import { io } from "https://deno.land/x/s3si@ci/deps.ts";
const { BufReader } = io;
readString() reads until the first occurrence of delim in the input,
returning a string containing the data up to and including the delimiter.
If ReadString encounters an error before finding a delimiter,
it returns the data read before the error and the error itself
(often null).
ReadString returns err != nil if and only if the returned data does not end
in delim.
For simple uses, a Scanner may be more convenient.