diff options
Diffstat (limited to 'module/hnh/util/lens.scm')
| -rw-r--r-- | module/hnh/util/lens.scm | 8 |
1 files changed, 7 insertions, 1 deletions
diff --git a/module/hnh/util/lens.scm b/module/hnh/util/lens.scm index 7a8fbd19..26c75be7 100644 --- a/module/hnh/util/lens.scm +++ b/module/hnh/util/lens.scm @@ -9,7 +9,9 @@ compose-lenses lens-compose - ref car* cdr*)) + ref car* cdr* + + each)) (define (modify object lens f . args) @@ -97,3 +99,7 @@ (define car* (make-lens car (lambda (pair value) (cons value (cdr pair))))) (define cdr* (make-lens cdr (lambda (pair value) (cons (car pair) value)))) + +(define (each obj lens proc) + (modify obj lens + (lambda (lst) (map proc lst)))) |