package Ġarrow . fold Ċ Ċ import Ġarrow . common . utils . fullName Ċ import Ġarrow . common . utils . known Error Ċ import Ġarrow . common . utils . remove Back ticks Ċ import Ġme . e ug eni om ar let ti . kotlin . metadata . escaped ClassName Ċ import Ġjava . io . File Ċ Ċ class ĠAuto Fold File Generator ( ĊĠ Ġprivate Ġval Ġannotated List : ĠCollection < Annotated Fold >, ĊĠ Ġprivate Ġval Ġgenerated Dir : ĠFile Ċ ) Ġ{ ĊĊĠ Ġfun Ġgenerate () Ġ= Ġannotated List . map ( this :: process Element ) ĊĠĠĠ Ġ. map Ġ{ Ġ( element , Ġfold ) Ġ-> ĊĠĠĠĠĠ Ġ"${ fold Annotation Class . simple Name }.${ element . type . simple Name . toString (). toLowerCase ()}. kt " Ġto ĊĠĠĠĠĠĠĠ Ġfile Header ( element . class Data .` package `. escaped ClassName ) Ġ+ Ġfold ĊĠĠĠ Ġ}. map Ġ{ Ġ( name , Ġfile String ) Ġ-> ĠFile ( generated Dir , Ġname ). write Text ( file String ) Ġ} ĊĊĠ Ġprivate Ġfun Ġprocess Element ( annotated Fold : ĠAnnot ated Fold ): ĠPair < Annotated Fold , ĠString > Ġ= ĊĠĠĠ Ġannotated Fold Ġto Ġannotated Fold . targets . let Ġ{ Ġtargets Ġ-> ĊĠĠĠĠĠ Ġval Ġsource ClassName Ġ= Ġannotated Fold . class Data . fullName . escaped ClassName ĊĠĠĠĠĠ Ġval Ġsum Type Params Ġ= Ġtype Params ( annotated Fold . type Params ) ĊĠĠĠĠĠ Ġval ĠreturnType Ġ= Ġget Fold Type ( annotated Fold . type Params ) ĊĠĠĠĠĠ Ġval Ġfunction Type Params Ġ= Ġfunction Type Params ( annotated Fold . type Params , ĠreturnType ) ĊĊĠĠĠĠĠ Ġ""" inline Ġfun Ġ$ function Type Params Ġ$ source ClassName $ sum Type Params . fold ( ĊĠĠĠĠĠĠĠĠĠĠĠĠĠĠĠ Ġ| ${ params ( targets , ĠreturnType , Ġannotated Fold )} ĊĠĠĠĠĠĠĠĠĠĠĠĠĠĠĠ Ġ| ): Ġ$ returnType Ġ= Ġwhen Ġ( this ) Ġ{ ĊĠĠĠĠĠĠĠĠĠĠĠĠĠĠĠ Ġ| ${ pattern Matching ( targets )} ĊĠĠĠĠĠĠĠĠĠĠĠĠĠĠĠ Ġ| } ĊĠĠĠĠĠĠĠĠĠĠĠĠĠĠĠ Ġ""" . trim Margin () ĊĠĠĠ Ġ} ĊĊĠ Ġprivate Ġfun Ġtype Params ( params : ĠList < String >): ĠString Ġ= ĊĠĠĠ Ġif Ġ( params . isNotEmpty ()) Ġparams . join ToString ( prefix Ġ= Ġ"< ", Ġpostfix Ġ= Ġ"> ") ĊĠĠĠ Ġelse Ġ"" ĊĊĠ Ġprivate Ġfun Ġparams ( variants : ĠList < Variant >, ĠreturnType : ĠString , Ġannotated Fold : ĠAnnot ated Fold ): ĠString Ġ= Ġvariants . join ToString ( transform Ġ= Ġ{ Ġvariant Ġ-> ĊĠĠĠ Ġif Ġ( variant . type Params . size Ġ> Ġannotated Fold . type Params . size ) Ġauto Fold Generic Error ( annotated Fold , Ġvariant ) ĊĠĠĠ Ġelse Ġ" ĠĠĠĠĠĠĠ Ġcross inline Ġ${ variant . simple Name . de capitalize ()} : Ġ(${ variant . fullName . escaped ClassName }${ type Params ( variant . type Params )}) Ġ-> Ġ$ returnType " ĊĠ Ġ}, Ġseparator Ġ= Ġ", \ n ") ĊĊĠ Ġprivate Ġfun Ġfile Header ( packageName : ĠString ) Ġ= Ġ""" ĊĠĠĠ Ġ| package Ġ$ packageName ĊĠĠĠ Ġ| ĊĠĠĠ Ġ| """. trim Margin () ĊĊĠ Ġprivate Ġfun Ġpattern Matching ( variants : ĠList < Variant >): ĠString Ġ= Ġvariants . join ToString ( transform Ġ= Ġ{ Ġvariant Ġ-> ĊĠĠĠ Ġ" ĠĠĠ Ġis Ġ${ variant . fullName . escaped ClassName } Ġ-> Ġ${ variant . simple Name . de capitalize (). escaped ClassName }( this )" ĊĠ Ġ}, Ġseparator Ġ= Ġ"\ n ") ĊĊĠ Ġprivate Ġfun Ġfunction Type Params ( params : ĠList < String >, ĠreturnType : ĠString ): ĠString Ġ= ĊĠĠĠ Ġif Ġ( params . isEmpty ()) Ġ"< $ returnType >" ĊĠĠĠ Ġelse Ġparams . join ToString ( prefix Ġ= Ġ"< ", Ġpostfix Ġ= Ġ", Ġ$ returnType >") ĊĊĠ Ġprivate Ġfun Ġget Fold Type ( params : ĠList < String >): ĠString Ġ{ ĊĠĠĠ Ġfun Ġcheck ( param : ĠString , Ġnext : ĠList < String >): ĠString Ġ= Ġ( param [ 0 ] Ġ+ Ġ 1 ). let Ġ{ ĊĠĠĠĠĠ Ġif Ġ( next . contains ( it . toString ())) Ġcheck ( next . first OrNull () Ġ?: Ġ"", Ġnext . drop ( 1 )) ĊĠĠĠĠĠ Ġelse Ġit . toString () ĊĠĠĠ Ġ} ĊĊĠĠĠ Ġreturn Ġif Ġ( params . isNotEmpty ()) Ġcheck ( params . first (), Ġparams . drop ( 1 )) Ġelse Ġ" A " ĊĠ Ġ} ĊĊĠ Ġprivate Ġfun Ġauto Fold Generic Error ( annotated Fold : ĠAnnot ated Fold , Ġvariant : ĠVariant ): ĠNothing Ġ= Ġknown Error ( ĊĠĠĠ Ġ""" ĊĠĠĠĠĠ Ġ| @ aut of old Ġcannot Ġcreate Ġa Ġfold Ġmethod Ġfor Ġsealed Ġclass Ġ${ annotated Fold . class Data . fullName . escaped ClassName . remove Back ticks ()} ĊĠĠĠĠĠ Ġ| sealed Ġclass Ġ${ annotated Fold . class Data . fullName . escaped ClassName . remove Back ticks ()} ${ type Params ( annotated Fold . type Params )} ĊĠĠĠĠĠ Ġ| ${ " Ġ". repeat (" sealed Ġclass Ġ${ annotated Fold . class Data . fullName . escaped ClassName . remove Back ticks ()} ". length )} Ġ^ Ġcontains Ġless Ġgeneric Ġinformation Ġthan Ġvariant ĊĠĠĠĠĠ Ġ| ĊĠĠĠĠĠ Ġ| ${ variant . fullName . escaped ClassName . remove Back ticks ()} ${ type Params ( variant . type Params )} ĊĠĠĠĠĠ Ġ| ${ " Ġ". repeat ( variant . fullName . escaped ClassName . remove Back ticks (). length )} Ġ^ ĊĠĠĠĠĠ Ġ""" . trim Margin (), Ġannotated Fold . type ) Ċ } Ċ