effect-io-ai

Package: effect
Module: SchemaGetter

SchemaGetter.passthrough

Returns the identity getter — passes the value through unchanged.

When to use

Use when you need a schema getter for one side of a decodeTo pair, either encode or decode, to pass values through unchanged.

Details

• Pure, no allocation (singleton instance).
• Optimized away during .compose() — composing with a passthrough is free.
• The default overload requires T === E. Pass { strict: false } to opt out of the type constraint.

Example (Passing through identity transformations)

import { Schema, SchemaGetter } from "effect"

// No transformation needed — types already match
const StringToString = Schema.String.pipe(
  Schema.decodeTo(Schema.String, {
    decode: SchemaGetter.passthrough(),
    encode: SchemaGetter.passthrough()
  })
)

See

• passthroughSupertype when T extends E
• passthroughSubtype when E extends T
• transform when you need to change the value

Signature

declare const passthrough: { <T, E>(options: { readonly strict: false; }): Getter<T, E>; <T>(): Getter<T, T>; }

Source

Since v4.0.0