* 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>,
) {
  /**

 * limitations under the License.
 */
@file:Suppress("ktlint:standard:filename")

package okhttp3.internal

import okhttp3.internal.idn.IDNA_MAPPING_TABLE
import okhttp3.internal.idn.Punycode
import okio.Buffer

/**
 * Quick and dirty pattern to differentiate IP addresses from hostnames. This is an approximation
 * of Android's private InetAddress#isNumeric API.
 *

IDN Data
========

In order to implement Nameprep (RFC 3491), OkHttp uses Unicode tables specified in Stringprep
(RFC 3454). Fragments of this RFC are dumped into the files in this directory and parsed by
`StringprepTablesReader` into a model that can be used at runtime.

This format is chosen to make it easy to validate that these tables are consistent with the RFC.

```
cd okhttp/src/test/resources/okhttp3/internal/idn/

  private const val SETTINGS_HEADER_TABLE_SIZE = 4_096

  /**
   * The decoder has ultimate control of the maximum size of the dynamic table but we can choose
   * to use less. We'll put a cap at 16K. This is arbitrary but should be enough for most purposes.
   */
  private const val SETTINGS_HEADER_TABLE_SIZE_LIMIT = 16_384

  val STATIC_HEADER_TABLE =
    arrayOf(
      Header(TARGET_AUTHORITY, ""),

OkHttp IDNA Mapping Table
=========================

This module contains supporting tools for building the IDNA mapping table.

    assertThat(settings.getMaxConcurrentStreams()).isEqualTo(Int.MAX_VALUE)
  }

  @Test
  fun setFields() {
    val settings = Settings()
    settings[Settings.HEADER_TABLE_SIZE] = 8096
    assertThat(settings.headerTableSize).isEqualTo(8096)
    assertThat(settings.getEnablePush(true)).isTrue()
    settings[Settings.ENABLE_PUSH] = 1
    assertThat(settings.getEnablePush(false)).isTrue()

      .isEqualTo("<< 0x00000003 10000 DATA          COMPRESSED")
  }

  /**
   * Ensures that valid flag combinations appear visually correct, and invalid show in hex.  This
   * also demonstrates how sparse the lookup table is.
   */
  @Test
  fun allFormattedFlagsWithValidBits() {
    val formattedFlags = mutableListOf<String>() // Highest valid flag is 0x20.
    for (i in 0..0x3f) formattedFlags.add(formatFlags(TYPE_HEADERS, i))

  }

  @Test fun peerHttp2ServerZerosCompressionTable() {
    val client = false // Peer is server, so we are client.
    val settings = Settings()
    settings[Settings.HEADER_TABLE_SIZE] = 0
    val connection = connectWithSettings(client, settings)

    // Verify the peer's settings were read and applied.
    assertThat(connection.peerSettings.headerTableSize).isEqualTo(0)

    frame.writeByte(Http2.TYPE_SETTINGS)
    frame.writeByte(FLAG_NONE)
    frame.writeInt(0) // Settings are always on the connection stream 0.
    frame.writeShort(1) // SETTINGS_HEADER_TABLE_SIZE
    frame.writeInt(reducedTableSizeBytes)
    frame.writeShort(2) // SETTINGS_ENABLE_PUSH
    frame.writeInt(0)
    reader.nextFrame(
      requireSettings = false,
      object : BaseTestHandler() {

2F0E          ; mapped                 ; 51AB          # 3.0  KANGXI RADICAL ICE
2F0F          ; mapped                 ; 51E0          # 3.0  KANGXI RADICAL TABLE
2F10          ; mapped                 ; 51F5          # 3.0  KANGXI RADICAL OPEN BOX
2F11          ; mapped                 ; 5200          # 3.0  KANGXI RADICAL KNIFE