New Issue: I/O module: replace readstring/readbytes with readUtf8/readBytes/readData

19496, "mppf", "I/O module: replace readstring/readbytes with readUtf8/readBytes/readData", "2022-03-18T15:10:46Z"

Today we have this:

proc channel.readstring(ref str_out: string, len: int(64) = -1) : bool throws
proc channel.readbytes(ref bytes_out: bytes, len: int(64) = -1) : bool throws
  • read a given number of bytes from a channel into a string / bytes
  • if the length is -1 then it reads until EOF
  • Returns true if something was read, false upon EOF
  • Issue [#13168] requests a version that can read into a pointer


proc reader.readUtf8(maxCodepoints: int = -1, maxBytes: int = -1) : string throws
proc reader.readBytes(maxBytes: int = -1) : bytes throws
proc reader.readData(data, maxBytes: int) : int throws
  • All of these can read less than the max requested if there was some data and then an EOF (following Python)
  • string/bytes returning functions return “” on EOF and use -1 to mean unlimited length (following Python)
  • readData accepts same types as writeData and returns the number of bytes read or 0 on EOF
  • These functions will ignore the channel’s Encoder

See also #19495 which proposes a similar change.