log:collectAllIn passes multiple times

[tpluscode]

Consider this rule

prefix log: <http://www.w3.org/2000/10/swap/log#>
prefix ex: <http://example.com/>

[
  ex:arg "1", "2", "3"
] .

{
   (
    ?arg
    {
      [ ex:arg ?arg ] .
    }
    ?args
  ) log:collectAllIn [] .

  ?args^log:trace .
} => {
  [] ex:combined ?args
} .

While the result is only a single triple with a list object, eye prints the log:trace line multiple times. This is a problem for me because in my actual rule, this is followed by calls with side effects so I need to ensure that the list is collected and "consumed" only once.

I can apply the same trick with log:becomes and contextual flag that @josd suggested before but I'm wondering if maybe the above behaviour is indeed not expected...

[tpluscode]

Curiously, when I run with --pass, the log appears three times. But when I run with --pass-only-new or no --pass* flag, only two traces are printed.

[josd]

This is because of how EYE basically works

% ----------------------------
% EAM (Euler Abstract Machine)
% ----------------------------
%
% In a nutshell:
%
% 1/ Select rule P => C
% 2/ Prove P & NOT(C) (backward chaining) and if it fails backtrack to 1/
% 3/ If P & NOT(C) assert C (forward chaining) and remove brake
% 4/ If C = answer(A) and tactic limited-answer stop, else backtrack to 2/
% 5/ If brake or tactic linear-select stop, else start again at 1/
%

so the "start again at 1/" and it can be many times in some cases.

[tpluscode]

So I thought. In this case it is apparently as many times as there are list items although I'm surprised the behaviour changes slightly with the different flags being used