/**
 * This module provides a data structure called `Context` that can be used for dependency injection in effectful
 * programs. It is essentially a table mapping `Tag`s to their implementations (called `Service`s), and can be used to
 * manage dependencies in a type-safe way. The `Context` data structure is essentially a way of providing access to a set
 * of related services that can be passed around as a single unit. This module provides functions to create, modify, and
 * query the contents of a `Context`, as well as a number of utility types for working with tags and services.
 *
 * @since 2.0.0
 */
import type { Equal } from "./Equal.js";
import type { LazyArg } from "./Function.js";
import type { Inspectable } from "./Inspectable.js";
import type { Option } from "./Option.js";
import type { Pipeable } from "./Pipeable.js";
import type * as Types from "./Types.js";
import type * as Unify from "./Unify.js";
declare const TagTypeId: unique symbol;
/**
 * @since 2.0.0
 * @category symbol
 */
export type TagTypeId = typeof TagTypeId;
/**
 * @since 3.5.9
 * @category models
 */
export interface Tag<in out Id, in out Value> extends Pipeable, Inspectable {
    readonly _op: "Tag";
    readonly Service: Value;
    readonly Identifier: Id;
    readonly [TagTypeId]: {
        readonly _Service: Types.Invariant<Value>;
        readonly _Identifier: Types.Invariant<Id>;
    };
    of(self: Value): Value;
    context(self: Value): Context<Id>;
    readonly stack?: string | undefined;
    readonly key: string;
    [Unify.typeSymbol]?: unknown;
    [Unify.unifySymbol]?: TagUnify<this>;
    [Unify.ignoreSymbol]?: TagUnifyIgnore;
}
declare const ReferenceTypeId: unique symbol;
/**
 * @since 3.11.0
 * @category symbol
 */
export type ReferenceTypeId = typeof ReferenceTypeId;
/**
 * @since 3.11.0
 * @category models
 */
export interface Reference<in out Id, in out Value> extends Pipeable, Inspectable {
    readonly [ReferenceTypeId]: ReferenceTypeId;
    readonly defaultValue: () => Value;
    readonly _op: "Tag";
    readonly Service: Value;
    readonly Identifier: Id;
    readonly [TagTypeId]: {
        readonly _Service: Types.Invariant<Value>;
        readonly _Identifier: Types.Invariant<Id>;
    };
    of(self: Value): Value;
    context(self: Value): Context<Id>;
    readonly stack?: string | undefined;
    readonly key: string;
    [Unify.typeSymbol]?: unknown;
    [Unify.unifySymbol]?: TagUnify<this>;
    [Unify.ignoreSymbol]?: TagUnifyIgnore;
}
/**
 * @since 2.0.0
 * @category models
 */
export interface TagClassShape<Id, Shape> {
    readonly [TagTypeId]: TagTypeId;
    readonly Type: Shape;
    readonly Id: Id;
}
/**
 * @since 2.0.0
 * @category models
 */
export interface TagClass<Self, Id extends string, Type> extends Tag<Self, Type> {
    new (_: never): TagClassShape<Id, Type>;
    readonly key: Id;
}
/**
 * @since 3.11.0
 * @category models
 */
export interface ReferenceClass<Self, Id extends string, Type> extends Reference<Self, Type> {
    new (_: never): TagClassShape<Id, Type>;
    readonly key: Id;
}
/**
 * @category models
 * @since 2.0.0
 */
export interface TagUnify<A extends {
    [Unify.typeSymbol]?: any;
}> {
    Tag?: () => Extract<A[Unify.typeSymbol], Tag<any, any>>;
}
/**
 * @category models
 * @since 2.0.0
 */
export interface TagUnifyIgnore {
}
/**
 * @since 2.0.0
 */
export declare namespace Tag {
    /**
     * @since 2.0.0
     */
    type Service<T extends Tag<any, any> | TagClassShape<any, any>> = T extends Tag<any, any> ? T["Service"] : T extends TagClassShape<any, infer A> ? A : never;
    /**
     * @since 2.0.0
     */
    type Identifier<T extends Tag<any, any> | TagClassShape<any, any>> = T extends Tag<any, any> ? T["Identifier"] : T extends TagClassShape<any, any> ? T : never;
}
/**
 * Creates a new `Tag` instance with an optional key parameter.
 *
 * @example
 * ```ts
 * import * as assert from "node:assert"
 * import { Context } from "effect"
 *
 * assert.strictEqual(Context.GenericTag("PORT").key === Context.GenericTag("PORT").key, true)
 * ```
 *
 * @since 2.0.0
 * @category constructors
 */
export declare const GenericTag: <Identifier, Service = Identifier>(key: string) => Tag<Identifier, Service>;
declare const TypeId: unique symbol;
/**
 * @since 2.0.0
 * @category symbol
 */
export type TypeId = typeof TypeId;
/**
 * @since 2.0.0
 * @category models
 */
export type ValidTagsById<R> = R extends infer S ? Tag<S, any> : never;
/**
 * @since 2.0.0
 * @category models
 */
export interface Context<in Services> extends Equal, Pipeable, Inspectable {
    readonly [TypeId]: {
        readonly _Services: Types.Contravariant<Services>;
    };
    readonly unsafeMap: Map<string, any>;
}
/**
 * @since 2.0.0
 * @category constructors
 */
export declare const unsafeMake: <Services>(unsafeMap: Map<string, any>) => Context<Services>;
/**
 * Checks if the provided argument is a `Context`.
 *
 * @example
 * ```ts
 * import * as assert from "node:assert"
 * import { Context } from "effect"
 *
 * assert.strictEqual(Context.isContext(Context.empty()), true)
 * ```
 *
 * @since 2.0.0
 * @category guards
 */
export declare const isContext: (input: unknown) => input is Context<never>;
/**
 * Checks if the provided argument is a `Tag`.
 *
 * @example
 * ```ts
 * import * as assert from "node:assert"
 * import { Context } from "effect"
 *
 * assert.strictEqual(Context.isTag(Context.GenericTag("Tag")), true)
 * ```
 *
 * @since 2.0.0
 * @category guards
 */
export declare const isTag: (input: unknown) => input is Tag<any, any>;
/**
 * Checks if the provided argument is a `Reference`.
 *
 * @since 3.11.0
 * @category guards
 * @experimental
 */
export declare const isReference: (u: unknown) => u is Reference<any, any>;
/**
 * Returns an empty `Context`.
 *
 * @example
 * ```ts
 * import * as assert from "node:assert"
 * import { Context } from "effect"
 *
 * assert.strictEqual(Context.isContext(Context.empty()), true)
 * ```
 *
 * @since 2.0.0
 * @category constructors
 */
export declare const empty: () => Context<never>;
/**
 * Creates a new `Context` with a single service associated to the tag.
 *
 * @example
 * ```ts
 * import * as assert from "node:assert"
 * import { Context } from "effect"
 *
 * const Port = Context.GenericTag<{ PORT: number }>("Port")
 *
 * const Services = Context.make(Port, { PORT: 8080 })
 *
 * assert.deepStrictEqual(Context.get(Services, Port), { PORT: 8080 })
 * ```
 *
 * @since 2.0.0
 * @category constructors
 */
export declare const make: <I, S>(tag: Tag<I, S>, service: Types.NoInfer<S>) => Context<I>;
/**
 * Adds a service to a given `Context`.
 *
 * @example
 * ```ts
 * import * as assert from "node:assert"
 * import { Context, pipe } from "effect"
 *
 * const Port = Context.GenericTag<{ PORT: number }>("Port")
 * const Timeout = Context.GenericTag<{ TIMEOUT: number }>("Timeout")
 *
 * const someContext = Context.make(Port, { PORT: 8080 })
 *
 * const Services = pipe(
 *   someContext,
 *   Context.add(Timeout, { TIMEOUT: 5000 })
 * )
 *
 * assert.deepStrictEqual(Context.get(Services, Port), { PORT: 8080 })
 * assert.deepStrictEqual(Context.get(Services, Timeout), { TIMEOUT: 5000 })
 * ```
 *
 * @since 2.0.0
 */
export declare const add: {
    /**
     * Adds a service to a given `Context`.
     *
     * @example
     * ```ts
     * import * as assert from "node:assert"
     * import { Context, pipe } from "effect"
     *
     * const Port = Context.GenericTag<{ PORT: number }>("Port")
     * const Timeout = Context.GenericTag<{ TIMEOUT: number }>("Timeout")
     *
     * const someContext = Context.make(Port, { PORT: 8080 })
     *
     * const Services = pipe(
     *   someContext,
     *   Context.add(Timeout, { TIMEOUT: 5000 })
     * )
     *
     * assert.deepStrictEqual(Context.get(Services, Port), { PORT: 8080 })
     * assert.deepStrictEqual(Context.get(Services, Timeout), { TIMEOUT: 5000 })
     * ```
     *
     * @since 2.0.0
     */
    <I, S>(tag: Tag<I, S>, service: Types.NoInfer<S>): <Services>(self: Context<Services>) => Context<Services | I>;
    /**
     * Adds a service to a given `Context`.
     *
     * @example
     * ```ts
     * import * as assert from "node:assert"
     * import { Context, pipe } from "effect"
     *
     * const Port = Context.GenericTag<{ PORT: number }>("Port")
     * const Timeout = Context.GenericTag<{ TIMEOUT: number }>("Timeout")
     *
     * const someContext = Context.make(Port, { PORT: 8080 })
     *
     * const Services = pipe(
     *   someContext,
     *   Context.add(Timeout, { TIMEOUT: 5000 })
     * )
     *
     * assert.deepStrictEqual(Context.get(Services, Port), { PORT: 8080 })
     * assert.deepStrictEqual(Context.get(Services, Timeout), { TIMEOUT: 5000 })
     * ```
     *
     * @since 2.0.0
     */
    <Services, I, S>(self: Context<Services>, tag: Tag<I, S>, service: Types.NoInfer<S>): Context<Services | I>;
};
/**
 * Get a service from the context that corresponds to the given tag.
 *
 * @example
 * ```ts
 * import * as assert from "node:assert"
 * import { pipe, Context } from "effect"
 *
 * const Port = Context.GenericTag<{ PORT: number }>("Port")
 * const Timeout = Context.GenericTag<{ TIMEOUT: number }>("Timeout")
 *
 * const Services = pipe(
 *   Context.make(Port, { PORT: 8080 }),
 *   Context.add(Timeout, { TIMEOUT: 5000 })
 * )
 *
 * assert.deepStrictEqual(Context.get(Services, Timeout), { TIMEOUT: 5000 })
 * ```
 *
 * @since 2.0.0
 * @category getters
 */
export declare const get: {
    /**
     * Get a service from the context that corresponds to the given tag.
     *
     * @example
     * ```ts
     * import * as assert from "node:assert"
     * import { pipe, Context } from "effect"
     *
     * const Port = Context.GenericTag<{ PORT: number }>("Port")
     * const Timeout = Context.GenericTag<{ TIMEOUT: number }>("Timeout")
     *
     * const Services = pipe(
     *   Context.make(Port, { PORT: 8080 }),
     *   Context.add(Timeout, { TIMEOUT: 5000 })
     * )
     *
     * assert.deepStrictEqual(Context.get(Services, Timeout), { TIMEOUT: 5000 })
     * ```
     *
     * @since 2.0.0
     * @category getters
     */
    <I, S>(tag: Reference<I, S>): <Services>(self: Context<Services>) => S;
    /**
     * Get a service from the context that corresponds to the given tag.
     *
     * @example
     * ```ts
     * import * as assert from "node:assert"
     * import { pipe, Context } from "effect"
     *
     * const Port = Context.GenericTag<{ PORT: number }>("Port")
     * const Timeout = Context.GenericTag<{ TIMEOUT: number }>("Timeout")
     *
     * const Services = pipe(
     *   Context.make(Port, { PORT: 8080 }),
     *   Context.add(Timeout, { TIMEOUT: 5000 })
     * )
     *
     * assert.deepStrictEqual(Context.get(Services, Timeout), { TIMEOUT: 5000 })
     * ```
     *
     * @since 2.0.0
     * @category getters
     */
    <Services, I extends Services, S>(tag: Tag<I, S>): (self: Context<Services>) => S;
    /**
     * Get a service from the context that corresponds to the given tag.
     *
     * @example
     * ```ts
     * import * as assert from "node:assert"
     * import { pipe, Context } from "effect"
     *
     * const Port = Context.GenericTag<{ PORT: number }>("Port")
     * const Timeout = Context.GenericTag<{ TIMEOUT: number }>("Timeout")
     *
     * const Services = pipe(
     *   Context.make(Port, { PORT: 8080 }),
     *   Context.add(Timeout, { TIMEOUT: 5000 })
     * )
     *
     * assert.deepStrictEqual(Context.get(Services, Timeout), { TIMEOUT: 5000 })
     * ```
     *
     * @since 2.0.0
     * @category getters
     */
    <Services, I, S>(self: Context<Services>, tag: Reference<I, S>): S;
    /**
     * Get a service from the context that corresponds to the given tag.
     *
     * @example
     * ```ts
     * import * as assert from "node:assert"
     * import { pipe, Context } from "effect"
     *
     * const Port = Context.GenericTag<{ PORT: number }>("Port")
     * const Timeout = Context.GenericTag<{ TIMEOUT: number }>("Timeout")
     *
     * const Services = pipe(
     *   Context.make(Port, { PORT: 8080 }),
     *   Context.add(Timeout, { TIMEOUT: 5000 })
     * )
     *
     * assert.deepStrictEqual(Context.get(Services, Timeout), { TIMEOUT: 5000 })
     * ```
     *
     * @since 2.0.0
     * @category getters
     */
    <Services, I extends Services, S>(self: Context<Services>, tag: Tag<I, S>): S;
};
/**
 * Get a service from the context that corresponds to the given tag, or
 * use the fallback value.
 *
 * @since 3.7.0
 * @category getters
 */
export declare const getOrElse: {
    /**
     * Get a service from the context that corresponds to the given tag, or
     * use the fallback value.
     *
     * @since 3.7.0
     * @category getters
     */
    <S, I, B>(tag: Tag<I, S>, orElse: LazyArg<B>): <Services>(self: Context<Services>) => S | B;
    /**
     * Get a service from the context that corresponds to the given tag, or
     * use the fallback value.
     *
     * @since 3.7.0
     * @category getters
     */
    <Services, S, I, B>(self: Context<Services>, tag: Tag<I, S>, orElse: LazyArg<B>): S | B;
};
/**
 * Get a service from the context that corresponds to the given tag.
 * This function is unsafe because if the tag is not present in the context, a runtime error will be thrown.
 *
 * For a safer version see {@link getOption}.
 *
 * @example
 * ```ts
 * import * as assert from "node:assert"
 * import { Context } from "effect"
 *
 * const Port = Context.GenericTag<{ PORT: number }>("Port")
 * const Timeout = Context.GenericTag<{ TIMEOUT: number }>("Timeout")
 *
 * const Services = Context.make(Port, { PORT: 8080 })
 *
 * assert.deepStrictEqual(Context.unsafeGet(Services, Port), { PORT: 8080 })
 * assert.throws(() => Context.unsafeGet(Services, Timeout))
 * ```
 *
 * @since 2.0.0
 * @category unsafe
 */
export declare const unsafeGet: {
    /**
     * Get a service from the context that corresponds to the given tag.
     * This function is unsafe because if the tag is not present in the context, a runtime error will be thrown.
     *
     * For a safer version see {@link getOption}.
     *
     * @example
     * ```ts
     * import * as assert from "node:assert"
     * import { Context } from "effect"
     *
     * const Port = Context.GenericTag<{ PORT: number }>("Port")
     * const Timeout = Context.GenericTag<{ TIMEOUT: number }>("Timeout")
     *
     * const Services = Context.make(Port, { PORT: 8080 })
     *
     * assert.deepStrictEqual(Context.unsafeGet(Services, Port), { PORT: 8080 })
     * assert.throws(() => Context.unsafeGet(Services, Timeout))
     * ```
     *
     * @since 2.0.0
     * @category unsafe
     */
    <S, I>(tag: Tag<I, S>): <Services>(self: Context<Services>) => S;
    /**
     * Get a service from the context that corresponds to the given tag.
     * This function is unsafe because if the tag is not present in the context, a runtime error will be thrown.
     *
     * For a safer version see {@link getOption}.
     *
     * @example
     * ```ts
     * import * as assert from "node:assert"
     * import { Context } from "effect"
     *
     * const Port = Context.GenericTag<{ PORT: number }>("Port")
     * const Timeout = Context.GenericTag<{ TIMEOUT: number }>("Timeout")
     *
     * const Services = Context.make(Port, { PORT: 8080 })
     *
     * assert.deepStrictEqual(Context.unsafeGet(Services, Port), { PORT: 8080 })
     * assert.throws(() => Context.unsafeGet(Services, Timeout))
     * ```
     *
     * @since 2.0.0
     * @category unsafe
     */
    <Services, S, I>(self: Context<Services>, tag: Tag<I, S>): S;
};
/**
 * Get the value associated with the specified tag from the context wrapped in an `Option` object. If the tag is not
 * found, the `Option` object will be `None`.
 *
 * @example
 * ```ts
 * import * as assert from "node:assert"
 * import { Context, Option } from "effect"
 *
 * const Port = Context.GenericTag<{ PORT: number }>("Port")
 * const Timeout = Context.GenericTag<{ TIMEOUT: number }>("Timeout")
 *
 * const Services = Context.make(Port, { PORT: 8080 })
 *
 * assert.deepStrictEqual(Context.getOption(Services, Port), Option.some({ PORT: 8080 }))
 * assert.deepStrictEqual(Context.getOption(Services, Timeout), Option.none())
 * ```
 *
 * @since 2.0.0
 * @category getters
 */
export declare const getOption: {
    /**
     * Get the value associated with the specified tag from the context wrapped in an `Option` object. If the tag is not
     * found, the `Option` object will be `None`.
     *
     * @example
     * ```ts
     * import * as assert from "node:assert"
     * import { Context, Option } from "effect"
     *
     * const Port = Context.GenericTag<{ PORT: number }>("Port")
     * const Timeout = Context.GenericTag<{ TIMEOUT: number }>("Timeout")
     *
     * const Services = Context.make(Port, { PORT: 8080 })
     *
     * assert.deepStrictEqual(Context.getOption(Services, Port), Option.some({ PORT: 8080 }))
     * assert.deepStrictEqual(Context.getOption(Services, Timeout), Option.none())
     * ```
     *
     * @since 2.0.0
     * @category getters
     */
    <S, I>(tag: Tag<I, S>): <Services>(self: Context<Services>) => Option<S>;
    /**
     * Get the value associated with the specified tag from the context wrapped in an `Option` object. If the tag is not
     * found, the `Option` object will be `None`.
     *
     * @example
     * ```ts
     * import * as assert from "node:assert"
     * import { Context, Option } from "effect"
     *
     * const Port = Context.GenericTag<{ PORT: number }>("Port")
     * const Timeout = Context.GenericTag<{ TIMEOUT: number }>("Timeout")
     *
     * const Services = Context.make(Port, { PORT: 8080 })
     *
     * assert.deepStrictEqual(Context.getOption(Services, Port), Option.some({ PORT: 8080 }))
     * assert.deepStrictEqual(Context.getOption(Services, Timeout), Option.none())
     * ```
     *
     * @since 2.0.0
     * @category getters
     */
    <Services, S, I>(self: Context<Services>, tag: Tag<I, S>): Option<S>;
};
/**
 * Merges two `Context`s, returning a new `Context` containing the services of both.
 *
 * @example
 * ```ts
 * import * as assert from "node:assert"
 * import { Context } from "effect"
 *
 * const Port = Context.GenericTag<{ PORT: number }>("Port")
 * const Timeout = Context.GenericTag<{ TIMEOUT: number }>("Timeout")
 *
 * const firstContext = Context.make(Port, { PORT: 8080 })
 * const secondContext = Context.make(Timeout, { TIMEOUT: 5000 })
 *
 * const Services = Context.merge(firstContext, secondContext)
 *
 * assert.deepStrictEqual(Context.get(Services, Port), { PORT: 8080 })
 * assert.deepStrictEqual(Context.get(Services, Timeout), { TIMEOUT: 5000 })
 * ```
 *
 * @since 2.0.0
 */
export declare const merge: {
    /**
     * Merges two `Context`s, returning a new `Context` containing the services of both.
     *
     * @example
     * ```ts
     * import * as assert from "node:assert"
     * import { Context } from "effect"
     *
     * const Port = Context.GenericTag<{ PORT: number }>("Port")
     * const Timeout = Context.GenericTag<{ TIMEOUT: number }>("Timeout")
     *
     * const firstContext = Context.make(Port, { PORT: 8080 })
     * const secondContext = Context.make(Timeout, { TIMEOUT: 5000 })
     *
     * const Services = Context.merge(firstContext, secondContext)
     *
     * assert.deepStrictEqual(Context.get(Services, Port), { PORT: 8080 })
     * assert.deepStrictEqual(Context.get(Services, Timeout), { TIMEOUT: 5000 })
     * ```
     *
     * @since 2.0.0
     */
    <R1>(that: Context<R1>): <Services>(self: Context<Services>) => Context<R1 | Services>;
    /**
     * Merges two `Context`s, returning a new `Context` containing the services of both.
     *
     * @example
     * ```ts
     * import * as assert from "node:assert"
     * import { Context } from "effect"
     *
     * const Port = Context.GenericTag<{ PORT: number }>("Port")
     * const Timeout = Context.GenericTag<{ TIMEOUT: number }>("Timeout")
     *
     * const firstContext = Context.make(Port, { PORT: 8080 })
     * const secondContext = Context.make(Timeout, { TIMEOUT: 5000 })
     *
     * const Services = Context.merge(firstContext, secondContext)
     *
     * assert.deepStrictEqual(Context.get(Services, Port), { PORT: 8080 })
     * assert.deepStrictEqual(Context.get(Services, Timeout), { TIMEOUT: 5000 })
     * ```
     *
     * @since 2.0.0
     */
    <Services, R1>(self: Context<Services>, that: Context<R1>): Context<Services | R1>;
};
/**
 * Merges any number of `Context`s, returning a new `Context` containing the services of all.
 *
 * @example
 * ```ts
 * import * as assert from "node:assert"
 * import { Context } from "effect"
 *
 * const Port = Context.GenericTag<{ PORT: number }>("Port")
 * const Timeout = Context.GenericTag<{ TIMEOUT: number }>("Timeout")
 * const Host = Context.GenericTag<{ HOST: string }>("Host")
 *
 * const firstContext = Context.make(Port, { PORT: 8080 })
 * const secondContext = Context.make(Timeout, { TIMEOUT: 5000 })
 * const thirdContext = Context.make(Host, { HOST: "localhost" })
 *
 * const Services = Context.mergeAll(firstContext, secondContext, thirdContext)
 *
 * assert.deepStrictEqual(Context.get(Services, Port), { PORT: 8080 })
 * assert.deepStrictEqual(Context.get(Services, Timeout), { TIMEOUT: 5000 })
 * assert.deepStrictEqual(Context.get(Services, Host), { HOST: "localhost" })
 * ```
 *
 * @since 3.12.0
 */
export declare const mergeAll: <T extends Array<unknown>>(...ctxs: [...{
    [K in keyof T]: Context<T[K]>;
}]) => Context<T[number]>;
/**
 * Returns a new `Context` that contains only the specified services.
 *
 * @example
 * ```ts
 * import * as assert from "node:assert"
 * import { pipe, Context, Option } from "effect"
 *
 * const Port = Context.GenericTag<{ PORT: number }>("Port")
 * const Timeout = Context.GenericTag<{ TIMEOUT: number }>("Timeout")
 *
 * const someContext = pipe(
 *   Context.make(Port, { PORT: 8080 }),
 *   Context.add(Timeout, { TIMEOUT: 5000 })
 * )
 *
 * const Services = pipe(someContext, Context.pick(Port))
 *
 * assert.deepStrictEqual(Context.getOption(Services, Port), Option.some({ PORT: 8080 }))
 * assert.deepStrictEqual(Context.getOption(Services, Timeout), Option.none())
 * ```
 *
 * @since 2.0.0
 */
export declare const pick: <Tags extends ReadonlyArray<Tag<any, any>>>(...tags: Tags) => <Services>(self: Context<Services>) => Context<Services & Tag.Identifier<Tags[number]>>;
/**
 * @since 2.0.0
 */
export declare const omit: <Tags extends ReadonlyArray<Tag<any, any>>>(...tags: Tags) => <Services>(self: Context<Services>) => Context<Exclude<Services, Tag.Identifier<Tags[number]>>>;
/**
 * @example
 * ```ts
 * import * as assert from "node:assert"
 * import { Context, Layer } from "effect"
 *
 * class MyTag extends Context.Tag("MyTag")<
 *  MyTag,
 *  { readonly myNum: number }
 * >() {
 *  static Live = Layer.succeed(this, { myNum: 108 })
 * }
 * ```
 *
 * @since 2.0.0
 * @category constructors
 */
export declare const Tag: <const Id extends string>(id: Id) => <Self, Shape>() => TagClass<Self, Id, Shape>;
/**
 * Creates a context tag with a default value.
 *
 * **Details**
 *
 * `Context.Reference` allows you to create a tag that can hold a value. You can
 * provide a default value for the service, which will automatically be used
 * when the context is accessed, or override it with a custom implementation
 * when needed.
 *
 * **Example** (Declaring a Tag with a default value)
 *
 * ```ts
 * import * as assert from "node:assert"
 * import { Context, Effect } from "effect"
 *
 * class SpecialNumber extends Context.Reference<SpecialNumber>()(
 *   "SpecialNumber",
 *   { defaultValue: () => 2048 }
 * ) {}
 *
 * //      ┌─── Effect<void, never, never>
 * //      ▼
 * const program = Effect.gen(function* () {
 *   const specialNumber = yield* SpecialNumber
 *   console.log(`The special number is ${specialNumber}`)
 * })
 *
 * // No need to provide the SpecialNumber implementation
 * Effect.runPromise(program)
 * // Output: The special number is 2048
 * ```
 *
 * **Example** (Overriding the default value)
 *
 * ```ts
 * import { Context, Effect } from "effect"
 *
 * class SpecialNumber extends Context.Reference<SpecialNumber>()(
 *   "SpecialNumber",
 *   { defaultValue: () => 2048 }
 * ) {}
 *
 * const program = Effect.gen(function* () {
 *   const specialNumber = yield* SpecialNumber
 *   console.log(`The special number is ${specialNumber}`)
 * })
 *
 * Effect.runPromise(program.pipe(Effect.provideService(SpecialNumber, -1)))
 * // Output: The special number is -1
 * ```
 *
 * @since 3.11.0
 * @category constructors
 * @experimental
 */
export declare const Reference: <Self>() => <const Id extends string, Service>(id: Id, options: {
    readonly defaultValue: () => Service;
}) => ReferenceClass<Self, Id, Service>;
export {};
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