merge from master

README.md

@@ -52,8 +52,8 @@ structures comprise (some modules in `misc/`, some other in `core/`):
 - `CCPersistentHashtbl`, a semi-persistent hashtable (similar to [persistent arrays](https://www.lri.fr/~filliatr/ftp/ocaml/ds/parray.ml.html))
 - `CCVector`, a growable array (pure OCaml, no C) with mutability annotations
 - `CCGen` and `CCSequence`, generic iterators structures (with structural types so they can be defined in several places). Now also in their own repository and opam packages (`gen` and `sequence`).
-- `CCKlist`, a persistent iterator structure (akin to a lazy list)
-- `CCList`, functions and lists including tail-recursive implementations of `map` and `append` and many other utilities
+- `CCKList`, a persistent iterator structure (akin to a lazy list)
+- `CCList`, functions on lists, including tail-recursive implementations of `map` and `append` and many other things
 - `CCArray`, utilities on arrays and slices
 - `CCLinq`, high-level query language over collections
 - `CCMultimap` and `CCMultiset`, functors defining persistent structures
@@ -62,14 +62,14 @@ structures comprise (some modules in `misc/`, some other in `core/`):
   - `CCInt`
   - `CCString` (basic string operations)
   - `CCPair` (cartesian products)
-  - `CCOpt` (options)
+  - `CCOpt` (options, very useful)
   - `CCFun` (function combinators)
   - `CCBool`
   - `CCOrd` (combinators for total orderings)
   - `CCRandom` (combinators for random generators)
   - `CCPrint` (printing combinators)
   - `CCHash` (hashing combinators)
-  - `CCError` (monadic error handling)
+  - `CCError` (monadic error handling, very useful)
 
 ### String
 

core/CCOpt.ml

@@ -64,6 +64,8 @@ let flat_map f o = match o with
   | None -> None
   | Some x -> f x
 
+let pure x = Some x
+
 let (<*>) f x = match f, x with
   | None, _
   | _, None -> None

core/CCOpt.mli

@@ -68,6 +68,9 @@ val sequence_l : 'a t list -> 'a list t
 
 (** {2 Applicative} *)
 
+val pure : 'a -> 'a t
+(** Alias to {!return} *)
+
 val (<*>) : ('a -> 'b) t -> 'a t -> 'b t
 
 val (<$>) : ('a -> 'b) -> 'a t -> 'b t