open
Open and cache large‑buffer appenders for FUN/VAR of the current run/target.
Ensures clean files exist, then returns append‑mode writers.
Return
StreamHandles with FUN and VAR buffered writers.
Open and cache large‑buffer appenders for FUN/VAR of the current run/target.
Ensures clean files exist, then returns append‑mode writers.
StreamHandles with FUN and VAR buffered writers.