On Thu, Nov 23, 2017 at 2:47 PM, Tony Allevato <tony.allev...@gmail.com> wrote:
> > > On Thu, Nov 23, 2017 at 12:21 PM Xiaodi Wu via swift-evolution < > swift-evolution@swift.org> wrote: > >> On Thu, Nov 23, 2017 at 2:14 PM, John Holdsworth via swift-evolution < >> swift-evolution@swift.org> wrote: >> >>> I’m beginning to wish I hadn’t tied this proposal so strongly to regular >>> expressions! >>> It is indeed the wrong motivation. Even as a ten year veteran of Perl >>> development >>> I’m not sure we want to bake it into the language quite so tightly >>> (isn’t a part of >>> Foundation?) What would /regex/ represent - an instance of >>> NSRegularExpression? >>> Would the flags be pattern options or matching options? This is a whole >>> other debate. >>> >>> For me the focus of raw strings was a sort of super-literal literal >>> which has many >>> applications. The r”literal” syntax has a precedent in Python and there >>> seemed >>> to be a syntactic gap that could be occupied but perhaps there are other >>> alternatives >>> we could discuss. It would be a shame to see ‘quoted strings’ be used >>> for this however. >>> I still live in hope one day it will be used for single character >>> UNICODE values. >>> >>> Since what passes for a single character changes by Unicode >> revision--such as whenever they get around to enumerating the permitted >> modifying attributes of the poop emoji--it is quite impossible (and Swift's >> `Character` doesn't attempt to) to enforce single-characterness at compile >> time. We should put any such notions to rest up front. >> > > Unless I'm misunderstanding you here, I don't think that's true: writing > something like `let c: Character = "ab"` is definitely a compile-time > error: https://gist.github.com/allevato/ae267e2aaaa7939d6233d66a87b48fc0 > Hmm, yes, it still attempts to make a best effort, it seems. I had thought that this compile-time check was removed altogether, as it cannot be done in the general case. > To the original point though, I don't think Swift needs to use single > quotes for single characters (or single scalars). Type inference already > infers Characters from single-character String literals in contexts where a > Character is expected, and the only time you need to be explicit is if > you're trying to resolve an overload or initialize a variable by itself. > Using single quotes to avoid writing "as Character" would feel like a waste. > >> Agree. > On 23 Nov 2017, at 19:10, Brent Royal-Gordon <br...@architechies.com> >>> wrote: >>> >>> On Nov 23, 2017, at 11:15 AM, Chris Lattner via swift-evolution < >>> swift-evolution@swift.org> wrote: >>> >>> Until we figure out that path forward for regex’s, I think they aren’t >>> the right motivation for this proposal. >>> >>> >>> 1. Even in our shining pattern matching future—a future which I, for >>> one, am eager to hasten—we will still need to interoperate with >>> NSRegularExpression and other Perl 5-compatible regex engines. >>> >>> 2. Code generation. >>> >>> 3. Windows-style paths. >>> >>> 4. Doesn’t LaTeX use backslashes? >>> >>> 5. Etc. >>> >>> I think the Motivation section undersells this proposal. Regexes are a >>> strong short-run use case, but in the long run, we’ll need this for other >>> things. In both cases, though, raw literals will be a useful addition to >>> the language, improving the clarity of Swift code much like multiline >>> literals already have. >>> >>> -- >>> Brent Royal-Gordon >>> Sent from my iPhone >>> >>> >>> >>> _______________________________________________ >>> swift-evolution mailing list >>> swift-evolution@swift.org >>> https://lists.swift.org/mailman/listinfo/swift-evolution >>> >>> _______________________________________________ >> swift-evolution mailing list >> swift-evolution@swift.org >> https://lists.swift.org/mailman/listinfo/swift-evolution >> >
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