Iterative Schema Building with Extendable Fields

// Initialize an empty Struct schema
let personSchema: S.Struct<{}> = S.struct({})

// Function to add fields iteratively using S.extend
function addField<A extends object, B extends object>(
  schema: S.Struct<A>,
  newFields: S.Struct<B>,
): S.Struct<A & B> {
  return S.extend(schema, newFields)
}

// Add the 'name' field
personSchema = addField(personSchema, S.struct({
  name: S.string
}))

// Add the 'age' field
personSchema = addField(personSchema, S.struct({
  age: S.number
}))