lexer.ll: Introduce Scheme functions

[lilypond.git] / scm / ly-syntax-constructors.scm

diff --git a/scm/ly-syntax-constructors.scm b/scm/ly-syntax-constructors.scm
index 82aee84d0a7190b1a9c0cdcec230f933d00d483b..540cc24d741ec655faebb126f7a19d841a3db496 100644 (file)
--- a/scm/ly-syntax-constructors.scm
+++ b/scm/ly-syntax-constructors.scm
@@ -1,6 +1,6 @@
 ;;;; This file is part of LilyPond, the GNU music typesetter.
 ;;;;
-;;;; Copyright (C) 2006--2010 Erik Sandberg <mandolaerik@gmail.com>
+;;;; Copyright (C) 2006--2011 Erik Sandberg <mandolaerik@gmail.com>
 ;;;;
 ;;;; LilyPond is free software: you can redistribute it and/or modify
 ;;;; it under the terms of the GNU General Public License as published by
@@ -17,7 +17,8 @@
 
 ;; TODO: use separate module for syntax
 ;; constructors. Also create wrapper around the constructor?
-(define define-ly-syntax define-public)
+(defmacro define-ly-syntax (args . body)
+  `(define-public ,args ,(cons 'begin body)))
 
 ;; A ly-syntax constructor takes two extra parameters, parser and
 ;; location. These are mainly used for reporting errors and
@@ -25,26 +26,29 @@
 ;; location arg to set the origin of the returned music object; this
 ;; behaviour is usually desired
 (defmacro define-ly-syntax-loc (args . body)
-  (primitive-eval `(define-ly-syntax ,args
-                    (let ((m ,(cons 'begin body)))
-                      (set! (ly:music-property m 'origin) ,(third args))
-                      m))))
-
+  `(define-public ,args
+     (let ((m ,(cons 'begin body)))
+       (set! (ly:music-property m 'origin) ,(third args))
+       m)))
 ;; Like define-ly-syntax-loc, but adds parser and location
 ;; parameters. Useful for simple constructors that don't need to
 ;; report errors.
 (defmacro define-ly-syntax-simple (args . body)
-  (primitive-eval `(define-ly-syntax ,(cons* (car args) 
-                                            'parser
-                                            'location 
-                                            (cdr args))
-                    (let ((m ,(cons 'begin body)))
-                      (set! (ly:music-property m 'origin) location)
-                      m))))
+  `(define-public ,(cons* (car args)
+                         'parser
+                         'location
+                         (cdr args))
+     (let ((m ,(cons 'begin body)))
+       (set! (ly:music-property m 'origin) location)
+       m)))
+
+;; Scheme function: Apply function, return value can be anything
+(define-ly-syntax (scheme-function parser loc fun args)
+      (apply fun parser loc args))
 
 ;; Music function: Apply function and check return value.
 (define-ly-syntax-loc (music-function parser loc fun args)
-  (let ((m (apply fun (cons* parser loc args))))
+  (let ((m (apply fun parser loc args)))
     (if (ly:music? m)
        m
        (begin
@@ -89,29 +93,34 @@
   (make-music 'TransposedMusic
              'element (ly:music-transpose music pitch)))
 
-(define-ly-syntax-simple (tempo text duration tempo)
-  (let ((props (list
-                 (make-property-set 'tempoWholesPerMinute
-                       (ly:moment-mul (ly:make-moment tempo 1)
-                                      (ly:duration-length duration)))
-                 (make-property-set 'tempoUnitDuration duration)
-                 (make-property-set 'tempoUnitCount tempo))))
-    (set! props (cons 
-            (if text (make-property-set 'tempoText text)
-                     (make-property-unset 'tempoText)) 
-            props))
-    (context-spec-music
-      (make-sequential-music props)
-      'Score)))
-
-(define-ly-syntax-simple (tempoText text)
-  (context-spec-music
-   (make-sequential-music
-    (list
-     (make-property-unset 'tempoUnitDuration)
-     (make-property-unset 'tempoUnitCount)
-     (make-property-set 'tempoText text)))
-   'Score))
+(define-ly-syntax (tempo parser location text . rest)
+  (let* ((unit (and (pair? rest)
+                   (car rest)))
+        (count (and unit
+                    (cadr rest)))
+        (range-tempo? (pair? count))
+        (tempo-change (make-music 'TempoChangeEvent
+                                  'origin location
+                                  'text text
+                                  'tempo-unit unit
+                                  'metronome-count count))
+        (tempo-set
+         (and unit
+              (context-spec-music
+               (make-property-set 'tempoWholesPerMinute
+                                  (ly:moment-mul
+                                   (ly:make-moment
+                                    (if range-tempo?
+                                        (round (/ (+ (car count) (cdr count))
+                                                  2))
+                                        count)
+                                    1)
+                                   (ly:duration-length unit)))
+               'Score))))
+
+    (if tempo-set
+       (make-sequential-music (list tempo-change tempo-set))
+       tempo-change)))
 
 (define-ly-syntax-simple (skip-music dur)
   (make-music 'SkipMusic
@@ -238,15 +247,14 @@ into a @code{MultiMeasureTextEvent}."
   (let* ((set (and (integer? label)
                   (context-spec-music (make-property-set 'rehearsalMark label)
                                      'Score)))
-        (ev (make-music 'MarkEvent))
-        (ch (make-event-chord (list ev))))
+        (ev (make-music 'MarkEvent
+                        'origin location)))
 
-    (set! (ly:music-property ev 'origin) location)
     (if set
-       (make-sequential-music (list set ch))
+       (make-sequential-music (list set ev))
        (begin
          (set! (ly:music-property ev 'label) label)
-         ch))))
+         ev))))
 
 (define-ly-syntax (partial parser location dur)
   "Make a partial measure."