Mailing List Archive: 49091 messages
  • Home
  • Script library
  • AltME Archive
  • Mailing list
  • Articles Index
  • Site search

[REBOL] Re: Does the REBOL book clarify REBOL semantics?

From: sw:paradise at: 22-Nov-2000 18:28

At 12:31 21/11/00 +0100, the illustrious Gabriele wrote:
>j-sw wrote: > >> There doesn't seem to be a place in the manual where >> this crucial matter is explained in terms of say >> 'by copy', 'by value', 'by reference', etc - conventional >> usage that can clarify matters greatly. > >This is because REBOL just passes values. Some REBOL values are >immutable (=> "passed by value"), some (mainly SERIES!) are >mutable (=> "passed by reference"). > >The use of 'word or :word in function definitions fro argument >names changes the way function arguments are retrieved, not how >they are passed. 'word means: if the argument is a word, don't >evaluate it, but just pass the word, as if it was a lit-word; >:word means: if the argument is a word, pass its value without >evaluating it; otherwise just pass the next value without >evaluating it. > >If you find this unclear, just let me know, and I'll try to >explain it better.
Thanks for the notions of "mutable" and "immutable". I shall be having a look at the relevant parts of the manual and considering these in light of what you and Andrew Martin have said so far. Q. Are these notions in Scheme and are there parallels? Q. If yes, is there a close mapping between the use of the terms in the two languages? If yes then if I look up these terms in Scheme I can get more info. With thanks. s narayan s (aka j-sw) --examining other world views