Re: UAX #9: applicability of higher-level protocols to bidi plaintext

[Asmus Freytag via Unicode]

On 7/16/2018 8:30 PM, Richard Wordingham via Unicode wrote: On Mon, 16 Jul 2018 10:53:03 +0300 Shai Berger via Unicode <unicode@unicode.org> wrote: What I'm not OK with is: !Hello, World Which is what you'll see if your editor decides to use RTL directionality for this file, as the FAQ says it may. Using 'left aligned' for RTL and 'right aligned' for LTR are 'marked' styles; they are not appropriate for uninterpreted plain text. Thus if text is to displayed as left aligned, LTR defaults are appropriate. With RTL default and right alignment, what looks like !Hello, World is much more acceptable for "Hello, World!". An interesting ambiguity is "!True" v. "True!". "!True" can be read as "Not true". The solution may be to encourage the determination of the (default) paragraph direction from the first paragraph for implementations with only one margin. I am not sure if this behaviour is 'standard compliant'. The Unicode Standard uses the term "conformant". Its conformance clause is written to allow implementations to solve real-world issues without becoming formally non-conformant. Given that the Unicode Standard is intended to be applicable to all applications and all texts, a certain latitude is not only expected, it is essential. In this case, the rules are clear, implementations may override the paragraph direction and there is no constraint as to how they arrive at their choice. Ideally, there choice is documented, and users who want something different would have the choice of a setting (or an alternate implementation). Likewise, plain text is generally not sufficient for all real and imagined contents. At some point you will run into special needs that require some amount of "styling" information to be sure the receiver can interpret it unambiguously. (A mild form of that is the common device of using  italics in marking the stress for some ambiguous sentences in English. A historic example would have have been the alternation between Fraktur font and Roman font for German texts containing foreign words - there are examples where you will loose some content if you cannot mark that distinction). I really like the way Ken put it, essentially, if you (as an author) want to have control over how the reader sees your text, then you need to agree on a higher-level protocol. Normally, that would mean styled text, in practice, but it could also be an agreement on what text editor to use (perhaps one with two margins ..) A./