parser.yy et al: implement optional arguments for music functions

diff --git a/lily/lexer.ll b/lily/lexer.ll
index 8a07f1b2c00e64cd74208bdc6fdffc479b711746..e88ed791c4eb55383a55c6219b404eca83131559 100644 (file)
--- a/lily/lexer.ll
+++ b/lily/lexer.ll
@@ -828,7 +828,14 @@ Lily_lexer::scan_escaped_word (string str)
                push_extra_token (EXPECT_NO_MORE_ARGS);
                for (s = scm_cdr (s); scm_is_pair (s); s = scm_cdr (s))
                {
+                       SCM optional = SCM_UNDEFINED;
                        cs = scm_car (s);
+
+                       if (scm_is_pair (cs))
+                       {
+                               optional = SCM_CDR (cs);
+                               cs = SCM_CAR (cs);
+                       }
                        
                        if (cs == ly_music_p_proc)
                                push_extra_token (EXPECT_MUSIC);
@@ -840,7 +847,13 @@ Lily_lexer::scan_escaped_word (string str)
                                push_extra_token (EXPECT_MARKUP);
                        else if (ly_is_procedure (cs))
                                push_extra_token (EXPECT_SCM);
-                       else programming_error ("Function parameter without type-checking predicate");
+                       else
+                       {
+                               programming_error ("Function parameter without type-checking predicate");
+                               continue;
+                       }
+                       if (!scm_is_eq (optional, SCM_UNDEFINED))
+                               push_extra_token (EXPECT_OPTIONAL, optional);
                }
                return funtype;
        }

diff --git a/lily/parser.yy b/lily/parser.yy
index c34c4acee4e7de013a7b6a8097b54250fec5de58..a74587fd0efaf98f005d3b9108ff1a1ae0d78cdb 100644 (file)
--- a/lily/parser.yy
+++ b/lily/parser.yy
@@ -43,9 +43,6 @@ of the parse stack onto the heap. */
 %left PREC_BOT
 %nonassoc REPEAT
 %nonassoc ALTERNATIVE
-%left ADDLYRICS
-%left PREC_TOP
-
 
 /* The above precedences tackle the shift/reduce problem
 
@@ -59,6 +56,20 @@ or
     \repeat { \repeat } \alternative
 */
 
+%right FUNCTION_ARGUMENTS
+      MARKUP LYRICS_STRING MARKUP_IDENTIFIER STRING STRING_IDENTIFIER
+      SEQUENTIAL SIMULTANEOUS DOUBLE_ANGLE_OPEN MUSIC_IDENTIFIER '{'
+      PITCH_IDENTIFIER NOTENAME_PITCH TONICNAME_PITCH
+      SCM_FUNCTION SCM_IDENTIFIER SCM_TOKEN
+      UNSIGNED DURATION_IDENTIFIER
+
+ /* The above are the symbols that can start function arguments */
+
+%left ADDLYRICS
+%left PREC_TOP
+
+
+
 
 %pure_parser
 %locations
@@ -270,6 +281,7 @@ If we give names, Bison complains.
 %token <i> EXPECT_DURATION "ly:duration?"
 %token <i> EXPECT_SCM "scheme?"
 %token <i> EXPECT_MARKUP_LIST "markup-list?"
+%token <scm> EXPECT_OPTIONAL "optional?"
 /* After the last argument. */
 %token <i> EXPECT_NO_MORE_ARGS;
 
@@ -402,8 +414,12 @@ If we give names, Bison complains.
 %type <scm> full_markup
 %type <scm> full_markup_list
 %type <scm> function_arglist
+%type <scm> function_arglist_optional
+%type <scm> function_arglist_keep
 %type <scm> function_arglist_bare
 %type <scm> function_arglist_closed
+%type <scm> function_arglist_closed_optional
+%type <scm> function_arglist_closed_keep
 %type <scm> identifier_init
 %type <scm> lilypond
 %type <scm> lilypond_header
@@ -1114,24 +1130,133 @@ and this rule returns the reversed list of arguments. */
 
 function_arglist:
        function_arglist_bare
-       | EXPECT_MUSIC function_arglist music {
+       | EXPECT_MUSIC function_arglist_optional music
+       {
+               $$ = scm_cons ($3, $2);
+       }
+       | EXPECT_SCM function_arglist_optional embedded_scm
+       {
                $$ = scm_cons ($3, $2);
        }
-       | EXPECT_SCM function_arglist embedded_scm {
-               $$ = scm_cons ($3, $2);
+       ;
+
+function_arglist_optional:
+       function_arglist_keep %prec FUNCTION_ARGUMENTS
+       | EXPECT_OPTIONAL EXPECT_MUSIC function_arglist_optional
+       {
+               $$ = scm_cons ($1, $3);
+       }
+       | EXPECT_OPTIONAL EXPECT_PITCH function_arglist_optional
+       {
+               $$ = scm_cons ($1, $3);
+       }
+       | EXPECT_OPTIONAL EXPECT_DURATION function_arglist_optional
+       {
+               $$ = scm_cons ($1, $3);
+       }
+       | EXPECT_OPTIONAL EXPECT_MARKUP function_arglist_optional
+       {
+               $$ = scm_cons ($1, $3);
+       }
+       | EXPECT_OPTIONAL EXPECT_SCM function_arglist_optional
+       {
+               $$ = scm_cons ($1, $3);
+       }
+       ;
+
+function_arglist_keep:
+       EXPECT_OPTIONAL EXPECT_MARKUP function_arglist_keep full_markup {
+               $$ = scm_cons ($4, $3);
+       }
+       | EXPECT_OPTIONAL EXPECT_MARKUP function_arglist_keep simple_string {
+               $$ = scm_cons ($4, $3);
+       }
+       | EXPECT_OPTIONAL EXPECT_PITCH function_arglist_keep pitch_also_in_chords {
+               $$ = scm_cons ($4, $3);
+       }
+       | EXPECT_OPTIONAL EXPECT_DURATION function_arglist_closed_keep duration_length {
+               $$ = scm_cons ($4, $3);
+       }
+       | EXPECT_OPTIONAL EXPECT_SCM function_arglist_keep simple_string
+       {
+               $$ = scm_cons ($4, $3);
+       }
+       | EXPECT_OPTIONAL EXPECT_MUSIC function_arglist_keep closed_music
+       {
+               $$ = scm_cons ($4, $3);
+       }
+       | EXPECT_OPTIONAL EXPECT_SCM function_arglist_keep embedded_scm
+       {
+               $$ = scm_cons ($4, $3);
        }
+       | function_arglist
        ;
 
+
 function_arglist_closed:
        function_arglist_bare
-       | EXPECT_MUSIC function_arglist closed_music {
+       | EXPECT_MUSIC function_arglist_optional closed_music
+       {
                $$ = scm_cons ($3, $2);
        }
-       | EXPECT_SCM function_arglist embedded_scm_closed {
-               $$ = scm_cons ($3, $2);
+       | EXPECT_SCM function_arglist_optional embedded_scm_closed
+       {
+               $$ = scm_cons ($3, $2);
+       }
+       ;
+
+function_arglist_closed_optional:
+       function_arglist_closed_keep %prec FUNCTION_ARGUMENTS
+       | EXPECT_OPTIONAL EXPECT_MUSIC function_arglist_closed_optional
+       {
+               $$ = scm_cons ($1, $3);
+       }
+       | EXPECT_OPTIONAL EXPECT_PITCH function_arglist_closed_optional
+       {
+               $$ = scm_cons ($1, $3);
+       }
+       | EXPECT_OPTIONAL EXPECT_DURATION function_arglist_closed_optional
+       {
+               $$ = scm_cons ($1, $3);
+       }
+       | EXPECT_OPTIONAL EXPECT_MARKUP function_arglist_closed_optional
+       {
+               $$ = scm_cons ($1, $3);
+       }
+       | EXPECT_OPTIONAL EXPECT_SCM function_arglist_closed_optional
+       {
+               $$ = scm_cons ($1, $3);
        }
        ;
 
+function_arglist_closed_keep:
+       EXPECT_OPTIONAL EXPECT_MARKUP function_arglist_keep full_markup {
+               $$ = scm_cons ($4, $3);
+       }
+       | EXPECT_OPTIONAL EXPECT_MARKUP function_arglist_keep simple_string {
+               $$ = scm_cons ($4, $3);
+       }
+       | EXPECT_OPTIONAL EXPECT_PITCH function_arglist_keep pitch_also_in_chords {
+               $$ = scm_cons ($4, $3);
+       }
+       | EXPECT_OPTIONAL EXPECT_DURATION function_arglist_closed_keep duration_length {
+               $$ = scm_cons ($4, $3);
+       }
+       | EXPECT_OPTIONAL EXPECT_SCM function_arglist_keep simple_string
+       {
+               $$ = scm_cons ($4, $3);
+       }
+       | EXPECT_OPTIONAL EXPECT_MUSIC function_arglist_keep closed_music
+       {
+               $$ = scm_cons ($4, $3);
+       }
+       | EXPECT_OPTIONAL EXPECT_SCM function_arglist_keep embedded_scm_closed
+       {
+               $$ = scm_cons ($4, $3);
+       }
+       | function_arglist_closed
+       ;
+
 embedded_scm_closed:
        embedded_scm_bare
        | scm_function_call_closed
@@ -1146,24 +1271,22 @@ scm_function_call_closed:
 
 function_arglist_bare:
        EXPECT_NO_MORE_ARGS {
-               /* This is for 0-ary functions, so they don't need to
-                  read a lookahead token */
                $$ = SCM_EOL;
        }
-       | EXPECT_MARKUP function_arglist full_markup {
+       | EXPECT_MARKUP function_arglist_optional full_markup {
                $$ = scm_cons ($3, $2);
        }
-       | EXPECT_MARKUP function_arglist simple_string {
+       | EXPECT_MARKUP function_arglist_optional simple_string {
                $$ = scm_cons ($3, $2);
        }
-       | EXPECT_PITCH function_arglist pitch_also_in_chords {
-               $$ = scm_cons ($3, $2);
+       | EXPECT_PITCH function_arglist_optional pitch_also_in_chords {
+               $$ = scm_cons ($3, $2);
        }
-       | EXPECT_DURATION function_arglist_closed duration_length {
-               $$ = scm_cons ($3, $2);
+       | EXPECT_DURATION function_arglist_closed_optional duration_length {
+               $$ = scm_cons ($3, $2);
        }
-       | EXPECT_SCM function_arglist simple_string {
-               $$ = scm_cons ($3, $2);
+       | EXPECT_SCM function_arglist_optional simple_string {
+               $$ = scm_cons ($3, $2);
        }
        ;
 
@@ -1635,7 +1758,7 @@ music_function_chord_body_arglist:
        | EXPECT_MUSIC music_function_chord_body_arglist chord_body_element {
                $$ = scm_cons ($3, $2);
        }
-       | EXPECT_SCM function_arglist embedded_scm_chord_body {
+       | EXPECT_SCM function_arglist_optional embedded_scm_chord_body {
                $$ = scm_cons ($3, $2);
        }
        ;
@@ -1665,7 +1788,7 @@ music_function_event_arglist:
        | EXPECT_MUSIC music_function_event_arglist post_event {
                $$ = scm_cons ($3, $2);
        }
-       | EXPECT_SCM function_arglist embedded_scm_event {
+       | EXPECT_SCM function_arglist_optional embedded_scm_event {
                $$ = scm_cons ($3, $2);
        }
        ;

diff --git a/scm/lily.scm b/scm/lily.scm
index 6230940860ab2edb66e4998e8367f1c07acfc832..ec7aebfd4348712ada0b21ca30ed0edbd5528aeb 100644 (file)
--- a/scm/lily.scm
+++ b/scm/lily.scm
@@ -350,6 +350,8 @@ messages into errors.")
 Print a message at LOCATION if any predicate failed."
   (define (recursion-helper signature arguments count)
     (define (helper pred? arg count)
+      (if (pair? pred?)
+         (set! pred? (car pred?)))
       (if (not (pred? arg))
           (begin
             (ly:input-warning