<R>(context: Context.Context<R>): <A, E>(
effect: Effect<A, E, R>,
options?: RunOptions | undefined
) => Promise<A>Executes an effect as a Promise with the provided services.
When to use
Use when you already have a Context and need Promise interop that rejects on
effect failure.
Example (Running with services as a promise)
import { Context, Effect } from "effect"
interface Config {
apiUrl: string
}
const Config = Context.Service<Config>("Config")
const context = Context.make(Config, {
apiUrl: "https://api.example.com"
})
const program = Effect.gen(function*() {
const config = yield* Config
return `Connecting to ${config.apiUrl}`
})
Effect.runPromiseWith(context)(program).then(console.log)export const const runPromiseWith: <R>(
context: Context.Context<R>
) => <A, E>(
effect: Effect<A, E, R>,
options?: RunOptions | undefined
) => Promise<A>
Executes an effect as a Promise with the provided services.
When to use
Use when you already have a Context and need Promise interop that rejects on
effect failure.
Example (Running with services as a promise)
import { Context, Effect } from "effect"
interface Config {
apiUrl: string
}
const Config = Context.Service<Config>("Config")
const context = Context.make(Config, {
apiUrl: "https://api.example.com"
})
const program = Effect.gen(function*() {
const config = yield* Config
return `Connecting to ${config.apiUrl}`
})
Effect.runPromiseWith(context)(program).then(console.log)
runPromiseWith: <function (type parameter) R in <R>(context: Context.Context<R>): <A, E>(effect: Effect<A, E, R>, options?: RunOptions | undefined) => Promise<A>R>(
context: Context.Context<R>(parameter) context: {
mapUnsafe: ReadonlyMap<string, any>;
mutable: boolean;
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;
}
import ContextContext.interface Context<in Services>Immutable collection of service implementations used for dependency
injection in Effect programs.
Details
The type parameter tracks the service identifiers available in the context.
At runtime, services are stored by each key's string key.
Example (Creating a context with multiple services)
import { Context } from "effect"
// Create a context with multiple services
const Logger = Context.Service<{ log: (msg: string) => void }>("Logger")
const Database = Context.Service<{ query: (sql: string) => string }>(
"Database"
)
const context = Context.make(Logger, {
log: (msg: string) => console.log(msg)
})
.pipe(Context.add(Database, { query: (sql) => `Result: ${sql}` }))
Context<function (type parameter) R in <R>(context: Context.Context<R>): <A, E>(effect: Effect<A, E, R>, options?: RunOptions | undefined) => Promise<A>R>
) => <function (type parameter) A in <A, E>(effect: Effect<A, E, R>, options?: RunOptions | undefined): Promise<A>A, function (type parameter) E in <A, E>(effect: Effect<A, E, R>, options?: RunOptions | undefined): Promise<A>E>(effect: Effect<A, E, R>(parameter) effect: {
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;
}
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<function (type parameter) A in <A, E>(effect: Effect<A, E, R>, options?: RunOptions | undefined): Promise<A>A, function (type parameter) E in <A, E>(effect: Effect<A, E, R>, options?: RunOptions | undefined): Promise<A>E, function (type parameter) R in <R>(context: Context.Context<R>): <A, E>(effect: Effect<A, E, R>, options?: RunOptions | undefined) => Promise<A>R>, options: RunOptions | undefinedoptions?: RunOptions | undefined) => interface Promise<T>Represents the completion of an asynchronous operation
Promise<function (type parameter) A in <A, E>(effect: Effect<A, E, R>, options?: RunOptions | undefined): Promise<A>A> = import internalinternal.const runPromiseWith: <R>(
context: Context.Context<R>
) => <A, E>(
effect: Effect.Effect<A, E, R>,
options?: Effect.RunOptions | undefined
) => Promise<A>