diff options
Diffstat (limited to 'lib')
| -rw-r--r-- | lib/util.ml | 14 | ||||
| -rw-r--r-- | lib/util.mli | 12 |
2 files changed, 17 insertions, 9 deletions
diff --git a/lib/util.ml b/lib/util.ml index 009dfbe1c..9fb0d48ee 100644 --- a/lib/util.ml +++ b/lib/util.ml @@ -87,13 +87,17 @@ let matrix_transpose mat = let identity x = x -(** Function composition: the mathematical [∘] operator. +(** Left-to-right function composition: + + [f1 %> f2] is [fun x -> f2 (f1 x)]. - So [g % f] is a synonym for [fun x -> g (f x)]. + [f1 %> f2 %> f3] is [fun x -> f3 (f2 (f1 x))]. - Also because [%] is right-associative, [h % g % f] means [fun x -> h (g (f x))]. - *) -let (%) f g x = f (g x) + [f1 %> f2 %> f3 %> f4] is [fun x -> f4 (f3 (f2 (f1 x)))] + + etc. +*) +let (%>) f g x = g (f x) let const x _ = x diff --git a/lib/util.mli b/lib/util.mli index 6bed7e355..cf8041a0d 100644 --- a/lib/util.mli +++ b/lib/util.mli @@ -84,13 +84,17 @@ val matrix_transpose : 'a list list -> 'a list list val identity : 'a -> 'a -(** Function composition: the mathematical [∘] operator. +(** Left-to-right function composition: + + [f1 %> f2] is [fun x -> f2 (f1 x)]. - So [g % f] is a synonym for [fun x -> g (f x)]. + [f1 %> f2 %> f3] is [fun x -> f3 (f2 (f1 x))]. - Also because [%] is right-associative, [h % g % f] means [fun x -> h (g (f x))]. + [f1 %> f2 %> f3 %> f4] is [fun x -> f4 (f3 (f2 (f1 x)))] + + etc. *) -val (%) : ('a -> 'b) -> ('c -> 'a) -> 'c -> 'b +val ( %> ) : ('a -> 'b) -> ('b -> 'c) -> 'a -> 'c val const : 'a -> 'b -> 'a val iterate : ('a -> 'a) -> int -> 'a -> 'a |