Issue 4797: Let the parser interpret alist variables

After

x.y = { c d e f }

this allows using

\x.y

instead of #(assoc-ref x 'y) in most places where the latter would work.

diff --git a/lily/parser.yy b/lily/parser.yy
index 29ecf1c3222f88e4d8a7b6325486d24c098fa605..62cf8301e34fa54b03f656d0a31bfb49fcc72bc4 100644 (file)
--- a/lily/parser.yy
+++ b/lily/parser.yy
@@ -119,6 +119,7 @@ FIXME:
 using namespace std;
 
 #include "book.hh"
+#include "context.hh"
 #include "context-def.hh"
 #include "context-mod.hh"
 #include "dimensions.hh"
@@ -353,6 +354,7 @@ If we give names, Bison complains.
 %token EVENT_IDENTIFIER
 %token EVENT_FUNCTION
 %token FRACTION
+%token LOOKUP_IDENTIFIER
 %token LYRIC_ELEMENT
 %token MARKUP_FUNCTION
 %token MARKUP_LIST_FUNCTION
@@ -492,6 +494,15 @@ toplevel_expression:
        }
        ;
 
+lookup:
+       LOOKUP_IDENTIFIER
+       | LOOKUP_IDENTIFIER '.' symbol_list_rev
+       {
+               $$ = loc_on_music (parser, @$,
+                                  nested_property ($1, scm_reverse_x ($3, SCM_EOL)));
+       }
+       ;
+
 embedded_scm_bare:
        SCM_TOKEN
        {
@@ -503,6 +514,7 @@ embedded_scm_bare:
 embedded_scm_active:
        SCM_IDENTIFIER
        | scm_function_call
+       | lookup
        ;
 
 embedded_scm_bare_arg:
@@ -520,6 +532,7 @@ embedded_scm_bare_arg:
        | book_block
        | bookpart_block
        | output_def
+       | lookup
        ;
 
 /* The generic version may end in music, or not */
@@ -527,6 +540,7 @@ embedded_scm_bare_arg:
 embedded_scm:
        embedded_scm_bare
        | scm_function_call
+       | lookup
        ;
 
 /* embedded_scm_arg is _not_ casting pitches to music by default, this
@@ -4034,8 +4048,12 @@ Lily_lexer::try_special_identifiers (SCM *destination, SCM sid)
        } else if (unsmob<Score> (sid)) {
                *destination = unsmob<Score> (sid)->clone ()->unprotect ();
                return SCM_IDENTIFIER;
+       } else if (scm_is_pair (sid)
+                  && scm_is_pair (scm_car (sid))
+                  && scm_is_symbol (scm_caar (sid))) {
+               *destination = sid;
+               return LOOKUP_IDENTIFIER;
        }
-
        return -1;
 }