Either で想定内のエラーと想定外のエラーを別ものにしたい！

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&JUIFSד  䟝㹀ⰻךؒٓ٦ה  䟝㹀㢩ךؒٓ٦׾  ⴽ׮ךח׃׋ְ 3Y+B/JHIU7PM

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㹧♴畆㣐龤 $IBU8PSL吳䒭⠓爡 ،فٔ؛٦ءّٝꟚ涪鿇ث٦ئ٦ت٦ !SZVHPP@

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⹛堣䟝㹀ⰻך㣟侁䟝㹀㢩ך㣟侁׾ⴓֽ׋ְ 䟝㹀ⰻ 8FC"1*ؙٔؒأزָة؎ي،ؐز׃׋ 䟝㹀㢩 ءأذيך㉏겗זו

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3Y+BWBךؒٓ٦عٝسؚٔٝ 0CTFSWBCMFPO&SSPS 'MPXBCMFPO&SSPS 4JOHMFPO&SSPS $PNQMFUBCMFPO&SSPS .BZCFPO&SSPS ؒٓ٦ך「ֽ《׶⯓כא

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⢽ ؙٔحؙ̔ؿ؋؎ٕ《䖤̔،حفٗ٦س RxBinding.clicks(button) .map { /* Get file */ } .flatMap { /* Upload */ } ~~~~~ .subscribe({ /* Success */ }, { /* IOException or Request failure */ })

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RxBinding.clicks(button) .map { /* Get file */ } .flatMap { /* Upload */ } ~~~~~ .subscribe({ /* Success */ }, { /* IOException or Request failure */ }) ֿֿדPO&SSPSָ鸐濼ׁ׸׷ה ⢽ ؙٔحؙ̔ؿ؋؎ٕ《䖤̔،حفٗ٦س

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RxBinding.clicks(button) .map { /* Get file */ } .flatMap { /* Upload */ } ~~~~~ .subscribe({ /* Success */ }, { /* IOException or Request failure */ }) 4VCTDSJCFSPO&SSPSחⳢ椚ָ獳׶ ⢽ ؙٔحؙ̔ؿ؋؎ٕ《䖤̔،حفٗ٦س

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RxBinding.clicks(button) .map { /* Get file */ } .flatMap { /* Upload */ } ~~~~~ .subscribe({ /* Success */ }, { /* IOException or Request failure */ }) ؙٔحؙ؎كٝزכ׮ֲ굲׿דֿזְ ⢽ ؙٔحؙ̔ؿ؋؎ٕ《䖤̔،حفٗ٦س

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ؒٓ٦عٝسؚٔٝؔلٖ٦ةכ葿ղ֮׷ PO&SSPS3FUVSO PO&SSPS3FTVNF/FYU SFUSZ SFUSZ8IFO ˑؒٓ٦˒׏גז׿׌׏׋׏ֽ 3Y+BWBךؒٓ٦عٝسؚٔٝ

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ؿ؋؎ָٕ鼅䫛ׁ׸גְזְךַ ؿ؋؎ָٕ《䖤דֹזַ׏׋ךַ ،حفٗ٦س㼎韋㢩ךؿ؋؎ٕ䕎䒭׌׏׋ךַ 8FC؟٦غ٦ָتؐٝ׃גְ׷ךַ ؔؿٓ؎ٝזךַ ˑؒٓ٦˒ה♧〡ח鎉׏ג׮˘˘ ،فٔה׃גˑ姻׃ְ˒䮙⹛כؒٓ٦

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RxBinding.clicks(button) .map { /* Get file */ } .flatMap { /* Upload */ } ~~~~~ .subscribe({ if (it.isSuccessful) { /* Success */ } else { /* Request failure */ } }, { /* IOException */ }) PO/FYUח3FTVMU㘗׫׋ְז׮ך׾굲לׅ

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PO/FYUח &JUIFS׾굲לׅ

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public abstract class Either { public static Either left(A a) { new Left<>(a); } public static Either right(B b) { new Right<>(b); } public abstract boolean isLeft(); public abstract boolean isRight(); public abstract X fold(Fold l, Fold r); } &JUIFSKBWB

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public class Left extends Either { private final A a; public Left(A a) { this.a = a; } @Override public boolean isLeft() { return true; } @Override public boolean isRight() { return false; } @Override public X fold(Fold l, Fold r) { return l.fold(a); } } -FGUKBWB 3JHIUKBWB

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public interface FoldJ { Y fold(X value); } 'PMEKBWB

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&JUIFS אך㘗ךֲ׍ծְ׆׸ַ㘗ך⦼׾䭯א ؟ـؙٓأה׃ג-FGU3JHIU㘗ָ֮׷ 䧭⸆כ姻׃ְ SJHIU חַֽג3JHIUד鵤ׅ 㣟侁כ-FGUד鵤ׅ 3Y+BWBדכ-FGU׾5ISPXBCMFחׅ׷ה葺ׁ׉ֲ

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fun a(): Observable> = Observable.create { it.onNext(Either.left(RuntimeException())) it.onNext(Either.left(RuntimeException())) it.onNext(Either.left(RuntimeException())) it.onNext(Either.right(“Hello”)) it.onNext(Either.right(“World”)) it.onNext(Either.right(“Foo Bar Buzz”)) } ⢽ 0CTFSWBCMFDSFBUF

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⢽ 0CTFSWBCMFDSFBUF a().subscribe({ either -> either.fold({ /* left, “it” is Throwable */ }, { /* right, “it” is String */ }) }, { /* Error */ })

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⢽ 0CTFSWBCMFDSFBUF a().subscribe({ either -> either.fold({ /* left, “it” is Throwable */ }, { /* right, “it” is String */ }) }, { /* Error */ }) 4VCTDSJCFSPO/FYUך⚥ח׮ֲ媮「ֽ〡׾⡲׷ &JUIFS" #ד䭷㹀׃׋ˑ㘗˒ד穠卓׾「ֽ《׸׷

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,PUMJOד׮׏הأو٦زחדֹזְַז

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sealed class Either { abstract val isLeft: Boolean abstract val isRight: Boolean } &JUIFSLU

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&JUIFSLU data class Left(val value: A) : Either() { override val isLeft: Boolean = true override val isRight: Boolean = false } data class Right(val value: B) : Either() { override val isLeft: Boolean = false override val isRight: Boolean = true }

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&JUIFSLU inline fun Either.fold( left: (A) -> X, right: (B) -> X ): X = when (this) { is Left -> left(value) is Right -> right(value) }

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&JUIFSLU inline fun Either.fold( left: (A) -> X, right: (B) -> X ): X = when (this) { is Left -> left(value) is Right -> right(value) } ꟼ侧׾「ֽ《׏ג

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&JUIFSLU inline fun Either.fold( left: (A) -> X, right: (B) -> X ): X = when (this) { is Left -> left(value) is Right -> right(value) } XIFO䒭ד㘗ח䘔ׄג㹋遤ׅ׷ꟼ侧׾ⴖ׶剏ִ

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fun b(): Observable> = Observable.create { it.onNext(Left(RuntimeException())) it.onNext(Left(RuntimeException())) it.onNext(Left(RuntimeException())) it.onNext(Right(“Hello”)) it.onNext(Right(“World”)) it.onNext(Right(“Foo Bar Buzz”)) } ⢽ 0CTFSWBCMFDSFBUF

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⢽ 0CTFSWBCMFDSFBUF b().subscribe({ either -> either.fold({ /* left, “it” is Throwable */ }, { /* right, “it” is String */ }) }, { /* Error */ }) +BWBד㹀纏׃׋הֹה「ֽ《׶倯כずׄ

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ׁ׵ח typealias RxEither = Either typealias RxRight = Right typealias RxLeft = Left fun Observable.either(): Observable> = map { RxRight(it) as RxEither } .onErrorReturn { RxLeft(it) }

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ׁ׵ח typealias RxEither = Either typealias RxRight = Right typealias RxLeft = Left fun Observable.either(): Observable> = map { RxRight(it) as RxEither } .onErrorReturn { RxLeft(it) } -FGU㘗ָ5ISPXBCMFך㘗׾UZQFBMJBTד欽䠐

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ׁ׵ח fun c(): Observable = Observable.create { it.onNext(“Hello, world”) it.onError(RuntimeException()) } c().either().subscribe({ either -> either.fold({ /* left, “it” is Throwable */ }, { /* right, “it” is String */ }) }, { /* Error */ })

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תה׭ 䟝㹀ⰻך㣟侁䟝㹀㢩ך㣟侁׾ⴓֽ׋ְ &JUIFS㘗׾⡲׏גⴓֽ׷ֿהָדֹ׷ ؔلٖ٦ة٦דכזֻ㘗דⴓֽ׷ ,PUMJO׾⢪ֲה刿חأو٦زח㹀纏דֹ׷ 䭁䓸ꟼ侧׾⢪׏ג傀㶷ך0CTFSWBCMF׮  &JUIFS5ISPXBCMF 5ח㢌䳔〳腉 &JUIFS荈⡤כ4DBMBח׮׏הؼٝزָ֮׷ -FGU 3JHIUךNBQװTXBQזוזו

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ֶ׃תְ IUUQTHJUIVCDPNSZVHPP&JUIFS4BNQMF