LogLevel API Reference

Constructors

All

Since v2.0.0

Signature

declare const All: LogLevel

allLevels

Since v2.0.0

Signature

declare const allLevels: readonly Array<LogLevel>

Debug

Since v2.0.0

Signature

declare const Debug: LogLevel

Error

Since v2.0.0

Signature

declare const Error: LogLevel

Fatal

Since v2.0.0

Signature

declare const Fatal: LogLevel

Info

Since v2.0.0

Signature

declare const Info: LogLevel

None

Since v2.0.0

Signature

declare const None: LogLevel

Trace

Since v2.0.0

Signature

declare const Trace: LogLevel

Warning

Since v2.0.0

Signature

declare const Warning: LogLevel

Conversions

fromLiteral

Since v2.0.0

Signature

declare function fromLiteral(literal: "All" | "Fatal" | "Error" | "Warning" | "Info" | "Debug" | "Trace" | "None"): LogLevel

Instances

Order

Since v2.0.0

Signature

declare const Order: order.Order<LogLevel>

A LogLevel represents the log level associated with an individual logging operation. Log levels are used both to describe the granularity (or importance) of individual log statements, as well as to enable tuning verbosity of log output.

Signature

type LogLevel = All | Fatal | Error | Warning | Info | Debug | Trace | None

None

interface

Since v2.0.0

Signature

interface None extends Pipeable {
  readonly _tag: "None";
  readonly label: "OFF";
  readonly ordinal: number;
  readonly syslog: 7;
}

Trace

interface

Since v2.0.0

Signature

interface Trace extends Pipeable {
  readonly _tag: "Trace";
  readonly label: "TRACE";
  readonly ordinal: number;
  readonly syslog: 7;
}

Warning

interface

Since v2.0.0

Signature

interface Warning extends Pipeable {
  readonly _tag: "Warning";
  readonly label: "WARN";
  readonly ordinal: number;
  readonly syslog: 4;
}

Ordering

greaterThan

Since v2.0.0

Signature

declare const greaterThan: {
  (that: LogLevel): (self: LogLevel) => boolean;
  (self: LogLevel, that: LogLevel): boolean;
}

greaterThanEqual

Since v2.0.0

Signature

declare const greaterThanEqual: {
  (that: LogLevel): (self: LogLevel) => boolean;
  (self: LogLevel, that: LogLevel): boolean;
}

lessThan

Since v2.0.0

Signature

declare const lessThan: {
  (that: LogLevel): (self: LogLevel) => boolean;
  (self: LogLevel, that: LogLevel): boolean;
}

lessThanEqual

Since v2.0.0

Signature

declare const lessThanEqual: {
  (that: LogLevel): (self: LogLevel) => boolean;
  (self: LogLevel, that: LogLevel): boolean;
}

Utils

locally

Since v2.0.0

Temporarily sets a LogLevel for an Effect workflow.

Details

This function allows you to apply a specific LogLevel locally to an Effect workflow. Once the workflow completes, the LogLevel reverts to its previous state.

When to Use

This is particularly useful when you want to adjust the verbosity of logging for specific parts of your program without affecting the global log level.

Signature

declare const locally: {
  (self: LogLevel): <A, E, R>(use: Effect<A, E, R>) => Effect<A, E, R>;
  <A, E, R>(use: Effect<A, E, R>, self: LogLevel): Effect<A, E, R>;
}

Example

import { Effect, LogLevel } from "effect"

const program = Effect.gen(function*() {
  yield* Effect.log("message1")
  yield* Effect.gen(function*() {
    yield* Effect.log("message2")
    yield* Effect.log("message3")
  }).pipe(LogLevel.locally(LogLevel.Warning))
})

Effect.runFork(program)
// timestamp=... level=INFO fiber=#0 message=message1
// timestamp=... level=WARN fiber=#0 message=message2
// timestamp=... level=WARN fiber=#0 message=message3