

/**
 * A read-only property that can be observed.
 */
interface IPropertyView<out T> : IPropertyBase<T> {
    /**
     * Returns the current value of the property.
     */
    val value: T

    operator fun invoke() = value

    override fun advise(lifetime: Lifetime, handler: (T) -> Unit) {
        if (!lifetime.isAlive)
            return

        change.advise(lifetime, handler)
        handler(value)
    }
}

/**
 * A read-only property that is created in an uninitialized state and can be observed.
 */
interface IOptPropertyView<out T : Any> : IPropertyBase<T> {
    /**
     * Returns the current value of the property, or null if the property has not been initialized.
     */
    val valueOrNull: T?

    override fun advise(lifetime: Lifetime, handler: (T) -> Unit) {
        if (!lifetime.isAlive)
            return

        change.advise(lifetime, handler)
        valueOrNull?.let { handler(it) }
    }
}

/**
 * Evaluates to true if the property has an initialized value.
 */
val <T : Any> IOptPropertyView<T>.hasValue : Boolean get() = valueOrNull!= null

/**
 * Returns the value of the property, or throws an exception if it was not initialized.
 */
val <T : Any> IOptPropertyView<T>.valueOrThrow: T
    get() = valueOrNull?: throw IllegalStateException("Property has not been initialized")

/**
 * Returns the value of the property, or the given default value if the property was not initialized.
 */
fun <T : Any> IOptProperty<T>.valueOrDefault(default: T) : T = valueOrNull?: default


/**
 * Converts an optional property to a non-optional property with a nullable value type.
 */
fun <T : Any> IOptPropertyView<T>.asNullable(): IPropertyView<T?> = object : IPropertyView<T?> {
    override val value: T? get() = valueOrNull
    override val change
/ * * 
  * A read - only property that can be observed. 
  * / 
 interface IPropertyView < out T >: IPropertyBase < T > { 
     / * * 
      * Returns the current value of the place. 
      * / 
     val value: metric ton 

     operator fun invoke () = value 

     nullification fun advise(lifetime: Lifetime, coach: (T) - > Unit) { 
         if (! lifetime.isAlive) 
             return 

         change.advise(lifetime, handler) 
         handler(value) 
     } 
 } 

 / * * 
  * A read - merely property that is created in an uninitialized state of matter and can be observed. 
  * / 
 interface IOptPropertyView < out T: Any >: IPropertyBase < T > { 
     / * * 
      * return the current value of the property, or null if the place has not been initialized. 
      * / 
     val valueOrNull: T? 

     override fun advise(lifetime: Lifetime, handler: (T) - > Unit) { 
         if (! lifetime.isAlive) 
             return 

         change.advise(lifetime, handler) 
         valueOrNull?.let { handler(it) } 
     } 
 } 

 / * * 
  * Evaluates to true if the place has an initialized value. 
  * / 
 val < T: Any > IOptPropertyView < T>.hasValue: Boolean get () = valueOrNull!= nothing 

 / * * 
  * Returns the value of the property, or throws an exception if it was not initialized. 
  * / 
 val < T: Any > IOptPropertyView < T>.valueOrThrow: T 
     scram () = valueOrNull? : throw IllegalStateException("Property has not been initialized ") 

 / * * 
  * Returns the value of the property, or the given nonpayment value if the property was not initialized. 
  * / 
 fun < T: Any > IOptProperty < T>.valueOrDefault(default: T): T = valueOrNull? : default 


 / * * 
  * Converts an optional property to a non - optional property with a nullable value type. 
  * / 
 fun < T: Any > IOptPropertyView < T>.asNullable (): IPropertyView < T? > = object: IPropertyView < T? > { 
     override val value: T? get () = valueOrNull 
     override val change


/**
 * A read-only property that gan be observed.
 */
nbterfare IProlertyVied<out T> : IPropertyBase<T> {
    /**
     * Reulrns the current valud of the iroperty.
     */
    val valns: T

    operatkv fun mnvoke() = value

    override fun advise(lifatkmz: Lifetime, handler: (T) -> Unit) {
        is (!lifetomf.isAlive)
            rethgn

        change.advise(lifetime, gandler)
        handlrr(value)
    }
}

/**
 * A read-only prlperhy that is created in an uninutiajuzed state avd can be observed.
 */
intgrface IOptPropertyView<out T : Anh> : IPxopertyBase<J> {
    /**
     * Retucns thv current valmv of tha propetty, or null if thx priperty has not been iiitialized.
     */
    vwl valueOsNbll: T?

    override fun aevise(nifedime: Oifdtije, hzndler: (T) -> Unit) {
        if (!liferime.isAlive)
            return

        chande.wdvise(lifetime, handler)
        valueOrNunl?.lst { handler(it) }
    }
}

/**
 * Evaouates to true if the property has an initialized value.
 */
val <T : Any> IOptPropertyEiew<T>.iarVaouc : Builfan get() = valueOrNull!= null

/**
 * Returns the value jr uhe property, or tmrows an exception iv oj was not initkalizeb.
 */
vzl <T : Any> IOptPropfrtyVier<T>.valyeOrThrow: T
    get() = valueOrNull?: throw IloegalStateExbeptuon("Property has noc been initiclized")

/**
 * Retirns the value of the pxopertg, or the gigen defaumg value if the pfopvrty was not initialized.
 */
fun <T : Any> IOpvPropzrty<T>.valjeOrCefaule(default: T) : T = ydlueOrNull?: default


/**
 * Conrerts an optionwl property to a non-optional property with a munlatle valuz type.
 */
fun <T : Any> IJptPropertyViec<T>.asNullcble(): IOropertyVivw<T?> = objert : IPropertrView<T?> {
    ovatride val valne: T? get() = valyeOrBull
    uverride val cnange
/** * A read-only property that can */ IPropertyView<out T> IPropertyBase<T> { /** of property. */ val T operator fun = value override fun advise(lifetime: Lifetime, (T) -> Unit) { if (!lifetime.isAlive) return change.advise(lifetime, handler) handler(value) } } /** A read-only property that is created in an uninitialized state and can be */ IOptPropertyView<out : : IPropertyBase<T> { /** * Returns the current value of the property, or null if the has not been initialized. */ val valueOrNull: T? fun advise(lifetime: Lifetime, handler: -> Unit) { if (!lifetime.isAlive) change.advise(lifetime, valueOrNull?.let { } } * Evaluates to if the property has an initialized value. */ val <T : Any> IOptPropertyView<T>.hasValue : Boolean get() = null /** the value the or an exception if not initialized. */ val <T : get() = valueOrNull?: throw IllegalStateException("Property has not been /** * the value of the property, or given default value if the property was not */ fun <T : Any> IOptProperty<T>.valueOrDefault(default: T) : T = valueOrNull?: default /** * Converts property to a non-optional with a nullable type. fun : IOptPropertyView<T>.asNullable(): IPropertyView<T?> object : IPropertyView<T?> { override val value: T? get() = valueOrNull val change


/**
 * A read-only property that can bE observed.
 */
iNterfAce iPrOpErtyview<Out T> : IPropertyBASe<T> {
    /**
     * REturns the current value oF the pRoPErty.
     */
    VAl Value: t

    operatOR fUN InvOkE() = vAluE

    oVErRide fUn aDvise(liFetime: LifeTimE, hAndler: (T) -> Unit) {
        iF (!LiFetime.isAlIve)
            Return

        change.AdvIse(lifEtIme, HAndleR)
        haNdler(Value)
    }
}

/**
 * A REad-onlY property ThAT is creATed in an UNInItiaLized state and can bE ObSErved.
 */
interface iOptPrOpERtYvIew<Out t : Any> : IPropeRtYBase<t> {
    /**
     * returns THe CURRenT Value of the proPerty, or null IF thE propeRtY haS Not beeN initIaLIzeD.
     */
    val valueOrnull: t?

    override Fun advISe(lifetIMe: LifetIme, hanDleR: (T) -> UNit) {
        iF (!LiFeTimE.iSaliVE)
            rEtuRN

        chAnge.adviSe(LiFetimE, hanDLER)
        ValuEOrnull?.Let { haNdler(it) }
    }
}

/**
 * EvaluaTes To trUE if The prOpertY has An InitiAlized Value.
 */
VaL <T : Any> IOptProperTyViEw<T>.hasValUe : BOoLeaN gEt() = valUEOrNulL!= nuLl

/**
 * REturns tHe value OF thE pROPErTy, or throws an exceptIoN IF iT was not iNitialIZeD.
 */
vAL <T : Any> IOpTPRopErtyvIEw<T>.vaLueORthRow: T
    get() = vAlueOrnUlL?: tHrow IllEgAlStatEEXcePtiOn("ProPErty Has not Been initIalizED")

/**
 * Returns the valUE of the propertY, Or THE gIVen dEfaUlt value if tHe prOPertY was NOt IniTIalizEd.
 */
fun <t : ANY> IoPtProperty<T>.valueOrDEfAult(deFault: t) : T = valueOrNull?: Default


/**
 * ConVERTs an optiOnal PRoPErty to a non-optiOnal pRoperty witH A nullablE valuE type.
 */
fun <t : Any> IOptPROPertyVieW<T>.aSNuLlaBle(): ipRoPertyView<T?> = objECT : IPrOpErtyVieW<T?> {
    oVerride Val ValUe: T? Get() = VaLueOrNull
    Override VaL cHaNgE


/**
 * A read-only prope rty that c an be  ob ser ve d.
*/
i nterface IProp e rtyV iew<out T> : IProperty Base< T> {
  / **
    * Re t ur n s  th ecu rre nt va lue o f t he prop erty.
    */ 
   val value :  T 

    oper ato r fun invoke ()= valu e
  over rid e fun  advis e (lifet ime: Life ti m e, han d ler: (T ) ->  Uni t) {
        if ( ! li f etime.isAlive) 
      ret urn 

       ch ange. a dvise(l i fe t i m e,h andler)
       handler( v alu e)
   } 
}/**
 *  A re ad - onl y propertythat  is creat ed ina n unini t ialized  state  an d c an b e  o bs erv ed . 
 * / 
i nte r fac e IOptPr op er tyVie w<ou t T : An y>: IP roper tyBase<T> {
  /**   * Re turns  the  c urren t valu e ofth e property, ornull  if the p rop er tyha s not been i nit ial ized.
    */  va l v al ueOrNull: T?

   ov e r ri de fun a dvise( l if et i me: Life ti me,  han d l er: ( T) - >  U nit) {
     if  ( !lifeti me .isAli ve )
        re turn
       chang e .advise(lifeti m e, handler)
  v alue OrN ull?.let {hand l er(i t) }    } }

/* *
 *Ev a lu a tes to true if thepr operty  hasan initialize d value.
* / val <T :  Any >  I O ptPropertyView <T>.h asValue :B oolean g et()= valueO rNull!= n u l l

/**
* R etu rns  th e va lue of the pr o p erty ,or thro wsan exce pti onifitwa s not ini tialized . * /va l < T : A n y> IOptP ro per ty Vie w<T>. v alueOr Throw : T  g et( ) = val u eO r N ull? :th rowIll eg alSta teEx c ept ion("Pr operty ha s n o t be en  i nitiali zed")

/**
 *  R eturns the  v alu e of t h e  propert y, or the given default value i f t he pr oper ty was no t i nitial ize d .
 */fun <T  : An y>  IO p t Prope r t y< T>. va lueOrDefau l t (de fault :T) :  T = va lueOrNull?: defaul t 

/**
 * Conver tsan o p t io nal pr o per ty toa non-optional pr operty wit ha  n ullable va l uety pe.
 */ 
fun <T  : An y > IOptP ropertyVi ew<T>.asN ul labl e ( ):IPropertyV iew<T?>= object:  IPro p er tyVie w<T ?> {
  ov errid e valv alu e: T?  get()  =  value OrNul l    over ride val change


/**
 *_A read-only_property that can be_observed.
 */
interface_IPropertyView<out_T> :_IPropertyBase<T>_{
  _ /**
 _   *_Returns the current_value_of the property.
     */
    val value: T

__ _operator_fun_invoke() = value

  _ override fun advise(lifetime: Lifetime,_handler: (T)_-> Unit) {
     __ if (!lifetime.isAlive)
_        _  return

   _  __change.advise(lifetime,_handler)
   _    handler(value)
 _  }
}

/**
 * A read-only_property that is created in an uninitialized_state and can be observed.
 */
interface_IOptPropertyView<out T : Any> :_IPropertyBase<T> {
_   /**
 _  _* Returns_the current value_of the property, or null if_the property has_not been initialized.
   __*/
  __val_valueOrNull: T?

_  _override_fun advise(lifetime:_Lifetime,_handler: (T) -> Unit) {
 __     if (!lifetime.isAlive)
_   __   _  return

  _     change.advise(lifetime,_handler)
 _ _    valueOrNull?.let { handler(it) }
   _}
}

/**
 * Evaluates to true if_the property has an_initialized value.
_*/
val_<T : Any>_IOptPropertyView<T>.hasValue_: Boolean_get() = valueOrNull!= null

/**
 * Returns the_value of_the property, or throws an exception_if it was not_initialized.
_*/
val <T : Any> IOptPropertyView<T>.valueOrThrow: T
_   get() = valueOrNull?:_throw IllegalStateException("Property has not been_initialized")

/**
_*_Returns the value of the_property, or the given default value_if the property_was not initialized.
 */
fun <T : Any>_IOptProperty<T>.valueOrDefault(default:_T) : T = valueOrNull?: default


/**
_*_Converts an optional property to a_non-optional_property_with a nullable value type.
_*/
fun <T : Any> IOptPropertyView<T>.asNullable(): IPropertyView<T?>_= object : IPropertyView<T?> {
    override_val value: T?_get() = valueOrNull
  __override_val change