New Issue: I/O module: deprecate readwrite methods

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1

19500, "mppf", "I/O module: deprecate readwrite methods", "2022-03-18T15:29:40Z"

Today we have these:

proc channel.readwrite(const x) : void throws where this.writing
proc channel.readwrite(ref x) : void throws where !this.writing
proc channel.readWriteLiteral(lit:string, ignoreWhiteSpace=true) : void throws
proc channel.readWriteNewline() : void throws
  • Single method for both reading and writing was based on an idea in Boost
    • with the Boost serialization library, one can write one routine for both reading and writing
  • Has not stood the test of time in Chapel in part due to compiler-generated readThis/writeThis
    • Simple types just use the compiler-generated readThis/writeThis and then there is no problem
    • Complex types (e.g. a list) need special logic for reading, e.g.
      if writing {
  for e in elts {
    writeElt(e);
  }
} else {
  while true {
    if atEnd() then break;
    addElt(readElt());
  }
}

Proposal:

  • Deprecate readwrite() readWriteLiteral() and readWriteNewline()
  • Call methods specific to reading or writing instead