On Thursday, August 16, 2012 at 5:24 AM, Andreas Rossberg wrote: > On 16 August 2012 00:35, Rick Waldron <[email protected]> wrote: > > On Wed, Aug 15, 2012 at 6:02 PM, Erik Reppen <[email protected]> wrote: > > > > > > This topic has probably been beaten to death years before I was even aware > > > of es-discuss but it continues to get mentioned occasionally as a point of > > > pain so I thought I'd see if I couldn't attempt to hatch a conversation > > > and > > > maybe understand the design concerns better than I likely do now. > > > > > > > > > Consistent Type Return for Pass and Fail? > > > > > > The principle of consistent type-return has occasionally skewered me as > > > somebody who came to non-amateur levels of understanding code primarily > > > through JavaScript. I can see the value in maintaining consistent types > > > for > > > positive results but not so much for indicators that you didn't get > > > anything > > > useful. For instance: > > > > > > * [0,1].indexOf('wombat'); //returns an index on success or -1 to > > > indicate failure. -1 passed on to a lot of other array methods of course, > > > indicates the last element. If you'd asked me the day I made that mistake > > > I > > > could have told you indexOf probably returns -1 on failure to find > > > something > > > but it didn't occur to me in the moment. > > > > > > > > > It would be far worse to have a different type of value as a return, right? > > Actually, no. It is far better to have something that produces failure > as immediately and as reliably as possible when used improperly. > Sentinel values are a prominent anti-pattern. > >
Rereading my initial response now and it's not clear that i meant that changing APIs to return different value would be worse. So yes, I agree with your correction and I apologize for being unclear. Rick > > However, I agree that there is no chance of fixing that for existing > libraries. > > /Andreas
_______________________________________________ es-discuss mailing list [email protected] https://mail.mozilla.org/listinfo/es-discuss
