list.find and list.find_map

2 files changed, 31 insertions, 10 deletions

diff --git a/gen/src/gleam@list.erl b/gen/src/gleam@list.erl
index 508da27..586a5aa 100644
--- a/gen/src/gleam@list.erl
+++ b/gen/src/gleam@list.erl
@@ -1,7 +1,7 @@
 -module(gleam@list).
 -compile(no_auto_import).
 
--export([length/1, reverse/1, is_empty/1, contains/2, head/1, tail/1, filter/2, map/2, index_map/2, traverse/2, drop/2, take/2, new/0, append/2, flatten/1, fold/3, fold_right/3, find/2, all/2, any/2, zip/2, strict_zip/2, intersperse/2, at/2, unique/1, sort/2, range/2, repeat/2, split/2, split_while/2, key_find/2]).
+-export([length/1, reverse/1, is_empty/1, contains/2, head/1, tail/1, filter/2, map/2, index_map/2, traverse/2, drop/2, take/2, new/0, append/2, flatten/1, fold/3, fold_right/3, find/2, find_map/2, all/2, any/2, zip/2, strict_zip/2, intersperse/2, at/2, unique/1, sort/2, range/2, repeat/2, split/2, split_while/2, key_find/2]).
 
 length(A) ->
     erlang:length(A).
@@ -169,18 +169,33 @@ fold_right(List, Initial, Fun) ->
             Fun(X, fold_right(Rest, Initial, Fun))
     end.
 
-find(Haystack, Predicate) ->
+find(Haystack, IsDesired) ->
     case Haystack of
         [] ->
             {error, nil};
 
         [X | Rest] ->
-            case Predicate(X) of
+            case IsDesired(X) of
+                true ->
+                    {ok, X};
+
+                _ ->
+                    find(Rest, IsDesired)
+            end
+    end.
+
+find_map(Haystack, Fun) ->
+    case Haystack of
+        [] ->
+            {error, nil};
+
+        [X | Rest] ->
+            case Fun(X) of
                 {ok, X1} ->
                     {ok, X1};
 
                 _ ->
-                    find(Rest, Predicate)
+                    find_map(Rest, Fun)
             end
     end.
 
@@ -375,7 +390,7 @@ split_while(List, Predicate) ->
     do_split_while(List, Predicate, []).
 
 key_find(Haystack, Needle) ->
-    find(Haystack, fun(P) -> case gleam@pair:first(P) =:= Needle of
+    find_map(Haystack, fun(P) -> case gleam@pair:first(P) =:= Needle of
                 true ->
                     {ok, gleam@pair:second(P)};
 
diff --git a/gen/test/gleam@list_test.erl b/gen/test/gleam@list_test.erl
index ae1f786..6281c9e 100644
--- a/gen/test/gleam@list_test.erl
+++ b/gen/test/gleam@list_test.erl
@@ -1,7 +1,7 @@
 -module(gleam@list_test).
 -compile(no_auto_import).
 
--export([length_test/0, reverse_test/0, is_empty_test/0, contains_test/0, head_test/0, tail_test/0, filter_test/0, map_test/0, traverse_test/0, drop_test/0, take_test/0, new_test/0, append_test/0, flatten_test/0, fold_test/0, fold_right_test/0, find_test/0, all_test/0, any_test/0, zip_test/0, strict_zip_test/0, intersperse_test/0, at_test/0, unique_test/0, sort_test/0, index_map_test/0, range_test/0, repeat_test/0, split_test/0, split_while_test/0, key_find_test/0]).
+-export([length_test/0, reverse_test/0, is_empty_test/0, contains_test/0, head_test/0, tail_test/0, filter_test/0, map_test/0, traverse_test/0, drop_test/0, take_test/0, new_test/0, append_test/0, flatten_test/0, fold_test/0, fold_right_test/0, find_map_test/0, find_test/0, all_test/0, any_test/0, zip_test/0, strict_zip_test/0, intersperse_test/0, at_test/0, unique_test/0, sort_test/0, index_map_test/0, range_test/0, repeat_test/0, split_test/0, split_while_test/0, key_find_test/0]).
 
 length_test() ->
     gleam@expect:equal(gleam@list:length([]), 0),
@@ -102,7 +102,7 @@ fold_right_test() ->
         [1, 2, 3]
     ).
 
-find_test() ->
+find_map_test() ->
     F = fun(X) -> case X of
             2 ->
                 {ok, 4};
@@ -110,9 +110,15 @@ find_test() ->
             _ ->
                 {error, 0}
         end end,
-    gleam@expect:equal(gleam@list:find([1, 2, 3], F), {ok, 4}),
-    gleam@expect:equal(gleam@list:find([1, 3, 2], F), {ok, 4}),
-    gleam@expect:equal(gleam@list:find([1, 3], F), {error, nil}).
+    gleam@expect:equal(gleam@list:find_map([1, 2, 3], F), {ok, 4}),
+    gleam@expect:equal(gleam@list:find_map([1, 3, 2], F), {ok, 4}),
+    gleam@expect:equal(gleam@list:find_map([1, 3], F), {error, nil}).
+
+find_test() ->
+    IsTwo = fun(X) -> X =:= 2 end,
+    gleam@expect:equal(gleam@list:find([1, 2, 3], IsTwo), {ok, 2}),
+    gleam@expect:equal(gleam@list:find([1, 3, 2], IsTwo), {ok, 2}),
+    gleam@expect:equal(gleam@list:find([1, 3], IsTwo), {error, nil}).
 
 all_test() ->
     gleam@expect:equal(