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One common idiom you lose by making exceptions case classes is the pattern of creating a subclass hierarchy of exceptions with subclassing used to indicate greater specificity of the error condition. Case classes can't be subclassed. Share Improve this answer Follow answered Jan 23, 2013 at 13:35 Dave Griffith 20.4k 3 54 76 3 Good point.

abstract class Expr case class Var(name: String) extends Expr case class ... "a variable" case _ => throw new RuntimeException // Should not happen } ...

Oct 21, 2021 · All exception and error types in Scala are subclasses of the Throwable class, the base class of the Scala exception hierarchy: Fig1: Scala Exceptions Hierarchy. As evident from the diagram shown above, one branch of the hierarchy under Throwable is headed by Exception, which is the class used for exceptional conditions that programs should catch. An example of an exception is NullPointerException. Another branch is Error, which is used by the Java Virtual Machine (JVM) to indicate errors ...

Exactly like Java, we create custom exceptions in Scala by extending the Exception class. Let's create an exception: case class DivideByZero() extends ...

In this tutorial, we’re going to cover custom exceptions and multiple ways to handle exceptions in Scala — including a couple of ways to avoid exceptions …

Scala Case Class serialization. I've been trying to binary serialize a composite case class object that kept throwing a weird exception. I don't really …

You say that case classes give you incorrect equality semantics. I don't think so. You, as the writer of the exception class gets to decides what equality semantics makes sense. After all when you catch an exception, the catch block is where you decide which exceptions to catch usually based on the type alone, but could be based on the value of its fields or whatever, as in my example.

All exception and error types in Scala are subclasses of the Throwable class, the base class of the Scala exception hierarchy: Fig1: Scala Exceptions …

VerkkoDefining a case class A minimal case class requires the keywords case class, an identifier, and a parameter list (which may be empty): Scala 2 and 3 case class …

Apr 12, 2018 · case class CustomException(message: String) extends Exception(message) with MyException { override val details: JsValue = Json.obj("message" -> message, "etc" -> "Anything else") } Now, the whole point of using Scala is walking towards a more functional programming style, it will make your app more concurrent, so if you need to use your new custom exception, you might want to try something like this:

with Apply You Don’T Need New

Option/Some/None

This hints that there should be a class named :: that corresponds to the pattern constructor. Indeed there is such as class. It is named scala.:: and is exactly the …

You can also read about some related ideas in Make error ADTs subtypes of Exception. Now if we use MyError in a test: import scala.util.control.

Exceptions can be checked or unchecked. Scala only allows unchecked exceptions, though. This means that, at compile-time, we won’t be able to know if a …

VerkkoScala Classes; Auxiliary Class Constructors; Supplying Default Values for Constructor Parameters; A First Look at Scala Methods; Enumerations (and a Complete Pizza …

As far as I know, you don't need to explicitly implement Serializable interface, as both case classes and case objects are already implicitly use …

This is very subjective of course, but in my opinion it is good practice to have exception classes as case classes. The main rationale being ...

As evident from the diagram shown above, one branch of the hierarchy under Throwable is headed by Exception , which is the class used for ...

Exceptions to the rule. There's at least one scenario I know of where a non- final case class is desirable: when you wish to declare a case class ...

This lesson provides an introduction to 'case classes' in Scala. ... Case class constructor parameters are public val fields by default, so accessor methods ...

In scala, you can create your own exception. It is also known as custom exceptions. You must extend Exception class while declaring custom exception class.