Function encodeKeys

repos/effect/packages/effect/src/Schema.ts:3494–3526

(mapping: M)

   *   after the transformation.
   */
  mapFields<To extends Struct.Fields>(
    f: (fields: Fields) => To,
    options?: {
      readonly unsafePreserveChecks?: boolean | undefined
    } | undefined
  ): Struct<Simplify<Readonly<To>>>
}

function makeStruct<const Fields extends Struct.Fields>(ast: SchemaAST.Objects, fields: Fields): Struct<Fields> {
  return make(ast, {
    fields,
    mapFields<To extends Struct.Fields>(
      this: Struct<Fields>,
      f: (fields: Fields) => To,
      options?: {
        readonly unsafePreserveChecks?: boolean | undefined
      } | undefined
    ): Struct<To> {
      const fields = f(this.fields)
      return makeStruct(SchemaAST.struct(fields, options?.unsafePreserveChecks ? this.ast.checks : undefined), fields)
    }
  })
}

/**
 * Defines a struct schema from a map of field schemas.
 *
 * **Details**
 *
 * Each field value is a schema. Use {@link optionalKey} or {@link optional} to
 * mark fields as optional, and {@link mutableKey} to mark them as mutable.
 *
 * The resulting schema's `Type` is a readonly object type with the fields'
 * decoded types. The `Encoded` form mirrors the field schemas' encoded types.
 *
 * **Example** (Defining a basic struct)