On Thursday, 21 January 2016 at 12:17:26 UTC, default0 wrote:
On Thursday, 21 January 2016 at 02:36:05 UTC, Ivan Kazmenko
wrote:
An alternative would be to define min(one argument) to just be
that argument. That would be consistent with what we have
now, but violates the principle of least astonishment for
newcomers: why would min ([3, 1, 2]) return [3, 1, 2] and not
1? Currently, it just does not compile.
As a newcomer to the language, and as a reader of
https://dlang.org/phobos/std_algorithm_comparison.html#min
which states "Iterates the passed arguments and returns the
minimum value." my intuitive understanding would be that yes of
course min(x) returns x.
However the above could of course also be reworded as "Iterates
the passed list of arguments and returns the minimum value." to
be even more clear about it NOT iterating individual arguments
but the argument list as a whole :-)
If I were to be a newcomer to programming in general this might
be confusing, though. However, it's certainly consistent and
easy to wrap your head around and also what I would have
expected it to do the first time I came across the function.
Still, looks like Java, C# and Python have min work this way:
given a single argument which is a collection, it returns the
minimum in that collection, not the collection itself. A Python
example:
min ([1]) // 1
min ([2, 1]) // 1
min ((([1, 2], [2, 3]))) // [1, 2]
min ((([1, 2]))) // 1
min ((([1, 2],),)) // ([1, 2],)
In Python, the what happens is also tricky:
def g(): return (1, 2) // tuple of two values
g() // (1, 2)
min (g()) // 1 from tuple
min (*g()) // 1 from expanded tuple
def f(): return (1,) // tuple of a single value
f() // (1,)
min (f()) // 1
min (*f()) // error, cannot expand
