Change compile to compile-site and add clean param.

alley-cat.scm

@@ -12,7 +12,7 @@
    ; core functions
    add-page! delete-page! add-css! delete-css!
    add-file-resource! delete-file-resource!
-   compile
+   compile-site
   )
 
 (import chicken scheme files srfi-1 extras ports irregex)
@@ -110,8 +110,8 @@
        (file-copy (++ (res-dir) "/" p) path-out)))
    *file-resources*))
 
-(define (compile)
-  (and (directory? (out-dir)) (delete-directory (out-dir) #t))
+(define (compile-site #!key (clean #t))
+  (when clean (and (directory? (out-dir)) (delete-directory (out-dir) #t)))
   (output-pages)
   (output-stylesheets)
   (copy-file-resources))