random_seed.c

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/*
 * This file is part of the Fun programming language.
 * https://fun-lang.xyz/
 *
 * Copyright 2025 Johannes Findeisen <you@hanez.org>
 * Licensed under the terms of the Apache-2.0 license.
 * https://opensource.org/license/apache-2-0
 */
 
/**
 * @file random_seed.c
 * @brief Implements the OP_RANDOM_SEED opcode for seeding the random number generator in the VM.
 *
 * This file handles the OP_RANDOM_SEED instruction, which seeds the random number generator
 * with a specified value. The seed is popped from the stack.
 *
 * Behavior:
 * - Pops the seed value from the stack.
 * - Seeds the random number generator with the value.
 *
 * Error Handling:
 * - Exits with an error if the seed is not an integer.
 *
 * Example:
 * - Bytecode: OP_RANDOM_SEED
 * - Stack before: [42]
 * - Stack after: []
 */
 
case OP_RANDOM_SEED: {
  Value seed = pop_value(vm);
  if (seed.type != VAL_INT) {
    fprintf(stderr, "RANDOM_SEED expects int\n");
    exit(1);
  }
  srand((unsigned int)seed.i);
  free_value(seed);
  push_value(vm, make_int(0));
  break;
}