[PATCH] D108742: [WIP] Reclassify form-feed and vertical tab as vertical WS for the purposes of lexing.

[Corentin Jabot via Phabricator via cfe-commits]

cor3ntin added a comment.

In D108742#2970263 <https://reviews.llvm.org/D108742#2970263>, @rsmith wrote:

> I assume this is intended to form part of the implementation of https://wg21.link/p2348 and so shouldn't be considered for review right now?

Yes, I wanted your feedback anyway but that was before I realized `\n` was hardcoded in many places in the lexer, notably in comment parsing. Which makes me question my entire reasoning. Sorry for the noise.

> Drive-by observation: under P2348 <https://reviews.llvm.org/P2348>, Clang's behavior of treating `\n\r` as a single new-line would be "non-standard" (requiring special phase 1 mapping). Is that intentional? `\n\r` is used as a new-line character on old Mac systems.

Somewhat. `\n\r` is not described by Unicode so we could either mandate that all implementation support that or leave it as implementation-defined mapping. Correct me if I am wrong, but as the line number is itself implementation-defined, whether there are one or 2 line breaks would not materially affect the standard, either way.
But also, when I looked at it, I was under the impression that older macs used a single `\r`.


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https://reviews.llvm.org/D108742