[chuck-users] While loop with condition =>NOW

Hi, In the flossmanuals i found this exemple of modulation of the freq of a SinOsc. Normally in the while() loop, between the brackets is the condition to keep the loop running. In the example it is a time. Complete confusion! Kind regards Herman SinOsc s => dac; SinOsc lfo; 5 => lfo.freq; while (20::ms => now) { ( lfo.last() * 10 ) + 440 => s.freq; }