SIP Meeting Minutes - 8th May 2017



The following agenda was distributed to attendees:

Topic Reviewers Accepted/Rejected
SIP-NN - comonadic-comprehensions Shimi Bandiel Rejected
SIP-33 - Match infix & prefix types to meet expression rules Oron Port Pending
Scala Library Changes Adriaan Moors Scala-dev proposal

Jorge Vicente Cantero was the Process Lead.

Date and Location

The meeting took place on 8 May 2017 via Google Hangouts at EPFL in Lausanne, Switzerland as well as other locations.

Watch on Scala Center YouTube channel

Minutes were taken by Darja Jovanovic.



Opening Remarks

Jorge going over the agenda, points out that the second item will be skipped because they are waiting for the prototype from the author of the proposal.

SIP-NN - comonadic-comprehensions

YouTube time: 1:39

Proposal aims to introduce new syntax from comprehension for monads to comonads. Martin is the reviewer. He asks others attendees for their opinion on this. Everyone had read the SIP.

Eugene referred to original proposal and wishes to see a better motivation for this language feature encouraging use of “plain English” to simplify the use of Scala as practice oriented language. He believes that it could be critical how this SIP can be improved. During the recent conference, organized by Facebook, he spoke with typescript guys that are developing idiomic solutions that would benefit typescript and javascript and allow community users to give their inputs. Refers to the paper “Denotation” he linked in a proposal, that is not enough for Scala, but a good start.

Jorge is getting back discussion on voting on this proposal and he mentioned that Josh insisted on more examples and suggestions on motivation of this SIP.

Eugene wanted to add more syntax (map and flatmap), but Martin opposed to that saying that Scala is quite serious program and needs more reason to add any additional syntax to it. Martin would like to see more widespread use of comonadic constructs and Libraries, and before doing that, he wouldn’t consider any further change. Sebastian agrees with Martin and says that he doesn’t really understand Josh’s and Eugene’s proposal. Iulian agrees that the proposal is quite complicated and he wonders how it can be useful. He believes that it is an interesting research direction, but that it needs more users feedbacks in aim to be included in the Scala, therefore questioning if the proposal should be numbered in the current form. Seth and Adriaan agree with Martin and Iulian.

Conclusion Proposal discarded unanimously. They will send the feedback to the author.

SIP-33 - Match infix & prefix types to meet expression rules

Skipped since they are waiting for the prototype from the author of the proposal.

Scala Library Changes

YouTube time 10:52

Adriaan starts presentation and notes that feedbacks on his proposal are available through the 2.13 platform. It is more reorganization of things in different modules. He suggests list of packages, from the ticket, that he believes shouldn’t be in the core: Scala concurrent, Scala.ref, Scala.sys, Scala.compat (that is already totally deprecated), Scala.text (that has already couple of things that are deprecated), Scala.util; whereas and Scala.sys are good candidates for replacements with better community modules. Also, some hashing could be removed in separate package and make Scala package cut clean. He is open to discuss if some of these packages should stay in the Scala Library jar. Most of these packages are subjects of deprecations. Scala concurrent could live in its current form, but it could be split out since it’s platform dependent however.

Jorge asks what they should change in XML. Adriaan says that it’s already a model and all these packages should wing as Scala changes. If no one from the community does push forward to maintain that, they should continue maintaining them through depreciation cycle, helped by replacement through SPPs. All these packages and classes of packages should be available in 2.13 as jars, but you should add them by yourself to your classpath if you are using them.

Martin asks what they’ll get with this breaking of the system, since each package depends on each other.

Adriaan propose that Scala concurrent can stay, if there is no use of separation. He also agrees that Scala.util should not be removed. But others are good candidates for separation, due to their lower quality. That will allow them faster cycle of reparation.

Martin says to keep Scala math.

Sebastian also suggests that Scala.ref also should rest.

Adriaan said that it was just a proposal of maximal list of packages that they could split out and he’s ready to put it down to the more reasonable size. (Adriaan sent a document). The document shows the list of parts that are dependable and how platform would work if they’d be split out.

Sebastian believes that these platforms should not be split out for the moment.

Adriaan agrees with that. He believes that is probably too painful to change anything about it.

Jorge proposes to keep thinking on this and to discuss it in the next two months, migration cycle.

Seth said that as the 2.13 cycle progresses will bring more information and feedback about the usage. He believes that it is a good start to begin with and they’ll know more as they go through it.

Adriaan agreed and said that he’d love to get some statistics on the usage of the sub-packages.

Conclusion They should keep thinking on it, keep sending suggestions and to discuss more on it during the next meeting.