Don Wrote: > Lutger wrote: > > Justin Johansson wrote: > > > >> Lutger Wrote: > >> > >>> Justin Johansson wrote: > >>> > >>>> I assert that the semantics of "toString" or similarly named/purposed > >>>> methods/functions in many PL's (including and not limited to D) is > >>>> ill-defined. > >>>> > >>>> To put this statement into perspective, I would be most appreciative of > >>>> D NG readers responding with their own idea(s) of what the semantics of > >>>> "toString" are (or should be) in a language agnostic ideology. > >>>> > >>> My other reply didn't take the language agnostic into account, sorry. > >>> > >>> Semantics of toString would depend on the object, I would think there are > >>> three general types of objects: > >>> > >>> 1. objects with only one sensible or one clear default string > >>> representations, like integers. Maybe even none of these exist (except > >>> strings themselves?) > >>> > >>> 2. objects that, given some formatting options or locale have a clear > >>> string representation. floating points, dates, curreny and the like. > >>> > >>> 3. objects that have no sensible default representation. > >>> > >>> toString() would not make sense for 3) type objects and only for 2) type > >>> objects as part of a formatting / localization package. > >>> > >>> toString() as a debugging aid sometimes doubles as a formatter for 1) and > >>> 2) class objects, but that may be more confusing than it's worth. > >>> > >> Thanks for that Lutger. > >> > >> Do you think it would make better sense if programming languages/their > >> libraries separated functions/methods which are currently loosely purposed > >> as "toString" into methods which are more specific to the types you > >> suggest (leaving only the types/classifications and number thereof to > >> argue about)? > >> > >> In my own D project, I've introduced a toDebugString method and left > >> toString alone. There are times when I like D's default toString printing > >> out the name of the object > >> class. For debug purposes there are times also when I like to see a > >> string printed > >> out in quotes so you can tell the difference between "123" and 123. Then > >> again, and since I'm working on a scripting language, sometimes I like to > >> see debug output distinguish between different numeric types. > >> > >> Anyway going by the replies on this topic, looks like most people view > >> toString as being good for debug purposes and that about it. > >> > >> Cheers > >> Justin > >> > > > > Your design makes better sense (to me at least) because it is based on why > > you want a string from some object. > > > > Take .NET for example: it does provide very elaborate and nice formatting > > options based and toString() with parameters. For some types however, the > > default toString() gives you the name of the type itself which is in no way > > related to formatting an object. You learn to work with it, but I find it a > > bit muddled. > > > > As a last note, I think people view toString as a debug thing mostly > > because > > it is very underpowered. > > There is a definite use for such as thing. But the existing toString() > is much, much worse than useless. People think you can do something with > it, but you can't. > eg, people have asked for BigInt to support toString(). That is an > over-my-dead-body.
s/over-my-dead-body/over-your-dead-body/ :-) At least those are the words that Brendan Eich uses when people seek to make JavaScript multi-threaded. http://weblogs.mozillazine.org/roadmap/archives/2007/02/threads_suck.html http://www.teknico.net/misc/fortune/concurrency.en.txt Google: http://www.google.com.au/#hl=en&q=Brendan+Eich+"your+dead+body"; Best regards and thanks to all respondents on "toString" topic, Justin
