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How does one add a mathematical bar over a character in Vim?

I'd like to be able to type characters "a bar," "e bar," and so on - as variable names for vectors, let's say - but I can't find them in :digraphs. I've tried searching digraphs.txt and come up empty. It's possible this isn't an option in Vim, but I thought I'd ask here before writing it off.

Solution

  • You will have to be more precise about what you want, because it is very easy to obtain a character with a macron:

    <C-k>a-

    which :digraphs definitely has:

    :digraphs

    which is also listed in :help digraphs under :help digraph-table-mbyte:

    help

    a list that is a bit redundant given this other list:

    char name           char    meaning
Exclamation mark    !       Grave
Apostrophe          '       Acute accent
Greater-Than sign   >       Circumflex accent
Question mark       ?       Tilde
Hyphen-Minus        -       Macron
Left parenthesis    (       Breve
Full stop           .       Dot above
Colon               :       Diaeresis
Comma               ,       Cedilla
Underline           _       Underline
Solidus             /       Stroke
Quotation mark      "       Double acute accent
Semicolon           ;       Ogonek
Less-Than sign      <       Caron
Zero                0       Ring above
Two                 2       Hook
Nine                9       Horn

Equals              =       Cyrillic (= used as second char)
Asterisk            *       Greek
Percent sign        %       Greek/Cyrillic special
Plus                +       smalls: Arabic, capitals: Hebrew
Three               3       some Latin/Greek/Cyrillic letters
Four                4       Bopomofo
Five                5       Hiragana
Six                 6       Katakana

    found under :help digraphs-default.

    Note that, as mentioned in the doc, the whole thing is designed after RFC 1345, and Unicode, which don't have any other way to produce "bar over character".

    Note also that:

    • <C-k>d- produces a ð and not really a d with a macron over it,
    • and some combinations don't produce anything useful, like b-, c-, etc. YMMV.

    Note also that there is no "overline" styling possible in Vim so all you have, really, is digraphs using a macron, with all their limitations.