+" This function can be error prone if the caller forgets to use +1 to vim line
+" so use lsp#utils#position#lsp_to_vim instead
+" Convert a character-index (0-based) to byte-index (1-based)
+" This function requires a buffer specifier (expr, see :help bufname()),
+" a line number (lnum, 1-based), and a character-index (char, 0-based).
+function! s:to_col(expr, lnum, char) abort
+ let l:lines = getbufline(a:expr, a:lnum)
+ if l:lines == []
+ if type(a:expr) != v:t_string || !filereadable(a:expr)
+ " invalid a:expr
+ return a:char + 1
+ endif
+ " a:expr is a file that is not yet loaded as a buffer
+ let l:lines = readfile(a:expr, '', a:lnum)
+ if l:lines == []
+ " when the file is empty. a:char should be 0 in the case
+ return a:char + 1
+ endif
+ endif
+ let l:linestr = l:lines[-1]
+ return strlen(strcharpart(l:linestr, 0, a:char)) + 1
+endfunction
+
+" The inverse version of `s:to_col`.
+" Convert [lnum, col] to LSP's `Position`.
+function! s:to_char(expr, lnum, col) abort
+ let l:lines = getbufline(a:expr, a:lnum)
+ if l:lines == []
+ if type(a:expr) != v:t_string || !filereadable(a:expr)
+ " invalid a:expr
+ return a:col - 1
+ endif
+ " a:expr is a file that is not yet loaded as a buffer
+ let l:lines = readfile(a:expr, '', a:lnum)
+ endif
+ let l:linestr = l:lines[-1]
+ return strchars(strpart(l:linestr, 0, a:col - 1))
+endfunction
+
+" @param expr = see :help bufname()
+" @param position = {
+" 'line': 1,
+" 'character': 1
+" }
+" @returns [
+" line,
+" col
+" ]
+function! lsp#utils#position#lsp_to_vim(expr, position) abort
+ let l:line = lsp#utils#position#lsp_line_to_vim(a:expr, a:position)
+ let l:col = lsp#utils#position#lsp_character_to_vim(a:expr, a:position)
+ return [l:line, l:col]
+endfunction
+
+" @param expr = see :help bufname()
+" @param position = {
+" 'line': 1,
+" 'character': 1
+" }
+" @returns
+" line
+function! lsp#utils#position#lsp_line_to_vim(expr, position) abort
+ return a:position['line'] + 1
+endfunction
+
+" @param expr = see :help bufname()
+" @param position = {
+" 'line': 1,
+" 'character': 1
+" }
+" @returns
+" line
+function! lsp#utils#position#lsp_character_to_vim(expr, position) abort
+ let l:line = a:position['line'] + 1 " optimize function overhead by not calling lsp_line_to_vim
+ let l:char = a:position['character']
+ return s:to_col(a:expr, l:line, l:char)
+endfunction
+
+" @param expr = :help bufname()
+" @param pos = [lnum, col]
+" @returns {
+" 'line': line,
+" 'character': character
+" }
+function! lsp#utils#position#vim_to_lsp(expr, pos) abort
+ return {
+ \ 'line': a:pos[0] - 1,
+ \ 'character': s:to_char(a:expr, a:pos[0], a:pos[1])
+ \ }
+endfunction
+