エンタープライズ Scala

「2018/11/10 Scala関西Summit 2018」でお話したエンタープライズScalaの発表スライドです。

Transcript

1. 
   SCALA
   2018-11-10
   

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2. 
   • #&"%$"
   • Java 17Scala 3
   • !%
   $&
   
   Yohei TSUJI
   @crossroad0201
   2
   

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3. E8IC
   • 5D[]WbeE)ScalaDQ!6O?.N)ScalaQ.
   I;Q %C
   +@ScalaQ/CE)5D-;MQ0?14F.D@E,
   A /aSe^GAI;TIPS(@9*
   • Ue\f`cSZD `dXTV^@J +Scala=?HL/2B, A8?.;
   <4OF.@9*
   • ScalaD #KAPIC>.?C$7?.NP4@E-MG:R*
   • YcS_DCE)P2MK96Q7?'@EB."&3-MG9*
   3
   

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4. 
   1. # !"
   2.
   3.
   4. case class #"
   5.
   
   6. #
   7. Java
   8.
   4
   

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5. View Slide

6. $ val )
   ) .*
   .* 0) * . .* 1 // %
   ) .*
   ) .* 1* ()8 0) * . .* 1
   • * val !)!"()-,*%
   • & var *)$ #/0+. "
   %'
   !
   6
   

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7. )67=159.:+/8
   16 65=> - 2 ( 2 (
   16 65=> - 65=> ," ) 2 ( )
   16 65=>( - 65=> "" 2 + 2 ( ) +
   16 1: - /1: 2 > >4 22 (
   /1: 2 > >4 22 (
   16 1: - 1: " 3 )
   /1: 2 > >4 22 ( 3 )
   16 1:( - 1: " 35 2 =5 +
   /1: 2 > >4 22 ( 3 ) 35 2 =5 +
   • @)67=159.:+/8 %'
   3,("
   • 67=159.:+/8<>scala.collection.mutable42-=0?#&"!
   
   ;=*9
   "$
   7
   

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8. 
   (.
   4 34 ,
   4 4 , 34 " 1 - 1
   4 , 2 $ ($ )"
   4 4( , = + " = / ($ )$ "
   4 4) ,
   4 ,
   4 ( , <
   (
   G <
   • Scala' if + for-yieldmatch %$'
   ( #-'.)
   • var #!&!-56;248%09/17:&."
   ',%0;3. &*)
   8
   

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9. 8A79@B()
   ,2
   >L>= L.L4: L( L) L L+
   L L.L
   L @L- >= L
   L .L@
   =@ >@ LL L +
   L L.L>= > 2: L
   :L L@ L./L L L@
   LL L +
   0 => :
   : L > : ,L2= 51@ L ,L1@ L.L ,L1@ L.L
   > : L :L3=>L./L
   :LI,,I L./L I L L LI
   >L (L.L >= 2= LL L +
   • 8A79@B'0) #map() , #fold()0)2*
   • %'64B=3;?!/0.&+ var 21 ' *
   • 2 )
   '&0.'*-
   • @tailrec 3>

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10. View Slide

11. ),$2
    0 D 5I
    0 ( 3 I
    I 0 5 D I D I 5 5I 8
    0 L
    ( 0 1 2 : B (
    ) 0 1 2 : B )
    ( " )
    1 2 : B
    = 2 I 6 B / 5I / 4D: 2 I 6 B 0 L
    4D: 2 I 6 B
    I 0 2 I 6 B ) (. (( ( 6()/ +/,- 4D: 2 I 6 B
    • )( ),(!.$
    • %+
    1,#)- +*,#($
    • +
    13 #%- +13'"0$6745/1.$
    11
    

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12. ==
    
    ( " / ) ( . /
    ( / ) ( . /
    • Scala !#"
    • #equals() ==
    
    ( ( . /
    !
    12
    

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13. -)/*)0(, &$
    8 . ) . ( 8
    8 . *+: ( 8
    8 . *+:( .) . ( 8
    . + *+: . ) . *+:
    +80 . . 8 ( 8
    =
    . + *+:( .) . . ) . *+:( .) .
    . + *+: .
    =
    • *)0(,23&$"
    • *)0(,&$+1. &$"
    •
    $%!#"'
    13
    

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14. ACF0&-
    1 = > , 1> ) / 31 .1 =1> ) ( $(($( ""
    =>8 = > 0(" 1>
    =>8 = > 0)" )
    =>8 = > 0 " ) ( $(($(
    1 1 1 0" , = >
    = > 1 3
    31 1 0 28> 1 " ,- 1 , 1 28> 1 , 28> 1
    D
    • (1, 2, … 22) +

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15. 2$6-71
    • 2$6- 78* .53.&5*&
    • 45.%)"0&
    • >9*&@(+/Try[Option[String]] -,A
    • 8*57 4&?:;= #get() !40&!0'8
    
    Option[] - 2$6- Some() None
    Try[] 2$6- Success() Failure(Throwable)
    Either[, ] 2$6- Right() Left()
    15
    

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16. implicit class
    , 0@NB: (8
    . = = A
    : = )= (: : = $ )= " = A
    : = =
    : = " // "Hello World"
    • implicit class :!%-, 0@NB:(8%-.$MCEH:,#3(
    SEnrich my libraryIDRQ-293(T
    • ;HKE@.0)40MCEH:'+ $%-,@NB"(8%-:,#3
    (
    • 67
    .1DDD,>QF

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17. View Slide

18. !92
    F FF B ECD EG? F( FF
    C= GE?B="
    AC= GE?B="
    CC GE?B= ) "
    E GE?B= )
    B ECD EG? F( FF
    C= , "
    AC= , "
    CC
    : A B E A G EF HB G?CB
    C= GE?B="
    AC= GE?B="
    CC GE?B= ) "
    E GE?B= )
    A B E A G EF HB G?CB
    C= , "
    AC= , "
    CC
    • 2.$(!+9=9 ,'9?
    '@'!/$
    +9 *)+4>8, /0/$
    • 92&%1"('.#'2$1"( '!/$
    18
    

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19. ' ".*,%
    10 1/0 1 1 1 ( = ( = )
    10 1/0 =0 .0= ( * + 1 80 )
    1 =0 .0= =: =
    B
    1 10 1/0
    B
    0 0 ) 10 1/0 1 1
    • ! (.*, #
    • 3& " private (/1+, %!"
    .*, %!*)20()2-!
    $#
    19
    

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20. -36>@'4
    >:B * / A * / A * / A +
    : + >:B (
    : >:B + >:B 4 / A +, / A
    : + >:B (
    :==>2 .3 :B * * +, . * 1 2.3 +
    :B >
    : + :==> (
    :B +, :B
    A ( )
    • .0/;=<8>7:5)(4%,"+#1' A6>@B
    • *-2.
    Haskell Curry / .'43&!
    • / , />9=? 5$45&)!,#
    • implicit parameter +;=<85.&)!,# AB
    20
    

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21. 163'JRNF6
    implicit parameter 1!4-
    2 ?0 = >? ) >? " 1 ) - 1 C
    1 =20 .0= 0: = >? 0: " 0 = >? 0
    0 1 ) - 1 ,,,
    ?0 >? 0> " " 1
    ?0 >? 0 08 " ( " 1
    2 ?0 = >? ) >? := 1 1 ) - 1 C
    1 =20 .0= 0: = >? 0: " 0 = >? 0
    := 1 0 1 ) - 1 ,,,
    ?0 >? 0> "
    ?0 >? 0 08 " (
    • implicit parameter =(+21"JRNF=!4,0 =7-+2)1*8-#
    • UB?WPXDX
    9DBCIAEQW5:(3"%5 163')4 * -&
    6"implicit parameter 1-:(4,8-#
    • ./,61-#6$5)4(:;">X@HAGO9KTXMVX
    ATLS1'2'8-#
    !
    21
    

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22. (178-
    • #
    %$"% implicit parameter !&
    052,'!
    Scala$PureFunctional6)48/(8*.+-3
    https://www.fringeneer-blog.com/entry/2018/11/01/100531
    22
    

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23. 3A:A?A9.0
    4>62(1/2)
    > >: > .
    >: A >
    F
    . A := >: > . => " >: A
    . : A )= . := >: > >: > .
    : A :
    : A A
    ( =>
    F
    F
    • ;>=7'# *12&1,3A:A?A9.04>6;7A@2
    &1$)2 %-&
    • 5=72 )/+&1$) (!
    "*0-&
    23
    

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24. 
    
    (2/2)
    FM [5ETL 9 SOE ST[
    LO NL L [ EN[LP 9 SOE S1[9 SOE SB:P C[2
    EN 1[:P "[23[ EN SLP
    LO NL L [ EN[N EN7E ALO 9 SOE S1[9 SOE SB EN7E ALO C[2
    EN 1[ EN7E ALO "[23[7E ALO 9 SOE S : >D >64 D74A8DA: 8 I SOE EN "
    LO S [5ETL 9 SOE ST D
    T ("[[ [ (
    T EN7E ALO P ""[[ [ ) (/$(($( A()1 1,- ./0
    EN[T O :P 1[> L PB:P C 2[ O ("
    T T O :P "[[ [ (
    EN[P P :P 1[> L PB:P C[2[= P
    T P P :P "[[ [
    ET [ NETT[ ST P PEO 1[ SLP [E 1[:P "
    LO NL L [ EN[ ST P9 SOE S1[9 SOE SB ST PC[2[
    EN 1[ ST P"[23[T PEO 2 EN PEO [E 2 EN E
    T ST P ES [) "" // "name=taro, age=20"
    24
    

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25. case class
    
    25
    

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26. case class
    0/ 2 0 / 2
    / 2) .=
    / 2) , =
    "
    / =/ 2 =/ ( "
    : = =/ $ / 2" =/
    : = =/ $/ 2" (
    : = =/ " 2 =/ ( "
    : = =/ 2 =/ ( "" = >2
    =/ /=0
    0/ 2 2 / 2 / 2"
    : = / 2 / 2 2/ 1$ "
    =/ ( 2/ 1$
    / =/ ( =/ $0 : / 2 ( "
    : = =/ ( $/ 2" (
    • R[OJ@( 6 val 65=72#
    AUW]GQY5K]G?
    62):.$
    • R[OJ@? .=7285*#
    6!,>= #copy() VFIM2
    -%?/A\EG\E?-*-:.$
    • K]G8 case class 2#
    B\L[]X];C]PE548 "7 class#
    7%+65=3%:.$
    • equals()#hashCode()#toString() ( 6
    ,>=72SAX]RZ]L?2):.$
    • .917R[OJ@60%17#
    NIDWB]M(,>:.$
    • OG]\TIH2R[OJ@6<=(
    
    6':.$^_
    26
    

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27. +&0/-('
    ) A A"A >
    ) A A"A A ) A
    ) A > A" A
    ) A AA" A )
    ) A(AAAAA" A A A ) = A )
    A // true
    • +&0/-('! !
    
    • "+&0/-('
    • -('$0%1),#.*2 '_ => '
    27
    

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28. -)21/+*'%
    > 1 A ) 2 = " ) .
    > A 1 A A "
    > = 8 > A <
    1 A " =: ( ,
    , : >
    I
    > A ) 0 =A 2 =
    /A
    > = A <
    2A , A.
    /A ,
    I
    • case class ! !.0-,('%$
    •
    ! .0-,(" '_' $
    • Option / Try / Either ' '%$
    • !#List !%%&&$
    28
    

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29. sealed 2/65')
    . . : .: .
    . . .: . A
    . . . . .: .
    . . > . . .: .
    = " .: . .: .
    = .: A
    . .: . .
    . .: . > : /
    .
    • sealed
    7.3' "!)&8! %(&! 2/65#
    '"!)-52*4#0+1, $
    • 2/65#'&!-52*4# match may not be exhaustive.$
    29
    

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30. View Slide

31. 532
    • 532MQ62\nvsgMDK@
    Y27
    • JavaL,

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32. flatten()
    / /. (. , , , ,
    / /. /. (. / ,1 (.
    / 23 (. , 2 , )21, 2 ,
    / /. 23 (. / ,1 (.
    •
    • "!#…
    • None
    Some …
    32
    

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33. map()
    3 => /
    3 344 2 => 3 +
    / (
    3 344 2 => 3 2 / (
    3 : > ) . > : , >1 /:
    3 : > 3 2 /:
    3 : > ) . > : , >1 :
    3 : > 3 2 :
    • -!)#
    ($,&
    • /2.013!%$#
    ,&
    • Option / Try / Either !%'*" #,&
    $ %%+*$ $&&*&
    33
    

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34. flatMap()
    O O O CB O C "
    O > O O < C.> , L"OO O/ C O B O O O O C "
    O > 'O O A C.> , L" < BOO O/ C O B O O O O C "
    : O BC OO O CA < "
    O OOOOO O CB
    N
    N
    OC (O2 CB B= O O CA >C= "
    OC 'O OC < O O C-CC B ""O O CB
    • ,/+-.0"#map() #flatten() (!
    • Option / Try / Either "%) %) *$
    • #flatMap() *&'for
    !# %…
    34
    OC 'O OO) C
    O) C-CC B "
    NOL :O
    

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35. fold() (1/2)
    I I,I1 I( I)
    I =I,I I
    6 I 66 I> I, I 66I"I>
    II I
    I = +I0 >21 >:3I,I1 =
    I I,I = .> II I
    I> > +I0 >21 >:3I,I/ >
    I (I,I> > .> II I
    • (&&%
    • '2730*1! ## ( #fold() '
    • -8,.69
    / Option $)+548:/:" # (&%
    35
    

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36. fold() (2/2)
    • Try / Either
    
    I S EL+S EL E > S,S/ E S02. : .3323
    I S )S,S EL =
    S S/ E O R
    : F S +S02. : S,-S
    : F S SSSSSSSSSSSSSS,-S (
    0 SS S :: FF O R
    SS S
    I S E+S. E E > S0 S,S1 = .3323
    I S S,S E =
    SSSSS,-S S1 = O R
    E > S,-SE > S"S(SS S :: FF O R
    SS S
    36
    

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37. foldLeft() / foldRight()
    0 L =>L+L/3 L( L)
    0 L= L+L => 2. 6> L
    10=3L 011 L L+,
    L L )L ,L(L ,L L
    011L L
    LL L
    0 L =>L+L/3 L( L)
    0 L= (L+L => 2-3 > L
    10=3L L011 L+,
    L L L ,L(L ,L)L
    011L L
    LL L
    • &)%'(*$
    • #fold() !
    !#!
    "#!
    "
    
    • &)%'(* #fold() #foldLeft()
    37
    

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38. View Slide

39. ,24$Either
    ? : ?? A A . " = ??C .
    , ??C C, ??C . " : , ??C .
    B : , ??C " A
    ? : ?? B : , ??C ? (A? ??
    B B : ) B : , ??C
    A = ? E
    A . " A
    ? B A A " A
    • ,24$+.34*#$!
    ) Either # Left +&
    • Left $! String #,2410/4-+(
    !,24+'"$",24+*%
    39
    

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40. &/;?.-
    D = EC E CC C
    = DE C CC .E C = ?E
    D = DD . DE CC C FD :C = E ? D CC C
    D = DD = E ? CC C E =D . B CC C E = E ? D CC C
    D = DD CC C E = AC A CE .EC ? " C D ? .EC ?
    EC E (FD ? DD CC C E ? D CC C
    = CC C) .EC ?
    = C D . B ? . B AE
    D = DD E E, F? CC C
    ? .EC ? "
    .EC ?
    E ? D (FD ? DD CC C
    CC = CC C) CC C E E, F?
    CC = C D . B ? "
    • case class #/;?.)
    • */;?#93?>:54#-/;?8>7<>1
    *$,)
    • /;?&'/;?8>7<>1&93?>%" sealed #,)
    • /;?%'23506=?2. ! " .#-+%!(#
    40
    

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41. >JL")!95for0/2&
    : C< ) ) < < E
    = C< ( : • for5 HCF)- #flatMap() 1 #map() 4BKDE@CBI?L0*
    • >JL328!9M=Either*N2$ ;+.')- 1#3
    6*3291,:45
    (:6+=
    • Scala0ALG%1#4 0840786*!
    41
    

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42. #& %$%Either!&%"
    ? B A B A E E )))
    B A A EE B B * @C? B@ """"" """"" @ L
    P
    E = B A ( C =A ?A B A
    R P
    E / : , E=A EE. B ( C =A ?A
    R P
    E / : ?= =BA. B ( C =A ?A =?E @> =A
    STUVR P
    E / : E @. B ( E C =A >
    • #& %$%Either!&%"
    • #& sealed
    #& %$%
    42
    

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43. Java
    43
    

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44. Java'6G!.
    • Scala6G&Java6G-)%,&Java&!.6G)!
    • null
    • 6E47BF
    •
    
    • JavaC2>CD
    • ' JavaC2>CD 0!.#/!.'"
    1?D5G7BF0E2AJavaC2>CD'( 'E2AH2F=C8;C4:@E
    2A+2F9G=3G8E2A%$I& *.,&)!
    44
    

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45. null Option
    =15 55/15 2) . :4 3 (
    =15 4 55/15 2 " 1 " . 2 (
    =15 55/15 2) . :4 3 55
    =15 4 55/15 2 " 1 " 2
    • null Option( ) NULL
    
    45
    

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46. Scala%19027:$,
    : : :5 I. : :%JI %5 I 3 I8 / : :%JI %1 :L %: 5 I ( ) * ,"
    : : / : :5 I% I :C "
    %= I /0 ) // "
    %C: /0 )"
    I : :%JI %1 :L %I I > :%I 1 :L""
    C I : :% I %4: :2 I %
    : :) / : :5 I%: : :
    %= I ) // "
    %C: )"
    I :)%CA I > ""
    • Java%19027:

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47. )Try$3$Either' 0 (1/3)
    A > A ,> F > > A
    E AA > ) A > : A AA A >
    /A
    TL RJ OS O
    I = :
    A : A
    ( A = AA A
    I
    I
    I
    • 0Java7?9) Try{ } $+*
    Try{ } $,% Success(
    ) *!) Failure( ) ( 1'&/*
    • .' Try 2 Either ' 0%$4:=6?8;>$52 Either $0-
    '*#&% for $".$
    47
    

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48. Try Either (2/3)
    > F C F L
    = C = =F EE ,CE ( C = F ( ( JF A E A L
    : F ( ( , ( : < ( , (=F< ( , ( L
    ( F < L
    E EE E = E ) = :F :
    : F EF ( (=F< EF ( ( F ( EF (
    • Try -> Either $!%'#&'"
    
    
    48
    

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49. TryEither
    (3/3)
    A :A_ = A = :A= E ) _ A _ = A = :A= E_
    : = A_) , = A
    = : _ _ A = A( _,A : _ :A . = _ = A/_ _
    E_
    _) T ST JR O [JI ]
    _A=,E A =
    49
    

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50. View Slide

51. H@=?>,ScalaTest6
    > DFi D F: F L > :A =:A =:A"i A > :"i. F =:D "i D : M
    i GAF : >F DK A.: DK :
    : F:A i D : iI>F=i > :A =:A =:A
    I>F=i. F =:D iI>F=i A > :iL
    :F iI=:AiL
    (U fS ebRTOda i = G iL
    NUT i>AiA:Ii >F=)> FGD:iL
    > :A ebRTO
    =:A cgS
    i FG i i GF :F ,
    =:A N h W
    >A > : FG iL
    :i : F : : i i
    : :i = G i : GAFiA Fi GA
    M
    M
    M
    • ScalaTest: http://www.scalatest.org
    • Scala&, /CAGIM)
    ><>7L:BJMDKM9
    • )>+
    ;CM? 4%-!
    NWordSpecFreeSpec8<• GivenWhenThen
    &>
    6!3'520!
    • ScalaMock: https://scalamock.org
    )('.5"%F=9>/
    • should be xxxx.#)DSL
    +
    *,$1!
    51
    

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52. Scalaz : Cats 45>/";
    Scala0GMCJHNC@ *=,84JAFJK#?>='1#<7*#
    GMCJHNC3>=705
    0)2 6!# 1 7*
    7+5Scala4JAFJK0(>/ = DLBEINOptionTryEither @
    !-&090*
    '>;@)/<2%2./$,; Scalaz : Cats 4@*=1 1 7
    *
    • Scalaz: https://github.com/scalaz/scalaz
    • Cats: https://github.com/typelevel/cats
    52
    

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53. IDE.IntelliJ IDEA3
    • IntelliJ IDEA: https://www.jetbrains.com/idea/
    • JetBrains - Scala Plugin )%
    https://plugins.jetbrains.com/plugin/1347-scala
    • +7J?
    • !2+8I:;59A4F4>
    • BH?

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54. $ !$"$
    • $ !$"$ $
    
    • Scalafmt: https://github.com/scalameta/scalafmt #
    • Scalariform: https://github.com/scala-ide/scalariform
    • scalafmt:
    https://speakerdeck.com/norinori3/scalafmtnituitediao-hetemita
    :
    ---- ---- ---
    ---- ----
    >
    :
    ---- ---- ---
    ---- ----
    >
    <
    ) < : <
    ( < = :: : : <
    ( < >>>>>> :: : : <
    <
    ) < : <
    ( < = :: : : <
    ( < >>>>>> :: : : <
    54
    

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55. -2
    • The Scala Programming Language: https://www.scala-lang.org/
    • %12Scala "!$: https://dwango.github.io/scala_text/
    • Effective Scala: http://twitter.github.io/effectivescala/index-ja.html
    • Scala*+: http://www.ne.jp/asahi/hishidama/home/tech/scala/
    • Scala!3,'.(0,)2
    3: http://amzn.asia/d/f56DXon
    • Scala: http://amzn.asia/d/1TQ38iG
    • Scala / &: http://amzn.asia/d/7igHuwm
    • Scala#2&(0,)2: http://amzn.asia/d/hgUMwzq
    55
    

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56. 
    !
    HAVE A GOOD
    SCALA LIFE !!
    56
    

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