# Function nom::bits::complete::take

source · [−]

    pub fn take<I, O, C, E: ParseError<(I, usize)>>(
        count: C
    ) -> impl Fn((I, usize)) -> IResult<(I, usize), O, E> where
        I: Slice<RangeFrom<usize>> + InputIter<Item = u8> + InputLength,
        C: ToUsize,
        O: From<u8> + AddAssign + Shl<usize, Output = O> + Shr<usize, Output = O>,

Expand description

Generates a parser taking `count` bits

## Example

    // Input is a tuple of (input: I, bit_offset: usize)
    fn parser(input: (&[u8], usize), count: usize)-> IResult<(&[u8], usize), u8> {
     take(count)(input)
    }

    // Consumes 0 bits, returns 0
    assert_eq!(parser(([0b00010010].as_ref(), 0), 0), Ok((([0b00010010].as_ref(), 0), 0)));

    // Consumes 4 bits, returns their values and increase offset to 4
    assert_eq!(parser(([0b00010010].as_ref(), 0), 4), Ok((([0b00010010].as_ref(), 4), 0b00000001)));

    // Consumes 4 bits, offset is 4, returns their values and increase offset to 0 of next byte
    assert_eq!(parser(([0b00010010].as_ref(), 4), 4), Ok((([].as_ref(), 0), 0b00000010)));

    // Tries to consume 12 bits but only 8 are available
    assert_eq!(parser(([0b00010010].as_ref(), 0), 12), Err(nom::Err::Error(Error{input: ([0b00010010].as_ref(), 0), code: ErrorKind::Eof })));