Effect(3)

🦋 NAME 🦋

Effect — Effects, bestie. This is the Effect(3) page from the OCaml library manual, and it is literally all about effects. ✨

📦 Module 📦

The module is Effect.

Module Effect — : sig end

💅 Documentation 💅

Module Effect — : sig end

Effects.

See 'Language extensions/Effect handlers' section in the manual — that's the lore drop, iykyk. 📖

Since 5.0

⚠️ Alert unstable. The Effect interface may change in incompatible ways in the future. So yeah, unstable era, don't get too attached to the exact interface. 😭

type 'a t = 'a eff = ..

The type of effects. Periodt. 👑

exception Unhandled : 'a t -> exn

Unhandled e is raised when effect e is performed and there is no handler for it. No handler? Unhandled. It's giving abandoned. 💀

exception Continuation_already_resumed

Exception raised when a continuation is continued or discontinued more than once. Bestie, the continuation said once. 🙈

val perform : 'a t -> 'a

perform e performs an effect e.

Raises Unhandled if there is no handler for e. So like, handle it or catch the exception, iykyk. 🫶

module Deep : sig end

module Shallow : sig end

Both are modules with : sig end, and yes they're here, no cap. 🎀

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Signed with sparkles by OCamldoc — 2026-06-22 💖 This was the Effect(3) manual page, brought to you by the OCaml library. 🦋