diff options
Diffstat (limited to 'checklink/Lens.ml')
-rw-r--r-- | checklink/Lens.ml | 32 |
1 files changed, 32 insertions, 0 deletions
diff --git a/checklink/Lens.ml b/checklink/Lens.ml new file mode 100644 index 00000000..43359334 --- /dev/null +++ b/checklink/Lens.ml @@ -0,0 +1,32 @@ +type ('a, 'b) t = { + get: 'a -> 'b; + set: 'b -> 'a -> 'a; +} + +let ( |- ) f g x = g (f x) + +let modify l f a = + let oldval = l.get a in + let newval = f oldval in + l.set newval a + +let compose l1 l2 = { + get = l2.get |- l1.get; + set = l1.set |- modify l2 +} + +let _get a l = l.get a + +let _set v a l = l.set v a + +let _modify f l = modify l f + +let (|.) = _get + +let (^=) l v = fun a -> _set v a l + +let (^%=) l f = _modify f l + +let (|--) l1 l2 = compose l2 l1 + +let (--|) = compose |