On Thu, May 15, 2008 at 9:58 PM, Gabriel Dos Reis wrote: > "Bill Page" <[EMAIL PROTECTED]> writes: > > | On Thu, May 15, 2008 at 5:57 AM, Gabriel Dos Reis wrote: > | > Bill Page writes: > | I agree with Waldek (in a different thread). I think the original > | developers of Axiom explicitly decided against variable name > | overloading. Do you know of any mainstream language where > | this is a common programming paradigm? > > I mention the `real' overload solution to counter the assertion > *must be a Union*. The `must' does not follow. >
Ok, granted. > As for a language that has overload on variable, well have a look > at Perl. It certainly is more mainstream than Spad. > I believe Perl uses name mangling (sigilia), doesn't it? http://en.wikipedia.org/wiki/Sigil_%28computer_programming%29 > ... > On another tone, it appears odd to me that one would argue for > overloaded constants (which OpenAxiom supports, as well as > other Axioms in one form or another), and at the same time > argue against overload of variables? What is the fundamental > reason? > One can guess or one can ask the original designers. :-) It would be extraordinarily inconvenient if one had to invent different names of common constants such as 0 and 1. These are members of many different domains. Constants are really a form of nullary operator and are treated uniformly with other exports. Do you agree? > | One of the design goals of a static strongly typed language is to > | ensure type correctness by associating static types with variables. > | Allowing variable overloading by type seems to defeat this purpose - > > How? I mean, constants are overloaded, why isn't that also defeating > the purpose -- assuming that is the case for variables? > Constants are, um well, constant. Their value does not/cannot depend on the execution history of the program. As such they are inherently "safe". > | especially when it is combined with implicit typing rules. > > How? Please be more specific. I mean that if I can write: y := x + 1 and expect the compiler to provide an implicit type for y based on knowledge of x, + and 1 where all of these potentially overloaded, the number of possibilities rises rapidly. The greater the number of possibilites, the greater that chance of making a type error. > > | Overloading constants (including functions) however is obviously very > | convenient and supported in all flavors plus Aldor. > > But, why isn't that also `defeating the purpose of static typing'? > Just because `it is claimed to be convenient'? That cannot be the > reason. > No. It is because constants are already static. > ... Regards, Bill Page. ------------------------------------------------------------------------- This SF.net email is sponsored by: Microsoft Defy all challenges. Microsoft(R) Visual Studio 2008. http://clk.atdmt.com/MRT/go/vse0120000070mrt/direct/01/ _______________________________________________ open-axiom-devel mailing list open-axiom-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/open-axiom-devel
