On Tue, 24 Jan 2023 at 11:40, Greg Stark <stark@mit.edu> wrote:
At the end of the day Unicode kind of assumes a variable-width display where the rendering is handled by something that has access to the actual font metrics. So anything trying to line things up in columns in a way that works with any rendering system down the line using any font is going to be making a best guess.
Really what is needed is another Unicode attribute: how many columns of a monospaced display each character (or grapheme cluster) should take up. The standard should include a precisely defined function that can take any sequence of characters and give back its width in monospaced display character spaces. Typefaces should only qualify as monospaced if they respect this standard-defined computation.
Note that this is not actually a new thing: this was included in ASCII implicitly, with a value of 1 for every character, and a value of n for every n-character string. It has always been possible to line up values displayed on monospaced displays by adding spaces, and it is only the omission of this feature from Unicode which currently makes it impossible.
