preference directory functionality added

main.rkt

@@ -10,8 +10,15 @@
          make-ini
          )
 
+
+(define (get-ini-file f)
+  (if (symbol? f) 
+    (let* ((pref-dir (find-system-path 'pref-dir)))
+       (build-path pref-dir (string-append (symbol->string f) ".ini")))
+    (build-path f)))
+
 (define (ini->file ini file)
-  (let ((out (open-output-file file #:exists 'replace)))
+  (let ((out (open-output-file (get-ini-file file) #:exists 'replace)))
     (let ((last-is-newline #f))
       (for-each (lambda (section)
                   (let ((section-name (car section)))
@@ -64,8 +71,9 @@
                       #f)
                   s)))))))
 
-(define (file->ini file)
+(define (file->ini file*)
-  (let* ((lines (file->lines file))
+  (let* ((file (get-ini-file file*))
+	 (lines (if (file-exists? file) (file->lines file) '()))
          (re-section #px"^\\[([a-zA-Z0-9_-]+)\\]$")
          (re-keyval #px"^([a-zA-Z0-9_-]+)[=](.*)$")
          (re-comment #px"^[;](.*)$"))

scribblings/ini.scrbl

@@ -23,6 +23,8 @@
 
 @defproc[(file->ini [file path-string?]) mc-pair?]{
   Reads an INI file from disk and parses it into an internal mutable cons pair (mc-pair) structure.
+  If the file does noet exist, an empty ini structure is made. 
+  If file is a symbol?, the file will be constructed from the prefs-dir, the symbol and a suffix ".ini".
   
   The parser supports:
   
@@ -43,6 +45,7 @@
 
 @defproc[(ini->file [ini mc-pair?] [file path-string?]) void?]{
    Writes an INI structure (as produced by @racket[file->ini] or @racket[make-ini]) to the specified file.
+   If file is a symbol?, the file will be constructed from the prefs-dir, the symbol and a suffix ".ini".
   
   The output preserves:
   @itemlist[