What are the disadvantages to declaring Scala case classes?

Posted by Graham Lea on Stack Overflow See other posts from Stack Overflow or by Graham Lea
Published on 2011-01-11T01:46:28Z Indexed on 2011/01/11 1:53 UTC
Read the original article Hit count: 502

Filed under:

scala

|

case-class

|

disadvantages

If you're writing code that's using lots of beautiful, immutable data structures, case classes appear to be a godsend, giving you all of the following for free with just one keyword:

Everything immutable by default
Getters automatically defined
Decent toString() implementation
Compliant equals() and hashCode()
Companion object with unapply() method for matching

But what are the disadvantages of defining an immutable data structure as a case class?

What restrictions does it place on the class or its clients?

Are there situations where you should prefer a non-case class?

© Stack Overflow or respective owner

Related posts about scala

ensime scala errors (class scala.Array not found, object scala not found)

as seen on Stack Overflow - Search for 'Stack Overflow'
I've installed ensime according to the README.md file, however, I get errors in the inferior-ensime-server buffer with the following: INFO: Fatal Error: scala.tools.nsc.MissingRequirementError: object scala not found. scala.tools.nsc.MissingRequirementError: object scala not found. at scala… >>> More
infinite loop shutting down ensime

as seen on Stack Overflow - Search for 'Stack Overflow'
When I run M-X ensime-disconnect I get the following forever: string matching regex `\"((?:[^\"\\]|\\.)*)\"' expected but `^@' found and I see this exception when I use C-c C-c Uncaught exception in com.ensime.server.SocketHandler@769aba32 java.net.SocketException: Broken pipe at java… >>> More
How to resolve java.nio.charset.UnmappableCharacterException in Scala 2.8.0?

as seen on Stack Overflow - Search for 'Stack Overflow'
I'm using Scala 2.8.0 and trying to read pipe delimited file like in code snipped below: object Main { def main(args: Array[String]) :Unit = { if (args.length > 0) { val lines = scala.io.Source.fromPath("QUICK!LRU-2009-11-15.psv") for (line <-lines) print(line) } … >>> More
Question on Scala Closure (From "Programming in Scala")

as seen on Stack Overflow - Search for 'Stack Overflow'
I don't understand why authors said that Code Listing 9.1 from "Programming in Scala" use closure. In chapter 9, they show how to refactor code into more less duplicated form, from this original code: object FileMatcher { private def filesHere = (new java.io.File(".")).listFiles def filesEnding(query:… >>> More
Common idiom in Java to Scala, traverse/Iterate Java list into Scala list

as seen on Stack Overflow - Search for 'Stack Overflow'
I am processing a XML document and iterating through nodes. I want to iterate through the nodes and build a new List of some type. How would I do this with Scala: Here is my XML traverse code: def findClassRef(xmlNode: Elem) = { xmlNode\"classDef" foreach { (entry) => val name… >>> More

Related posts about case-class

Case class copy() method abstraction.

as seen on Stack Overflow - Search for 'Stack Overflow'
I would like to know if it is possible to abstract the copy method of case classes. Basically I have something like sealed trait Op and then something like case class Push(value: Int) extends Op and case class Pop() extends Op. The first problem: A case class without arguments/members does not define… >>> More
Scala wont pattern match with java.lang.String and Case Class

as seen on Stack Overflow - Search for 'Stack Overflow'
Hello fellow Scala Programmers I have been working with Scala for some month now, however I have a problem with some properly basic stuff, I am hoping you will help my out with it. case class PersonClass(name: String, age: Int) object CaseTester { def main(args:Array[String]) { val string =… >>> More
Why do case class companion objects extend FunctionN?

as seen on Stack Overflow - Search for 'Stack Overflow'
When you create a case class, the compiler creates a corresponding companion object with a few of the case class goodies: an apply factory method matching the primary constructor, equals, hashCode, and copy. Somewhat oddly, this generated object extends FunctionN. scala> case class A(a: Int)… >>> More
Case Class naming convention

as seen on Programmers - Search for 'Programmers'
In my recent adventures in Scala, I've found case classes to be a really nice alternative to enums when I need to include a bit of logic or several values with them. I often find myself writing structures that look like this, however: object Foo{ case class Foo(name: String, value: Int, other:… >>> More
Scala - Enumeration vs. Case-Classes

as seen on Stack Overflow - Search for 'Stack Overflow'
I've created akka actor called LogActor. The LogActors's receive method handling messages from other actors and logging them to the specified log level. I can distinguish between the different levels in 2 ways. The first one: import LogLevel._ object LogLevel extends Enumeration { type LogLevel… >>> More