round.c

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/*
 * This file is part of the Fun programming language.
 * https://fun-lang.xyz/
 *
 * Copyright 2026 Johannes Findeisen <you@hanez.org>
 * Licensed under the terms of the Apache-2.0 license.
 * https://opensource.org/license/apache-2-0
 */
 
/**
 * @file round.c
 * @brief Implements the OP_ROUND opcode using C99 math.h round().
 *        C99 round() rounds half away from zero.
 */
 
#include <math.h>
 
case OP_ROUND: {
  Value v = pop_value(vm);
  if (v.type == VAL_INT) {
    push_value(vm, make_int(v.i));
    free_value(v);
  } else if (v.type == VAL_FLOAT) {
    double r = round(v.d);
    if (r >= (double)INT64_MIN && r <= (double)INT64_MAX) {
      int64_t ii = (int64_t)r;
      if ((double)ii == r) {
        push_value(vm, make_int(ii));
      } else {
        push_value(vm, make_float(r));
      }
    } else {
      push_value(vm, make_float(r));
    }
    free_value(v);
  } else {
    fprintf(stderr, "Runtime type error: ROUND expects number, got %s\n", value_type_name(v.type));
    exit(1);
  }
  break;
}