Types and specifications have been modified and added

1 files changed, 113 insertions, 34 deletions

diff --git a/lib/stdlib/src/gb_sets.erl b/lib/stdlib/src/gb_sets.erl
index fc5beb28b0..91d21d869c 100644
--- a/lib/stdlib/src/gb_sets.erl
+++ b/lib/stdlib/src/gb_sets.erl
@@ -197,6 +197,7 @@
 %% Some types.
 
 -type gb_set_node() :: 'nil' | {term(), _, _}.
+-opaque iter() :: [gb_set_node()].
 
 %% A declaration equivalent to the following is currently hard-coded
 %% in erl_types.erl
@@ -205,38 +206,47 @@
 
 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 
--spec empty() -> gb_set().
+-spec empty() -> Set when
+      Set :: gb_set().
 
 empty() ->
     {0, nil}.
 
--spec new() -> gb_set().
+-spec new() -> Set when
+      Set :: gb_set().
 
 new() -> empty().
 
--spec is_empty(gb_set()) -> boolean().
+-spec is_empty(Set) -> boolean() when
+      Set :: gb_set().
 
 is_empty({0, nil}) ->
     true;
 is_empty(_) ->
     false.
 
--spec size(gb_set()) -> non_neg_integer().
+-spec size(Set) -> non_neg_integer() when
+      Set :: gb_set().
 
 size({Size, _}) ->
     Size.
 
--spec singleton(term()) -> gb_set().
+-spec singleton(Element) -> gb_set() when
+      Element :: term().
 
 singleton(Key) ->
     {1, {Key, nil, nil}}.
 
--spec is_element(term(), gb_set()) -> boolean().
+-spec is_element(Element, Set) -> boolean() when
+      Element :: term(),
+      Set :: gb_set().
 
 is_element(Key, S) ->
     is_member(Key, S).
 
--spec is_member(term(), gb_set()) -> boolean().
+-spec is_member(Element, Set) -> boolean() when
+      Element :: term(),
+      Set :: gb_set().
 
 is_member(Key, {_, T}) ->
     is_member_1(Key, T).
@@ -250,7 +260,10 @@ is_member_1(_, {_, _, _}) ->
 is_member_1(_, nil) ->
     false.
 
--spec insert(term(), gb_set()) -> gb_set().
+-spec insert(Element, Set1) -> Set2 when
+      Element :: term(),
+      Set1 :: gb_set(),
+      Set2 :: gb_set().
 
 insert(Key, {S, T}) ->
     S1 = S + 1,
@@ -306,7 +319,9 @@ count({_, Sm, Bi}) ->
 count(nil) ->
     {1, 0}.
 
--spec balance(gb_set()) -> gb_set().
+-spec balance(Set1) -> Set2 when
+      Set1 :: gb_set(),
+      Set2 :: gb_set().
 
 balance({S, T}) ->
     {S, balance(T, S)}.
@@ -331,12 +346,18 @@ balance_list_1([Key | L], 1) ->
 balance_list_1(L, 0) ->
     {nil, L}.
 
--spec add_element(term(), gb_set()) -> gb_set().
+-spec add_element(Element, Set1) -> Set2 when
+      Element :: term(),
+      Set1 :: gb_set(),
+      Set2 :: gb_set().
 
 add_element(X, S) ->
     add(X, S).
 
--spec add(term(), gb_set()) -> gb_set().
+-spec add(Element, Set1) -> Set2 when
+      Element :: term(),
+      Set1 :: gb_set(),
+      Set2 :: gb_set().
 
 add(X, S) ->
     case is_member(X, S) of
@@ -346,23 +367,33 @@ add(X, S) ->
 	    insert(X, S)
     end.
 
--spec from_list([term()]) -> gb_set().
+-spec from_list(List) -> Set when
+      List :: [term()],
+      Set :: gb_set().
 
 from_list(L) ->
     from_ordset(ordsets:from_list(L)).
 
--spec from_ordset([term()]) -> gb_set().
+-spec from_ordset(List) -> Set when
+      List :: [term()],
+      Set :: gb_set().
 
 from_ordset(L) ->
     S = length(L),
     {S, balance_list(L, S)}.
 
--spec del_element(term(), gb_set()) -> gb_set().
+-spec del_element(Element, Set1) -> Set2 when
+      Element :: term(),
+      Set1 :: gb_set(),
+      Set2 :: gb_set().
 
 del_element(Key, S) ->
     delete_any(Key, S).
 
--spec delete_any(term(), gb_set()) -> gb_set().
+-spec delete_any(Element, Set1) -> Set2 when
+      Element :: term(),
+      Set1 :: gb_set(),
+      Set2 :: gb_set().
 
 delete_any(Key, S) ->
     case is_member(Key, S) of
@@ -372,7 +403,10 @@ delete_any(Key, S) ->
  	    S
     end.
 
--spec delete(term(), gb_set()) -> gb_set().
+-spec delete(Element, Set1) -> Set2 when
+      Element :: term(),
+      Set1 :: gb_set(),
+      Set2 :: gb_set().
 
 delete(Key, {S, T}) ->
     {S - 1, delete_1(Key, T)}.
@@ -394,7 +428,10 @@ merge(Smaller, Larger) ->
     {Key, Larger1} = take_smallest1(Larger),
     {Key, Smaller, Larger1}.
 
--spec take_smallest(gb_set()) -> {term(), gb_set()}.
+-spec take_smallest(Set1) -> {Element, Set2} when
+      Set1 :: gb_set(),
+      Set2 :: gb_set(),
+      Element :: term().
 
 take_smallest({S, T}) ->
     {Key, Larger} = take_smallest1(T),
@@ -406,7 +443,8 @@ take_smallest1({Key, Smaller, Larger}) ->
     {Key1, Smaller1} = take_smallest1(Smaller),
     {Key1, {Key, Smaller1, Larger}}.
 
--spec smallest(gb_set()) -> term().
+-spec smallest(Set) -> term() when
+      Set :: gb_set().
 
 smallest({_, T}) ->
     smallest_1(T).
@@ -416,7 +454,10 @@ smallest_1({Key, nil, _Larger}) ->
 smallest_1({_Key, Smaller, _Larger}) ->
     smallest_1(Smaller).
 
--spec take_largest(gb_set()) -> {term(), gb_set()}.
+-spec take_largest(Set1) -> {Element, Set2} when
+      Set1 :: gb_set(),
+      Set2 :: gb_set(),
+      Element :: term().
 
 take_largest({S, T}) ->
     {Key, Smaller} = take_largest1(T),
@@ -428,7 +469,8 @@ take_largest1({Key, Smaller, Larger}) ->
     {Key1, Larger1} = take_largest1(Larger),
     {Key1, {Key, Smaller, Larger1}}.
 
--spec largest(gb_set()) -> term().
+-spec largest(Set) -> term() when
+      Set :: gb_set().
 
 largest({_, T}) ->
     largest_1(T).
@@ -438,7 +480,9 @@ largest_1({Key, _Smaller, nil}) ->
 largest_1({_Key, _Smaller, Larger}) ->
     largest_1(Larger).
 
--spec to_list(gb_set()) -> [term()].
+-spec to_list(Set) -> List when
+      Set :: gb_set(),
+      List :: [term()].
 
 to_list({_, T}) ->
     to_list(T, []).
@@ -449,7 +493,9 @@ to_list({Key, Small, Big}, L) ->
     to_list(Small, [Key | to_list(Big, L)]);
 to_list(nil, L) -> L.
 
--spec iterator(gb_set()) -> [term()].
+-spec iterator(Set) -> Iter when
+      Set :: gb_set(),
+      Iter :: iter().
 
 iterator({_, T}) ->
     iterator(T, []).
@@ -464,7 +510,10 @@ iterator({_, L, _} = T, As) ->
 iterator(nil, As) ->
     As.
 
--spec next([term()]) -> {term(), [term()]} | 'none'.
+-spec next(Iter1) -> {Element, Iter2} | 'none' when
+      Iter1 :: iter(),
+      Iter2 :: iter(),
+      Element :: term().
 
 next([{X, _, T} | As]) ->
     {X, iterator(T, As)};
@@ -494,7 +543,10 @@ next([]) ->
 %% traversing the elements can be devised, but they all have higher
 %% overhead.
 
--spec union(gb_set(), gb_set()) -> gb_set().
+-spec union(Set1, Set2) -> Set3 when
+      Set1 :: gb_set(),
+      Set2 :: gb_set(),
+      Set3 :: gb_set().
 
 union({N1, T1}, {N2, T2}) when N2 < N1 ->
     union(to_list_1(T2), N2, T1, N1);
@@ -596,7 +648,9 @@ balance_revlist_1([Key | L], 1) ->
 balance_revlist_1(L, 0) ->
     {nil, L}.
 
--spec union([gb_set()]) -> gb_set().
+-spec union(SetList) -> Set when
+      SetList :: [gb_set(),...],
+      Set :: gb_set().
 
 union([S | Ss]) ->
     union_list(S, Ss);
@@ -609,7 +663,10 @@ union_list(S, []) -> S.
 
 %% The rest is modelled on the above.
 
--spec intersection(gb_set(), gb_set()) -> gb_set().
+-spec intersection(Set1, Set2) -> Set3 when
+      Set1 :: gb_set(),
+      Set2 :: gb_set(),
+      Set3 :: gb_set().
 
 intersection({N1, T1}, {N2, T2}) when N2 < N1 ->
     intersection(to_list_1(T2), N2, T1, N1);
@@ -657,7 +714,9 @@ intersection_2([], _, As, S) ->
 intersection_2(_, [], As, S) ->
     {S, balance_revlist(As, S)}.
 
--spec intersection([gb_set(),...]) -> gb_set().
+-spec intersection(SetList) -> Set when
+      SetList :: [gb_set(),...],
+      Set :: gb_set().
 
 intersection([S | Ss]) ->
     intersection_list(S, Ss).
@@ -666,7 +725,9 @@ intersection_list(S, [S1 | Ss]) ->
     intersection_list(intersection(S, S1), Ss);
 intersection_list(S, []) -> S.
 
--spec is_disjoint(gb_set(), gb_set()) -> boolean().
+-spec is_disjoint(Set1, Set2) -> boolean() when
+      Set1 :: gb_set(),
+      Set2 :: gb_set().
 
 is_disjoint({N1, T1}, {N2, T2}) when N1 < N2 ->
     is_disjoint_1(T1, T2);
@@ -694,12 +755,18 @@ is_disjoint_1(_, nil) ->
 %% the sets. Therefore, we always build a new tree, and thus we need to
 %% traverse the whole element list of the left operand.
 
--spec subtract(gb_set(), gb_set()) -> gb_set().
+-spec subtract(Set1, Set2) -> Set3 when
+      Set1 :: gb_set(),
+      Set2 :: gb_set(),
+      Set3 :: gb_set().
 
 subtract(S1, S2) ->
     difference(S1, S2).
 
--spec difference(gb_set(), gb_set()) -> gb_set().
+-spec difference(Set1, Set2) -> Set3 when
+      Set1 :: gb_set(),
+      Set2 :: gb_set(),
+      Set3 :: gb_set().
 
 difference({N1, T1}, {N2, T2}) ->
     difference(to_list_1(T1), N1, T2, N2).
@@ -747,7 +814,9 @@ difference_2(Xs, [], As, S) ->
 %% Subset testing is much the same thing as set difference, but
 %% without the construction of a new set.
 
--spec is_subset(gb_set(), gb_set()) -> boolean().
+-spec is_subset(Set1, Set2) -> boolean() when
+      Set1 :: gb_set(),
+      Set2 :: gb_set().
 
 is_subset({N1, T1}, {N2, T2}) ->
     is_subset(to_list_1(T1), N1, T2, N2).
@@ -788,18 +857,28 @@ is_subset_2(_, []) ->
 
 %% For compatibility with `sets':
 
--spec is_set(term()) -> boolean().
+-spec is_set(Term) -> boolean() when
+      Term :: term().
 
 is_set({0, nil}) -> true;
 is_set({N, {_, _, _}}) when is_integer(N), N >= 0 -> true;
 is_set(_) -> false.
 
--spec filter(fun((term()) -> boolean()), gb_set()) -> gb_set().
+-spec filter(Pred, Set1) -> Set2 when
+      Pred :: fun((E :: term()) -> boolean()),
+      Set1 :: gb_set(),
+      Set2 :: gb_set().
 
 filter(F, S) ->
     from_ordset([X || X <- to_list(S), F(X)]).
 
--spec fold(fun((term(), term()) -> term()), term(), gb_set()) -> term().
+-spec fold(Function, Acc0, Set) -> Acc1 when
+      Function :: fun((E :: term(), AccIn) -> AccOut),
+      Acc0 :: term(),
+      Acc1 :: term(),
+      AccIn :: term(),
+      AccOut :: term(),
+      Set :: gb_set().
 
 fold(F, A, {_, T}) when is_function(F, 2) ->
     fold_1(F, A, T).