Move fetch to list module as key_find

6 files changed, 43 insertions, 27 deletions

diff --git a/gen/src/gleam@list.erl b/gen/src/gleam@list.erl
index 7781dcc..e8eabd2 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]).
+-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]).
 
 length(A) ->
     erlang:length(A).
@@ -373,3 +373,12 @@ do_split_while(List, F, Acc) ->
 
 split_while(List, F) ->
     do_split_while(List, F, []).
+
+key_find(Haystack, Needle) ->
+    find(Haystack, fun(P) -> case gleam@pair:first(P) =:= Needle of
+                true ->
+                    {ok, gleam@pair:second(P)};
+
+                false ->
+                    {error, nil}
+            end end).
diff --git a/gen/test/gleam@list_test.erl b/gen/test/gleam@list_test.erl
index fb04d25..dcb4ceb 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]).
+-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]).
 
 length_test() ->
     gleam@expect:equal(gleam@list:length([]), 0),
@@ -265,3 +265,9 @@ split_while_test() ->
         gleam@list:split_while([1, 2, 3, 4, 5], fun(X) -> X =< -3 end),
         {[], [1, 2, 3, 4, 5]}
     ).
+
+key_find_test() ->
+    Proplist = [{0, <<"1">>}, {1, <<"2">>}],
+    gleam@expect:equal(gleam@list:key_find(Proplist, 0), {ok, <<"1">>}),
+    gleam@expect:equal(gleam@list:key_find(Proplist, 1), {ok, <<"2">>}),
+    gleam@expect:is_error(gleam@list:key_find(Proplist, 2)).
diff --git a/src/gleam/list.gleam b/src/gleam/list.gleam
index e0e7016..ed63a4b 100644
--- a/src/gleam/list.gleam
+++ b/src/gleam/list.gleam
@@ -312,3 +312,12 @@ fn do_split_while(list, f, acc) {
 pub fn split_while(list, f) {
   do_split_while(list, f, [])
 }
+
+pub fn key_find(haystack, needle) {
+  find(haystack, fn(p) {
+    case pair.first(p) == needle {
+    | True -> p |> pair.second |> Ok
+    | False -> Error(Nil)
+    }
+  })
+}
diff --git a/src/gleam/pair.gleam b/src/gleam/pair.gleam
index 7df33ca..0a51fd3 100644
--- a/src/gleam/pair.gleam
+++ b/src/gleam/pair.gleam
@@ -19,12 +19,3 @@ pub fn swap(tup) {
   let Pair(a, b) = tup
   Pair(b, a)
 }
-
-// pub fn fetch(haystack, needle) {
-//   list.find(haystack, fn(tuple) {
-//     case first(tuple) == needle {
-//     | True -> tuple |> second |> Ok
-//     | False -> Error([])
-//     }
-//   })
-// }
diff --git a/test/gleam/list_test.gleam b/test/gleam/list_test.gleam
index e211947..cdb7a8d 100644
--- a/test/gleam/list_test.gleam
+++ b/test/gleam/list_test.gleam
@@ -358,3 +358,20 @@ pub fn split_while_test() {
   list.split_while([1, 2, 3, 4, 5], fn(x) { x <= -3 })
   |> expect.equal(_, pair.Pair([], [1, 2, 3, 4, 5]))
 }
+
+
+pub fn key_find_test() {
+  let proplist = [pair.Pair(0, "1"), pair.Pair(1, "2")]
+
+  proplist
+  |> list.key_find(_, 0)
+  |> expect.equal(_, Ok("1"))
+
+  proplist
+  |> list.key_find(_, 1)
+  |> expect.equal(_, Ok("2"))
+
+  proplist
+  |> list.key_find(_, 2)
+  |> expect.is_error
+}
diff --git a/test/gleam/pair_test.gleam b/test/gleam/pair_test.gleam
index 86a9e1e..d8cb324 100644
--- a/test/gleam/pair_test.gleam
+++ b/test/gleam/pair_test.gleam
@@ -18,19 +18,3 @@ pub fn swap_test() {
   |> pair.swap
   |> expect.equal(_, pair.Pair("2", 1))
 }
-
-// pub fn fetch_test() {
-//   let proplist = [pair.Pair(0, "1"), pair.Pair(1, "2")]
-
-//   proplist
-//   |> pair.fetch(_, 0)
-//   |> expect.equal(_, Ok("1"))
-
-//   proplist
-//   |> pair.fetch(_, 1)
-//   |> expect.equal(_, Ok("2"))
-
-//   proplist
-//   |> pair.fetch(_, 2)
-//   |> expect.is_error
-// }