X-Git-Url: https://git.xandkar.net/?a=blobdiff_plain;f=src%2Fhope_option.erl;h=572162881ec9d85c7d6728ceff7b04c56666758a;hb=b69220d7a75faba9743d5b89b6fa40443cd39eec;hp=180c41687cd7ea5582c8c6901b5fba7dbba8e72e;hpb=4af0774b16181c76d0deedf0911d53409c8f1078;p=hope.git

diff --git a/src/hope_option.erl b/src/hope_option.erl
index 180c416..5721628 100644
--- a/src/hope_option.erl
+++ b/src/hope_option.erl
@@ -1,6 +1,6 @@
 -module(hope_option).
 
--behavior(hope_monad).
+-behavior(hope_gen_monad).
 
 -export_type(
     [ t/1
@@ -14,6 +14,7 @@
     , iter/2
     , pipe/2
     , of_result/1
+    , of_undefined/1
     ]).
 
 
@@ -65,3 +66,8 @@ pipe([F|Fs], X) ->
     t(A).
 of_result({ok, X})    -> {some, X};
 of_result({error, _}) -> none.
+
+-spec of_undefined(undefined | A) ->
+    t(A).
+of_undefined(undefined) -> none;
+of_undefined(X)         -> {some, X}.