The type for decoders.

The type for input sources. With a `Manual source the client must provide input with src.

pp_decode ppf v prints an unspecified representation of v on ppf.

src d s j l provides d with l bytes to read, starting at j in s. This byte range is read by calls to decode with d until `Await is returned. To signal the end of input call the function with l = 0.

decoder encoding src is a decoder that inputs from src.

Encoding. encoding specifies the decoded encoding scheme.

decode d is:

• `Await if d has a `Manual input source and awaits for more input. The client must use src to provide it.
• `Uchar u if a Unicode scalar value u was decoded.
• `End if the end of input was reached.
• `Malformed err if d encountered an error err.

Note. Repeated invocation always eventually returns `End, even in case of errors.

decoder_byte_count d is the number of characters already decoder on d (including malformed ones). This is the last decode's end byte offset counting from beginning of the stream.

decoder_src d is d's input source.