If we read the doc, !prefix[fu]] is equivalent t !regexp[^fu]] (leaving aside case sensitivity).
But it is not, fo [[]!prefix[fu]then[OK]] does not produce OK but [[]!regexp[^fu]then[OK]] does.
Except in the case of a tiddler tagged with $:/tags/ViewTemplateBodyFilter where both hae a void output.
I think it would be better to raise issues at GitHub for problems like this one: Issues · Jermolene/TiddlyWiki5 · GitHub
Is this equivalent to [all[] ?
If so I can experiment with more confidence, keep in mind prefix came before regexp in tiddlywikis history abd if there is subtle difference it is with regexp most likely.
[[]prefix[fu]else[OK]]
It says for [all[cat]] “Unrecognised categories contribute nothing to the output”. so is this what an empyy all does?
Both produce OK for me when tested in Advanced Search:
No. It’s an empty string.
[[fiver]] [[four]] [[thr]] [[tw]] [[o]] [[]] :map[length[]]
<!-- ^--- empty string --->
yields
5 4 3 2 1 0
@vilc You’re right! How have I been tricked by myself here?
And now I can see there is no prlem with the $:/tags/ViewTemplateBodyFilter either.
A day where my performace is too poor. I’d rather call it a day as far as TW is concerned.
So I thank all of you for your help! May you accept my excuses too for the whole lot!
Here is a simplified tag filter that is working:
[prefix[todo-]then{!!text}!prefix[<<]then[$:/user/aims/templates/journal.template]]