<Key, A>(key: Key): <E, R>(
self: ScopedCache<Key, A, E, R>
) => Effect.Effect<boolean>
<Key, A, E, R>(
self: ScopedCache<Key, A, E, R>,
key: Key
): Effect.Effect<boolean>Checks whether the cache contains an entry for the specified key.
When to use
Use to test whether an unexpired entry exists for a key without running the cache lookup.
Details
This does not start lookups and does not refresh access order. Expired entries are treated as absent and their scopes are closed while checking. If the cache is closed, the effect is interrupted.
export const const has: {
<Key, A>(key: Key): <E, R>(
self: ScopedCache<Key, A, E, R>
) => Effect.Effect<boolean>
<Key, A, E, R>(
self: ScopedCache<Key, A, E, R>,
key: Key
): Effect.Effect<boolean>
}
Checks whether the cache contains an entry for the specified key.
When to use
Use to test whether an unexpired entry exists for a key without running the
cache lookup.
Details
This does not start lookups and does not refresh access order. Expired
entries are treated as absent and their scopes are closed while checking. If
the cache is closed, the effect is interrupted.
has: {
<function (type parameter) Key in <Key, A>(key: Key): <E, R>(self: ScopedCache<Key, A, E, R>) => Effect.Effect<boolean>Key, function (type parameter) A in <Key, A>(key: Key): <E, R>(self: ScopedCache<Key, A, E, R>) => Effect.Effect<boolean>A>(key: Keykey: function (type parameter) Key in <Key, A>(key: Key): <E, R>(self: ScopedCache<Key, A, E, R>) => Effect.Effect<boolean>Key): <function (type parameter) E in <E, R>(self: ScopedCache<Key, A, E, R>): Effect.Effect<boolean>E, function (type parameter) R in <E, R>(self: ScopedCache<Key, A, E, R>): Effect.Effect<boolean>R>(self: ScopedCache<Key, A, E, R>(parameter) self: {
state: State<Key, A, E>;
capacity: number;
lookup: (key: Key) => Effect.Effect<A, E, R | Scope.Scope>;
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 ScopedCache<in out Key, in out A, in out E = never, out R = never>A scoped cache whose values are acquired by a lookup effect and stored in
per-entry scopes.
When to use
Use to cache values that acquire scoped resources and must release those
resources when entries expire, are evicted, or are invalidated.
Details
Concurrent requests for the same key share the same in-flight lookup.
Entries can expire based on the lookup exit, are evicted when capacity is
exceeded, and release their entry scopes when invalidated, evicted, expired,
or when the cache's owning scope closes.
ScopedCache<function (type parameter) Key in <Key, A>(key: Key): <E, R>(self: ScopedCache<Key, A, E, R>) => Effect.Effect<boolean>Key, function (type parameter) A in <Key, A>(key: Key): <E, R>(self: ScopedCache<Key, A, E, R>) => Effect.Effect<boolean>A, function (type parameter) E in <E, R>(self: ScopedCache<Key, A, E, R>): Effect.Effect<boolean>E, function (type parameter) R in <E, R>(self: ScopedCache<Key, A, E, R>): Effect.Effect<boolean>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<boolean>
<function (type parameter) Key in <Key, A, E, R>(self: ScopedCache<Key, A, E, R>, key: Key): Effect.Effect<boolean>Key, function (type parameter) A in <Key, A, E, R>(self: ScopedCache<Key, A, E, R>, key: Key): Effect.Effect<boolean>A, function (type parameter) E in <Key, A, E, R>(self: ScopedCache<Key, A, E, R>, key: Key): Effect.Effect<boolean>E, function (type parameter) R in <Key, A, E, R>(self: ScopedCache<Key, A, E, R>, key: Key): Effect.Effect<boolean>R>(self: ScopedCache<Key, A, E, R>(parameter) self: {
state: State<Key, A, E>;
capacity: number;
lookup: (key: Key) => Effect.Effect<A, E, R | Scope.Scope>;
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 ScopedCache<in out Key, in out A, in out E = never, out R = never>A scoped cache whose values are acquired by a lookup effect and stored in
per-entry scopes.
When to use
Use to cache values that acquire scoped resources and must release those
resources when entries expire, are evicted, or are invalidated.
Details
Concurrent requests for the same key share the same in-flight lookup.
Entries can expire based on the lookup exit, are evicted when capacity is
exceeded, and release their entry scopes when invalidated, evicted, expired,
or when the cache's owning scope closes.
ScopedCache<function (type parameter) Key in <Key, A, E, R>(self: ScopedCache<Key, A, E, R>, key: Key): Effect.Effect<boolean>Key, function (type parameter) A in <Key, A, E, R>(self: ScopedCache<Key, A, E, R>, key: Key): Effect.Effect<boolean>A, function (type parameter) E in <Key, A, E, R>(self: ScopedCache<Key, A, E, R>, key: Key): Effect.Effect<boolean>E, function (type parameter) R in <Key, A, E, R>(self: ScopedCache<Key, A, E, R>, key: Key): Effect.Effect<boolean>R>, key: Keykey: function (type parameter) Key in <Key, A, E, R>(self: ScopedCache<Key, A, E, R>, key: Key): Effect.Effect<boolean>Key): 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<boolean>
} = dual<(...args: Array<any>) => any, <Key, A, E>(self: ScopedCache<Key, A, E>, key: Key) => Effect.Effect<boolean>>(arity: 2, body: <Key, A, E>(self: ScopedCache<Key, A, E>, key: Key) => Effect.Effect<boolean>): ((...args: Array<any>) => any) & (<Key, A, E>(self: ScopedCache<Key, A, E>, key: Key) => Effect.Effect<boolean>) (+1 overload)Creates a function that can be called in data-first style or data-last
(pipe-friendly) style.
When to use
Use to expose one implementation through both direct and pipe-friendly
call styles.
Details
Pass either the arity of the uncurried function or a predicate that decides
whether the current call is data-first. Arity is the common case. Use a
predicate when optional arguments make arity ambiguous.
Example (Selecting data-first or data-last style by arity)
import { Function, pipe } from "effect"
const sum = Function.dual<
(that: number) => (self: number) => number,
(self: number, that: number) => number
>(2, (self, that) => self + that)
console.log(sum(2, 3)) // 5
console.log(pipe(2, sum(3))) // 5
Example (Defining overloads with call signatures)
import { Function, pipe } from "effect"
const sum: {
(that: number): (self: number) => number
(self: number, that: number): number
} = Function.dual(2, (self: number, that: number): number => self + that)
console.log(sum(2, 3)) // 5
console.log(pipe(2, sum(3))) // 5
Example (Selecting data-first or data-last style with a predicate)
import { Function, pipe } from "effect"
const sum = Function.dual<
(that: number) => (self: number) => number,
(self: number, that: number) => number
>(
(args) => args.length === 2,
(self, that) => self + that
)
console.log(sum(2, 3)) // 5
console.log(pipe(2, sum(3))) // 5
dual(
2,
<function (type parameter) Key in <Key, A, E>(self: ScopedCache<Key, A, E>, key: Key): Effect.Effect<boolean>Key, function (type parameter) A in <Key, A, E>(self: ScopedCache<Key, A, E>, key: Key): Effect.Effect<boolean>A, function (type parameter) E in <Key, A, E>(self: ScopedCache<Key, A, E>, key: Key): Effect.Effect<boolean>E>(self: ScopedCache<Key, A, E>(parameter) self: {
state: State<Key, A, E>;
capacity: number;
lookup: (key: Key) => Effect.Effect<A, E, R | Scope.Scope>;
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 ScopedCache<in out Key, in out A, in out E = never, out R = never>A scoped cache whose values are acquired by a lookup effect and stored in
per-entry scopes.
When to use
Use to cache values that acquire scoped resources and must release those
resources when entries expire, are evicted, or are invalidated.
Details
Concurrent requests for the same key share the same in-flight lookup.
Entries can expire based on the lookup exit, are evicted when capacity is
exceeded, and release their entry scopes when invalidated, evicted, expired,
or when the cache's owning scope closes.
ScopedCache<function (type parameter) Key in <Key, A, E>(self: ScopedCache<Key, A, E>, key: Key): Effect.Effect<boolean>Key, function (type parameter) A in <Key, A, E>(self: ScopedCache<Key, A, E>, key: Key): Effect.Effect<boolean>A, function (type parameter) E in <Key, A, E>(self: ScopedCache<Key, A, E>, key: Key): Effect.Effect<boolean>E>, key: Keykey: function (type parameter) Key in <Key, A, E>(self: ScopedCache<Key, A, E>, key: Key): Effect.Effect<boolean>Key): 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<boolean> =>
import effecteffect.const uninterruptible: <A, E, R>(
self: Effect.Effect<A, E, R>
) => Effect.Effect<A, E, R>
import corecore.const withFiber: <
A,
E = never,
R = never
>(
evaluate: (
fiber: FiberImpl<unknown, unknown>
) => Effect.Effect<A, E, R>
) => Effect.Effect<A, E, R>
fiber: effect.FiberImpl<unknown, unknown>(parameter) fiber: {
id: number;
interruptible: boolean;
currentOpCount: number;
currentLoopCount: number;
_stack: Array<Primitive>;
_observers: Array<(exit: Exit.Exit<A, E>) => void>;
_exit: Exit.Exit<A, E> | undefined;
_currentExit: Exit.Exit<A, E> | undefined;
_children: Set<FiberImpl<any, any>> | undefined;
_interruptedCause: Cause.Cause<never> | undefined;
_yielded: Exit.Exit<any, any> | (() => void) | undefined;
context: Context.Context<never>;
currentScheduler: Scheduler.Scheduler;
currentTracerContext: Tracer.Tracer["context"];
currentSpan: Tracer.AnySpan | undefined;
currentLogLevel: LogLevel.LogLevel;
minimumLogLevel: LogLevel.LogLevel;
currentStackFrame: StackFrame | undefined;
runtimeMetrics: Metric.FiberRuntimeMetricsService | undefined;
maxOpsBeforeYield: number;
currentPreventYield: boolean;
_dispatcher: Scheduler.SchedulerDispatcher | undefined;
currentDispatcher: SchedulerDispatcher;
getRef: <X>(ref: Context.Reference<X>) => X;
addObserver: (cb: (exit: Exit.Exit<unknown, unknown>) => void) => () => void;
interruptUnsafe: (fiberId?: number | undefined, annotations?: Context.Context<never> | undefined) => void;
pollUnsafe: () => Exit.Exit<unknown, unknown> | undefined;
evaluate: (effect: core.Primitive) => void;
runLoop: (effect: core.Primitive) => typeof core.Yield | Exit.Exit<unknown, unknown>;
getCont: <S extends core.contA | core.contE>(symbol: S) => (core.Primitive & Record<S, (value: any, fiber: effect.FiberImpl) => core.Primitive>) | undefined;
yieldWith: (value: Exit.Exit<any, any> | (() => void)) => core.Yield;
children: () => Set<Fiber.Fiber<any, any>>;
pipe: () => unknown;
setContext: (context: Context.Context<never>) => void;
currentSpanLocal: Span | undefined;
}
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 getImpl: <Key, A, E, R>(
self: ScopedCache<Key, A, E, R>,
key: Key,
fiber: Fiber.Fiber<any, any>,
isRead?: boolean
) => Effect.Effect<Entry<A, E> | undefined>
self: ScopedCache<Key, A, E>(parameter) self: {
state: State<Key, A, E>;
capacity: number;
lookup: (key: Key) => Effect.Effect<A, E, R | Scope.Scope>;
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; <…;
}
key: Keykey, fiber: effect.FiberImpl<unknown, unknown>(parameter) fiber: {
id: number;
interruptible: boolean;
currentOpCount: number;
currentLoopCount: number;
_stack: Array<Primitive>;
_observers: Array<(exit: Exit.Exit<A, E>) => void>;
_exit: Exit.Exit<A, E> | undefined;
_currentExit: Exit.Exit<A, E> | undefined;
_children: Set<FiberImpl<any, any>> | undefined;
_interruptedCause: Cause.Cause<never> | undefined;
_yielded: Exit.Exit<any, any> | (() => void) | undefined;
context: Context.Context<never>;
currentScheduler: Scheduler.Scheduler;
currentTracerContext: Tracer.Tracer["context"];
currentSpan: Tracer.AnySpan | undefined;
currentLogLevel: LogLevel.LogLevel;
minimumLogLevel: LogLevel.LogLevel;
currentStackFrame: StackFrame | undefined;
runtimeMetrics: Metric.FiberRuntimeMetricsService | undefined;
maxOpsBeforeYield: number;
currentPreventYield: boolean;
_dispatcher: Scheduler.SchedulerDispatcher | undefined;
currentDispatcher: SchedulerDispatcher;
getRef: <X>(ref: Context.Reference<X>) => X;
addObserver: (cb: (exit: Exit.Exit<unknown, unknown>) => void) => () => void;
interruptUnsafe: (fiberId?: number | undefined, annotations?: Context.Context<never> | undefined) => void;
pollUnsafe: () => Exit.Exit<unknown, unknown> | undefined;
evaluate: (effect: core.Primitive) => void;
runLoop: (effect: core.Primitive) => typeof core.Yield | Exit.Exit<unknown, unknown>;
getCont: <S extends core.contA | core.contE>(symbol: S) => (core.Primitive & Record<S, (value: any, fiber: effect.FiberImpl) => core.Primitive>) | undefined;
yieldWith: (value: Exit.Exit<any, any> | (() => void)) => core.Yield;
children: () => Set<Fiber.Fiber<any, any>>;
pipe: () => unknown;
setContext: (context: Context.Context<never>) => void;
currentSpanLocal: Span | undefined;
}
import PredicatePredicate.function isNotUndefined<A>(
input: A
): input is Exclude<A, undefined>
Checks whether a value is not undefined.
When to use
Use when you need a Predicate refinement that filters out undefined
while preserving other falsy values.
Details
Returns a refinement that excludes undefined.
Example (Filtering undefined values)
import { Predicate } from "effect"
const values = [1, undefined, 2]
const defined = values.filter(Predicate.isNotUndefined)
console.log(defined)
isNotUndefined))
)
)