Effect<MemoMap, never, never>Constructs a MemoMap effectfully so it can be used to build additional layers.
Example (Creating a memo map in an effect)
import { Context, Effect, Layer } from "effect"
class Database extends Context.Service<Database, {
readonly query: (sql: string) => Effect.Effect<string>
}>()("Database") {}
// Create a memo map safely within an Effect
const program = Effect.gen(function*() {
const memoMap = yield* Layer.makeMemoMap
const scope = yield* Effect.scope
const dbLayer = Layer.succeed(Database, {
query: Effect.fn("Database.query")((sql: string) => Effect.succeed("result"))
})
const context = yield* Layer.buildWithMemoMap(dbLayer, memoMap, scope)
return Context.get(context, Database)
})export const const makeMemoMap: Effect<MemoMap>const makeMemoMap: {
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; <…;
toString: () => string;
toJSON: () => unknown;
}
Constructs a MemoMap effectfully so it can be used to build additional layers.
Example (Creating a memo map in an effect)
import { Context, Effect, Layer } from "effect"
class Database extends Context.Service<Database, {
readonly query: (sql: string) => Effect.Effect<string>
}>()("Database") {}
// Create a memo map safely within an Effect
const program = Effect.gen(function*() {
const memoMap = yield* Layer.makeMemoMap
const scope = yield* Effect.scope
const dbLayer = Layer.succeed(Database, {
query: Effect.fn("Database.query")((sql: string) => Effect.succeed("result"))
})
const context = yield* Layer.buildWithMemoMap(dbLayer, memoMap, scope)
return Context.get(context, Database)
})
makeMemoMap: 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<MemoMap> = import internalEffectinternalEffect.const sync: <A>(
thunk: LazyArg<A>
) => Effect.Effect<A>
const makeMemoMapUnsafe: () => MemoMapConstructs a MemoMap synchronously so it can be used to build additional layers.
Example (Creating a memo map unsafely)
import { Context, Effect, Layer } from "effect"
class Database extends Context.Service<Database, {
readonly query: (sql: string) => Effect.Effect<string>
}>()("Database") {}
// Create a memo map for manual layer building
const program = Effect.gen(function*() {
const memoMap = Layer.makeMemoMapUnsafe()
const scope = yield* Effect.scope
const dbLayer = Layer.succeed(Database, {
query: Effect.fn("Database.query")((sql: string) => Effect.succeed("result"))
})
const context = yield* Layer.buildWithMemoMap(dbLayer, memoMap, scope)
return Context.get(context, Database)
})
makeMemoMapUnsafe)