<A>(self: TxPriorityQueue<A>): Effect.Effect<Option<A>>Observes the smallest element without removing it, returning None when the
queue is empty.
When to use
Use to inspect the next prioritized value without retrying on an empty queue.
Example (Peeking without retrying)
import { Effect, Option, Order, TxPriorityQueue } from "effect"
const program = Effect.gen(function*() {
const pq = yield* TxPriorityQueue.empty<number>(Order.Number)
const result = yield* TxPriorityQueue.peekOption(pq)
console.log(Option.isNone(result)) // true
})export const const peekOption: <A>(
self: TxPriorityQueue<A>
) => Effect.Effect<Option<A>>
Observes the smallest element without removing it, returning None when the
queue is empty.
When to use
Use to inspect the next prioritized value without retrying on an empty queue.
Example (Peeking without retrying)
import { Effect, Option, Order, TxPriorityQueue } from "effect"
const program = Effect.gen(function*() {
const pq = yield* TxPriorityQueue.empty<number>(Order.Number)
const result = yield* TxPriorityQueue.peekOption(pq)
console.log(Option.isNone(result)) // true
})
peekOption = <function (type parameter) A in <A>(self: TxPriorityQueue<A>): Effect.Effect<Option<A>>A>(self: TxPriorityQueue<A>(parameter) self: {
ref: TxRef.TxRef<Chunk<A>>;
ord: Order<A>;
toString: () => string;
toJSON: () => unknown;
pipe: { <A>(this: A): A; <A, B = never>(this: A, ab: (_: A) => B): B; <A, B = never, C = never>(this: A, ab: (_: A) => B, bc: (_: B) => C): C; <A, B = never, C = never, D = never>(this: A, ab: (_: A) => B, bc: (_: B) => C, cd: (_: C) => D): D; <…;
}
interface TxPriorityQueue<in out A>A transactional priority queue backed by a sorted Chunk.
Details
Elements are stored in ascending order according to the Order provided at
construction time. take returns the smallest element, peek observes it
without removing.
Example (Dequeuing values by priority)
import { Effect, Order, TxPriorityQueue } from "effect"
const program = Effect.gen(function*() {
const pq = yield* TxPriorityQueue.empty<number>(Order.Number)
yield* TxPriorityQueue.offer(pq, 3)
yield* TxPriorityQueue.offer(pq, 1)
yield* TxPriorityQueue.offer(pq, 2)
const first = yield* TxPriorityQueue.take(pq)
console.log(first) // 1
})
TxPriorityQueue<function (type parameter) A in <A>(self: TxPriorityQueue<A>): Effect.Effect<Option<A>>A>): import EffectEffect.interface Effect<out A, out E = never, out R = never>The Effect interface defines a value that lazily describes a workflow or
job. The workflow requires some context R, and may fail with an error of
type E, or succeed with a value of type A.
When to use
Use when you need to represent a lazy, composable workflow that can require
services, fail with a typed error, or succeed with a typed value.
Details
Effect values model resourceful interaction with the outside world,
including synchronous, asynchronous, concurrent, and parallel interaction.
They use a fiber-based concurrency model, with built-in support for
scheduling, fine-grained interruption, structured concurrency, and high
scalability.
To run an Effect value, you need a Runtime, which is a type that is
capable of executing Effect values.
Effect<type Option<A> = O.None<A> | O.Some<A>The Option data type represents optional values. An Option<A> is either
Some<A>, containing a value of type A, or None, representing absence.
When to use
Use to represent initial values that may not yet exist
- Returning from partial functions (not defined for all inputs)
- Managing optional fields in data structures
Namespace containing utility types for Option.
When to use
Use to access type-level helpers associated with Option.
Option<function (type parameter) A in <A>(self: TxPriorityQueue<A>): Effect.Effect<Option<A>>A>> =>
import EffectEffect.const map: {
<A, B>(f: (a: A) => B): <E, R>(
self: Effect<A, E, R>
) => Effect<B, E, R>
<A, E, R, B>(
self: Effect<A, E, R>,
f: (a: A) => B
): Effect<B, E, R>
}
import TxRefTxRef.const get: <A>(
self: TxRef<A>
) => Effect.Effect<A>
Reads the current value of the TxRef.
When to use
Use to read the current value of a TxRef.
Example (Reading transactional references)
import { Effect, TxRef } from "effect"
const program = Effect.gen(function*() {
const counter = yield* TxRef.make(42)
// Read the value within a transaction
const value = yield* Effect.tx(
TxRef.get(counter)
)
console.log(value) // 42
})
get(self: TxPriorityQueue<A>(parameter) self: {
ref: TxRef.TxRef<Chunk<A>>;
ord: Order<A>;
toString: () => string;
toJSON: () => unknown;
pipe: { <A>(this: A): A; <A, B = never>(this: A, ab: (_: A) => B): B; <A, B = never, C = never>(this: A, ab: (_: A) => B, bc: (_: B) => C): C; <A, B = never, C = never, D = never>(this: A, ab: (_: A) => B, bc: (_: B) => C, cd: (_: C) => D): D; <…;
}
TxPriorityQueue<A>.ref: TxRef.TxRef<Chunk<A>>(property) TxPriorityQueue<A>.ref: {
version: number;
pending: Map<unknown, () => void>;
value: A;
pipe: { <A>(this: A): A; <A, B = never>(this: A, ab: (_: A) => B): B; <A, B = never, C = never>(this: A, ab: (_: A) => B, bc: (_: B) => C): C; <A, B = never, C = never, D = never>(this: A, ab: (_: A) => B, bc: (_: B) => C, cd: (_: C) => D): D; <…;
}
import CC.const head: <A>(
self: Chunk<A>
) => Option<A>
Returns the first element of this chunk safely if it exists.
Example (Getting the first element)
import { Chunk } from "effect"
console.log(Chunk.head(Chunk.empty())) // { _tag: "None" }
console.log(Chunk.head(Chunk.make(1, 2, 3))) // { _tag: "Some", value: 1 }
head)