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>
pub fn read_partial<F, R, E>(&mut self, read: F) -> Result<(Input<'a>, 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.