CHUTIL: expand API for traceresult

Author: sipma

CodeHawk/CH/chutil/cHTraceResult.ml

@@ -48,12 +48,26 @@ let tmap ?(msg="") (f: 'a -> 'c) (r: 'a traceresult) =
   | Error e -> Error (msg :: e)
 
 
+let tmap2
+      ?(msg1="")
+      ?(msg2="")
+      (f: 'a -> 'b  -> 'c)
+      (r1: 'a traceresult)
+      (r2: 'b traceresult): 'c traceresult =
+  match r1, r2 with
+  | Ok v1, Ok v2 -> Ok (f v1 v2)
+  | Error e1, Ok _ -> Error (msg1 :: e1)
+  | Ok _, Error e2 -> Error (msg2 :: e2)
+  | Error e1, Error e2 -> Error (msg1 :: msg2 :: (e1 @ e2))
+
+
 let tbind ?(msg="") (f: 'a -> 'c traceresult) (r: 'a traceresult) =
   match r with
   | Ok v -> f v
   | Error e when msg = "" -> Error e
   | Error e -> Error (msg :: e)
 
+
 let tfold ~(ok:'a -> 'c) ~(error:string list -> 'c) (r: 'a traceresult): 'c =
   match r with
   | Ok v -> ok v
@@ -96,6 +110,19 @@ let tfold_list_default
       | Error _ -> err acc) initacc rl
 
 
+let tfold_list_fail
+      (ok: 'c -> 'a -> 'c)
+      (initacc: 'c traceresult)
+      (rl: ('a traceresult) list): 'c traceresult =
+  List.fold_left (fun acc r ->
+      match acc with
+      | Error e -> Error e
+      | Ok accv ->
+         match r with
+         | Error e -> Error e
+         | Ok v -> Ok (ok accv v)) initacc rl
+
+
 let to_bool (f: 'a -> bool) (r: 'a traceresult) =
   match r with
   | Ok v -> f v

CodeHawk/CH/chutil/cHTraceResult.mli

@@ -53,6 +53,18 @@ val tvalue: 'a traceresult -> default:'a -> 'a
 val tmap: ?msg:string -> ('a -> 'c) -> ('a traceresult) -> 'c traceresult
 
 
+(** [tmap2 f r1 r2] is [Ok (f v1 v2)] if [r1] is [Ok v1] and [r2] is [Ok v2];
+    otherwise it returns an [Error] appending the messages corresponding to
+    the error value as appropriate.*)
+val tmap2:
+  ?msg1: string
+  -> ?msg2: string
+  -> ('a -> 'b -> 'c)
+  -> 'a traceresult
+  -> 'b traceresult
+  -> 'c traceresult
+
+
 (** [tfold ~ok ~error r] is [ok v] if [r] is [Ok v] and [error e] if [r] is
     [Error e].*)
 val tfold: ok:('a -> 'c) -> error:(string list -> 'c) -> 'a traceresult -> 'c
@@ -84,7 +96,7 @@ val tfold_list: ok:('c -> 'a -> 'c) -> 'c -> ('a traceresult) list -> 'c
 
 
 (** [tfold_list_default ~ok ~err init rl] folds [Ok] values left to right,
-    startint from [init], using a default accumulator [err] for [Error]
+    starting from [init], using a default accumulator [err] for [Error]
     values.
 
     This function differs from [tfold_list] in that it enables making the
@@ -93,6 +105,13 @@ val tfold_list_default:
   ok:('c -> 'a -> 'c) -> err:('c -> 'c) -> 'c -> ('a traceresult) list -> 'c
 
 
+(** [tfold_list_fail f init rl] folds [Ok] values left to right starting
+    from [init], failing on the first value in [rl] that has an error value.
+ *)
+val tfold_list_fail:
+  ('c -> 'a -> 'c) -> 'c traceresult -> ('a traceresult) list -> 'c traceresult
+
+
 (** [to_bool f r] is [f v] if [r] is [Ok v] and [false] otherwise.*)
 val to_bool: ('a -> bool) -> 'a traceresult -> bool