Struct RunReadEvalLoop 

pub struct RunReadEvalLoop(pub for<'a> fn(&'a RefCell<&mut Env>, Config<'a>) -> Pin<Box<dyn Future<Output = Result> + 'a>>);

Wrapper for running a read-eval-loop

This struct declares a function type for running a read-eval-loop. An implementation of this function type should be provided and stored in the environment’s any storage so that it can be used by modules depending on read-eval-loop execution.

The function takes two arguments. The first argument is a mutable reference to an environment wrapped in a RefCell. The second argument is a configuration for the parser, which contains the input function and source information. The configuration will be used by the function to create a lexer for reading commands.

Note that the RefCell is passed as a shared reference. It can be shared with the input function, allowing the input function to access and modify the environment while reading commands. The input function must release the borrow on the RefCell before returning control to the caller so that the caller can borrow the RefCell mutably to execute commands read from the parser.

The function returns a future which resolves to a Result when awaited. The function should execute commands read from the lexer until the end of input or a Divert is encountered.

The function should set Env::exit_status appropriately after the loop ends. If the input contains no commands, the exit status should be set to ExitStatus(0).

The function should also update subshell statuses and handle traps during the loop execution as specified in the shell semantics.

The most standard implementation of this function type is provided in the yash-semantics crate:

let mut env = yash_env::Env::new_virtual();
env.any.insert(Box::new(RunReadEvalLoop(|env, config| {
    Box::pin(async move {
        yash_semantics::read_eval_loop(env, &mut config.into()).await
    })
})));

Tuple Fields

0: for<'a> fn(&'a RefCell<&mut Env>, Config<'a>) -> Pin<Box<dyn Future<Output = Result> + 'a>>

Trait Implementations

impl Clone for RunReadEvalLoop

fn clone(&self) -> RunReadEvalLoop

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for RunReadEvalLoop

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Copy for RunReadEvalLoop