Rust Programming By Example

Changing the current directory

Let's add another case in our match expression in the handle_cmd() method:

#[async]
fn handle_cmd(mut self, cmd: Command) -> Result<Self> {
    match cmd {
        Command::Cwd(directory) => self = await!(self.cwd(directory))?,
        // …
    }
}

It simply calls the following method:

#[async]
fn cwd(mut self, directory: PathBuf) -> Result<Self> {
    let path = self.cwd.join(&directory);
    let (new_self, res) = self.complete_path(path);
    self = new_self;
    if let Ok(dir) = res {
        let (new_self, res) = self.strip_prefix(dir);
        self = new_self;
        if let Ok(prefix) = res {
            self.cwd = prefix.to_path_buf();
            self = await!(self.send(Answer::new(ResultCode::Ok,
                                                &format!("Directory changed to \"              {}\"", directory.display()))))?;
            return Ok(self)
        }
    }