I'm currently using vim and the vim-airline plugin. This already shows the number of lines in a file which works but I also want some kind of visual guide to remind me when a file is too long (similar to set colorcolumn for long lines)
For example here I have a file thats 360 lines. Say I don't like having files longer than 300 lines, I would still want it to show 358/360 but have the 360 show up with a red foreground text color.
I saw can do something like thislet g:airline_section_c = '%{hostname()}' to customize sections but how would you go about changing colors based on other functions. I would like it to be customized based on file length and also file type, for example straight .txt files I don't want the warning but I want it for .js, or .py.
Or more generally how can vim show some visual cue when a file is too long based on length and file type?