> On Oct 30, 2016, at 11:02 AM, meino.cra...@gmx.de wrote: > > Hi, > > (still fiddling around with those data of shortwave broadcasters and > their schedules...) > > The data in question consists of 7400 lines of 16 fields each. Not all > fields are filled in eacht line. The already existing code reads the > data into lists of sublists of 16 fields/items. > > I want to prepare those data in a way, that I will be able to do searches > like "give me all broadcaster, which broadcasts are in English. > Furthermore give me broadcasts on Thursdays only between 5:30 > pm and 8:00 pm on bands between 9000Khz and 12000khz”.
This looks like a “one-liner” to me in Racket: (filter (lambda (r) (and (language-is r English) (broadcast-day-is Thursday) (broadcast-time-is-between 5:30 8:00) (broadcast-frequencies-are-between 9000 12000)) list-of-data) What’s not linear about this? — Matthias > > For the learning effect I want to do this in racket onlu and (despite > knowing that this may be a better solultion performance wise) dont > want to use tools like sqlite or such. > > What I read/think is: > Lists processing is not linear: The longer the list, the slower the > data processing. > Hashes are somehow problematic due to the data: > There is no real unique key beside an artificial, additonally created > ID....which is of no information to the user... > Vectors? Linear performance in opposite to lists...but searching > in a vector of vectors ,,, is that sane enough to be implementable? ;) > What else? > > > Cheers, > Meino > > -- > You received this message because you are subscribed to the Google Groups > "Racket Users" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to racket-users+unsubscr...@googlegroups.com. > For more options, visit https://groups.google.com/d/optout. -- You received this message because you are subscribed to the Google Groups "Racket Users" group. To unsubscribe from this group and stop receiving emails from it, send an email to racket-users+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
