Adding char-set-fold and char-set-for-each.

lib/chibi/char-set.sld

@@ -4,6 +4,7 @@
   (export
    Char-Set char-set? char-set-contains?
    char-set ucs-range->char-set char-set-copy char-set-size
+   char-set-fold char-set-for-each
    list->char-set char-set->list string->char-set char-set->string
    char-set-adjoin! char-set-adjoin char-set-union char-set-union!
    char-set-intersection char-set-intersection!

lib/chibi/char-set/extras.scm

@@ -10,6 +10,12 @@
 
 (define char-set-size iset-size)
 
+(define (char-set-fold kons knil cset)
+  (iset-fold (lambda (i acc) (kons (integer->char i) acc)) knil cset))
+
+(define (char-set-for-each proc cset)
+  (iset-for-each (lambda (i) (proc (integer->char i))) cset))
+
 (define (list->char-set ls)
   (list->iset (map char->integer ls)))
 (define (char-set->list cset)

lib/chibi/char-set/extras.sld

@@ -4,6 +4,7 @@
   (include "extras.scm")
   (export
    char-set ucs-range->char-set char-set-copy char-set-size
+   char-set-fold char-set-for-each
    list->char-set char-set->list string->char-set char-set->string
    char-set-adjoin! char-set-adjoin char-set-union char-set-union!
    char-set-intersection char-set-intersection!