Verbose and flexible args and kwargs syntax

[Eelco]

On Dec 13, 8:11 pm, Cameron Simpson <c... at zip.com.au> wrote:
> On 13Dec2011 00:30, Eelco <hoogendoorn.ee... at gmail.com> wrote:
> | On Dec 13, 1:27 am, alex23 <wuwe... at gmail.com> wrote:
> | > On Dec 13, 3:12 am, Eelco <hoogendoorn.ee... at gmail.com> wrote:
> | > > But to relate it to the topic of this thread: no, the syntax does not
> | > > allow one to select the type of the resulting sequence. It always
> | > > constructs a list.
> | >
> | > So by this argument, _every_ function that returns a list should take
> | > an optional argument to specify an alternative form of sequence.
> | >
> | > What, exactly, is so onerous about coercing your list to _whatever_
> | > type you want? You know, like everybody else has been.
> | >
> | > What does this _gain_ you other than one less line of code?
> |
> | 1) Turning two lines of code into a single more readable one is
> | nothing to scoff at
> | 2) After-the-fact conversion is O(n), getting the view you want right
> | away is O(1)
>
> Regarding (2), it has already cost you O(n) to get there. So your O(1)
> is a little ingenuous.

Well, yes, but if one takes a given sequence as input (at least O(n)
complexity to obtain it in the first place, indeed), and then wants
to, say, recursively unwind it, the cost of the total operation is
O(n) versus O(n^2)

And besides, O(n) < 2*O(n); perhaps of lesser concern than different
orders, but still.