Danny, Thanks for the explanations. These are powerful ideas. It appears not to generate the sequence until needed, very nice.
How could I modify this to do the "less than n" idea? -joe On Mon, Feb 13, 2012 at 9:20 PM, Danny Yoo <d...@cs.wpi.edu> wrote: > > (let ([fib-sequence (in-producer fib 'donttellmecauseithurts)]) > > I realize that I forgot to add explanation. > > This line creates a "sequence" by repeatedly calling your fib > function. in-producer will continue to call fib until it sees the > second argument. But since the fibonacci numbers don't end, I want to > tell in-producer to go on forever, so I passed it something that fib > won't ever produce. > > ... and It's from a song by the music group No Doubt. Why? Dunno. > Valentine's Day brought it to mind for some reason. :) > > > The second part: > > ;; Let's wrap it and turn it into a stream that remembers... > (sequence->stream fib-sequence) > > turns the sequence into another sequence. But this one will remember > its previous values as we walk across it. > > > So when we do start walking the streamified sequence, we can do that > repeatedly without losing the old values. >
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