, get/2
, set/3
, update/3
+ , pop/2
, iter/2
, map/2
, filter/2
% TODO: Eliminate the 2nd lookup.
set(T, K, V2).
+pop(T1, K) ->
+ case lists:keytake(K, 1, T1)
+ of {value, {K, V}, T2} -> {{some, V}, T2}
+ ; false -> {none , T1}
+ end.
+
iter(T, F1) ->
F2 = lift_map(F1),
lists:foreach(F2, T).
fold(T, F1, Accumulator) ->
F2 = fun ({K, V}, Acc) -> F1(K, V, Acc) end,
- lists:foldl(F2, T, Accumulator).
+ lists:foldl(F2, Accumulator, T).
to_kv_list(T) ->
T.
%% Helpers
%% ============================================================================
+-spec lift_map(F) ->
+ G
+ when F :: fun(( K, V1 ) -> V2)
+ , G :: fun(({K, V1}) -> V2)
+ .
lift_map(F) ->
fun (X) -> apply_map(F, X) end.
+-spec apply_map(fun((K, V1) -> V2), {K, V1}) ->
+ V2.
apply_map(F, {K, V}) ->
F(K, V).