Why are constructor parameters made into members for case classes?

Why are constructor parameters made into members for case classes?

Content Index :

Why are constructor parameters made into members for case classes?
Tag : scala , By : user147496
Date : November 26 2020, 01:01 AM

No Comments Right Now !

Boards Message :
You Must Login Or Sign Up to Add Your Comments .

Share : facebook icon twitter icon

Classes, constructor and pointer class members

Tag : cpp , By : iyogee
Date : March 29 2020, 07:55 AM
hope this fix your issue It depends on whether you want to share the underyling vector or not. In general, I think it is a good practice to avoid sharing wherever possible, since it removes the question of object ownership. Without sharing:
class ListHandler 
        ListHandler(const std::vector<int>& list) : _list(list) {}
        std::vector<int> _list;
class ListHandler 
        ListHandler(std::vector<int>& list) : _list(&list) {}
        std::vector<int>* _list;
class ListHandler 
        ListHandler(std::vector<int>* list) : _list(list) {}
        ListHandler(const ListHandler& o) : _list(new std::vector<int>(o._list)) {}
        ~ListHandler(){ delete _list; _list=0; }

        ListHandler& swap(ListHandler& o){ std::swap(_list,o._list); return *this; }
        ListHandler& operator=(const ListHandler& o){ ListHandler cpy(o); return swap(cpy); }
        std::vector<int>* _list;
class ListHandler 
        ListHandler(const boost::shared_ptr< std::vector<int> >& list) : _list(list) {}
        boost::shared_ptr< std::vector<int> > _list;

How to define case classes with members with unbound type parameters?

Tag : scala , By : Sharad
Date : March 29 2020, 07:55 AM
Does that help A type X[_] is hardly ever what you want. When you use _ on a type, you are basically saying you don't care what that parameter is, because you'll never need to use it.
Anyway, this compiles. It may well bite you down the road, existential types being the tricky stuff that they are, but...
case class University(p: Person[t] forSome { type t <: Person[t] })

Is it ok for case classes to have members of themselves?

Tag : scala , By : John Miller
Date : March 29 2020, 07:55 AM
Hope this helps This is a perfectly fine use of a case class. Case classes are great for defining Recursive structures like this.
For instance, if I wanted to define my own linked-list class, I could use a case class to facilitate easy pattern-matching functionality:
trait MyList[T]
case class Link[T](head: T, tail: MyList[T]) extends MyList[T]
case class End[T]() extends MyList[T]

def last[T](list: MyList[T]): Option[T] =
  list match {
    case End() => None
    case Link(head, End()) => Some(head)
    case Link(head, tail) => last(tail)

println(last(Link(1, Link(2, Link(3, End())))))  // Some(3)
println(last(Link(1, End())))                    // Some(1)
println(last(End()))                             // None

Implicitly declared copy-constructor for classes without data-members and base-classes

Tag : cpp , By : Shitic
Date : March 29 2020, 07:55 AM
should help you out The implicitly declared copy constructor in both cases is of the form A(const A &), since that's the first case in the list and none of the restrictions apply.

How to add constructor without parameter, in case the base class having the constructor with parameters

Tag : java , By : Jouni
Date : March 29 2020, 07:55 AM
Related Posts Related QUESTIONS :
  • Filtering Dataframe by nested array
  • How do I access a nested function in a scala object
  • Execute operation on Future's value for its side effects, discarding result and retaining original value, but retaining
  • Skewed Window Function & Hive Source Partitions?
  • using the object in the match clause of pattern match in Scala
  • How to execute list of scala futures sequentially
  • is there a way to modify the sbt version of an existing project in IntelliJ IDEA?
  • Is it possible to make a generic function that takes different case classes
  • How do I implement a function that generates natural numbers 1,3,5,7...?
  • how to implement flatten for stream using flatmap
  • Akka Streams - How to check if a stream ran successfully?
  • How can I combine shared tests with fixtures that require cleanup?
  • is it possible (and how) to specify an sql query on command line with spark-submit
  • How do I compare tuple values?
  • Updating column value in loop in spark
  • Parallelism in Cassandra read using Scala
  • How to create my own custom scalafmt style that my projects can depend on?
  • how to sort each line on the file in scala?
  • Iterate boolean comparison over two DataFrames?
  • Eliminating identity wrapper types from Scala APIs
  • When running scala code in spark I get "Task not serializable" , why?
  • Akka - Best Approach to configure an Actor that consumes a REST API service (blocking operation)
  • how to substring a variable string
  • How to write empty data frame headers only to csv file?
  • How to sort data in Scala?
  • What (exactly) are "First Class" modules?
  • How to divide values of two columns with another name in sqlcontext?
  • Is it possible to have a generic logging filter in finagle that can be "inserted anywhere" in a chain of andTh
  • Split one row into multiple rows of dataframe
  • Scala Tuple2Zipped vs IterableLike zip
  • How can i check for empty values on spark Dataframe using User defined functions
  • Import Scala object based on value of commandline argument
  • How to get the type parameters from an abstract class that is extended by an object
  • Databricks: Dataframe groupby agg, collector set include duplicate values
  • When to do .repartition(Int AnyValue) in Spark, right after reading the Parquet (or) after running computations on that
  • How can I get an empty collection of the same type as a given instance?
  • How to validate Date Column of dateframe
  • Tail recursion and call by name / value
  • Why there is a different error message on using += and a=x+y on a val variable?
  • Histogram for RDD in Scala?
  • What is value of '_.nextInt' in this expression in Scala
  • Modify keys in Spray JSON
  • base64 decoding of a dataframe
  • Identifying object fields with strings in Scala
  • ScalaTest can't verify mock function invocations inside Future
  • Is it safe to catch an Exception object
  • what is the optimal way to show differences between two data sets
  • case class inheriting another class/trait
  • Scala naming convention for Futures
  • Fs2 Stream.Compiler is not found (could not find implicit value Compiler[[x]F[x],G])
  • Can you mock a value rather than a method?
  • PureConfig ConfigLoader in Scala
  • How to extract latest/recent partition from the list of year month day partition columns
  • How can I partition a RDD respecting order?
  • How beneficial is Parallel Seq for executing sequence of statements?
  • How to obtain class type from case class value
  • How do I append an element to a list in Scala
  • scala - mock function and replace implementation in tests
  • Scala: no-name parameters in function with List and Option
  • How to add the schema in a dataframe from a config file
  • shadow
    Privacy Policy - Terms - Contact Us © scrbit.com