Struct NullIoProvider 

pub struct NullIoProvider;

A no-op I/O provider that silently discards all output and returns IoErrorKind::Unsupported for reads.

Useful as a default when no I/O back-end is configured.

Trait Implementations

impl IoProvider for NullIoProvider

fn read_char(&mut self, _port: PortId) -> Result<char, IoErrorKind>

Read a single character from the specified input port.

fn peek_char(&mut self, _port: PortId) -> Result<char, IoErrorKind>

Peek at the next character without consuming it.

fn char_ready(&mut self, _port: PortId) -> Result<bool, IoErrorKind>

Return true if a character is ready on the input port.

fn write_char(&mut self, _port: PortId, _c: char) -> Result<(), IoErrorKind>

Write a single character to the specified output port.

fn write_str(&mut self, _port: PortId, _s: &str) -> Result<(), IoErrorKind>

Write a string slice to the specified output port.

fn flush(&mut self, _port: PortId) -> Result<(), IoErrorKind>

Flush the specified output port.

fn close_port(&mut self, _port: PortId) -> Result<(), IoErrorKind>

Close the specified port.

fn is_input_port(&self, _port: PortId) -> bool

Return true if the port is an input port.

fn is_output_port(&self, _port: PortId) -> bool

Return true if the port is an output port.

fn open_input_string(&mut self, _s: &str) -> Result<PortId, IoErrorKind>

Open an input port that reads from the given string.

fn open_output_string(&mut self) -> Result<PortId, IoErrorKind>

Open an output port that accumulates characters into a string buffer.

fn get_output_string(&self, _port: PortId) -> Result<&str, IoErrorKind>

Retrieve the accumulated string from an output string port.