(char->integer #\0)))))
(string->list (number->string var-idx)))))))))
-(define-public (ly:parse-string-result str module)
+(define-public (ly:parse-string-result str parser module)
"Parse `str', which is supposed to contain a music expression."
(let ((music-sym (gen-lily-sym)))
(ly:parser-parse-string
the scheme music expression. The $ character may be used to introduce
scheme forms, typically symbols. $$ may be used to simply write a `$'
character."
- (let* ((format-args '())
- (lily-string (with-output-to-string
- (lambda ()
+ (let ((bindings '()))
+ (define (create-binding! val)
+ "Create a new symbol, bind it to `val' and return it."
+ (let ((tmp-symbol (gen-lily-sym)))
+ (set! bindings (cons (cons tmp-symbol val) bindings))
+ tmp-symbol))
+ (define (remove-dollars! form)
+ "Generate a form where `$variable' and `$ value' mottos are replaced
+ by new symbols, which are binded to the adequate values."
+ (cond (;; $variable
+ (and (symbol? form)
+ (string=? (substring (symbol->string form) 0 1) "$")
+ (not (and (<= 2 (string-length (symbol->string form)))
+ (string=? (substring (symbol->string form) 1 2) "$"))))
+ (create-binding! (string->symbol (substring (symbol->string form) 1))))
+ (;; atom
+ (not (pair? form)) form)
+ (;; ($ value ...)
+ (eqv? (car form) '$)
+ (cons (create-binding! (cadr form)) (remove-dollars! (cddr form))))
+ (else ;; (something ...)
+ (cons (remove-dollars! (car form)) (remove-dollars! (cdr form))))))
+ (let ((lily-string (call-with-output-string
+ (lambda (out)
(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))))
+ ((and (char=? c #\#)
+ (char=? (peek-char port) #\})) ;; we stop when #} is encoutered
+ (read-char port))
+ (cond
+ ;; a $form expression
+ ((and (char=? c #\$) (not (char=? (peek-char port) #\$)))
+ (format out "\\~a" (create-binding! (read port))))
+ ;; just a $ character
+ ((and (char=? c #\$) (char=? (peek-char port) #\$))
+ (display (read-char port) out)) ;; pop the second $
+ ;; a #scheme expression
+ ((char=? c #\#)
+ (let ((expr (read port)))
+ (format out "#~a" (if (eq? '$ expr)
+ (create-binding! (read port))
+ (remove-dollars! expr)))))
+ ;; other caracters
+ (else
+ (display c out))))))))
+ `(let ((parser-clone (ly:clone-parser parser)))
+ ,@(map (lambda (binding)
+ `(ly:parser-define parser-clone ',(car binding) ,(cdr binding)))
+ (reverse bindings))
+ (ly:parse-string-result ,lily-string parser-clone (current-module))))))
(read-hash-extend #\{ read-lily-expression)