sleep_ms.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 sleep_ms.c
 * @brief Implements OP_SLEEP_MS to suspend execution for a number of milliseconds.
 *
 * Behavior:
 * - Pops an integer value ms from the stack and sleeps for that many milliseconds.
 * - Always pushes Nil after completion to keep stack discipline for statement POPs.
 *
 * Errors:
 * - If the popped value is not an integer, prints an error, frees it, and pushes Nil.
 * - Negative durations are treated as no-op; Nil is still pushed.
 */
 
case OP_SLEEP_MS: {
  Value ms = pop_value(vm);
  if (ms.type != VAL_INT) {
    fprintf(stderr, "Runtime type error: sleep(ms) expects Number (milliseconds)\n");
    free_value(ms);
    /* push Nil so caller-side POP is safe */
    push_value(vm, make_nil());
    break;
  }
  long t = (long)ms.i;
  if (t > 0) fun_sleep_ms(t);
  free_value(ms);
  /* push Nil so statement POP does not underflow */
  push_value(vm, make_nil());
  break;
}