stdlib additions

1 files changed, 50 insertions, 0 deletions

diff --git a/src/tuple.gleam b/src/tuple.gleam
index d437a9f..5da1810 100644
--- a/src/tuple.gleam
+++ b/src/tuple.gleam
@@ -1,4 +1,18 @@
 import expect
+import result
+import list
+
+pub fn new(a, b) {
+  {a, b}
+}
+
+test new {
+  new(1, 2)
+  |> expect:equal(_, {1, 2})
+
+  new(2, "3")
+  |> expect:equal(_, {2, "3"})
+}
 
 pub fn first(tup) {
   let {a, _} = tup
@@ -21,3 +35,39 @@ test second {
   |> second
   |> expect:equal(_, 2)
 }
+
+pub fn swap(tup) {
+  let {a, b} = tup
+  {b, a}
+}
+
+test swap {
+  {1, "2"}
+  |> swap
+  |> expect:equal(_, {"2", 1})
+}
+
+pub fn fetch(haystack, needle) {
+  list:find(haystack, fn(tuple) {
+    case first(tuple) == needle {
+    | True -> Ok(second(tuple))
+    | False -> Error([])
+    }
+  })
+}
+
+test fetch {
+  let proplist = [{0, "1"}, {1, "2"}]
+
+  proplist
+  |> fetch(_, 0)
+  |> expect:equal(_, Ok("1"))
+
+  proplist
+  |> fetch(_, 1)
+  |> expect:equal(_, Ok("2"))
+
+  proplist
+  |> fetch(_, 2)
+  |> expect:is_error
+}