1 files changed, 152 insertions, 0 deletions
diff --git a/gen/list.erl b/gen/list.erl
new file mode 100644
index 0000000..ae1ef24
--- /dev/null
+++ b/gen/list.erl
@@ -0,0 +1,152 @@
+-module(list).
+-include_lib("eunit/include/eunit.hrl").
+
+-export([length/1, reverse/1, is_empty/1, has_member/2, head/1, tail/1, map/2, new/0, foldl/3, foldr/3]).
+
+length(A) ->
+    erlang:length(A).
+
+-ifdef(TEST).
+length_test() ->
+    _ = fun(Capture1) -> expect:equal(Capture1, 0) end(length([])),
+    _ = fun(Capture1) -> expect:equal(Capture1, 1) end(length([1])),
+    _ = fun(Capture1) -> expect:equal(Capture1, 2) end(length([1, 1])),
+    fun(Capture1) -> expect:equal(Capture1, 3) end(length([1, 1, 1])).
+-endif.
+
+reverse(A) ->
+    erlang:reverse(A).
+
+-ifdef(TEST).
+reverse_test() ->
+    _ = fun(Capture1) -> expect:equal(Capture1, 0) end(length([])),
+    fun(Capture1) -> expect:equal(Capture1, 5) end(length([1, 2, 3, 4, 5])).
+-endif.
+
+is_empty(List) ->
+    List =:= [].
+
+-ifdef(TEST).
+is_empty_test() ->
+    _ = expect:true(is_empty([])),
+    expect:false(is_empty([1])).
+-endif.
+
+has_member(List, Elem) ->
+    case List of
+        [] ->
+            false;
+
+        [Head | Rest] ->
+            Head =:= Elem orelse has_member(Rest, Elem)
+    end.
+
+-ifdef(TEST).
+has_member_test() ->
+    _ = expect:true(has_member([0, 4, 5, 1], 1)),
+    _ = expect:false(has_member([0, 4, 5, 7], 1)),
+    expect:false(has_member([], 1)).
+-endif.
+
+head(List) ->
+    case List of
+        [] ->
+            {error, empty};
+
+        [X | Xs] ->
+            {ok, X}
+    end.
+
+-ifdef(TEST).
+head_test() ->
+    _ = fun(Capture1) ->
+        expect:equal(Capture1, {ok, 0})
+    end(head([0, 4, 5, 7])),
+    fun(Capture1) -> expect:equal(Capture1, {error, empty}) end(head([])).
+-endif.
+
+tail(List) ->
+    case List of
+        [] ->
+            {error, empty};
+
+        [X | Xs] ->
+            {ok, Xs}
+    end.
+
+-ifdef(TEST).
+tail_test() ->
+    _ = fun(Capture1) ->
+        expect:equal(Capture1, {ok, [4, 5, 7]})
+    end(tail([0, 4, 5, 7])),
+    _ = fun(Capture1) -> expect:equal(Capture1, {ok, []}) end(tail([0])),
+    fun(Capture1) -> expect:equal(Capture1, {error, empty}) end(tail([])).
+-endif.
+
+do_map(List, Fun, Acc) ->
+    case List of
+        [] ->
+            reverse(Acc);
+
+        [X | Xs] ->
+            do_map(Xs, Fun, [Fun(X) | Acc])
+    end.
+
+map(List, Fun) ->
+    do_map(List, Fun, []).
+
+-ifdef(TEST).
+map_test() ->
+    _ = fun(Capture1) ->
+        expect:equal(Capture1, [])
+    end(fun(Capture1) -> map(Capture1, fun(X) -> X * 2 end) end([])),
+    fun(Capture1) ->
+        expect:equal(Capture1, [0, 8, 10, 14, 6])
+    end(fun(Capture1) ->
+            map(Capture1, fun(X) -> X * 2 end)
+        end([0, 4, 5, 7, 3])).
+-endif.
+
+new() ->
+    [].
+
+-ifdef(TEST).
+new_test() ->
+    fun(Capture1) -> expect:equal(Capture1, []) end(new()).
+-endif.
+
+foldl(List, Acc, Fun) ->
+    case List of
+        [] ->
+            Acc;
+
+        [X | Rest] ->
+            foldl(Rest, Fun(X, Acc), Fun)
+    end.
+
+-ifdef(TEST).
+foldl_test() ->
+    fun(Capture1) ->
+        expect:equal(Capture1, [3, 2, 1])
+    end(fun(Capture1) ->
+            foldl(Capture1, [], fun(X, Acc) -> [X | Acc] end)
+        end([1, 2, 3])).
+-endif.
+
+foldr(List, Acc, Fun) ->
+    case List of
+        [] ->
+            Acc;
+
+        [X | Rest] ->
+            Fun(X, foldr(Rest, Acc, Fun))
+    end.
+
+-ifdef(TEST).
+foldr_test() ->
+    fun(Capture1) ->
+        expect:equal(Capture1, [1, 2, 3])
+    end(fun(Capture1) ->
+            foldr(Capture1, [], fun(X, Acc) -> [X | Acc] end)
+        end([1, 2, 3])).
+-endif.