pub struct Reader<'a> { /* private fields */ }Expand description
A read-only, forward-only* cursor into the data in an Input.
Using Reader to parse input helps to ensure that no byte of the input
will be accidentally processed more than once. Using Reader in
conjunction with read_all and read_all_optional helps ensure that no
byte of the input is accidentally left unprocessed. The methods of Reader
never panic, so Reader also assists the writing of panic-free code.
* Reader is not strictly forward-only because of the method
get_input_between_marks, which is provided mainly to support calculating
digests over parsed data.
Implementations§
source§impl<'a> Reader<'a>
impl<'a> Reader<'a>
sourcepub fn new(input: Input<'a>) -> Self
pub fn new(input: Input<'a>) -> Self
Construct a new Reader for the given input. Use read_all or
read_all_optional instead of Reader::new whenever possible.
sourcepub fn at_end(&self) -> bool
pub fn at_end(&self) -> bool
Returns true if the reader is at the end of the input, and false
otherwise.
sourcepub fn get_input_between_marks(
&self,
mark1: Mark,
mark2: Mark
) -> Result<Input<'a>, EndOfInput>
pub fn get_input_between_marks( &self, mark1: Mark, mark2: Mark ) -> Result<Input<'a>, EndOfInput>
Returns an Input for already-parsed input that has had its boundaries
marked using mark.
sourcepub fn mark(&self) -> Mark
pub fn mark(&self) -> Mark
Return the current position of the Reader for future use in a call
to get_input_between_marks.
sourcepub fn peek(&self, b: u8) -> bool
pub fn peek(&self, b: u8) -> bool
Returns true if there is at least one more byte in the input and that
byte is equal to b, and false otherwise.
sourcepub fn read_byte(&mut self) -> Result<u8, EndOfInput>
pub fn read_byte(&mut self) -> Result<u8, EndOfInput>
Reads the next input byte.
Returns Ok(b) where b is the next input byte, or Err(EndOfInput)
if the Reader is at the end of the input.
sourcepub fn read_bytes(&mut self, num_bytes: usize) -> Result<Input<'a>, EndOfInput>
pub fn read_bytes(&mut self, num_bytes: usize) -> Result<Input<'a>, EndOfInput>
Skips num_bytes of the input, returning the skipped input as an
Input.
Returns Ok(i) if there are at least num_bytes of input remaining,
and Err(EndOfInput) otherwise.
sourcepub fn read_bytes_to_end(&mut self) -> Input<'a>
pub fn read_bytes_to_end(&mut self) -> Input<'a>
Skips the reader to the end of the input, returning the skipped input
as an Input.
sourcepub fn read_partial<F, R, E>(&mut self, read: F) -> Result<(Input<'a>, R), E>where
F: FnOnce(&mut Reader<'a>) -> Result<R, E>,
pub fn read_partial<F, R, E>(&mut self, read: F) -> Result<(Input<'a>, R), E>where F: FnOnce(&mut Reader<'a>) -> Result<R, E>,
Calls read() with the given input as a Reader. On success, returns a
pair (bytes_read, r) where bytes_read is what read() consumed and
r is read()’s return value.
sourcepub fn skip(&mut self, num_bytes: usize) -> Result<(), EndOfInput>
pub fn skip(&mut self, num_bytes: usize) -> Result<(), EndOfInput>
Skips num_bytes of the input.
Returns Ok(i) if there are at least num_bytes of input remaining,
and Err(EndOfInput) otherwise.
sourcepub fn skip_to_end(&mut self)
pub fn skip_to_end(&mut self)
Skips the reader to the end of the input.