X-Git-Url: https://git.xandkar.net/?a=blobdiff_plain;f=src%2Fhope_result.erl;h=1b217f845b4fa4c7cfff2a07cc272c9be3e7f762;hb=8fc25ea1d79ab2c6148b73260490e804bd76ff7c;hp=405f2e04eb9f9589731039d867f921b2a75189e1;hpb=6731749baadb46eda33393abbff36daae302cac8;p=hope.git

diff --git a/src/hope_result.erl b/src/hope_result.erl
index 405f2e0..1b217f8 100644
--- a/src/hope_result.erl
+++ b/src/hope_result.erl
@@ -1,18 +1,48 @@
 -module(hope_result).
 
--export_type([ t/2
-             ]).
 
--export([ pipe/2
-        ]).
+-export_type(
+    [ t/2
+    ]).
 
+-export(
+    [ pipe/2
+    , lift_exn/1
+    ]).
 
--type t(A, B) :: {ok, A} | {error, B}.
 
+-type t(A, B) ::
+      {ok, A}
+    | {error, B}
+    .
 
+
+-spec pipe([F], X) ->
+    t(Ok, Error)
+    when X     :: any()
+       , Ok    :: any()
+       , Error :: any()
+       , F     :: fun((X) -> t(Ok, Error))
+       .
 pipe([]    , X) -> X;
 pipe([F|Fs], X) ->
     case F(X)
     of  {error, _}=E -> E
     ;   {ok, Y}      -> pipe(Fs, Y)
     end.
+
+-spec lift_exn(F) -> G
+    when F     :: fun((A)-> B)
+       , G     :: fun((A)-> t(B, {Class, Reason :: any()}))
+       , Class :: error
+                | exit
+                | throw
+       .
+lift_exn(F) when is_function(F, 1) ->
+    fun(X) ->
+        try
+            {ok, F(X)}
+        catch Class:Reason ->
+            {error, {Class, Reason}}
+        end
+    end.