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Logger overview

Added in v2.0.0


Table of contents


console

withConsoleError

Signature

export declare const withConsoleError: <M, O>(self: Logger<M, O>) => Logger<M, void>

Added in v2.0.0

withConsoleLog

Signature

export declare const withConsoleLog: <M, O>(self: Logger<M, O>) => Logger<M, void>

Added in v2.0.0

constructors

defaultLogger

Signature

export declare const defaultLogger: Logger<unknown, void>

Added in v2.0.0

json

Signature

export declare const json: Layer.Layer<never, never, never>

Added in v2.0.0

jsonLogger

Signature

export declare const jsonLogger: Logger<unknown, string>

Added in v2.0.0

logFmt

Signature

export declare const logFmt: Layer.Layer<never, never, never>

Added in v2.0.0

logfmtLogger

Signature

export declare const logfmtLogger: Logger<unknown, string>

Added in v2.0.0

make

Signature

export declare const make: <Message, Output>(
  log: (options: Logger.Options<Message>) => Output
) => Logger<Message, Output>

Added in v2.0.0

none

A logger that does nothing in response to logging events.

Signature

export declare const none: Logger<unknown, void>

Added in v2.0.0

simple

Signature

export declare const simple: <A, B>(log: (a: A) => B) => Logger<A, B>

Added in v2.0.0

stringLogger

Signature

export declare const stringLogger: Logger<unknown, string>

Added in v2.0.0

structured

Signature

export declare const structured: Layer.Layer<never, never, never>

Added in v2.0.0

structuredLogger

Signature

export declare const structuredLogger: Logger<
  unknown,
  {
    readonly logLevel: string
    readonly fiberId: string
    readonly timestamp: string
    readonly message: unknown
    readonly cause: string | undefined
    readonly annotations: Record<string, unknown>
    readonly spans: Record<string, number>
  }
>

Added in v2.0.0

succeed

Signature

export declare const succeed: <A>(value: A) => Logger<unknown, A>

Added in v2.0.0

sync

Signature

export declare const sync: <A>(evaluate: LazyArg<A>) => Logger<unknown, A>

Added in v2.0.0

test

Signature

export declare const test: {
  <Message>(input: Message): <Output>(self: Logger<Message, Output>) => Output
  <Message, Output>(self: Logger<Message, Output>, input: Message): Output
}

Added in v2.0.0

tracerLogger

Signature

export declare const tracerLogger: Logger<unknown, void>

Added in v2.0.0

context

add

Signature

export declare const add: <B>(logger: Logger<unknown, B>) => Layer.Layer<never>

Added in v2.0.0

addEffect

Signature

export declare const addEffect: <A, E, R>(effect: Effect<Logger<unknown, A>, E, R>) => Layer.Layer<never, E, R>

Added in v2.0.0

addScoped

Signature

export declare const addScoped: <A, E, R>(
  effect: Effect<Logger<unknown, A>, E, R>
) => Layer.Layer<never, E, Exclude<R, Scope>>

Added in v2.0.0

minimumLogLevel

Signature

export declare const minimumLogLevel: (level: LogLevel.LogLevel) => Layer.Layer<never>

Added in v2.0.0

remove

Signature

export declare const remove: <A>(logger: Logger<unknown, A>) => Layer.Layer<never>

Added in v2.0.0

replace

Signature

export declare const replace: {
  <B>(that: Logger<unknown, B>): <A>(self: Logger<unknown, A>) => Layer.Layer<never>
  <A, B>(self: Logger<unknown, A>, that: Logger<unknown, B>): Layer.Layer<never>
}

Added in v2.0.0

replaceEffect

Signature

export declare const replaceEffect: {
  <B, E, R>(that: Effect<Logger<unknown, B>, E, R>): <A>(self: Logger<unknown, A>) => Layer.Layer<never, E, R>
  <A, B, E, R>(self: Logger<unknown, A>, that: Effect<Logger<unknown, B>, E, R>): Layer.Layer<never, E, R>
}

Added in v2.0.0

replaceScoped

Signature

export declare const replaceScoped: {
  <B, E, R>(
    that: Effect<Logger<unknown, B>, E, R>
  ): <A>(self: Logger<unknown, A>) => Layer.Layer<never, E, Exclude<R, Scope>>
  <A, B, E, R>(
    self: Logger<unknown, A>,
    that: Effect<Logger<unknown, B>, E, R>
  ): Layer.Layer<never, E, Exclude<R, Scope>>
}

Added in v2.0.0

withMinimumLogLevel

Signature

export declare const withMinimumLogLevel: {
  (level: LogLevel.LogLevel): <A, E, R>(self: Effect<A, E, R>) => Effect<A, E, R>
  <A, E, R>(self: Effect<A, E, R>, level: LogLevel.LogLevel): Effect<A, E, R>
}

Added in v2.0.0

filtering

filterLogLevel

Returns a version of this logger that only logs messages when the log level satisfies the specified predicate.

Signature

export declare const filterLogLevel: {
  (
    f: (logLevel: LogLevel.LogLevel) => boolean
  ): <Message, Output>(self: Logger<Message, Output>) => Logger<Message, Option.Option<Output>>
  <Message, Output>(
    self: Logger<Message, Output>,
    f: (logLevel: LogLevel.LogLevel) => boolean
  ): Logger<Message, Option.Option<Output>>
}

Added in v2.0.0

guards

isLogger

Returns true if the specified value is a Logger, otherwise returns false.

Signature

export declare const isLogger: (u: unknown) => u is Logger<unknown, unknown>

Added in v1.0.0

mapping

batched

Signature

export declare const batched: {
  <Output, R>(
    window: DurationInput,
    f: (messages: Types.NoInfer<Output>[]) => Effect<void, never, R>
  ): <Message>(self: Logger<Message, Output>) => Effect<Logger<Message, void>, never, Scope | R>
  <Message, Output, R>(
    self: Logger<Message, Output>,
    window: DurationInput,
    f: (messages: Types.NoInfer<Output>[]) => Effect<void, never, R>
  ): Effect<Logger<Message, void>, never, Scope | R>
}

Example

import { Console, Effect, Logger } from "effect"

const LoggerLive = Logger.replaceScoped(
  Logger.defaultLogger,
  Logger.logfmtLogger.pipe(Logger.batched("500 millis", (messages) => Console.log("BATCH", messages.join("\n"))))
)

Effect.gen(function* (_) {
  yield* _(Effect.log("one"))
  yield* _(Effect.log("two"))
  yield* _(Effect.log("three"))
}).pipe(Effect.provide(LoggerLive), Effect.runFork)

Added in v2.0.0

map

Signature

export declare const map: {
  <Output, Output2>(
    f: (output: Output) => Output2
  ): <Message>(self: Logger<Message, Output>) => Logger<Message, Output2>
  <Message, Output, Output2>(self: Logger<Message, Output>, f: (output: Output) => Output2): Logger<Message, Output2>
}

Added in v2.0.0

mapInput

Signature

export declare const mapInput: {
  <Message, Message2>(
    f: (message: Message2) => Message
  ): <Output>(self: Logger<Message, Output>) => Logger<Message2, Output>
  <Output, Message, Message2>(
    self: Logger<Message, Output>,
    f: (message: Message2) => Message
  ): Logger<Message2, Output>
}

Added in v2.0.0

mapInputOptions

Signature

export declare const mapInputOptions: {
  <Message, Message2>(
    f: (options: Logger.Options<Message2>) => Logger.Options<Message>
  ): <Output>(self: Logger<Message, Output>) => Logger<Message2, Output>
  <Output, Message, Message2>(
    self: Logger<Message, Output>,
    f: (options: Logger.Options<Message2>) => Logger.Options<Message>
  ): Logger<Message2, Output>
}

Added in v2.0.0

models

Logger (interface)

Signature

export interface Logger<in Message, out Output> extends Logger.Variance<Message, Output>, Pipeable {
  log(options: Logger.Options<Message>): Output
}

Added in v2.0.0

symbols

LoggerTypeId

Signature

export declare const LoggerTypeId: typeof LoggerTypeId

Added in v2.0.0

LoggerTypeId (type alias)

Signature

export type LoggerTypeId = typeof LoggerTypeId

Added in v2.0.0

tracing

withSpanAnnotations

Signature

export declare const withSpanAnnotations: <Message, Output>(self: Logger<Message, Output>) => Logger<Message, Output>

Added in v2.0.0

utils

Logger (namespace)

Added in v2.0.0

Options (interface)

Signature

export interface Options<out Message> {
  readonly fiberId: FiberId.FiberId
  readonly logLevel: LogLevel.LogLevel
  readonly message: Message
  readonly cause: Cause.Cause<unknown>
  readonly context: FiberRefs.FiberRefs
  readonly spans: List.List<LogSpan.LogSpan>
  readonly annotations: HashMap.HashMap<string, unknown>
  readonly date: Date
}

Added in v2.0.0

Variance (interface)

Signature

export interface Variance<in Message, out Output> {
  readonly [LoggerTypeId]: {
    readonly _Message: Types.Contravariant<Message>
    readonly _Output: Types.Covariant<Output>
  }
}

Added in v2.0.0

zipping

zip

Combines this logger with the specified logger to produce a new logger that logs to both this logger and that logger.

Signature

export declare const zip: {
  <Message2, Output2>(
    that: Logger<Message2, Output2>
  ): <Message, Output>(self: Logger<Message, Output>) => Logger<Message & Message2, [Output, Output2]>
  <Message, Output, Message2, Output2>(
    self: Logger<Message, Output>,
    that: Logger<Message2, Output2>
  ): Logger<Message & Message2, [Output, Output2]>
}

Added in v2.0.0

zipLeft

Signature

export declare const zipLeft: {
  <Message2, Output2>(
    that: Logger<Message2, Output2>
  ): <Message, Output>(self: Logger<Message, Output>) => Logger<Message & Message2, Output>
  <Message, Output, Message2, Output2>(
    self: Logger<Message, Output>,
    that: Logger<Message2, Output2>
  ): Logger<Message & Message2, Output>
}

Added in v2.0.0

zipRight

Signature

export declare const zipRight: {
  <Message2, Output2>(
    that: Logger<Message2, Output2>
  ): <Message, Output>(self: Logger<Message, Output>) => Logger<Message & Message2, Output2>
  <Message, Output, Message2, Output2>(
    self: Logger<Message, Output>,
    that: Logger<Message2, Output2>
  ): Logger<Message & Message2, Output2>
}

Added in v2.0.0