<A, E>(self: Dequeue<A, E>): Effect<number>Returns the current number of buffered messages in the queue.
Details
Completed queues report a size of 0.
Example (Checking queue size)
import { Cause, Effect, Option, Queue } from "effect"
const program = Effect.gen(function*() {
const queue = yield* Queue.bounded<number, Cause.Done>(10)
// Check size of empty queue
const size1 = yield* Queue.size(queue)
console.log(size1) // 0
// Add some messages
yield* Queue.offerAll(queue, [1, 2, 3, 4, 5])
// Check size after adding messages
const size2 = yield* Queue.size(queue)
console.log(size2) // 5
// End the queue
yield* Queue.end(queue)
// Size of ended queue is 0
const size3 = yield* Queue.size(queue)
console.log(size3) // 0
})export const const size: <A, E>(
self: Dequeue<A, E>
) => Effect<number>
Returns the current number of buffered messages in the queue.
Details
Completed queues report a size of 0.
Example (Checking queue size)
import { Cause, Effect, Option, Queue } from "effect"
const program = Effect.gen(function*() {
const queue = yield* Queue.bounded<number, Cause.Done>(10)
// Check size of empty queue
const size1 = yield* Queue.size(queue)
console.log(size1) // 0
// Add some messages
yield* Queue.offerAll(queue, [1, 2, 3, 4, 5])
// Check size after adding messages
const size2 = yield* Queue.size(queue)
console.log(size2) // 5
// End the queue
yield* Queue.end(queue)
// Size of ended queue is 0
const size3 = yield* Queue.size(queue)
console.log(size3) // 0
})
size = <function (type parameter) A in <A, E>(self: Dequeue<A, E>): Effect<number>A, function (type parameter) E in <A, E>(self: Dequeue<A, E>): Effect<number>E>(self: Dequeue<A, E>(parameter) self: {
strategy: "suspend" | "dropping" | "sliding";
dispatcher: SchedulerDispatcher;
capacity: number;
messages: MutableList.MutableList<any>;
state: Queue.State<any, any>;
scheduleRunning: boolean;
toString: () => string;
toJSON: () => unknown;
}
interface Dequeue<out A, out E = never>A Dequeue is a queue that can be taken from.
Details
This interface represents the read-only part of a Queue, allowing you to take
elements from the queue but not offer elements to it.
Example (Taking through dequeue handles)
import { Effect, Queue } from "effect"
const program = Effect.gen(function*() {
const queue = yield* Queue.bounded<string, never>(10)
// A Dequeue can only take elements
const dequeue: Queue.Dequeue<string> = queue
// Pre-populate the queue
yield* Queue.offerAll(queue, ["a", "b", "c"])
// Take elements using dequeue interface
const item = yield* Queue.take(dequeue)
console.log(item) // "a"
})
Companion namespace containing type-level metadata for the Dequeue
read-only queue interface.
Dequeue<function (type parameter) A in <A, E>(self: Dequeue<A, E>): Effect<number>A, function (type parameter) E in <A, E>(self: Dequeue<A, E>): Effect<number>E>): import EffectEffect<number> => import internalEffectinternalEffect.const sync: <A>(
thunk: LazyArg<A>
) => Effect.Effect<A>
const sizeUnsafe: <A, E>(
self: Dequeue<A, E>
) => number
Returns the current number of buffered messages in the queue synchronously.
When to use
Use when you need an immediate Queue size snapshot for diagnostics or
internals and do not need the read wrapped in Effect.
Details
Completed queues report a size of 0. This unsafe operation reads the queue
state directly without Effect wrapping.
Example (Checking queue size synchronously)
import { Cause, Effect, Option, Queue } from "effect"
const program = Effect.gen(function*() {
const queue = yield* Queue.bounded<number, Cause.Done>(10)
// Check size of empty queue
const size1 = Queue.sizeUnsafe(queue)
console.log(size1) // 0
// Add some messages
Queue.offerUnsafe(queue, 1)
Queue.offerUnsafe(queue, 2)
Queue.offerUnsafe(queue, 3)
// Check size after adding messages
const size2 = Queue.sizeUnsafe(queue)
console.log(size2) // 3
// End the queue
Queue.endUnsafe(queue)
// Size of ended queue is 0
const size3 = Queue.sizeUnsafe(queue)
console.log(size3) // 0
})
sizeUnsafe(self: Dequeue<A, E>(parameter) self: {
strategy: "suspend" | "dropping" | "sliding";
dispatcher: SchedulerDispatcher;
capacity: number;
messages: MutableList.MutableList<any>;
state: Queue.State<any, any>;
scheduleRunning: boolean;
toString: () => string;
toJSON: () => unknown;
}