Perl 6 Deep Dive

Generating data with supplies

In the previous section, values were sent to a supply using the emit method. For each data item, a separate call is done. Supplies can generate data themselves. The interval method of the Supply class emits data with the given interval. In the next example, it generates increasing numbers every 300 milliseconds:

Supply.interval(0.3).tap({    say $_; });sleep 5;

Every time a tap is triggered, it gets an increasing integer number. The first value is 0. Thus, the program above will print numbers from 0 to 16.

Calling the sleep function is needed here to see a few of the first results that the tap received. Without it, the program immediately stops.

By the way, if you want to use a named variable instead of $_, use ...