module pind.samples.ja.concurrency.concurrency_11;

import std.stdio;
import std.concurrency;
import std.conv;

struct CalculationFailure {
    string reason;
}

struct Exit {
}

void calculate() {
    bool isDone = false;

    while (!isDone) {
        receive(
            (string message) {
                try {
                    ownerTid.send(to!double(message) + 0.5);

                } catch (Exception exc) {
                    ownerTid.send(CalculationFailure(exc.msg));
                }
            },

            (Exit message) {
                isDone = true;
            });
    }
}

void main() {
    Tid calculator = spawn(&calculate);

    calculator.send("1.2");
    calculator.send("hello");  // ← 不正確な入力
    calculator.send("3.4");
    calculator.send(Exit());

    foreach (i; 0 .. 3) {
        writef("result %s: ", i);

        receive(
            (double message) {
                writeln(message);
            },

            (CalculationFailure message) {
                writefln("ERROR! '%s'", message.reason);
            });
    }
}