hello Waldek, hello folks, Le mer. 20 mars 2024 à 22:28, Waldek Hebisch <de...@fricas.org> a écrit : > > On Wed, Mar 20, 2024 at 07:41:11PM +0100, Grégory Vanuxem wrote: > > Hello, > > > > Do you happen to know why the declaration of string(Integer) is in > > StringCategory and its definition in the String domain? > > (STRINGIMAGE$Lisp) > > 'string' constructs a String and as all functions of similar sort > is defined in corresponding domain. As usual, 'string' is declared > in corresponding category, that is StringCategory
Yes, of course. I was just wondering why String(__Integer_) was declared there instead of a generic declaration like: string : % -> String That way, like Symbol, it can be defined in the Integer domain and thus avoid unexpected effects during interpreter coercion mechanisms. I encountered this with other integer related domains like another prime field domain, another integer mod domain... etc. In fact, instead of declaring string : % -> String in those domains I declare it at a 'Category' level and that solved this. To be more precise, I do not ask for its implementation, having a way to obtain an ASCII string representation of every Spad object would be handy I find. Even string(Type) like string(Integer) => "Integer". I guess this exists somewhere in Spad but I have not found where. A good candidate to use it could be the 'error' function. There seems to be no implicit rules to use this function and from memory I have seen an error like "Not invertible". Franckly, imagine you have a lot of code with integers, matrices etc. and you see this error. Euh... Not a field? rectangular matrix? Singular maybe? And so on. Personally I like to know the function who throws the error and more information could be handy. For example string(%) could be of use. I only know the 'latex' function declared in SetCategory that resembles but it is a typesetting function, not a simple string function. ,> > > That way if someone adds a domain, say, Foo, that has an Integer to > > Foo coercion and exports a 'string' operation the interpreter will > > choose the Foo one. It's a bit of a shame, isn't it? > > Well, that is how Spad overloading works: if you have two ways > they should give the same result or you need to be more specific > (hide Foo, add explicit '$Integer' etc.). If Foo can be coerced > to Integer, then maybe 'string' in Foo is not needed at all. Yes, but from my point of view string(Integer) should not be overloaded, it is up to the Integer domain author/programmer to handle this coercion Integer -> String. There is 'convert@String' though, but it uses 'string': convert(x : %) : String == string(x pretend Integer)$String > > Also, note that interpreter coercions are tuned to existing set > of domains. When you add new domains (or new operations to existing > domains) with current rules interpreter can make undesirable > choice. That is a shame, when adding exposed operations we need > to take into account what interpreter will do, or modify > interpreter to change its rules. I totally agree. > Ideally there should be a > user level way to add or remove interpreter inference rules. Ideally, yes. - Greg > > -- > 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/ZftU-WcPThCruCpy%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/CAHnU2dbuU7Pmssyc9yyJZcbWKnLsDEVdtxe7i0%3DYssOA3f4%3DDw%40mail.gmail.com.
