(): Transformation<string, string>Transforms strings by lowercasing on decode. Encode is passthrough.
When to use
Use when you need a schema transformation to normalize strings to lowercase (e.g. email addresses).
Details
Decoding applies String.prototype.toLowerCase(). Encoding is passthrough.
This is not round-trippable if the original had uppercase characters.
Example (Lowercasing on decode)
import { Schema, SchemaTransformation } from "effect"
const Lowered = Schema.String.pipe(
Schema.decode(SchemaTransformation.toLowerCase())
)export function function toLowerCase(): Transformation<
string,
string
>
Transforms strings by lowercasing on decode.
Encode is passthrough.
When to use
Use when you need a schema transformation to normalize strings to lowercase
(e.g. email addresses).
Details
Decoding applies String.prototype.toLowerCase(). Encoding is passthrough.
This is not round-trippable if the original had uppercase characters.
Example (Lowercasing on decode)
import { Schema, SchemaTransformation } from "effect"
const Lowered = Schema.String.pipe(
Schema.decode(SchemaTransformation.toLowerCase())
)
toLowerCase(): class Transformation<in out T, in out E, RD = never, RE = never>class Transformation {
_tag: 'Transformation';
decode: SchemaGetter.Getter<T, E, RD>;
encode: SchemaGetter.Getter<E, T, RE>;
flip: () => Transformation<E, T, RE, RD>;
compose: <T2, RD2, RE2>(other: Transformation<T2, T, RD2, RE2>) => Transformation<T2, E, RD | RD2, RE | RE2>;
}
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)
Transformation<string, string> {
return new constructor Transformation<string, string, never, never>(decode: SchemaGetter.Getter<string, string, never>, encode: SchemaGetter.Getter<string, string, never>): Transformation<string, string, never, never>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)
Transformation(
import SchemaGetterSchemaGetter.toLowerCase(),
import SchemaGetterSchemaGetter.passthrough()
)
}