Lookahead in a Stream (without "consuming" its next element?)

[elgiano]

Check out this discussion:

Event Pattern to scramble events

Hi there, I’m trying to write a Pattern that will scramble Events (reorder them in time). Of course, this needs to be “look ahead”, so I do like Pfindur and ask for events up to a specified duration, store them, then scramble them and return. I’ve got it mostly working, but it fails when I afterwards combine the scrambled events with other patterns (e.g. chaining). Here’s an example of what I’ve got: // (see definition of Pscramble and Pattern.scramble below) // Works as expected (random Eve…

I also don’t know if this is possible on Streams. At least it is possible on Patterns:

Pseq([0,1,2,3]).asStream.next // always 0, as Stream is always a copy
Prout{ (0..10).do(_.yield)}.asStream.next // same, embedding a custom routine function

The trick seems to be that .asStream actually creates a new stream.
One way to do it with routines would be to create a new routine from the same function, if we only had read access to its internal function (it’s a read-only variable).