diff options
Diffstat (limited to 'lib/stdlib/src/queue.erl')
| -rw-r--r-- | lib/stdlib/src/queue.erl | 16 |
1 files changed, 9 insertions, 7 deletions
diff --git a/lib/stdlib/src/queue.erl b/lib/stdlib/src/queue.erl index afe917b151..4bbf5de8a5 100644 --- a/lib/stdlib/src/queue.erl +++ b/lib/stdlib/src/queue.erl @@ -1,7 +1,7 @@ %% %% %CopyrightBegin% %% -%% Copyright Ericsson AB 1996-2011. All Rights Reserved. +%% Copyright Ericsson AB 1996-2013. 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 @@ -472,22 +472,24 @@ init(Q) -> drop_r(Q). -compile({inline, [{r2f,1},{f2r,1}]}). -%% Move all but two from R to F, if there are at least three +%% Move half of elements from R to F, if there are at least three r2f([]) -> {[],[]}; r2f([_]=R) -> {[],R}; r2f([X,Y]) -> {[X],[Y]}; -r2f([X,Y|R]) -> - {[X,Y],lists:reverse(R, [])}. +r2f(List) -> + {FF,RR} = lists:split(length(List) div 2 + 1, List), + {FF,lists:reverse(RR, [])}. -%% Move all but two from F to R, if there are enough +%% Move half of elements from F to R, if there are enough f2r([]) -> {[],[]}; f2r([_]=F) -> {F,[]}; f2r([X,Y]) -> {[Y],[X]}; -f2r([X,Y|F]) -> - {lists:reverse(F, []),[X,Y]}. +f2r(List) -> + {FF,RR} = lists:split(length(List) div 2 + 1, List), + {lists:reverse(RR, []),FF}. |