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Subject: During lexing, What constitute new lines and whitespaces ?
From: Corentin (corentin.jabot_at_[hidden])
Date: 2020-06-01 07:53:48


The standard doesn't specify what the new-line character is.
According to Unicode, the following codepoint sequences should be
considered lines terminators

 LF: Line Feed, U+000A
 VT: Vertical Tab, U+000B
 FF: Form Feed, U+000C
 CR: Carriage Return, U+000D
 CR+LF: CR (U+000D) followed by LF (U+000A)
 NEL: Next Line, U+0085
 LS: Line Separator, U+2028
 PS: Paragraph Separator, U+2029

Similarly, the standard defines "white spaces" loosely as "blanks,
horizontal and vertical tabs", however there are more white space
characters in unicode https://en.wikipedia.org/wiki/Whitespace_character

What I would like to do:

* Define new-line and white-spaces as grammar term, with an explicit list
of codepoint sequences.
* In phase 2, replace all characters which represent a line termination
with Line Feed (which is reverted later for raw string literals). this
would notably fix https://wg21.link/cwg1655
* It would also help to mandate that trailing whitespaces are removed in
phase 2

Does that make sense to anyone ?



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