On 27 October 2015 at 21:34, Waldek Hebisch <hebi...@math.uni.wroc.pl> wrote: > > Expanding on Bill's answer: this code is an abuse (wrong). The > core thing is that FriCAS list are homogeneous: all elements have > the same type. In Lisp lists are allowed to have elements of > different Lisp types. The integration routine returns two > machine float and one machine integer. On Lisp side Bill packs > this into a list. But on Spad side this List in an illegal > object, so Bill lies and tells Spad compiler that the list > contains DoubleFloat-s. Then he has to use 'pretend' to > tell Spad compiler that the third element is in fact an > integer. Currently this works, but will break down if > Spad compiler becomes only slightly smarter: claiming that > something is both DoubleFloat and Integer is a contradiction > and may lead to wrong code or compile time error. >
Yes, guilty. :) But this was only the first solution I could think of and so far this is just proof-of-concept code. There are other ways in Lisp of dealing with functions that return multiple values but this is only possible in FriCAS at a higher level, e.g. by use of Record. Perhaps there is some easy way of using routines already available in BOOT to construct a Record value directly? It would take me some time to find it. Do you know Waldek? Or can you suggest a different possible permanent solution? -- You received this message because you are subscribed to the Google Groups "FriCAS - computer algebra system" group. To unsubscribe from this group and stop receiving emails from it, send an email to fricas-devel+unsubscr...@googlegroups.com. To post to this group, send email to fricas-devel@googlegroups.com. Visit this group at http://groups.google.com/group/fricas-devel. For more options, visit https://groups.google.com/d/optout.
