generatorArg_VS_NextArg.js

function* noNextArgNoSelfArg(){
  var localVar = 'a';
  var FirstYieldRetval =  yield localVar;
  localVar = 'b';
  var SecondYieldRetval =  yield localVar;

  console.log('noNextArgNoSelfArg', {localVar})
}

function* noNextArgSelfArg(selfArg){
  var localVar = 'a';
  var FirstYieldRetval =  yield localVar;
  localVar = 'b';
  var SecondYieldRetval =  yield localVar;

  console.log('noNextArgSelfArg', {selfArg, localVar})
}

function* NextArgNoSelfArg(){
  var localVar = 'a';
  var FirstYieldRetval =  yield localVar;
  localVar = 'b';
  var SecondYieldRetval =  yield localVar;

  var YieldRetvals = {
    FirstYieldRetval,
    SecondYieldRetval
  }
  console.log('NextArgNoSelfArg', {localVar, YieldRetvals});
}

function* NextArgSelfArg(selfArg){
  var localVar = 'a';
  var FirstYieldRetval =  yield localVar;
  localVar = 'b';
  var SecondYieldRetval =  yield localVar;

  var YieldRetvals = {
    FirstYieldRetval,
    SecondYieldRetval
  }
  console.log('NextArgSelfArg', {selfArg ,localVar, YieldRetvals})
}

class GeneratorExecuter {
  constructor(generatorFunction, generatorFunctionArg, initialNextArg) {
    this.generatorObject = generatorFunction(generatorFunctionArg);
    this.initialNextArg = initialNextArg;
  }

  execute() {
    let i = 0;
    while(true) {
      const retVal = this.generatorObject.next(this.initialNextArg + i);
      const done = retVal.done;
      if(done) {
        console.log('---------------');
        break;
      }
      i ++;
    }
  }
}

console.log('*********** ***********');
[
  new GeneratorExecuter(noNextArgNoSelfArg, 1, 0),
  new GeneratorExecuter(noNextArgSelfArg, 1, 0),
  new GeneratorExecuter(NextArgNoSelfArg, 1, 0),
  new GeneratorExecuter(NextArgSelfArg, 1, 0)
].forEach((executer) => executer.execute());

console.log('*********** ***********');
[
  new GeneratorExecuter(noNextArgNoSelfArg, 1),
  new GeneratorExecuter(noNextArgSelfArg, 1),
  new GeneratorExecuter(NextArgNoSelfArg, 1),
  new GeneratorExecuter(NextArgSelfArg, 1)
].forEach((executer) => executer.execute());

/*
*********** ***********
noNextArgNoSelfArg { localVar: 'b' }
---------------
noNextArgSelfArg { selfArg: 1, localVar: 'b' }
---------------
NextArgNoSelfArg { localVar: 'b',
  YieldRetvals: { FirstYieldRetval: 1, SecondYieldRetval: 2 } }
---------------
NextArgSelfArg { selfArg: 1,
  localVar: 'b',
  YieldRetvals: { FirstYieldRetval: 1, SecondYieldRetval: 2 } }
---------------
*********** ***********
noNextArgNoSelfArg { localVar: 'b' }
---------------
noNextArgSelfArg { selfArg: 1, localVar: 'b' }
---------------
NextArgNoSelfArg { localVar: 'b',
  YieldRetvals: { FirstYieldRetval: NaN, SecondYieldRetval: NaN } }
---------------
NextArgSelfArg { selfArg: 1,
  localVar: 'b',
  YieldRetvals: { FirstYieldRetval: NaN, SecondYieldRetval: NaN } }
*/

generatorObj = generatorFunction(x)
generatorObj.next (y)

xは、yield式と関係しない。
yは、yield式と関係する。yが直前の yield式の結果として扱われる。