Three outstanding proposals

… the trouble being they have been outstanding for a while now :slightly_smiling_face:

As they have been PRs on the swift-evolution repo for a while now I’d like to stir the pot one more time to see if there is any appetite in the community to bring them to review seeing while there is a bit of a lull on S/E before the implementations get stale.

Accept Values for Custom Compilation Flags

Pros: This is a niche feature but when you need it there are very few alternatives available at present. It also has a bonus feature of being able to include a raw files to initialise a String as discussed in other threads.

Cons: There is a school of thought that this would be an anti-feature where some sources would require additional Xcode configuration/command line options to build though the proposal provides for providing defaults.

Single Quoted Character Literals

This is the rump of the much discussed Caharcter literals threads breaking the proposal up into two parts as suggested by the core team. The first (less contentious proposal) is to change Characrer and Unicode Scala literals to have their own single quote delimited syntax with a fixit for migration. At a later date perhaps this new syntax could be used to make available a convenience notation for ASCII literals but this would not be discussed at this stage in the interests of convergence.

Pros: A single quoted syntax distinguishing between String and Character literals would bring Swift into line with other commonly used languages and make explicit the contexts when a character literal is being used making code clearer. Whether this add to the mass of the Swift language that has to be leant by a newcomer is unclear as they would typically becoming from a language that makes this distinction. While the proposal has already had its place in the sun it has elicited 900 posts so there some evidence people like tat least to discuss it.

Cons: why change an existing language feature that works well and introduce a source breaking change so late in the day? The syntax could be optional and produce a warning for the foreseeable if this is seen to be a problem. But then again enough already…

Collection conditionals SR-8743

Pros: This would be useful allowing condition inclusion of collection elements dependant on build configuration useful for debug builds or testing on different architectures.

Cons: This proposal met a bit of a sticky end with the patch being rejected before it went to review as it complicated the AST but I’d like to keep the idea alive. The problem is it falls in the cracks between this who could like to implement conditionals as in the lexer as a preprocessor function and those who would like to see a residue in the AST for other purposes such as code generators etc.


A big +1 for the 3 proposals, especially the Single Quoted Character Literals (secretly hoping we'll be able to use it for ASCII literals in a near future ;)

What can we do to help?

Do you have link to the current thread on Single Quote Character Literal?
AFAIK it was part of a rejected SE-243. There’s no new thread for the modified (strip-down?) version and it never reenter the pitch phase.

Thanks @ladislas. At this stage is seems to me the proposals are well specified and implemented all that remains is to gather enough interest to get any of them scheduled for review, hence this post.

Have you read this other recent thread yet, @johnno1962?

I’m not sure if the core team’s comments are related to any of these three PRs in particular, but the general state of things would be good for anyone thinking about them to be aware of.

1 Like

Thanks for the pointer @SDGGiesbrecht, that is indeed a useful thread, This thread was intended to be a slightly playful nudge to the powers that be that these proposals are queued up and I forgot that while S/E if quiet at the moment for potential review managers this is the busiest time of the year as the Xcode release cycle reaches its crescendo.

This isn’t a complaint, just an attempt at keeping things moving along. My strategy until now has been to submit a PR to swift-evolution repo and be patient. I bank on the whole process taking about 18 months in my experience. The secondary purpose of this thread is to try to gauge/enguage interest in the proposals I mentioned to increase the likelyhood of them being selected. If people want to express an opinion on the viability/desirability of these ideas don’t hold back. What I am after is closure. They are all quite simple and won’t require a long-winded design process.


I would like the see the single-quoted Character literals proposal move forward. I had an irreconcilable difference of opinion with some people about whether it should default to Character or Unicode.Scalar, but I didn't want that to kill the proposal.

Terms of Service

Privacy Policy

Cookie Policy