<Key, A, E, R>(self: Cache<Key, A, E, R>): Effect.Effect<Iterable<A>>Retrieves all successfully cached values from the cache, excluding failed lookups and expired entries.
Example (Reading all cached values)
import { Cache, Effect } from "effect"
const program = Effect.gen(function*() {
const cache = yield* Cache.make({
capacity: 10,
lookup: (key: string) => Effect.succeed(key.length)
})
// Add some values to the cache
yield* Cache.get(cache, "a")
yield* Cache.get(cache, "ab")
yield* Cache.get(cache, "abc")
// Retrieve all cached values
const values = yield* Cache.values(cache)
const valuesArray = Array.from(values).sort()
console.log(valuesArray) // [1, 2, 3]
})export const const values: <Key, A, E, R>(
self: Cache<Key, A, E, R>
) => Effect.Effect<Iterable<A>>
Retrieves all successfully cached values from the cache, excluding failed
lookups and expired entries.
Example (Reading all cached values)
import { Cache, Effect } from "effect"
const program = Effect.gen(function*() {
const cache = yield* Cache.make({
capacity: 10,
lookup: (key: string) => Effect.succeed(key.length)
})
// Add some values to the cache
yield* Cache.get(cache, "a")
yield* Cache.get(cache, "ab")
yield* Cache.get(cache, "abc")
// Retrieve all cached values
const values = yield* Cache.values(cache)
const valuesArray = Array.from(values).sort()
console.log(valuesArray) // [1, 2, 3]
})
values = <function (type parameter) Key in <Key, A, E, R>(self: Cache<Key, A, E, R>): Effect.Effect<Iterable<A>>Key, function (type parameter) A in <Key, A, E, R>(self: Cache<Key, A, E, R>): Effect.Effect<Iterable<A>>A, function (type parameter) E in <Key, A, E, R>(self: Cache<Key, A, E, R>): Effect.Effect<Iterable<A>>E, function (type parameter) R in <Key, A, E, R>(self: Cache<Key, A, E, R>): Effect.Effect<Iterable<A>>R>(self: Cache<Key, A, E, R>(parameter) self: {
map: MutableHashMap.MutableHashMap<Key, Entry<A, E>>;
capacity: number;
lookup: (key: Key) => Effect.Effect<A, E, R>;
timeToLive: (exit: Exit.Exit<A, E>, key: Key) => Duration.Duration;
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 Cache<in out Key, in out A, in out E = never, out R = never>A cache interface that provides a mutable key-value store with automatic TTL management,
capacity limits, and lookup functions for cache misses.
Example (Creating a basic cache)
import { Cache, Effect } from "effect"
// Basic cache with string keys and number values
const program = Effect.gen(function*() {
const cache = yield* Cache.make<string, number>({
capacity: 100,
lookup: (key: string) => Effect.succeed(key.length)
})
// Cache operations
const value1 = yield* Cache.get(cache, "hello") // 5
const value2 = yield* Cache.get(cache, "world") // 5
const value3 = yield* Cache.get(cache, "hello") // 5 (cached)
return [value1, value2, value3]
})
Example (Handling lookup failures)
import { Cache, Effect } from "effect"
// Cache with error handling
const program = Effect.gen(function*() {
const cache = yield* Cache.make<string, number, string>({
capacity: 10,
lookup: (key: string) =>
key === "error"
? Effect.fail("Lookup failed")
: Effect.succeed(key.length)
})
// Handle successful and failed lookups
const success = yield* Cache.get(cache, "test") // 4
const failure = yield* Effect.exit(Cache.get(cache, "error")) // Exit.fail
return { success, failure }
})
Example (Using complex keys with TTL)
import { Cache, Data, Duration, Effect } from "effect"
// Cache with complex key types and TTL
class UserId extends Data.Class<{ id: number }> {}
const program = Effect.gen(function*() {
const userCache = yield* Cache.make<UserId, string>({
capacity: 1000,
lookup: (userId: UserId) => Effect.succeed(`User-${userId.id}`),
timeToLive: Duration.minutes(5)
})
const userId = new UserId({ id: 123 })
const userName = yield* Cache.get(userCache, userId)
return userName // "User-123"
})
Cache<function (type parameter) Key in <Key, A, E, R>(self: Cache<Key, A, E, R>): Effect.Effect<Iterable<A>>Key, function (type parameter) A in <Key, A, E, R>(self: Cache<Key, A, E, R>): Effect.Effect<Iterable<A>>A, function (type parameter) E in <Key, A, E, R>(self: Cache<Key, A, E, R>): Effect.Effect<Iterable<A>>E, function (type parameter) R in <Key, A, E, R>(self: Cache<Key, A, E, R>): Effect.Effect<Iterable<A>>R>): 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<interface Iterable<T, TReturn = any, TNext = any>Iterable<function (type parameter) A in <Key, A, E, R>(self: Cache<Key, A, E, R>): Effect.Effect<Iterable<A>>A>> =>
import effecteffect.const map: {
<A, B>(f: (a: A) => B): <E, R>(
self: Effect.Effect<A, E, R>
) => Effect.Effect<B, E, R>
<A, E, R, B>(
self: Effect.Effect<A, E, R>,
f: (a: A) => B
): Effect.Effect<B, E, R>
}
const entries: <Key, A, E, R>(
self: Cache<Key, A, E, R>
) => Effect.Effect<Iterable<[Key, A]>>
Retrieves all key-value pairs from the cache as an iterable. This function
only returns entries with successfully resolved values, filtering out any
failed lookups or expired entries.
Gotchas
Expired entries are removed from the cache while entries filters them out.
entries(self: Cache<Key, A, E, R>(parameter) self: {
map: MutableHashMap.MutableHashMap<Key, Entry<A, E>>;
capacity: number;
lookup: (key: Key) => Effect.Effect<A, E, R>;
timeToLive: (exit: Exit.Exit<A, E>, key: Key) => Duration.Duration;
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 IterableIterable.const map: {
<A, B>(f: (a: NoInfer<A>, i: number) => B): (
self: Iterable<A>
) => Iterable<B>
<A, B>(
self: Iterable<A>,
f: (a: NoInfer<A>, i: number) => B
): Iterable<B>
}
value: Avalue]) => value: Avalue))