Ok, thanks for this information. I am in the process of modifying my code, I heavily used the '==' form. Replacing '==' with '==>' does not work for SubDomain though.
BTW it seems a lot of code in FriCAS algebra uses '=='. Regards, - Greg Le mer. 29 nov. 2023 à 15:56, Waldek Hebisch <de...@fricas.org> a écrit : > > On Wed, Nov 29, 2023 at 02:51:52PM +0100, Grégory Vanuxem wrote: > > Hello, > > > > In Spad, with Exports or Implementation the macro or function > > definition operators can be used. What I mean is that: > > > > Exports == with > > Implementation == add > > > > seems to be identically treated with: > > > > Exports ==> with > > Implementation ==> add > > > > The two seem to compile identically (I have not looked at the Lisp > > code generated). > > > > So my questions are: are these pieces of code treated identically by > > the compiler, if not, is the second piece of code treated as a macro? > > And what is the difference? > > The second one, that is '==>' is the one which should be used. Yes, > '==>' is treated as a macro, it replaces symbol on the left hand side by > parse tree of thing on the right hand side. Difference is that '==' is > a definition, thing on the right hand side of '==' is supposed to have a > value. So '==' should work at semantic level, while '==>' works at syntactic > level. > > Currently semantic handling in Spad compiler has troubles at early > stage of compilation, so in some place '==' is treated as '==>'. > And in some other places '==' may fail when '==>' works. > But if semantic handling is improved differences may show up and > there is possiblity of errors when wrong thing is in use. > > Note: differences between the two are rather subtle, so in most > cases either should work. > > Remark: FriCAS book say that '==' is "delayed assignment". This > meaning should be considered obsolete now. > > -- > Waldek Hebisch > > -- > 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 view this discussion on the web visit > https://groups.google.com/d/msgid/fricas-devel/ZWdRC-jyKtJpYIe1%40fricas.org. -- 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 view this discussion on the web visit https://groups.google.com/d/msgid/fricas-devel/CAHnU2dZ7JC8TK_aMCDN5%2B%3DD6cdaz%2B7ovgseuKaojainY5cLyBQ%40mail.gmail.com.
