The `get_indent_str_vtab()` function currently calls `tabstop_padding()`
every time a tab is encountered (unless tabstops aren't used).
`tabstop_padding()` either does a division by 'tabstop' If 'vartabstop'
is not set, or iterates through the 'vartabstop' list to find current
tab width.
Since the virtual column only increases, we can keep track of where the
next tabstop would be, and update this information once it was reached.
`get_indent_str_vtab()` also depends on 'listchars' "tab" value from the
current window, even though it may be called for a line from the same
buffer in a different window. In most cases, it is called with tabstops
enabled (last argument was `false`), so I split the function into one
that uses tabstops and the other that doesn't.
I removed `get_indent_str()` since I couldn't find any calls to it.
Problem:
Not all Lua code is checked by stylua. Automating code-style is an
important mechanism for reducing time spent on accidental
(non-essential) complexity.
Solution:
- Enable lintlua for `test/unit/` directory.
- TODO: only `test/functional/` remains unchecked.
previous: 45fe4d11ad
previous: 517f0cc634
Problem: Some code in options.c fits better elsewhere.
Solution: Move functions from options.c to other files. (Yegappan
Lakshmanan, closesvim/vim#4889)
e677df8d93
