Function wezterm_input_types::ctrl_mapping

pub fn ctrl_mapping(c: char) -> Option<char>

Map c to its Ctrl equivalent. In theory, this mapping is simply translating alpha characters to upper case and then masking them by 0x1f, but xterm inherits some built-in translation from legacy X11 so that are some aliased mappings and a couple that might be technically tied to US keyboard layout (particularly the punctuation characters produced in combination with SHIFT) that may not be 100% the right thing to do here for users with non-US layouts.