case-class

My use case has case classes something like case class Address(name:String,pincode:String){ override def toString =name +"=" +pincode } case class Department(name:String){ override def toString =name } case class emp(address:Address,department:Department) I want to create a DSL like below.Can anyone share the links about how to create a DSL and any suggestions to achieve the below. emp.withAddress("abc","12222").withDepartment("HR") Update: Actual use case class may have more fields close to 20. I want to avoid redudancy of code I created a DSL using reflection so that we don't need to add

Is there a way in Scala to modify a parameter passed to a single-argument case class constructor / apply() method before it becomes a val ? E.g. case class AbsVal private(aVal: Double) object AbsVal { def apply(aVal: Double): AbsVal = AbsVal(Math.abs(aVal)) // doesn't compile } This fails of course with ambiguous reference to overloaded definition . I thought maybe I could trick it with named parameters (and different parameter names for the constructor vs apply() ), but that doesn't work either. Of course instead of apply() I could just have the private constructor and a factory method, but

While looking for something else, quite out of mere coincidence I stumbled upon few comments about how diabolical case class inheritance is. There was this thing called ProductN , wretches and kings, elves and wizards and how some kind of a very desirable property is lost with case classes inheritance. So what is so wrong with case class inheritance ? One word: equality case classes come with a supplied implementation of equals and hashCode . The equivalence relation, known as equals works like this (i.e. must have the following properties): For all x ; x equals x is true (reflexive) For x , y

I have made heavy use of case classes in my code, replying on the underlying equality definitions of case class to behave correctly. Then now I found that I need to add another field member to a case class. So if I add a var field member in case class, will it mess up the equality attributes for the case class? If 1 is yes, then what if I just change the var field value once, after that, no any reassignment will happen, before the case class goes into any collections or do equality comparison, will that still mess up the equality behaviors? Case class equality is based solely on its primary

Is it ok, to create case classes with floating point fields, like: case class SomeClass(a:Double, b:Double) I guess auto generated equal method won't work in this case. Is overriding equals the best solution? EDIT: if overriding equals is the way to go, I would like to avoid hardcoding epsilon ( where epsilon is defined like => |this.a-a|< epsilon). This won't compile: case class SomeClass(a:Double, b:Double, implicit epsilon:Double) I am looking for a way to pass epsilon without passing concert value each time (some "implicit" magic). I have also follow up more general question, how would you