	;
@@ -1063,6 +1062,12 @@ closed_music:
 	| grouped_music_list
 	;
 
+/* Music that potentially accepts additional events or durations */
+open_music:
+	simple_music
+	| prefix_composite_music
+	;
+ 
 grouped_music_list:
 	simultaneous_music		{ $$ = $1; }
 	| sequential_music		{ $$ = $1; }
@@ -1077,13 +1082,22 @@ function_scm_argument:
  MUSIC_FUNCTION EXPECT_MUSIC EXPECT_SCM EXPECT_SCM EXPECT_NO_MORE_ARGS
 and this rule returns the reversed list of arguments. */
 
-function_arglist_music_last:
-	EXPECT_MUSIC function_arglist music {
+
+function_arglist:
+	closed_function_arglist
+	| open_function_arglist
+	;
+
+open_function_arglist:
+	EXPECT_MUSIC function_arglist open_music {
 		$$ = scm_cons ($3, $2);
 	}
 	;
 
-function_arglist_nonmusic_last:
+/* a closed argument list is one that does not end in a music
+   expression that could still take a duration or event */
+
+closed_function_arglist:
 	EXPECT_NO_MORE_ARGS {
 		/* This is for 0-ary functions, so they don't need to
 		   read a lookahead token */
@@ -1098,37 +1112,15 @@ function_arglist_nonmusic_last:
 	| EXPECT_PITCH function_arglist pitch {
 	  	$$ = scm_cons ($3, $2);
 	}
-	| EXPECT_DURATION function_arglist_nonmusic_last duration_length {
+	| EXPECT_DURATION closed_function_arglist duration_length {
 	   	$$ = scm_cons ($3, $2);
 	}
 	| EXPECT_SCM function_arglist function_scm_argument {
 		$$ = scm_cons ($3, $2);
 	}
-	;
-
-function_arglist_nonmusic: EXPECT_NO_MORE_ARGS {
-		$$ = SCM_EOL;
-	}
-	| EXPECT_MARKUP function_arglist_nonmusic full_markup {
-		$$ = scm_cons ($3, $2);
-	}
-	| EXPECT_MARKUP function_arglist_nonmusic simple_string {
+	| EXPECT_MUSIC function_arglist closed_music {
 		$$ = scm_cons ($3, $2);
-	}
-	| EXPECT_PITCH function_arglist_nonmusic pitch {
-	  	$$ = scm_cons ($3, $2);
-	}
-	| EXPECT_DURATION function_arglist_nonmusic duration_length {
-	   	$$ = scm_cons ($3, $2);
-	}
-	| EXPECT_SCM function_arglist_nonmusic function_scm_argument {
-		$$ = scm_cons ($3, $2);
-	}
-	;
-
-function_arglist:
-	function_arglist_music_last
-	| function_arglist_nonmusic_last
+		}
 	;
 
 generic_prefix_music_scm:
@@ -1583,35 +1575,21 @@ chord_body_element:
 	}
 	;
 
-music_function_identifier_musicless_prefix: MUSIC_FUNCTION {
-		SCM sig = scm_object_property (yylval.scm, ly_symbol2scm ("music-function-signature"));
-		if (scm_is_pair (sig) && to_boolean (scm_memq (ly_music_p_proc, scm_cdr (scm_reverse (sig)))))
-		{
-			PARSER->parser_error (@$, "Music function applied to event may not have a Music argument, except as the last argument.");
-		}
-	}
-	;
 
 music_function_chord_body:
-	/* We could allow chord functions to have multiple music arguments,
-	   but it's more consistent with music_function_event if we
-	   prohibit it here too */
-	music_function_identifier_musicless_prefix EXPECT_MUSIC function_arglist_nonmusic chord_body_element {
+	MUSIC_FUNCTION EXPECT_MUSIC function_arglist chord_body_element {
 		$$ = scm_cons ($1, scm_cons (make_input (@$), scm_reverse_x ($3, scm_list_1 ($4))));
 	}
-	| music_function_identifier_musicless_prefix function_arglist_nonmusic {
+	| MUSIC_FUNCTION closed_function_arglist {
 		$$ = scm_cons ($1, scm_cons (make_input (@$), scm_reverse_x ($2, SCM_EOL)));
 	}
 	;
 
 music_function_event:
-	/* Post-events can only have the last argument as music, without this
-	   restriction we get a shift/reduce conflict from e.g.
-	   c8-\partcombine c8 -. */
-	music_function_identifier_musicless_prefix EXPECT_MUSIC function_arglist_nonmusic post_event {
+	MUSIC_FUNCTION EXPECT_MUSIC closed_function_arglist post_event {
 		$$ = scm_cons ($1, scm_cons (make_input (@$), scm_reverse_x ($3, scm_list_1 ($4))));
 	}
-	| music_function_identifier_musicless_prefix function_arglist_nonmusic {
+	| MUSIC_FUNCTION closed_function_arglist {
 		$$ = scm_cons ($1, scm_cons (make_input (@$), scm_reverse_x ($2, SCM_EOL)));
 	}
 	;
-- 
2.39.5