http://ampersandsoftworks.com/posts/iOS-16-formatstyle/

iOS-16-FormatStyle.swift

import Foundation

// MARK: - URL
// https://developer.apple.com/documentation/foundation/formatstyle/4013379-url

let appleURL = URL(string: "https://apple.com")!
appleURL.formatted() // "https://apple.com"
appleURL.formatted(.url) // "https://apple.com"
appleURL.formatted(.url.locale(Locale(identifier: "fr_FR"))) // "https://apple.com"

var httpComponents = URLComponents(url: appleURL, resolvingAgainstBaseURL: false)!
httpComponents.scheme = "https"
httpComponents.user = "jAppleseed"
httpComponents.password = "Test1234"
httpComponents.host = "apple.com"
httpComponents.port = 80
httpComponents.path = "/macbook-pro"
httpComponents.query = "get-free"
httpComponents.fragment = "someFragmentOfSomething"

let complexURL = httpComponents.url!
let everythingStyle = URL.FormatStyle(
    scheme: .always,
    user: .always,
    password: .always,
    host: .always,
    port: .always,
    path: .always,
    query: .always,
    fragment: .always
)

everythingStyle.format(complexURL) // "https://jAppleseed:Test1234@apple.com:80/macbook-pro?get-free#someFragmentOfSomething"

let omitStyle = URL.FormatStyle(
    scheme: .omitIfHTTPFamily,
    user: .omitIfHTTPFamily,
    password: .omitIfHTTPFamily,
    host: .omitIfHTTPFamily,
    port: .omitIfHTTPFamily,
    path: .omitIfHTTPFamily,
    query: .omitIfHTTPFamily,
    fragment: .omitIfHTTPFamily
)

var httpsComponent = httpComponents
httpsComponent.scheme = "https"
let httpsURL = httpsComponent.url!

var ftpComponents = httpComponents
ftpComponents.scheme = "ftp"
let ftpURL = ftpComponents.url!

omitStyle.format(complexURL) // ""
omitStyle.format(httpsURL) // ""
omitStyle.format(ftpURL) // "ftp://jAppleseed@apple.com:80/macbook-pro?get-free#someFragmentOfSomething"

let localhostURL = URL(string: "https://localhost:80/macbook-pro")!

let displayWhen = URL.FormatStyle(
    scheme: .always,
    user: .never,
    password: .never,
    host: .displayWhen(.host, matches: ["localhost"]),
    port: .always,
    path: .always,
    query: .never,
    fragment: .never
)

displayWhen.format(complexURL) // "https://:80/macbook-pro"
displayWhen.format(localhostURL) // "https://localhost:80/macbook-pro"

let omitWhen = URL.FormatStyle(
    scheme: .always,
    user: .never,
    password: .never,
    host: .omitWhen(.host, matches: ["localhost"]),
    port: .always,
    path: .always,
    query: .never,
    fragment: .never
)

omitWhen.format(complexURL) // "https://apple.com:80/macbook-pro"
omitWhen.format(localhostURL) // "https://:80/macbook-pro"

let omitSpecificWhen = URL.FormatStyle(
    scheme: .always,
    user: .never,
    password: .never,
    host: .omitSpecificSubdomains(["secret"], includeMultiLevelSubdomains: false),
    port: .always,
    path: .always,
    query: .never,
    fragment: .never
)

var secretAppleURL = URL(string: "https://secret.apple.com/macbook-pro")!

omitSpecificWhen.format(complexURL) // "https://apple.com:80/macbook-pro"
omitSpecificWhen.format(secretAppleURL) // "https://apple.com/macbook-pro"

let omitSpecificWhenWhere = URL.FormatStyle(
    scheme: .always,
    user: .never,
    password: .never,
    host: .omitSpecificSubdomains(["secret"], includeMultiLevelSubdomains: false, when: .user, matches: ["jAppleseed"]),
    port: .always,
    path: .always,
    query: .never,
    fragment: .never
)

let complexSecretURL = URL(string: "https://jAppleseed:Test1234@secret.apple.com:80/macbook-pro?get-free#someFragmentOfSomething")!

omitSpecificWhenWhere.format(complexSecretURL) // "https://apple.com:80/macbook-pro"
omitSpecificWhenWhere.format(secretAppleURL) // "https://secret.apple.com/macbook-pro"

// MARK: - ByteCount

// https://developer.apple.com/documentation/foundation/formatstyle/3931407-bytecount

let severalTerabytes = Measurement(value: 3, unit: UnitInformationStorage.terabytes)

severalTerabytes.formatted() // "3 TB"
severalTerabytes.formatted(.byteCount(style: .binary)) // "2.73 TB"
severalTerabytes.formatted(.byteCount(style: .decimal)) // "3 TB"
severalTerabytes.formatted(.byteCount(style: .file)) // "3 TB"
severalTerabytes.formatted(
    .byteCount(
        style: .binary,
        allowedUnits: .tb,
        spellsOutZero: true,
        includesActualByteCount: true
    )
) // "2.73 TB (3,000,000,000,000 bytes)"
severalTerabytes.formatted(
    .byteCount(
        style: .binary,
        allowedUnits: .tb,
        spellsOutZero: true,
        includesActualByteCount: false
    )
) // "2.73 TB"

severalTerabytes.formatted(
    .byteCount(
        style: .binary,
        allowedUnits: .tb,
        spellsOutZero: true,
        includesActualByteCount: true
    )
    .locale(Locale(identifier: "fr_FR"))
) // "2,73 To (3 000 000 000 000 octets)"

severalTerabytes.formatted(
    .byteCount(
        style: .binary,
        allowedUnits: .tb,
        spellsOutZero: true,
        includesActualByteCount: true
    )
    .attributed
)

let byteCountMeasurementStyle = Measurement<UnitInformationStorage>.FormatStyle.ByteCount(
    style: .binary,
    allowedUnits: .mb,
    spellsOutZero: true,
    includesActualByteCount: true,
    locale: Locale(identifier: "fr_FR")
)

severalTerabytes.formatted(byteCountMeasurementStyle) // "2 861 022,9 Mo (3 000 000 000 000 octets)"

// This no longer results in a crash.
let threeTerabytes = Int64(3_000_000_000_000)
threeTerabytes.formatted(
    .byteCount(
        style: .binary,
        allowedUnits: .tb,
        spellsOutZero: false,
        includesActualByteCount: true
    )
) // "2.73 TB (3,000,000,000,000 bytes)"



// MARK: - Duration
// https://developer.apple.com/documentation/foundation/formatstyle/3988407-time

let thousandSeconds: Duration = .seconds(1000)

thousandSeconds.formatted() // "0:16:40"
thousandSeconds.formatted(.time(pattern: .hourMinute)) // "0:17"
thousandSeconds.formatted(.time(pattern: .hourMinute(padHourToLength: 10, roundSeconds: .awayFromZero))) // "0,000,000,000:17"
thousandSeconds.formatted(.time(pattern: .hourMinuteSecond)) // "0:16:40"
thousandSeconds.formatted(.time(pattern: .hourMinuteSecond(padHourToLength: 3, fractionalSecondsLength: 3,  roundFractionalSeconds: .awayFromZero))) // "000:16:40.000"
thousandSeconds.formatted(.time(pattern: .minuteSecond)) // "16:40"
thousandSeconds.formatted(.time(pattern: .minuteSecond(padMinuteToLength: 3, fractionalSecondsLength: 3, roundFractionalSeconds: .awayFromZero))) // "016:40.000"

thousandSeconds.formatted(.time(pattern: .hourMinute).locale(Locale(identifier: "fr_FR"))) // "0:17"
let frenchTimeFormatStyle = Duration.TimeFormatStyle(pattern: .minuteSecond, locale: Locale(identifier: "fr_FR"))
frenchTimeFormatStyle.format(thousandSeconds) // "16:40"

// MARK: - Duration
// https://developer.apple.com/documentation/foundation/formatstyle/3988408-units

let halfSecond: Duration = .milliseconds(500)
halfSecond.formatted(.units()) // "0 sec"
halfSecond.formatted(
    .units(allowed: [.milliseconds])
) // "500 ms"
halfSecond.formatted(
    .units(
        allowed: [.milliseconds],
        width: .abbreviated
    )
) // "500 ms"
halfSecond.formatted(
    .units(
        allowed: [.milliseconds],
        width: .condensedAbbreviated
    )
) // "500ms"
halfSecond.formatted(
    .units(
        allowed: [.milliseconds],
        width: .narrow
    )
)
halfSecond.formatted(
    .units(
        allowed: [.milliseconds],
        width: .wide
    )
) // "500 milliseconds"
halfSecond.formatted(
    .units(
        allowed: [.milliseconds],
        width: .wide,
        maximumUnitCount: 1
    )
)
halfSecond.formatted(
    .units(
        allowed: [.milliseconds],
        width: .wide,
        maximumUnitCount: 1,
        zeroValueUnits: .hide
    )
) // "500 milliseconds"
halfSecond.formatted(
    .units(
        allowed: [.seconds, .milliseconds],
        width: .wide,
        maximumUnitCount: 2,
        zeroValueUnits: .show(length: 2)
    )
) // "00 seconds, 500 milliseconds"

halfSecond.formatted(
    .units(
        allowed: [.seconds, .milliseconds],
        width: .wide,
        maximumUnitCount: 2,
        zeroValueUnits: .show(length: 2),
        valueLength: 5
    )
) // "00,000 seconds, 00,500 milliseconds"
halfSecond.formatted(
    .units(
        allowed: [.seconds, .milliseconds],
        width: .wide,
        maximumUnitCount: 2,
        zeroValueUnits: .show(length: 2),
        valueLength: 5,
        fractionalPart: .hide
    )
)

halfSecond.formatted(
    .units(
        allowed: [.seconds, .milliseconds],
        width: .wide,
        maximumUnitCount: 2,
        zeroValueUnits: .show(length: 2),
        valueLength: 5,
        fractionalPart: .hide(rounded: .awayFromZero)
    )
)

halfSecond.formatted(
    .units(
        allowed: [.seconds, .milliseconds],
        width: .wide,
        maximumUnitCount: 2,
        zeroValueUnits: .show(length: 2),
        valueLength: 5,
        fractionalPart: .show(length: 5)
    )
)

halfSecond.formatted(
    .units(
        allowed: [.seconds, .milliseconds],
        width: .wide,
        maximumUnitCount: 2,
        zeroValueUnits: .show(length: 2),
        valueLength: 5,
        fractionalPart: .show(length: 2, rounded: .awayFromZero, increment: 0.000025)
    )
) // "00,000.000000 seconds, 00,500.000000 milliseconds"


let durationUnitsStyle = Duration.UnitsFormatStyle(
    allowedUnits: [.milliseconds],
    width: .abbreviated,
    maximumUnitCount: 5,
    zeroValueUnits: .show(length: 3),
    valueLength: 3,
    fractionalPart: .show(length: 10, rounded: .awayFromZero, increment: 0.1)
)
Duration.microseconds(1234).formatted(durationUnitsStyle) // "001.3000000000 ms"

let durationValueLenghLimitsStyle = Duration.UnitsFormatStyle(
    allowedUnits: [.milliseconds],
    width: .abbreviated,
    maximumUnitCount: 5,
    zeroValueUnits: .show(length: 3),
    valueLengthLimits: 0 ... 1,
    fractionalPart: .show(length: 3)
)

Duration.microseconds(1234).formatted(durationValueLenghLimitsStyle) // "01.234 ms"


// Verbatim
// https://developer.apple.com/documentation/foundation/formatstyle/3996606-verbatim

let twosdayDateComponents = DateComponents(
    year: 2022,
    month: 2,
    day: 22,
    hour: 2,
    minute: 22,
    second: 22,
    nanosecond: 22
)
let twosday = Calendar(identifier: .gregorian).date(from: twosdayDateComponents)!

twosday.formatted(
    .verbatim(
        "\(hour: .defaultDigits(clock: .twentyFourHour, hourCycle: .oneBased)):\(minute: .defaultDigits):\(minute: .defaultDigits) \(dayPeriod: .standard(.wide))",
        locale: Locale(identifier: "zh_CN"),
        timeZone: .current,
        calendar: .current
    )
) // "2:22:22 上午"