Y.A.M の雑記帳: Kotlin メモ : takeIf

Java


public Hoge createFromParcel(Parcel source) {
    final int length = source.readInt();
 final byte[] data;
    if (length > 0) {
        data = new byte[length];
        source.readByteArray(data);
    } else {
        data = null;
    }

    return new Hoge(data);
}

Kotlin 変換直後


override fun createFromParcel(source: Parcel): Hoge {
    val length = source.readInt()
    val data: ByteArray?
    if (length > 0) {
        data = ByteArray(length)
        source.readByteArray(data)
    } else {
        data = null
    }

    return Hoge(data)
}

source.run {} を使う


override fun createFromParcel(source: Parcel): Hoge = source.run {
    val length = readInt()
    val data: ByteArray?
    if (length > 0) {
        data = ByteArray(length)
        readByteArray(data)
    } else {
        data = null
    }

    Hoge(data)
}

also を使う


override fun createFromParcel(source: Parcel): Hoge = source.run {
    val length = readInt()
    val data: ByteArray?
    if (length > 0) {
        data = ByteArray(length).also { readByteArray(it) }
    } else {
        data = null
    }

    Hoge(data)
}

if 式にしてみる


override fun createFromParcel(source: Parcel): Hoge = source.run {
    val length = readInt()
    val data: ByteArray? = if (length > 0) {
        ByteArray(length).also { readByteArray(it) }
    } else {
        null
    }

    Hoge(data)
}

length に let を使う


override fun createFromParcel(source: Parcel): Hoge = source.run {
    val length = readInt()
    val data: ByteArray? = if (length > 0) {
        length.let { ByteArray(it).also { readByteArray(it) } }
    } else {
        null
    }

    Hoge(data)
}

readInt() に takeIf を使う


override fun createFromParcel(source: Parcel): Hoge = source.run {
    val data: ByteArray? = readInt()
            .takeIf { it > 0 }
            ?.let { ByteArray(it).also { readByteArray(it) } }

    Hoge(data)
}

Y.A.M の雑記帳

2017年8月1日火曜日

Kotlin メモ : takeIf

0 件のコメント:

コメントを投稿