From e510ecfca199f22128477250d8848a9c65a7a15f Mon Sep 17 00:00:00 2001
From: David Kastrup <dak@gnu.org>
Date: Fri, 26 Oct 2012 14:34:43 +0200
Subject: [PATCH] Issue 2931: Allow non-LilyPond identifiers like "violin1" to
 be called as \"violin1"

A frequent complaint is the absence of identifiers with numbers in
them, like violin1.

Defining such identifiers has always been possible with

    "violin1" = { c''4 c c c }

This patch lets one actually use them by calling them as

    \"violin1"
---
 lily/lexer.ll | 39 ++++++++++++++++++++++++++++++++++-----
 1 file changed, 34 insertions(+), 5 deletions(-)

diff --git a/lily/lexer.ll b/lily/lexer.ll
index e896de3d63..9a859e5a6a 100644
--- a/lily/lexer.ll
+++ b/lily/lexer.ll
@@ -91,6 +91,15 @@ bool is_valid_version (string s);
                 yylval = SCM_EOL;               \
         } while (0)
 
+/*
+  The inside of \"violin1" is marked by commandquote mode
+*/
+
+#define start_command_quote() do {		\
+                yy_push_state (commandquote);	\
+                yylval = SCM_EOL;               \
+        } while (0)
+
 #define yylval (*lexval_)
 
 #define yylloc (*lexloc_)
@@ -124,6 +133,7 @@ SCM (* scm_parse_error_handler) (void *);
 %x markup
 %x notes
 %x quote
+%x commandquote
 %x sourcefileline
 %x sourcefilename
 %x version
@@ -503,7 +513,9 @@ BOM_UTF8	\357\273\277
 	{WORD}	{
 		return scan_bare_word (YYText_utf8 ());
 	}
-
+	\\\"	{
+		start_command_quote ();
+	}
 	{COMMAND}/[-_]	| // backup rule
 	{COMMAND}	{
 		return scan_escaped_word (YYText_utf8 () + 1); 
@@ -527,7 +539,7 @@ BOM_UTF8	\357\273\277
 	}
 }
 
-<quote>{
+<quote,commandquote>{
 	\\{ESCAPED}	{
                 char c = escaped_char (YYText ()[1]);
 		yylval = scm_cons (scm_from_locale_stringn (&c, 1),
@@ -539,14 +551,19 @@ BOM_UTF8	\357\273\277
 	}
 	\"	{
 
-		yy_pop_state ();
-
 		/* yylval is union. Must remember STRING before setting SCM*/
 
                 yylval = scm_string_concatenate_reverse (yylval,
                                                          SCM_UNDEFINED,
                                                          SCM_UNDEFINED);
 
+		if (get_state () == commandquote) {
+			yy_pop_state ();
+			return scan_escaped_word (ly_scm2string (yylval));
+		}
+
+		yy_pop_state ();
+
 		return STRING;
 	}
 	\\	{
@@ -572,6 +589,9 @@ BOM_UTF8	\357\273\277
 		yylval = scm_c_read_string (YYText ());
 		return UNSIGNED;
 	}
+	\\\"	{
+		start_command_quote ();
+	}
 	{COMMAND}/[-_]	| // backup rule
 	{COMMAND}	{
 		return scan_escaped_word (YYText_utf8 () + 1);
@@ -609,6 +629,9 @@ BOM_UTF8	\357\273\277
 	{WORD}	{
 		return scan_bare_word (YYText_utf8 ());
 	}
+	\\\"	{
+		start_command_quote ();
+	}
 	{COMMAND}/[-_]	| // backup rule
 	{COMMAND}	{
 		return scan_escaped_word (YYText_utf8 () + 1);
@@ -650,6 +673,9 @@ BOM_UTF8	\357\273\277
                 yylval = SCM_UNSPECIFIED;
 		return SCORE;
 	}
+	\\\"	{
+		start_command_quote ();
+	}
 	{COMMAND}/[-_]	| // backup rule
 	{COMMAND} {
 		string str (YYText_utf8 () + 1);
@@ -718,7 +744,7 @@ BOM_UTF8	\357\273\277
 		yy_pop_state ();
 	}
 
-<quote><<EOF>> {
+<quote,commandquote><<EOF>> {
 	LexerError (_ ("EOF found inside string").c_str ());
 	yy_pop_state ();
 }
@@ -763,6 +789,9 @@ BOM_UTF8	\357\273\277
 	{WORD}	{
 		return scan_bare_word (YYText_utf8 ());
 	}
+	\\\"	{
+		start_command_quote ();
+	}
 	{COMMAND}/[-_]	| // backup rule
 	{COMMAND}	{
 		return scan_escaped_word (YYText_utf8 () + 1);
-- 
2.39.5