Add hope_option:of_result/1

[hope.git] / src / hope_option.erl

diff --git a/src/hope_option.erl b/src/hope_option.erl
index 622c06d..ab6eab7 100644 (file)
--- a/src/hope_option.erl
+++ b/src/hope_option.erl
@@ -9,6 +9,8 @@
     [ put/2
     , get/2
     , map/2
+    , iter/2
+    , of_result/1
     ]).
 
 
@@ -18,14 +20,30 @@
     .
 
 
+-spec put(A, fun((A) -> boolean())) ->
+    t(A).
 put(X, F) ->
     case F(X)
     of  true  -> {some, X}
     ;   false -> none
     end.
 
+-spec get(t(A), Default :: A) ->
+    A.
 get({some, X}, _) -> X;
 get(none     , Y) -> Y.
 
+-spec map(t(A), fun((A) -> (B))) ->
+    t(B).
 map({some, X}, F) -> {some, F(X)};
 map(none     , _) -> none.
+
+-spec iter(t(A), fun((A) -> (ok))) ->
+    ok.
+iter({some, X}, F) -> ok = F(X);
+iter(none     , _) -> ok.
+
+-spec of_result(hope_result:t(A, _B)) ->
+    t(A).
+of_result({ok, X})    -> {some, X};
+of_result({error, _}) -> none.