use qubit_codec::{
CapacityError,
CodecConvertError,
TranscodeDecoder,
TranscodeError,
TranscodeProgress,
Transcoder,
};
#[derive(Default)]
struct ByteToChar;
impl Transcoder<u8, char> for ByteToChar {
type Error =
CodecConvertError<core::convert::Infallible, core::convert::Infallible>;
fn max_output_len(&self, input_len: usize) -> Result<usize, CapacityError> {
Ok(input_len)
}
fn reset(
&mut self,
output: &mut [char],
output_index: usize,
) -> Result<usize, TranscodeError<Self::Error>> {
TranscodeError::<Self::Error>::ensure_output_index(
output.len(),
output_index,
)?;
Ok(0)
}
fn transcode(
&mut self,
input: &[u8],
input_index: usize,
output: &mut [char],
output_index: usize,
) -> Result<TranscodeProgress, TranscodeError<Self::Error>> {
let readable = input.len().saturating_sub(input_index);
let writable = output.len().saturating_sub(output_index);
let count = readable.min(writable);
for offset in 0..count {
output[output_index + offset] = input[input_index + offset] as char;
}
Ok(TranscodeProgress::complete(count, count))
}
fn finish(
&mut self,
output: &mut [char],
output_index: usize,
) -> Result<usize, TranscodeError<Self::Error>> {
TranscodeError::<Self::Error>::ensure_output_index(
output.len(),
output_index,
)?;
Ok(0)
}
}
impl TranscodeDecoder<u8, char> for ByteToChar {}
#[test]
fn test_transcode_decoder_is_a_semantic_transcoder_bound() {
fn assert_decoder<T: TranscodeDecoder<u8, char>>() {}
assert_decoder::<ByteToChar>();
}