Authored by Tim Smart

Effect 3.11 has been released! This release includes a number of new features and improvements. Here’s a summary of what’s new:

Effect.fn

The Effect.fn api allows you to create a function that is automatically traced, and also attaches the location where the function was called to any error traces.

It also doubles as a pipe function, allowing you to create a pipeline after the function definition.

1 import { Effect } from "effect"

2

3 const logExample = Effect.fn("example")(function* <N extends number>(n: N) {

4 yield* Effect.annotateCurrentSpan("n", n)

5 yield* Effect.logInfo(`got: ${n}`)

6 yield* Effect.fail(new Error())

7 }, Effect.delay("1 second"))

8

9 Effect.runFork(logExample(100).pipe(Effect.catchAllCause(Effect.logError)))

Time zone support in Cron

Cron expressions using the Cron module now support time zones. You can specify a time zone when creating a cron instance when using Cron.make or Cron.parse.

Context.Reference

You can now create a Context.Tag that also has a default value.

1 import { Context } from "effect"

2

3 export class SpecialNumber extends Context.Reference<SpecialNumber>()(

4 "SpecialNumber",

5 { defaultValue: () => 2048 }

6 ) {}

Micro runtime changes

Micro execution is now using a fiber-runtime based model. This results in the following benefits:

• Improved performance
• Improved interruption model
• Consistency with the Effect data type

Env & EnvRef have been removed in favour of Context.Reference.

Effect.scopedWith

Effect.scopedWith allows you to create & use a Scope without adding it to the Effect’s requirements.

1 import { Effect, Scope } from "effect"

2

3 Effect.scopedWith((scope) => Scope.addFinalizer(scope, Effect.log("finalized")))

BigDecimal updates

• BigDecimal.toExponential added - format a BigDecimal as a string in exponential notation.
• BigDecimal.fromNumber has been deprecated in favour of BigDecimal.unsafeFromNumber.

Other changes

There were several other smaller changes made. Take a look through the CHANGELOG to see them all: CHANGELOG.

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