Function head

packages/effect/src/Schema.ts:6532–6548

(
  self: S & Schema<A, Schema.Encoded<S>, Schema.Context<S>>
)

 * @since 3.10.0
 */
export function head<S extends Schema.Any, A extends ReadonlyArray<unknown>>(
  self: S & Schema<A, Schema.Encoded<S>, Schema.Context<S>>
): transform<S, OptionFromSelf<SchemaClass<A[number]>>> {
  return transform(
    self,
    OptionFromSelf(getNumberIndexedAccess(typeSchema(self))),
    {
      strict: false,
      decode: (i) => array_.head(i),
      encode: (a) =>
        option_.match(a, {
          onNone: () => [],
          onSome: array_.of
        })
    }
  )
}

/**
 * Get the first element of a `NonEmptyReadonlyArray`.