Controles evaluation of identifiers / variables The evaluation brackets work a bit like $eval though you can add multiple things to evaluate at different levels at once.
Now %a is "sometext" and %b is "%a"
echo -a [ %b ] returns %a
This would echo "%a" since %b is evaluated once. Note that this is the same as just echoing %b
echo -a [ [ %b ] ] returns sometext
This would echo "sometext" since %b is first evaluated to "%a" and then %a is evaluated to "sometext".
Now lets see how it works out in more complex forms.
echo -a [ %a $+ [ %b ] ] returns sometext%a
This would echo "sometext%a" In this case %a is evaluated once and so is %b. Note that echoing [ %a $+ %b ] won't work.
echo -a [ %a $+ [ [ %b ] ] ] returns sometextsometext
This would echo "sometextsometext" since %a is evaluated once and %b twice.
var %name = fish var %surname = bot set % $+ %name $+ . $+ %surname m00 echo -a % [ $+ [ %name ] $+ . $+ [ %surname ] ] returns m00
This would set %fish.bot to "m00" and echo "m00".