trixy/example/main/c/main.c

/*
 * Copyright (C) 2023 - 2024:
 * The Trinitrix Project <soispha@vhack.eu, antifallobst@systemausfall.org>
 * SPDX-License-Identifier: LGPL-3.0-or-later
 *
 * This file is part of the Trixy crate for Trinitrix.
 *
 * Trixy is free software: you can redistribute it and/or modify
 * it under the terms of the Lesser GNU General Public License as
 * published by the Free Software Foundation, either version 3 of
 * the License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * and the Lesser GNU General Public License along with this program.
 * If not, see <https://www.gnu.org/licenses/>.
 */

#include "../dist/interface.h"
#include <assert.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#define println(args...)                                                      \
  printf ("\33[32;1m(plugin):\33[0m \33[34;1m");                              \
  printf (args);                                                              \
  printf ("\n\33[0m");                                                        \
  fflush (stdout);
#define eprintln(args...)                                                     \
  printf ("\33[32;1m(plugin):\33[0m\33[31;1m ");                              \
  printf (args);                                                              \
  printf ("\n\33[0m");                                                        \
  fflush (stdout);

void
handle_error ()
{
  int error_length = last_error_length ();
  char *error = malloc (error_length);
  last_error_message (error, error_length);
  eprintln ("Encountered error: %s", error);
  free (error);
}

struct Dog
guess (const char *pers_name, uint32_t age)
{
  println ("Rust wants to name the dog %s, but that's not good!", pers_name);

  // The callback must free all its owned arguments, as rust just moved these
  // here and is not going to free them.
  string_free (pers_name);

  struct Dog dog = {
    .name = "James",
  };
  return dog;
}

int
plugin_main ()
{
  // You can simply call functions ..
  outstanding ("James");

  // .. but they check their inputs:
  // This call for example will fail, as a null pointer isn't supported.
  //
  // A error will be signaled by a 0 return code, then the error can be
  // obtained with the `last_error_length` and `last_error_message` functions
  // (which in our case is wrapped by the `handle_error` function)
  if (!outstanding (NULL))
    handle_error ();

  println ("Saying hi!");
  const char *hi;
  if (!dogs.hi (&hi, "Adam"))
    handle_error ();

  println ("Rust returned: %s", hi);
  string_free (hi);

  // The API also has full support for custom types (the `Dog` and `TrainedDog`
  // types are defined in the `api.tri` file)
  struct Dog dog = { .name = "Bruce" };
  Result (TrainedDog, TrainingMistake) tDog;
  if (!dogs.train_dog (&tDog, dog))
    handle_error ();

  if (tDog.tag == OK)
    {
      println ("Dog %s is now trained with specialization %i",
               tDog.value.ok.name, tDog.value.ok.training);

      // Beware that you need to free them with the appropriate free functions
      string_free (tDog.value.ok.name);
    }
  else
    {
      eprintln (
          "The dog could not be trained because of a training mistake: '%d'",
          tDog.value.err)
    }

  // Trixy also supports functions (i.e. callbacks):
  enum DogType output_dog;
  if (!dogs.guess_my_favourite_dog (&output_dog, guess))
    handle_error ();
  println ("Rust guessed %d", output_dog);

  return 0;
}