() of text () is a reporter block and is a operators block. It reports the length of a given text, or the all-lowercase or the all-uppercase forms of the text.
([length v] of text [world]::operators) //5 ([lower case v] of text [World]::operators) //world ([upper case v] of text [world]::operators) //WORLD
It can be used to decide who wins in a length-based typing competition:
if <([length v] of text (P1 text)::operators) \> ([length v] of text (P2 text)::operators)> {
say [The winner is Player 1]
} else {
say [The winner is Player 2]
}::control
([length v] of (split [hello world] by (letter v)::operators)::list)