On 05/17/2010 03:16 PM, Steven Schveighoffer wrote:
Comparing splitByOneOf(str, "; ")) to splitter(str, set(';', ' ')), I see one major difference here -- "; " is a literal, set(';', ' ') is not.I would expect that 'set' as a generic set type would implement it's guts as some sort of tree/hash, which means a lot of overhead for a simple argument. With the literal version, the notation is in the function, not the type. While it seems rather neat, the overhead should be considered. A compromise: foreach(x; splitter(str, either("; "))) Which can be implemented without heap activity.
These are good points. They have gone through my mind as well, but lately I've started to take a somewhat more liberal view of containers. For example, I'm thinking that Set!T (which would be the type returned by set()) could automatically use arrays and linear search for small sets. Other special cases come to mind, such as the small array optimization. In other words Set!T would not have a guaranteed implementation, but instead exploit magnitude to choose among a spectrum of implementation alternatives.
Of course using a different name such as either() is even better for the implementation because it can make additional implementation dictated by the restricted use of either(). For example either() could return a FixedSet!T that does not accept adding new members and is optimized accordingly.
Andrei
