comment's terminator shouldn't be a period

3.15: adda/comment/terminator shouldn't be a period:
. if using the period to end a comment,
then it's messy to use periods for
segmenting parentheticals;
conversely, it's not user-friendly either to
impose syntax on users' comments,
or make additional arbitrary rules .
. better to have syntax reusing other rules;
eg, use the [this is one lexical unit].enclosure
along with a comment operator:
--[here is a fine comment]
and then not use double dash
for any other operator .