import { selectmode } from "https://deno.land/x/denops_std@v3.9.0/option/mod.ts";
This is a comma separated list of words, which specifies when to start Select mode instead of Visual mode, when a selection is started. Possible values: mouse when using the mouse key when using shifted special keys cmd when using "v", "V" or CTRL-V See |Select-mode|. The 'selectmode' option is set by the |:behave| command.