//   of stdbool.h is avoided and unsigned char is used instead.
// * size_t is used to represent byte sizes of objects that are
//   materialized in the address space of the calling process.
// * int is used as an index into arrays.
// * Deletion functions are safe to call on nullptr.
//
// Questions left to address:
// * Might at some point need a way for callers to provide their own Env.

	{"byte", iotest.OneByteReader},
	{"half", iotest.HalfReader},
	{"data+err", iotest.DataErrReader},
	{"timeout", iotest.TimeoutReader},
}

// Call ReadString (which ends up calling everything else)
// to accumulate the text of a file.
func readLines(b *Reader) string {
	s := ""
	for {
		s1, err := b.ReadString('\n')
		if err == io.EOF {
			break
		}