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！

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

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

⹛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

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

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

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

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

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

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

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

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

PO/FYUח &JUIFS׾굲לׅ

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

public class Left<A, B> extends Either<A, B> { 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> X fold(Fold<A, X> l, Fold<B, X> r) { return l.fold(a); } } -FGUKBWB 3JHIUKBWB

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

&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葺ׁ׉ֲ

fun a(): Observable<Either<Throwable, String>> = 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

it.onNext(Either.right(“Hello”)) it.onNext(Either.right(“World”)) it.onNext(Either.right(“Foo Bar Buzz”)) } ⢽ 0CTFSWBCMFDSFBUF 䧭⸆儗כ4USJOH 㣟侁儗כ5ISPXBCMF׾䭯א&JUIFS

it.onNext(Either.right(“Hello”)) it.onNext(Either.right(“World”)) it.onNext(Either.right(“Foo Bar Buzz”)) } ⢽ 0CTFSWBCMFDSFBUF ⡦㔐ד׮㣟侁׾鵤ֿׅהָדֹ׷

it.onNext(Either.right(“Hello”)) it.onNext(Either.right(“World”)) it.onNext(Either.right(“Foo Bar Buzz”)) } ⢽ 0CTFSWBCMFDSFBUF ׮׍׹׿䧭⸆׮⡦㔐ד׮鵤ֿׅהָדֹ׷

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

⢽ 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׾「ֽ《׸׷

,PUMJOד׮׏הأو٦زחדֹזְַז

sealed class Either<out A, out B> { abstract val isLeft:
Boolean abstract val isRight: Boolean } &JUIFSLU

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

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

-> X, right: (B) -> X ): X = when (this) { is Left -> left(value) is Right -> right(value) } ꟼ侧׾「ֽ《׏ג

-> 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׶剏ִ

fun b(): Observable<Either<Throwable, String>> = 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

fun b(): Observable<Either<Throwable, String>> = 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 刿חأحؗٔ剅ֻֿהָדֹ׷

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

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

T> typealias RxLeft<T> = Left<Throwable, T> fun <T> Observable<T>.either(): Observable<RxEither<T>> = map { RxRight(it) as RxEither<T> } .onErrorReturn { RxLeft(it) } -FGU㘗ָ5ISPXBCMFך㘗׾UZQFBMJBTד欽䠐

T> typealias RxLeft<T> = Left<Throwable, T> fun <T> Observable<T>.either(): Observable<RxEither<T>> = map { RxRight(it) as RxEither<T> } .onErrorReturn { RxLeft(it) } 䭁䓸ꟼ侧ד0CTFSWBCMFFJUIFS׾欽䠐

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

} c().either().subscribe({ either -> either.fold({ /* left, “it” is Throwable */ }, { /* right, “it” is String */ }) }, { /* Error */ }) 兛鸐ך0CTFSWBCMFָ֮׏ג׮

} c().either().subscribe({ either -> either.fold({ /* left, “it” is Throwable */ }, { /* right, “it” is String */ }) }, { /* Error */ }) 䭁䓸ꟼ侧דFJUIFSؔلٖ٦ةך״ֲח䮶׷莸ֲ

} c().either().subscribe({ either -> either.fold({ /* left, “it” is Throwable */ }, { /* right, “it” is String */ }) }, { /* Error */ }) 0CTFSWBCMFNFSHFזוד䕵甧א

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

ֶ׃תְ IUUQTHJUIVCDPNSZVHPP&JUIFS4BNQMF

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！

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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