effect-io-ai

Package: effect
Module: SchemaTransformation

SchemaTransformation.Transformation

Represents a bidirectional transformation between a decoded type T and an encoded type E, built from a pair of Getters.

When to use

Use when you need a schema transformation that defines how a schema converts between two representations.

• You want to compose multiple transformations into a pipeline.
• You want to flip a transformation to swap decode/encode.

Details

This is the primary building block for Schema.decodeTo, Schema.encodeTo, Schema.decode, Schema.encode, and Schema.link. Each direction is a SchemaGetter.Getter that handles optionality, failure, and Effect services.

• Immutable — flip() and compose() return new instances.
• flip() swaps the decode and encode getters.
• compose(other) chains: this.decode then other.decode for decoding, other.encode then this.encode for encoding.

Example (Composing two transformations)

import { SchemaTransformation } from "effect"

const trimAndLower = SchemaTransformation.trim().compose(
  SchemaTransformation.toLowerCase()
)
// decode: trim then lowercase
// encode: passthrough (both directions)

See

• make — construct from { decode, encode } getters
• transform — construct from pure functions
• transformOrFail — construct from effectful functions
• Middleware — effect-pipeline-level alternative

Signature

declare class Transformation<T, E, RD, RE> { constructor(
    decode: SchemaGetter.Getter<T, E, RD>,
    encode: SchemaGetter.Getter<E, T, RE>
  ) }

Source

Since v4.0.0