The ..currentTiddler and currentTiddler inside a Function

[kookma]

• open https://tiddlywiki.com/
• Create a tiddler with below script

\procedure getType() [<..currentTiddler>addsuffix[ → ]addsuffix<currentTiddler>]
\function f.getType() [<..currentTiddler>addsuffix[ → ]addsuffix<currentTiddler>]

--- Direct filter

<$tiddler tiddler="HelloThere">
<$list
  filter="[all[current]links[]limit[5]]  
          :map[<..currentTiddler>addsuffix[ → ]addsuffix<currentTiddler>]">
<<currentTiddler>><br>
</$list>

</$tiddler>

--- With procedure

<$tiddler tiddler="HelloThere">
<$list
  filter="[all[current]links[]limit[5]]  
          :map[subfilter<getType>]">
<<currentTiddler>><br>
</$list>

</$tiddler>

--- With function

<$tiddler tiddler="HelloThere">
<$list
  filter="[all[current]links[]limit[5]]  
          :map[f.getType[]]">
<<currentTiddler>><br>
</$list>

</$tiddler>

This will produces

— Direct filter

HelloThere → TiddlyWiki
HelloThere → Philosophy of Tiddlers
HelloThere → Creating and editing tiddlers
HelloThere → Structuring TiddlyWiki
HelloThere → Sharing your tiddlers with others
— With procedure

HelloThere → TiddlyWiki
HelloThere → Philosophy of Tiddlers
HelloThere → Creating and editing tiddlers
HelloThere → Structuring TiddlyWiki
HelloThere → Sharing your tiddlers with others
— With function

→ HelloThere
→ HelloThere
→ HelloThere
→ HelloThere
→ HelloThere

That means the ..currentTiddler is not known inside a function and currentTiddler also refers to the value of the variable currentTiddler outside the filter run. Note that in the first two examples (direct use of ..currentTiddler in :map and subfilter) work as expected.

NOTE
If I change function like this: \function f.getType() [get[title]addprefix[ → ]addprefix<currentTiddler>], it will produce the correct answer.

Question
Is this the correct behaviour for function used inside a filter run prefix (here :map, but :sort and other filter run prefix may be used)?

[saqimtiaz]

There is a know bug to do with functions and the value of currentTiddler, see #8178

[kookma]

Thank you @saqimtiaz
Testing on https://tiddlywiki.com/prerelease/ seems my above function works correctly!