readPlainTextIdnaMappingTable()
    }
  return buildIdnaMappingTableData(table)
}

/**
 * Generate a file containing the mapping table's string literals, like this:
 *
 * ```
 * internal val IDNA_MAPPING_TABLE: IdnaMappingTable = IdnaMappingTable(
 *   sections = "...",
 *   ranges = "...",
 *   mappings = "",
 * )
 * ```
 */
fun generateMappingTableFile(data: IdnaMappingTableData): FileSpec {

  /** Confirm we didn't corrupt any data in code generation. */
  @Test fun compareConstructedAndGeneratedCompactTables() {
    assertThat(IDNA_MAPPING_TABLE.sections).isEqualTo(compactTable.sections)
    assertThat(IDNA_MAPPING_TABLE.ranges).isEqualTo(compactTable.ranges)
    assertThat(IDNA_MAPPING_TABLE.mappings).isEqualTo(compactTable.mappings)
  }

  private fun String.map(): String {
    val buffer = Buffer()

 *
 * This implementation's STD3 rules are configured to `UseSTD3ASCIIRules=false`. This is
 * permissive and permits the `_` character.
 *
 * [mapping table]: https://www.unicode.org/reports/tr46/#IDNA_Mapping_Table
 * [mapping step]: https://www.unicode.org/reports/tr46/#ProcessingStepMap
 */
class SimpleIdnaMappingTable internal constructor(
  internal val mappings: List<Mapping>,
) {
  /**