> On 10 Feb 2024, at 09:27, Al <frm...@mailgw.com> wrote: > > On 2024-02-10 10:13, Pietro Cerutti wrote: > >> I don't get your question: those two things are the same thing :) >> >> Referential transparency means you can substitute an expression with its >> expansion down to a value. If anything happening in between causes >> (observable *) changes, you can't do it anymore. >> >> (*) modifying the program counter is not an observable change, for example. >> > Those two things are the same thing in Haskell and languages that have a > mathematical model of the program, yes. Scheme is... not that, much of the > time. Chicken is implemented on top of C, so it's even less clear.
Both Haskell and CHICKEN ultimately compile to obiect code. That is not important: the important thing is the abstract machine you're programming against. This is why I specified "observable" in my previous reply. > But let's not get theoretical, yes, my question is if csc can (does?) > "memoize" the results of "pure" function. > > > In any case, the definitions I quoted above > > * https://wiki.call-cc.org/man/5/Declarations#pure > > * https://wiki.call-cc.org/man/5/Types#purity > > are not the same thing, so either the one or the other should stand. Though > I'm not sure what "local variables or data contained in local variables" > actually means. I think it means you can't "set!" globals. Yeah their wording is different but the meaning is the same, i.e., a --> function will be marked as pure (for the implementation, see the last value returned by validate-type in scrutinizer.scm). -- Pietro Cerutti I've pledged to give 10% of income to effective charities and invite you to join me. https://givingwhatwecan.org Sent from a small device - please excuse brevity and typos.
