Stdlib module async/future.vitl

Overview

`async/future.vitl` is a public stdlib surface inside the `async` family. It should be read as one focused slice of the broader family responsibility: Future, channel, executor, and task orchestration helpers.

Purpose

This file should be chosen because of responsibility, not because its name “sounds close enough”. Inside the async family, it carries one focused part of the contract and keeps that responsibility separate from neighboring concerns.

• Use this module when coordination and scheduling are explicit parts of the design.
• A pipeline can spawn tasks, exchange messages through channels, and join through the executor boundary.

Taxonomy

Think of this page as a generated encyclopedia entry rather than a hand-written tutorial. The goal is to show what kind of module this is, how dense it is, and what reading strategy makes sense before depending on it.

• Large algorithm surface: this file exposes many procedures and likely acts as a domain toolkit rather than a single thin wrapper.
• Owns domain vocabulary: the module declares data shapes in addition to executable helpers, so its types are part of the contract.
• Narrow dependency fan-in: a small set of imports suggests a focused collaboration surface.
• Explicit export surface: the file ends with visible export declarations instead of relying only on implicit namespace discovery.

Implementation profile

This profile is inferred directly from the source text. It does not replace reading the file, but it tells you quickly whether the module is mostly declarative, loop-heavy, branch-heavy, or organized around many small exits.

Top-level API inventory

Imported surfaces

• vitte/stdlib/core form Future

Position in family

This file is module 4 of 4 in the async family when ordered by path. By procedure count it ranks 3, and by line count it ranks 4. Those ranks are useful as rough signals of breadth, not as quality judgments.

Declaration map

The declaration map turns raw source into a scan-friendly catalog. It is useful when the file is large enough that a reader wants to orient by kinds of surfaces first.

The table is exhaustive for top-level declarations of the selected kinds. This file declares 27 matching surfaces.

Representative signatures

These signatures are shown in source order so the page keeps the feel of a reference manual, not just a keyword cloud.

• form Future<T> { (line 5)
• proc future_new<T>() -> Future<T> { (line 12)
• proc future_is_ready<T>(fut: Future<T>) -> bool { (line 22)
• proc future_is_completed<T>(fut: Future<T>) -> bool { (line 29)
• proc future_is_errored<T>(fut: Future<T>) -> bool { (line 33)
• proc future_await<T>(fut: Future<T>) -> T { (line 37)
• proc future_try_get<T>(fut: Future<T>) -> T { (line 55)
• proc future_resolve<T>(fut: Future<T>, value: T) -> bool { (line 74)
• proc future_reject<T>(fut: Future<T>, error: string) -> bool { (line 89)
• proc future_error_message<T>(fut: Future<T>) -> string { (line 104)
• proc future_map<T, U>(fut: Future<T>, mapper: proc) -> Future<U> { (line 108)
• proc future_chain<T, U>(fut: Future<T>, then: proc) -> Future<U> { (line 122)
• proc future_race<T>(futures: [Future<T>]) -> T { (line 134)
• proc future_all<T>(futures: [Future<T>]) -> [T] { (line 147)
• proc future_from_value<T>(value: T) -> Future<T> { (line 158)
• proc future_from_error<T>(error: string) -> Future<T> { (line 164)
• proc yield_cpu() -> bool { (line 170)
• proc mutex_new() -> int { (line 174)

The list is intentionally capped here; the source file declares 25 matching signatures in total.

How to use this module

Start by reading the file as an ownership boundary. Ask three questions: what enters this module, what stable types or procedures it exports, and what adjacent module should stay outside of it.

1. Read space and top-level imports first so the ownership boundary of async/future.vitl is explicit.
2. Read declared forms and picks before algorithms so the data vocabulary is stable in your head.
3. Traverse procedures in source order; the early helpers usually explain the naming and numeric conventions used later.
4. Only after that compare neighbor modules, because the right boundary choice matters more than memorizing one helper name.

User example

This example is generated from the actual stdlib module surface. Its job is not to be the smallest snippet possible; its job is to show a realistic consumer-shaped file that exercises the module and mirrors the language keywords the module itself relies on.

space demo/async_future
use vitte/stdlib/async/future
form UserReport {
  label: string,
  ready: bool
}
proc run_example() -> UserReport {
  let entries = future_all([])
  let ready: bool = future_is_ready(Future<T>())
  let failed: bool = false
  let stable: bool = ready and true
  let idx: int = 0
  let count: int = 0
  while idx < entries.len {
    set count = count + 1
    set idx = idx + 1
  }
  for sample in [1] {
    let seen: int = sample
  }
  if not ready {
    give UserReport { label: "not-ready", ready: false }
  }
    give UserReport { label: "ok", ready: true }
}
export run_example

Keyword coverage

This table makes the “all keywords of the module” requirement auditable. It compares the detected Vitte keywords in the source file with the generated consumer example above.

The generated snippet exercises every detected Vitte keyword used by this module.

Source shape

space vitte/stdlib/async/future
use vitte/stdlib/core
form Future<T> {
  state: int,      // 0=pending, 1=completed, 2=errored
  values: [T],     // Single-slot storage for resolved value
  error: string,   // Error message if failed
  mutex: int,      // Lock ID for thread-safe access
}
proc future_new<T>() -> Future<T> {
  let fut: Future<T> = Future<T> {

The excerpt is not meant to replace the file. It exists to make the module recognizable at first glance, the same way a Wikipedia infobox helps the reader orient before reading the whole article.

Source landmarks

Large files are easier to retain when they have visible landmarks. When the source contains explicit section banners, they are surfaced here; otherwise the first major declarations are used as anchors.

• Line 1: space vitte/stdlib/async/future
• Line 3: use vitte/stdlib/core
• Line 5: form Future<T> {
• Line 12: proc future_new<T>() -> Future<T> {
• Line 22: proc future_is_ready<T>(fut: Future<T>) -> bool {
• Line 29: proc future_is_completed<T>(fut: Future<T>) -> bool {
• Line 33: proc future_is_errored<T>(fut: Future<T>) -> bool {
• Line 37: proc future_await<T>(fut: Future<T>) -> T {

Source organization

When a file carries its own internal chaptering, those chapters usually reveal the intended reading order better than a flat symbol list. This section reconstructs that organization from the source itself.

Complete API catalog

This catalog is the exhaustive file-level index for the module. It is intentionally closer to a generated encyclopedia appendix than to a tutorial summary.

Data surfaces

Procedures

Imports

Exports

Integration boundaries

Within async, this file should remain focused. If a future helper changes the host boundary, scheduling boundary, or data-shape boundary, it probably belongs in a neighbor module instead of being added here by convenience.

• Family responsibility: Future, channel, executor, and task orchestration helpers.
• Family architecture role: Use `async` when work should be coordinated as tasks rather than as direct thread ownership.

Composition guidance

Choose this module when

• Choose async/future.vitl when the main question is owned by this module rather than by transport, storage, orchestration, or user-interface code.
• Use this module when coordination and scheduling are explicit parts of the design.
• A pipeline can spawn tasks, exchange messages through channels, and join through the executor boundary.

Pause before extending it when

• Avoid extending this file when the new helper mostly changes the boundary to host I/O, runtime coordination, or foreign integration instead of staying inside async.
• Check nearby modules such as async/async.vitl, async/channel.vitl, async/executor.vitl before adding convenience wrappers here.

Relationship table

This table keeps the page closer to a real encyclopedia entry: a module is easier to understand when compared with its nearest alternatives in the same family.

Neighbor modules

• async/async.vitl
• async/channel.vitl
• async/executor.vitl