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-rw-r--r--lib/stdlib/src/lists.erl144
1 files changed, 117 insertions, 27 deletions
diff --git a/lib/stdlib/src/lists.erl b/lib/stdlib/src/lists.erl
index e73c087753..af9d63ddd6 100644
--- a/lib/stdlib/src/lists.erl
+++ b/lib/stdlib/src/lists.erl
@@ -1,18 +1,19 @@
%%
%% %CopyrightBegin%
%%
-%% Copyright Ericsson AB 1996-2011. All Rights Reserved.
+%% Copyright Ericsson AB 1996-2016. All Rights Reserved.
%%
-%% The contents of this file are subject to the Erlang Public License,
-%% Version 1.1, (the "License"); you may not use this file except in
-%% compliance with the License. You should have received a copy of the
-%% Erlang Public License along with this software. If not, it can be
-%% retrieved online at http://www.erlang.org/.
+%% Licensed under the Apache License, Version 2.0 (the "License");
+%% you may not use this file except in compliance with the License.
+%% You may obtain a copy of the License at
%%
-%% Software distributed under the License is distributed on an "AS IS"
-%% basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
-%% the License for the specific language governing rights and limitations
-%% under the License.
+%% http://www.apache.org/licenses/LICENSE-2.0
+%%
+%% Unless required by applicable law or agreed to in writing, software
+%% distributed under the License is distributed on an "AS IS" BASIS,
+%% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+%% See the License for the specific language governing permissions and
+%% limitations under the License.
%%
%% %CopyrightEnd%
%%
@@ -22,7 +23,7 @@
-compile({no_auto_import,[min/2]}).
-export([append/2, append/1, subtract/2, reverse/1,
- nth/2, nthtail/2, prefix/2, suffix/2, last/1,
+ nth/2, nthtail/2, prefix/2, suffix/2, droplast/1, last/1,
seq/2, seq/3, sum/1, duplicate/2, min/1, max/1, sublist/2, sublist/3,
delete/2,
unzip/1, unzip3/1, zip/2, zip3/3, zipwith/3, zipwith3/4,
@@ -33,15 +34,67 @@
keysort/2, keymerge/3, rkeymerge/3, rukeymerge/3,
ukeysort/2, ukeymerge/3, keymap/3]).
-%% Bifs: member/2, reverse/2
-%% Bifs: keymember/3, keysearch/3, keyfind/3
-
-export([merge/3, rmerge/3, sort/2, umerge/3, rumerge/3, usort/2]).
-export([all/2,any/2,map/2,flatmap/2,foldl/3,foldr/3,filter/2,
- partition/2,zf/2,
+ partition/2,zf/2,filtermap/2,
mapfoldl/3,mapfoldr/3,foreach/2,takewhile/2,dropwhile/2,splitwith/2,
- split/2]).
+ split/2,
+ join/2]).
+
+%%% BIFs
+-export([keyfind/3, keymember/3, keysearch/3, member/2, reverse/2]).
+
+%% Shadowed by erl_bif_types: lists:keyfind/3
+-spec keyfind(Key, N, TupleList) -> Tuple | false when
+ Key :: term(),
+ N :: pos_integer(),
+ TupleList :: [Tuple],
+ Tuple :: tuple().
+
+keyfind(_, _, _) ->
+ erlang:nif_error(undef).
+
+%% Shadowed by erl_bif_types: lists:keymember/3
+-spec keymember(Key, N, TupleList) -> boolean() when
+ Key :: term(),
+ N :: pos_integer(),
+ TupleList :: [Tuple],
+ Tuple :: tuple().
+
+keymember(_, _, _) ->
+ erlang:nif_error(undef).
+
+%% Shadowed by erl_bif_types: lists:keysearch/3
+-spec keysearch(Key, N, TupleList) -> {value, Tuple} | false when
+ Key :: term(),
+ N :: pos_integer(),
+ TupleList :: [Tuple],
+ Tuple :: tuple().
+
+keysearch(_, _, _) ->
+ erlang:nif_error(undef).
+
+%% Shadowed by erl_bif_types: lists:member/2
+-spec member(Elem, List) -> boolean() when
+ Elem :: T,
+ List :: [T],
+ T :: term().
+
+member(_, _) ->
+ erlang:nif_error(undef).
+
+%% Shadowed by erl_bif_types: lists:reverse/2
+-spec reverse(List1, Tail) -> List2 when
+ List1 :: [T],
+ Tail :: term(),
+ List2 :: [T],
+ T :: term().
+
+reverse(_, _) ->
+ erlang:nif_error(undef).
+
+%%% End of BIFs
%% member(X, L) -> (true | false)
%% test if X is a member of the list L
@@ -84,7 +137,7 @@ append([]) -> [].
subtract(L1, L2) -> L1 -- L2.
-%% reverse(L) reverse all elements in the list L. Is now a BIF!
+%% reverse(L) reverse all elements in the list L. reverse/2 is now a BIF!
-spec reverse(List1) -> List2 when
List1 :: [T],
@@ -152,6 +205,19 @@ suffix(Suffix, List) ->
Delta = length(List) - length(Suffix),
Delta >= 0 andalso nthtail(Delta, List) =:= Suffix.
+%% droplast(List) returns the list dropping its last element
+
+-spec droplast(List) -> InitList when
+ List :: [T, ...],
+ InitList :: [T],
+ T :: term().
+
+%% This is the simple recursive implementation
+%% reverse(tl(reverse(L))) is faster on average,
+%% but creates more garbage.
+droplast([_T]) -> [];
+droplast([H|T]) -> [H|droplast(T)].
+
%% last(List) returns the last element in a list.
-spec last(List) -> Last when
@@ -579,8 +645,9 @@ flatlength([H|T], L) when is_list(H) ->
flatlength([_|T], L) ->
flatlength(T, L + 1);
flatlength([], L) -> L.
-
+
%% keymember(Key, Index, [Tuple]) Now a BIF!
+%% keyfind(Key, Index, [Tuple]) A BIF!
%% keysearch(Key, Index, [Tuple]) Now a BIF!
%% keydelete(Key, Index, [Tuple])
%% keyreplace(Key, Index, [Tuple], NewTuple)
@@ -1111,7 +1178,7 @@ rumerge(T1, []) ->
T1;
rumerge(T1, [H2 | T2]) ->
lists:reverse(rumerge2_1(T1, T2, [], H2), []).
-
+
%% all(Predicate, List)
%% any(Predicate, List)
%% map(Function, List)
@@ -1126,8 +1193,7 @@ rumerge(T1, [H2 | T2]) ->
%% takewhile(Predicate, List)
%% dropwhile(Predicate, List)
%% splitwith(Predicate, List)
-%% for list programming. Function here is a 'fun'. For backward compatibility,
-%% {Module,Function} is still accepted.
+%% for list programming. Function here is a 'fun'.
%%
%% The name zf is a joke!
%%
@@ -1240,18 +1306,28 @@ partition(Pred, [H | T], As, Bs) ->
partition(Pred, [], As, Bs) when is_function(Pred, 1) ->
{reverse(As), reverse(Bs)}.
--spec zf(fun((T) -> boolean() | {'true', X}), [T]) -> [(T | X)].
+-spec filtermap(Fun, List1) -> List2 when
+ Fun :: fun((Elem) -> boolean() | {'true', Value}),
+ List1 :: [Elem],
+ List2 :: [Elem | Value],
+ Elem :: term(),
+ Value :: term().
-zf(F, [Hd|Tail]) ->
+filtermap(F, [Hd|Tail]) ->
case F(Hd) of
true ->
- [Hd|zf(F, Tail)];
+ [Hd|filtermap(F, Tail)];
{true,Val} ->
- [Val|zf(F, Tail)];
+ [Val|filtermap(F, Tail)];
false ->
- zf(F, Tail)
+ filtermap(F, Tail)
end;
-zf(F, []) when is_function(F, 1) -> [].
+filtermap(F, []) when is_function(F, 1) -> [].
+
+-spec zf(fun((T) -> boolean() | {'true', X}), [T]) -> [(T | X)].
+
+zf(F, L) ->
+ filtermap(F, L).
-spec foreach(Fun, List) -> ok when
Fun :: fun((Elem :: T) -> term()),
@@ -1364,6 +1440,18 @@ split(N, [H|T], R) ->
split(_, [], _) ->
badarg.
+-spec join(Sep, List1) -> List2 when
+ Sep :: T,
+ List1 :: [T],
+ List2 :: [T],
+ T :: term().
+
+join(_Sep, []) -> [];
+join(Sep, [H|T]) -> [H|join_prepend(Sep, T)].
+
+join_prepend(_Sep, []) -> [];
+join_prepend(Sep, [H|T]) -> [Sep,H|join_prepend(Sep,T)].
+
%%% =================================================================
%%% Here follows the implementation of the sort functions.
%%%
@@ -2192,6 +2280,8 @@ ukeysplit_2(I, Y, EY, [Z | L], R) ->
ukeysplit_2(_I, Y, _EY, [], R) ->
[Y | R].
+-dialyzer({no_improper_lists, ukeymergel/3}).
+
ukeymergel(I, [T1, [H2 | T2], [H3 | T3] | L], Acc) ->
%% The fourth argument, [H2 | H3] (=HdM), may confuse type
%% checkers. Its purpose is to ensure that the tests H2 == HdM
generated by cgit v1.2.3 (git 2.25.1) at 2025-05-22 08:50:07 +0000