Add list:index_map

1 files changed, 12 insertions, 0 deletions

diff --git a/test/list_test.gleam b/test/list_test.gleam
index f9882c0..9c510c4 100644
--- a/test/list_test.gleam
+++ b/test/list_test.gleam
@@ -1,5 +1,6 @@
 import expect
 import list
+import str
 
 pub fn length_test() {
   list:length([]) |> expect:equal(_, 0)
@@ -248,3 +249,14 @@ pub fn sort_test() {
   list:sort([{1,2}, {4,5}, {3,2}])
   |> expect:equal(_, [{1,2}, {3,2}, {4,5}])
 }
+
+pub fn index_map_test() {
+  list:index_map([3,4,5], fn(i, x) { {i, x} })
+  |> expect:equal(_, [{0,3},{1,4},{2,5}])
+
+  let f = fn(i, x) {
+    str:append(x, str:from_int(i))
+  }
+  list:index_map(["a","b","c"], f)
+  |> expect:equal(_, ["a0", "b1", "c2"])
+}