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POScala class inheritance
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Id
12695823
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CommunityOwnedDate
CreationDate
2012-10-02T18:09:50.293
FavoriteCount
1
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2012-10-02T22:53:38.867
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2012-10-02T22:53:38.867
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1715087
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Score
2
ViewCount
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LastEditorDisplayName
text
Body
Tagged as homework. I'm having trouble in the object oriented world while trying to implement a class. I'm implenting various functions to take action on lists, that I'm using to mock a set. I'm not too worried about my logic on how to find union, for example, but really just the structure. For eg: <pre><code>abstract class parentSet[T] protected () { def union(other:parentSet[T]):parentSet[T] } </code></pre> Now I want a new class extending parentSet: <pre><code>class childSet[T] private (l: List[T]) extends parentSet[T] { def this() = this(List()) private val elems = l val toList = List[T] => new List(l) def union(other:parentSet[T]):childSet[T] = { for (i <- this.toList) { if (other contains i) {} else {l :: i} } return l } } </code></pre> Upon compiling, I receive errors such that type childSet isn't found in def union, nor is type T to keep it parametric. Also, I assume my toList isn't correct as it complains that it isn't a member of the object; to name a few. Where in my syntax am I wrong? EDIT Now I've got that figured out: <pre><code> def U(other:parentSet[T]):childSet[T] = { var w = other.toList for (i <- this.toList) { if (!(other contains i)) {w = i::w} } return new childSet(w) </code></pre> } Now, I'm trying to do the same operations with map, and this is what I'm working on/with: <pre><code>def U(other:parentSet[T]):MapSet[T] = { var a = Map[T,Unit] for (i <- this.toList) { if (!(other contains i)) {a = a + (i->())} } return new MapSet(elems + (a->())) } </code></pre> I still want to use toList to make it easily traversable, but I'm still getting type errors while messing with maps..
Tags
<oop><class><scala><inheritance>
Title
Scala class inheritance
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1. This table or related slice is empty.
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1. This table or related slice is empty.
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1. PTQuestion
UserLastEditorUserId
1. USHenry David
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1. USHenry David
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1. PO
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 POScala class inheritance
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