Monday 11 January 2016
SIP/SLIP meeting, January 2016
A video recording of this meeting is available.
Welcomes and apologies
January milestone issues
SIP for supporting named type arguments and partial type argument lists
Link to SIP: https://github.com/scala/scala.github.com/pull/456
Proposal by @ahmadsalim
- The SIP is a design proposal about the syntax and what the semantics of these features might be, but at this point has no code.
- This idea has come up a few times over the years and is based on those previous discussions.
This proposal and dotty:
- have considering something like this in dotty. Doing this involves considering quite a few rules (and their corner cases), which this SIP doesn’t cover.
- generally sympathetic, but not sure this has the format for a SIP.
@odersky thinks there should be a wider discussion about this, involving:
- for partial type application how do we want to support this?
- named parameters one way to do this, but there are possibly other ways and we want to use the same approach.
- for example another way of doing this is kind-projector, do we want to put something like that in the language (and if yes, under what syntax?)?
@odersky thinks this is promising, but needs to be fleshed out for a SIP. He also notes that dotty wants to do this, so we might want to wait and synchronize rather than have @ahmadsalim spend a lot of time working on this, only to find a different approach has been made in dotty.
@non, it’s good to be clear that there are two things people want here:
- partial application
- partial specification, where want to apply all the types but only want to specify some of them and infer the rest
@SethTisue sums up:
- partial application part could go in Scala before dotty
- the named type parameter feature would need to be tried in dotty first (it’s much more experimental) before any back port.