From 7e28feadd6394483b6f527d5aed7d663e189596e Mon Sep 17 00:00:00 2001
From: Hugo Herbelin
Date: Tue, 12 Jul 2016 23:26:44 +0200
Subject: Upgrading some local function as a general-purpose combinator
 Option.List.map.

---
 lib/option.ml  | 10 ++++++++++
 lib/option.mli |  6 ++++++
 2 files changed, 16 insertions(+)

(limited to 'lib')

diff --git a/lib/option.ml b/lib/option.ml
index fbb883d30a..f3047a3ca7 100644
--- a/lib/option.ml
+++ b/lib/option.ml
@@ -188,4 +188,14 @@ module List =
 	 |None -> find f t
 	 |x -> x
 
+  let map f l =
+    let rec aux f l = match l with
+    | [] -> []
+    | x :: l ->
+      match f x with
+      | None -> raise Exit
+      | Some y -> y :: aux f l
+    in
+    try Some (aux f l) with Exit -> None
+
 end
diff --git a/lib/option.mli b/lib/option.mli
index 5e085620e7..a336c895cc 100644
--- a/lib/option.mli
+++ b/lib/option.mli
@@ -123,4 +123,10 @@ module List : sig
   val flatten : 'a option list -> 'a list
 
   val find : ('a -> 'b option) -> 'a list -> 'b option
+
+  (** [List.map f [a1;...;an]] is the list [Some [b1;...;bn]] if
+      for all i, there is a [bi] such that [f ai] is [Some bi]; it is
+      [None] if, for at least one i, [f ai] is [None]. *)
+  val map : ('a -> 'b option) -> 'a list -> 'b list option
+
 end
-- 
cgit v1.2.3


From 3f4c29f8258d627c7dbacbf1157825d96b146a6d Mon Sep 17 00:00:00 2001
From: Hugo Herbelin
Date: Fri, 5 May 2017 17:34:43 +0200
Subject: Cosmetic: unifying style within option.ml.

---
 lib/option.ml | 34 ++++++++++++++++------------------
 1 file changed, 16 insertions(+), 18 deletions(-)

(limited to 'lib')

diff --git a/lib/option.ml b/lib/option.ml
index f3047a3ca7..50fdd079dc 100644
--- a/lib/option.ml
+++ b/lib/option.ml
@@ -20,24 +20,24 @@ let has_some = function
   | _ -> true
 
 let is_empty = function
-| None -> true
-| Some _ -> false
+  | None -> true
+  | Some _ -> false
 
 (** Lifting equality onto option types. *)
 let equal f x y = match x, y with
-| None, None -> true
-| Some x, Some y -> f x y
-| _, _ -> false
+  | None, None -> true
+  | Some x, Some y -> f x y
+  | _, _ -> false
 
 let compare f x y = match x, y with
-| None, None -> 0
-| Some x, Some y -> f x y
-| None, Some _ -> -1
-| Some _, None -> 1
+  | None, None -> 0
+  | Some x, Some y -> f x y
+  | None, Some _ -> -1
+  | Some _, None -> 1
 
 let hash f = function
-| None -> 0
-| Some x -> f x
+  | None -> 0
+  | Some x -> f x
 
 exception IsNone
 
@@ -57,13 +57,11 @@ let init b x =
   else
     None
 
-
 (** [flatten x] is [Some y] if [x] is [Some (Some y)] and [None] otherwise. *)
 let flatten = function
   | Some (Some y) -> Some y
   | _ -> None
 
-
 (** [append x y] is the first element of the concatenation of [x] and
     [y] seen as lists. *)
 let append o1 o2 =
@@ -134,6 +132,7 @@ let cata f a = function
   | Some c -> f c
   | None -> a
 
+
 (** {6 More Specific operations} ***)
 
 (** [default a x] is [y] if [x] is [Some y] and [a] otherwise. *)
@@ -165,7 +164,6 @@ let lift2 f x y =
   | _,_ -> None
 
 
-
 (** {6 Operations with Lists} *)
 
 module List =
@@ -183,10 +181,10 @@ module List =
     | [] -> []
 
   let rec find f = function
-    |[] -> None
-    |h :: t -> match f h with
-	 |None -> find f t
-	 |x -> x
+    | [] -> None
+    | h :: t -> match f h with
+	 | None -> find f t
+	 | x -> x
 
   let map f l =
     let rec aux f l = match l with
-- 
cgit v1.2.3


From f24d8876837e2f9121064f496d89803f60ec2c71 Mon Sep 17 00:00:00 2001
From: Hugo Herbelin
Date: Fri, 5 May 2017 17:41:00 +0200
Subject: Documenting Option.List.find.

---
 lib/option.mli | 3 +++
 1 file changed, 3 insertions(+)

(limited to 'lib')

diff --git a/lib/option.mli b/lib/option.mli
index a336c895cc..f06ad9f1d1 100644
--- a/lib/option.mli
+++ b/lib/option.mli
@@ -122,6 +122,9 @@ module List : sig
       [Some y] (in the same order). *)
   val flatten : 'a option list -> 'a list
 
+  (** [List.find f l] is the first [f a] different from [None],
+      scrolling through elements [a] of [l] in left-to-right order;
+      it is [None] if no such element exists. *)
   val find : ('a -> 'b option) -> 'a list -> 'b option
 
   (** [List.map f [a1;...;an]] is the list [Some [b1;...;bn]] if
-- 
cgit v1.2.3