On 2007-04-10, Duncan Booth <[EMAIL PROTECTED]> wrote: > Antoon Pardon <[EMAIL PROTECTED]> wrote: > >> On 2007-04-10, Duncan Booth <[EMAIL PROTECTED]> wrote: >>> There is a cost to every new language feature: it has to be >>> implemented, documented, maintained, and above all learned by the >>> users. Good design involves, in part, not adding to these burdens >>> except where there is a benefit at least equal to the cost. >> >> So what is the easiest to learn: "All sequences have an index method" >> or "Such and so sequences have an index method and others don't" >> >> Which of the above is the easiest to document? > > The second would be if it were true. However it would mean you would have > to add an index method to *all* sequences. > > FWIW, The current documentation says that 's.index' is a method defined on > all *mutable* sequence types: almost as simple as your second wording but > unfortunately misleading since strings also have index.
Which illustrate that the mutable unmutable distinction is not very usefull to decide whether a sequence could use "index" or not. >> If someone states: "Show me your use case for using tuple.index and I >> will show you how to avoid it." or words to that effect I think there >> is little use trying. > > I genuinely cannot think of a use case. I didn't ask you to suggest one so > I could show you how to avoid it, I asked you to suggest one so that we > could take the discussion from the purely hypothetical to a more concrete > discussion of whether it would be a worthwhile enhancement. I have given a use case in an other article in this thread. Feel free to comment. -- Antoon Pardon -- http://mail.python.org/mailman/listinfo/python-list
