automate tuple creation

[forkit]

On Saturday, 22 January 2022 at 01:33:16 UTC, Steven 
Schveighoffer wrote:
>
>
> That second `valuesPerRecord` is not used in the lambda, and 
> also it's not referring to the original element, it's the name 
> of a parameter in the lambda.
>
> Are you sure this is doing what you want?
>
> -Steve

It just worked, so i didn't think about it too much.. but it 
seems to work either way.

And to be honest, the only part of it I understand, is the dice 
part ;-)

In any case I changed it:

from: valuesPerRecord =>
to:  i =>

// ----

void CreateDataFile(const(int) recordsNeeded, const(int) 
valuesPerRecord, const(string) fname)
{
     auto rnd = Random(unpredictableSeed);

     auto file = File(fname, "w");
     scope(exit) file.close;

     Appender!string bigString = appender!string;
     bigString.reserve(recordsNeeded);

     const int iotaStartNum = 100_000_001;

     foreach(i, id; iota(iotaStartNum, iotaStartNum + 
recordsNeeded).enumerate)
     {
         bigString
             ~= id.to!string
             ~ ","
             ~ valuesPerRecord.iota.map!(i => rnd.dice(0.6, 
1.4)).format!"%(%s,%)"
             ~ "\n";
     }

     file.write(bigString[]);
}

// ---