src/calculator/client/main.cc

// Copyright 2019 The Fuchsia Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
//
/// A tool that connects to a calculator engine over FIDL to perform
/// arithmetic operations.
#include <fuchsia/examples/calculator/cpp/fidl.h>
#include <lib/async-loop/cpp/loop.h>
#include <lib/async-loop/default.h>

#include <iostream>
#include <string>

#include "client.h"

namespace calculator = fuchsia::examples::calculator;

namespace calculator_cli {

/// Structured request parameters for Calculator interface
struct Request {
  int a;
  int b;
  calculator::BinaryOp op;
};

std::ostream& operator << (std::ostream& os, const Request& arg)
{
    os << arg.a;
    switch (arg.op) {
      case calculator::BinaryOp::ADDITION:
        os << " + ";
        break;
      case calculator::BinaryOp::SUBTRACTION:
        os << " - ";
        break;
      case calculator::BinaryOp::MULTIPLICATION:
        os << " x ";
        break;
      case calculator::BinaryOp::DIVISION:
        os << " / ";
        break;
    }
    os << arg.b;
    return os;
}

}  // namespace calculator_cli

/// Entry point for the calculator CLI.
int main(int argc, char **argv) {
  async::Loop loop(&kAsyncLoopConfigAttachToCurrentThread);
  calculator_cli::CalculatorClient app;
  app.Start();

  // 2 + 2 = ?
  calculator_cli::Request args = {
    2, 2,
    calculator::BinaryOp::ADDITION,
  };
  std::cout << "Request: " << args << std::endl;
  
  app.calculator()->DoBinaryOp(args.op, args.a, args.b, [&loop](calculator::Result value) {
    if (value.is_error()) {
      std::cerr << "Error: " << value.error().message << std::endl;
    } else {
      std::cout << "Result: " << value.number() << std::endl;
    }
    loop.Quit();
  });
  return loop.Run();
}