list:flatten, list:append, test iodata

3 files changed, 48 insertions, 30 deletions

diff --git a/src/bool.gleam b/src/bool.gleam
index 5375d0e..5a89287 100644
--- a/src/bool.gleam
+++ b/src/bool.gleam
@@ -1,5 +1,5 @@
 import expect
-// import order:[Gt, Eq, Lt]
+import order
 
 // pub fn not(bool) {
 //   case bool {
@@ -9,7 +9,7 @@ import expect
 // }
 
 // test not {
-//   not(True)
+//   let _ = not(True)
 //     |> expect:false
 
 //   not(False)
@@ -18,10 +18,10 @@ import expect
 
 // pub fn compare(a, b) {
 //   case {a, b} {
-//   | {True, True} -> Eq
-//   | {True, False} -> Gt
-//   | {False, False} -> Eq
-//   | {False, True} -> Gt
+//   | {True, True} -> order:Eq
+//   | {True, False} -> order:Gt
+//   | {False, False} -> order:Eq
+//   | {False, True} -> order:Gt
 //   }
 // }
 
diff --git a/src/iodata.gleam b/src/iodata.gleam
index 1b28577..4d81e38 100644
--- a/src/iodata.gleam
+++ b/src/iodata.gleam
@@ -1,11 +1,10 @@
 import any
-
-// TODO: Tests
+import expect
 
 pub external type Iodata;
 
 pub external fn prepend(Iodata, String) -> Iodata =
-  "gleam__stdlib" "iodata_concat";
+  "gleam__stdlib" "iodata_prepend";
 
 pub external fn append(Iodata, String) -> Iodata =
   "gleam__stdlib" "iodata_append";
@@ -18,3 +17,13 @@ pub external fn to_string(Iodata) -> String =
 
 pub external fn byte_size(Iodata) -> Int =
   "erlang" "iolist_size";
+
+test iodata {
+  let iodata = from(["ello"])
+    |> append(_, ",")
+    |> append(_, " world!")
+    |> prepend(_, "H")
+
+  expect:equal(to_string(iodata), "Hello, world!")
+  expect:equal(byte_size(iodata), 13)
+}
diff --git a/src/list.gleam b/src/list.gleam
index 027afd6..f9fb3b6 100644
--- a/src/list.gleam
+++ b/src/list.gleam
@@ -48,7 +48,7 @@ test has_member {
 pub fn head(list) {
   case list {
   | [] -> Error(Empty)
-  | [x | xs] -> Ok(x)
+  | [x | _] -> Ok(x)
   }
 }
 
@@ -63,7 +63,7 @@ test head {
 pub fn tail(list) {
   case list {
   | [] -> Error(Empty)
-  | [x | xs] -> Ok(xs)
+  | [_ | xs] -> Ok(xs)
   }
 }
 
@@ -220,30 +220,39 @@ test new {
   new() |> expect:equal(_, [])
 }
 
-// fn do_flatten(lists, acc) {
-//   case lists {
-//   | [] -> acc
-//   | [l | rest] -> flatten(rest, acc ++ l)
-//   }
-// }
+pub external fn append(List(a), List(a)) -> List(a) = "lists" "append";
 
-// pub fn flatten(lists) {
-//   do_flatten(lists, [])
-// }
+test append {
+  expect:equal(
+    append([1], [2, 3]),
+    [1, 2, 3],
+  )
+}
 
-// test flatten {
-//   let _ = flatten([])
-//     |> expect:equal(_, [])
+fn do_flatten(lists, acc) {
+  case lists {
+  | [] -> acc
+  | [l | rest] -> do_flatten(rest, append(acc, l))
+  }
+}
 
-//   let _ = flatten([[]])
-//     |> expect:equal(_, [])
+pub fn flatten(lists) {
+  do_flatten(lists, [])
+}
 
-//   let _ = flatten([[], [], []])
-//     |> expect:equal(_, [])
+test flatten {
+  let _ = flatten([])
+    |> expect:equal(_, [])
 
-//   flatten([[1, 2], [], [3, 4]])
-//     |> expect:equal(_, [1, 2, 3, 4])
-// }
+  let _ = flatten([[]])
+    |> expect:equal(_, [])
+
+  let _ = flatten([[], [], []])
+    |> expect:equal(_, [])
+
+  flatten([[1, 2], [], [3, 4]])
+    |> expect:equal(_, [1, 2, 3, 4])
+}
 
 pub fn foldl(list, acc, fun) {
   case list {