Add generic module

Containing identity, always, flip, and compose functions.

1 files changed, 44 insertions, 0 deletions

diff --git a/gen/test/gleam@generic_test.erl b/gen/test/gleam@generic_test.erl
new file mode 100644
index 0000000..eecf650
--- /dev/null
+++ b/gen/test/gleam@generic_test.erl
@@ -0,0 +1,44 @@
+-module(gleam@generic_test).
+-compile(no_auto_import).
+
+-export([identity_test/0, always_test/0, flip_test/0, compose_test/0]).
+
+identity_test() ->
+    gleam@expect:equal(gleam@generic:identity(1), 1).
+
+always_test() ->
+    gleam@expect:equal(gleam@generic:always(1, 2), 2).
+
+flip_test() ->
+    Fun = fun(String, Int) ->
+        gleam@string:append(
+            gleam@string:append(
+                gleam@string:append(
+                    gleam@string:append(<<"String: '">>, String),
+                    <<"', Int: '">>
+                ),
+                gleam@int:to_string(Int)
+            ),
+            <<"'">>
+        )
+    end,
+    FlippedFun = gleam@generic:flip(Fun),
+    gleam@expect:equal(Fun(<<"Bob">>, 1), <<"String: 'Bob', Int: '1'">>),
+    gleam@expect:equal(
+        FlippedFun(2, <<"Alice">>),
+        <<"String: 'Alice', Int: '2'">>
+    ).
+
+compose_test() ->
+    AddTwo = fun(Int) -> Int + 2 end,
+    AddThree = fun(Int1) -> Int1 + 3 end,
+    AddFive = gleam@generic:compose(AddTwo, AddThree),
+    gleam@expect:equal(AddFive(1), 6),
+    HeadToString = gleam@generic:compose(
+        fun gleam@list:head/1,
+        fun(IntResult) ->
+            gleam@int:to_string(gleam@result:unwrap(IntResult, 0))
+        end
+    ),
+    gleam@expect:equal(HeadToString([1]), <<"1">>),
+    gleam@expect:equal(HeadToString([]), <<"0">>).