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POExtending Java Class with Scala Trait
 

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    <p>I would like to define a class <code>ContextItem</code> as the extension of java class <code>Predicate</code> with a trait <code>Confidence</code>.</p> <p>Confidence is a simple trait which simply adds a confidence field to whatever it extends.</p> <pre><code>trait Confidence{ def confidence:Double } </code></pre> <p>I am defining my <code>ContextItem</code> class by simply stating:</p> <pre><code>class ContextItem extends Predicate with Confidence{} </code></pre> <p>But attempting to compile this yields...</p> <pre><code>com/slug/berds/Berds.scala:11: error: overloaded method constructor Predicate with alternatives: (java.lang.String,&lt;repeated...&gt;[java.lang.String])com.Predicate &lt;and&gt; (java.lang.String,&lt;repeated...&gt;[com.Symbol])com.Predicate &lt;and&gt; (java.lang.String,java.util.ArrayList[com.Symbol])com.Predicate &lt;and&gt; (com.Predicate)com.Predicate &lt;and&gt; (com.Term)com.Predicate &lt;and&gt; (java.lang.String)com.Predicate cannot be applied to () class ContextItem(pred:Predicate) extends Predicate with Confidence{ ^ </code></pre> <p>This seems like a trivial example, so what's going wrong?</p> <p>Predicate (which is not mine) looks like:</p> <pre><code>/** Representation of predicate logical form. */ public class Predicate extends Term implements Serializable { public Predicate(String n) { super(n); } public Predicate(Term t) { super(t); } public Predicate(Predicate p) { super((Term)p); } public Predicate(String n, ArrayList&lt;Symbol&gt; a) { super(n, a); } public Predicate(String n, Symbol... a) { super(n, a); } public Predicate(String n, String... a) { super(n, a); } @Override public Predicate copy() { return new Predicate(this); } } </code></pre> <p>Neither Predicate nor any of its ancestors implements confidence.</p>
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    1. COCould we see the `Predicate` class? Does it implement the `confidence` method?
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