From 66714074fd18d3483371c91441bf3f7df6a4cfb2 Mon Sep 17 00:00:00 2001
From: David Kastrup <dak@gnu.org>
Date: Sun, 12 Jul 2015 18:16:58 +0200
Subject: [PATCH] Issue 4505: Add partial \override and \set commands

This allows \set and \override commands to be stopped short after
their `=' sign in order to be used in the manner of partial music
functions.
---
 lily/parser.yy | 40 ++++++++++++++++++++++++++++++++++++++++
 1 file changed, 40 insertions(+)

diff --git a/lily/parser.yy b/lily/parser.yy
index 552d699d25..6fb3a8708b 100644
--- a/lily/parser.yy
+++ b/lily/parser.yy
@@ -717,6 +717,26 @@ partial_function:
 	{
 		$$ = scm_acons ($1, $2, SCM_EOL);
 	}
+	| OVERRIDE grob_prop_path '='
+	{
+		if (SCM_UNBNDP ($2))
+			$$ = scm_list_1 (SCM_BOOL_F);
+		else
+			$$ = scm_cons
+				(scm_list_3 (Syntax::property_override_function,
+					     scm_cdr ($2), scm_car ($2)),
+				 SCM_EOL);
+	}
+	| SET context_prop_spec '='
+	{
+		if (SCM_UNBNDP ($2))
+			$$ = scm_list_1 (SCM_BOOL_F);
+		else
+			$$ = scm_cons
+				(scm_list_3 (Syntax::property_set_function,
+					     scm_cadr ($2), scm_car ($2)),
+				 SCM_EOL);
+	}
 	| MUSIC_FUNCTION EXPECT_SCM function_arglist_optional partial_function
 	{
 		$$ = scm_acons ($1, $3, $4);
@@ -729,6 +749,26 @@ partial_function:
 	{
 		$$ = scm_acons ($1, $3, $4);
 	}
+	| OVERRIDE grob_prop_path '=' partial_function
+	{
+		if (SCM_UNBNDP ($2))
+			$$ = scm_list_1 (SCM_BOOL_F);
+		else
+			$$ = scm_cons
+				(scm_list_3 (Syntax::property_override_function,
+					     scm_cdr ($2), scm_car ($2)),
+				 $4);
+	}
+	| SET context_prop_spec '=' partial_function
+	{
+		if (SCM_UNBNDP ($2))
+			$$ = scm_list_1 (SCM_BOOL_F);
+		else
+			$$ = scm_cons
+				(scm_list_3 (Syntax::property_set_function,
+					     scm_cadr ($2), scm_car ($2)),
+				 $4);
+	}
 	| MUSIC_FUNCTION EXPECT_OPTIONAL EXPECT_SCM function_arglist_nonbackup partial_function
 	{
 		$$ = scm_acons ($1, $4, $5);
-- 
2.39.2