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function / @typed/fx

Fx.struct

Combines a record of Fx streams into a single Fx that emits a record of the latest values. Similar to tuple, but for objects.

Package version
2.0.0-beta.13
Category
Combining sources
Since
1.0.0
Member of
Fx

Follow one execution

The latest-value join preserves field names rather than tuple positions.

Fx timelinestruct({ query, filter })struct
Operatorstruct({ query, filter })
Read this diagram

Follow each lane from left to right. Events stacked vertically share a tick; the green cursor marks the current time across every lane.

  • A value
    The text inside the pill is the emitted value.
  • Work starts
    The raised chevron starts an inner run (^ in the source).
  • The run returns
    The vertical bar ends this lane’s run.
  • A cause is delivered
    The exclamation mark belongs to this lane.
  • Work is interrupted
    The cross marks cancellation of this run.
  • Current time
    The line and diamond move together across all lanes.
  • Happening now
    A highlighted event is at the current tick.
  • Still ahead
    Muted, dashed values have not happened yet.
  • Time continues
    The lane’s arrow is not a return marker. An empty stretch can be quiet work that is still running.

Illustrated ticks start at 0. At 1×, one illustrated tick takes one second; captions specify real durations when timing matters. A cause or interruption belongs to its lane, and other work may continue. Scroll horizontally to inspect the rest of a long timeline.

It delegates concurrent ownership and retained latest values to tuple. Input failures and services are unioned, and all runs end with the consuming Fx.

Source implementation · Learn the surrounding model

Compare all Fx timelines →

Import

import { Fx } from "@typed/fx";

Access Fx.struct through the imported Fx export. Its declaration below describes the member.

This public exposure is a re-export. Its import path is supported; declaration documentation is shared with the other public exposures below.

Signatures

export declare function struct<FXS extends Readonly<Record<string, Fx<any, any, any>>>>(fxs: FXS): Fx<{
    readonly [K in keyof FXS]: Fx.Success<FXS[K]>;
}, Fx.Error<FXS[keyof FXS]>, Fx.Services<FXS[keyof FXS]>>;

Why

struct gives latest-value combination stable field names. It waits for every field once and then emits a new immutable record when any field source updates.

Ownership and lifetime

It delegates concurrent ownership and retained latest values to tuple. Input failures and services are unioned, and all runs end with the consuming Fx.

Examples

import { Fx } from "@typed/fx"
const user = Fx.struct({ name: Fx.succeed("Ada"), online: Fx.succeed(true) })

Other public imports

These import paths expose the same declaration. Each page retains its own public name and signature.

Source