improving functionals

[moodymudskipper]

taking inspiration from : https://gist.github.com/moodymudskipper/b41262109ef1065cb7c89c9bf351f8fd

We could either use those functions, with !~, or implement !~ "natively" in [.tb.

Problem is then how do we decide the output type ?

Solutions are :

• keep specific tag functions, but confusion, verbose, and possibly less efficient
• always have a list output, use unlist or conversions if necessary, stable but verbose for something that was supposed tobe simple
• use simplify2array() as sapply() does, not type stable
• have 2 latter options, but the issue is that these operators are found in the arguments, so to differentiate both approaches we'd need to inforce consistency and it might be a bit weird, though convenient...

I believe the 2 latter options are the most reasonable so we should start with option 3.

[moodymudskipper]

We went for ~~ and simplify array