Sun, 25 Apr 2004 12:37:13 +0200, Jan a dit :
> I've made another step (CVS), what do you think?
> #(ly:export 'result)
> #(module-define! (resolve-module '(scm toto)) 'result result)
oh, that's what I was desperately looking for!
We should use a symbol that is not likely to be already used.
The following function generate a symbol each time it is called:
/
| (define gen-lily-sym
| ;; Generate a lilyvartmpXX symbol, that may be (hopefully) unique.
| (let ((var-idx -1))
| (lambda ()
| (set! var-idx (1+ var-idx))
| (string->symbol (format #f "lilyvartmp~a"
| (list->string (map (lambda (chr)
| (integer->char (+ (char->integer
#\a)
| (-
(char->integer chr)
|
(char->integer #\0)))))
| (string->list (number->string
var-idx)))))))))
\
Then, ly:parse-string-result may look like:
/
| (define-public (ly:parse-string-result str module)
| "Parse `str', which is supposed to contain a music expression."
| (let ((music-sym (gen-lily-sym)))
| (ly:parser-parse-string
| parser
| (format #f "
| ~a = { ~a }
| #(ly:export '~a)
| #(module-define! (resolve-module '~a) '~a ~a)
| "
| music-sym str music-sym (module-name module) music-sym music-sym))
| (eval `,music-sym module)))
\
Maybe a single strange symbol is enough, and generating each time an
other symbol is useless, I don't know.
> What would be the best way to integrate this into Lily (the toto module?)
Can not it be in the (lily) module? For instance:
;;;; ly-from-scheme.scm -- parsing LilyPond music expressions from scheme
;;;;
;;;; source file of the GNU LilyPond music typesetter
;;;;
;;;; (c) 2000--2004 Han-Wen Nienhuys <[EMAIL PROTECTED]>
;;;; Jan Nieuwenhuizen <[EMAIL PROTECTED]>
(define gen-lily-sym
;; Generate a lilyvartmpXX symbol, that may be (hopefully) unique.
(let ((var-idx -1))
(lambda ()
(set! var-idx (1+ var-idx))
(string->symbol (format #f "lilyvartmp~a"
(list->string (map (lambda (chr)
(integer->char (+ (char->integer
#\a) (- (char->integer chr)
(char->integer #\0)))))
(string->list (number->string
var-idx)))))))))
(define-public (ly:parse-string-result str module)
"Parse `str', which is supposed to contain a music expression."
(let ((music-sym (gen-lily-sym)))
(ly:parser-parse-string
parser
(format #f "
~a = { ~a }
#(ly:export '~a)
#(module-define! (resolve-module '~a) '~a ~a)
"
music-sym str music-sym (module-name module) music-sym music-sym))
(eval `,music-sym module)))
(define-public (read-lily-expression chr port)
"Read a #{ lily music expression #} from port and return
the scheme music expression. The $ character may be used to introduce
scheme forms, typically symbols. $$ may be used to simply write a `$'
character."
(let* ((format-args '())
(lily-string (with-output-to-string
(lambda ()
(do ((c (read-char port) (read-char port)))
((and (char=? c #\#)
(char=? (peek-char port) #\}))
(read-char port))
(cond ((and (char=? c #\$)
(not (char=? (peek-char port) #\$)))
;; a $variable
(display "~a")
(set! format-args (cons (read port)
format-args)))
((and (char=? c #\$)
(char=? (peek-char port) #\$))
;; just a $ character
(display (read-char port)))
(else
;; other caracters
(display c))))))))
`(ly:parse-string-result (format #f ,lily-string ,@(reverse! format-args))
(current-module))))
(read-hash-extend #\{ read-lily-expression)
Index: ChangeLog
===================================================================
RCS file: /cvsroot/lilypond/lilypond/ChangeLog,v
retrieving revision 1.2121
diff -u -r1.2121 ChangeLog
--- ChangeLog 25 Apr 2004 09:55:27 -0000 1.2121
+++ ChangeLog 25 Apr 2004 13:27:08 -0000
@@ -1,3 +1,11 @@
+2004-04-25 Nicolas Sceaux <[EMAIL PROTECTED]>
+
+ * scm/lily.scm (ly:load): Add ly-from-scheme.scm loading.
+
+ * scm/ly-from-scheme.scm: New file. Introduce a new syntax:
+ #{ lily music expression #} that returns an equivalent scheme
+ music expression by parsing the string.
+
2004-04-25 Jan Nieuwenhuizen <[EMAIL PROTECTED]>
* lily/my-lily-parser.cc:
Index: scm/lily.scm
===================================================================
RCS file: /cvsroot/lilypond/lilypond/scm/lily.scm,v
retrieving revision 1.236
diff -u -r1.236 lily.scm
--- scm/lily.scm 24 Apr 2004 21:48:02 -0000 1.236
+++ scm/lily.scm 25 Apr 2004 13:27:11 -0000
@@ -442,6 +442,8 @@
"define-music-properties.scm"
"auto-beam.scm"
"chord-name.scm"
+
+ "ly-from-scheme.scm"
"define-context-properties.scm"
"translation-functions.scm"
#(define (textoffset dx dy)
#{ \override Voice.TextScript #'extra-offset = #(cons $dx $dy) #})
#(define (export-lily-expression chr port)
`(ly:export ,(read port)))
#(read-hash-extend #\x export-lily-expression)
\score {
\notes {
c'^"normal text"
##x(textoffset 3 -4)
c'^"text with offset hm"
}
}
nicolas
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