Hello D Language Forum!

I’m running the InputRange example below and it dutifully reads from stdin until it spots a tilde, printing each character in every loop iteration. I even tried to break out with F6 but couldn’t get it to stop. Curiously, swapping the tilde for the '\t' character makes everything work flawlessly. Any ideas why this is happening? I’d really appreciate your insights!

import std;

struct StdinByChar
{
  @property bool empty()
  {
    if(isEmpty)
      return true;

    if(!hasChar)
    {
      auto buff = new char[1];
      stdin.rawRead(buff);

      if (buff[0] == 0x7E) // tilde (~) character
      {
        isEmpty = true;
        return true;
      }
      chr = buff[0];
      hasChar = true;
    }
    return false;
  }

  @property auto front() =>  chr;

  auto popFront()  =>  hasChar = false;

  private:
    char   chr;
    bool   hasChar, isEmpty;
}

void main()
{
    auto r = StdinByChar();

    while (!r.empty)
    {
        write(r.front);
        r.popFront();
    }

    writeln();

    write("Range is ");
    if(!r.empty) write("not");
    writeln("empty!");
}

SDB@79

I've tested your code on the source code itself and it works as expected:

» ./salih2 < salih2.d
import std;

struct StdinByChar
{
  @property bool empty()
  {
    if(isEmpty)
      return true;

    if(!hasChar)
    {
      auto buff = new char[1];
      stdin.rawRead(buff);

      if (buff[0] == 0x7E) // tilde (
Range is empty!

On Sunday, 20 July 2025 at 08:46:08 UTC, Salih Dincer wrote:

No problem here either. Where are you running the program from (embedded terminal in an editor ? a terminal emulator ?). Are you on Windows or Linux ?

On Sunday, 20 July 2025 at 12:32:17 UTC, user1234 wrote:

I want the program to end with the F6 key on my keyboard instead of the tilde. I use Windows as the platform.

SDB@79

On Sunday, 20 July 2025 at 20:26:02 UTC, Salih Dincer wrote:

There is no F6 Unicode character. Are you seeing tildes when you press F6 and thinking it’s an actual tilde in the stream?

-Steve

On Sunday, 20 July 2025 at 21:59:48 UTC, Steven Schveighoffer wrote:

When I press the F6 key, ^Z characters appear on the screen. I want the program to terminate using this key instead of the tilde character. Should I increase the buffer to 2 bytes?

SDB@79

On Sunday, 20 July 2025 at 20:26:02 UTC, Salih Dincer wrote:

Thank you for all your responses. I checked the ASCII table, and 0x1A is indeed the character I was looking for. I'm not sure what this would be for Linux, but it works on Windows:

struct StdinByChar
{
  @property bool empty()
  {
    if(isEmpty)
      return true;

    if(!hasChar)
    {
      auto buff = new char[1];
      stdin.rawRead(buff);

      if (buff[0] == 0x1A) // F6 (^Z) character
      {
        isEmpty = true;
        return true;
      }
      chr = buff[0];
      hasChar = true;
    }
    return false;
  }

  @property auto front() => chr;

  auto popFront() => hasChar = false;

  private:
    char chr;
    bool hasChar, isEmpty;
}

SDB@79