You know, it's a very pleasant surprise to me how many messages I've recently seen on this list that began "I'm just getting started with Racket and...." Great to see that the Racket community is growing.
On Thu, Oct 27, 2016 at 2:42 PM, Jos Koot <jos.k...@gmail.com> wrote: > Hi > > Lisp (and Racket) programmers know the value, Fortran (and assembler) > programmers the cost. > Nowadays the PLTeam is working on effeciency too, I think. > But: the most important factor for efficient programming is to select > efficient algorithms. > Two very simple, but notorious examples where you can go wrong in efficiency > with the algorithm > are Fibonacci numbers and binomial coefficients. > > Nowadays we have lots of primary memory, but long ago, with machines with > limited primary memory, > there was a time that for some computations it was faster to recompute than > to store to and retrieve from disk. > Much depends on the architecture of the computer, which in the old days was > documented very well, > so well that you could predict how data were flowing through the processors > (even with virtual memory). > Nowaday manufactures of computers give less information. > For a good estimation of the efficiency of a program > you have to know which busses are used, their numbers of bits and their > frequencies > and how well these busses connect to each other. > Well, a little bit of nostalgia. > > MHO, Jos > > -----Original Message----- > From: racket-users@googlegroups.com [mailto:racket-users@googlegroups.com] On > Behalf Of Ken MacKenzie > Sent: jueves, 27 de octubre de 2016 19:28 > To: Racket Users > Cc: deviloc...@gmail.com > Subject: Re: [racket-users] Structs vs Lists > > Thank you for the information. Good to know. Performance isn't the first > thing I am thinking about, but as I am tinkering and > getting running with Racket I like to kind of dig into the underlying > structure to know the cost of certain operations. > > Ken > >> For accessing an arbitrary member, yes. A Racket vector is like, say, a C >> array: it's a contiguous chunk of memory, and you can > get at any member of it in constant time. >> >> >> For other purposes? Depends on the purpose. A struct is superior to a list >> for struct-like operations. A list is superior to a > struct for list-like operations. >> > > -- > 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. -- 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.
