On 12/10/13 9:47 AM, Max Klyga wrote:
On 2013-12-10 17:28:26 +0000, Andrei Alexandrescu said:
I talked to a programmer who knows Scala (among others) and he
mentioned the usefulness of the Option type - a zero or one element
collection (range in D terminology). Here's an article discussing it:
http://danielwestheide.com/blog/2012/12/19/the-neophytes-guide-to-scala-part-5-the-option-type.html
We have only(x) (http://dlang.org/phobos/std_range.html#.only) to be a
collection of exactly one value, but not a type for "a value of type T
or nothing at all". Should we follow Scala's example and add it?
Andrei
Yes! Option is super useful. Use it all the time in Scala and Java (via
Guava library).
I suppose it will be defined as a range, so map will work on it?
One of the useful things about options are the ability to chain them via
flatMap, will this usecase be handled?
Yah, looks like flatMap is also useful (independently from Option).
Should actually be flatMap!(R, uint depth = uint.max).
Andrei
