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6
7
8 package com.hp.hpl.jena.rdql.parser;
9
10
11 import java.io.PrintWriter  ;
12 import com.hp.hpl.jena.graph.query.IndexValues;
13 import com.hp.hpl.jena.graph.query.Expression ;
14 import com.hp.hpl.jena.rdql.*;
15
16 public class Q_UnaryMinus extends ExprNode implements ExprNumeric
17 {
18 Expr expr ;
19 private String printName = "unaryminus" ;
20 private String opSymbol = "-" ;
21
22 Q_UnaryMinus(int id) { super(id); }
23
24 Q_UnaryMinus(RDQLParser p, int id) { super(p, id); }
25
26 public NodeValue eval(Query q, IndexValues env)
27 {
28 NodeValue v = expr.eval(q, env) ;
29
30 if ( ! v.isNumber() )
31 throw new EvalTypeException("Q_UnaryMinus: Wanted a number: got "+expr) ;
32
33 NodeValueSettable result ;
34
40 result = new WorkingVar() ;
41
42 if ( v.isInt() )
43 result.setInt( - v.getInt() ) ;
44 else
45 result.setDouble( - v.getDouble() ) ;
46
47 return result ;
48 }
49
50 public void jjtClose()
51 {
52 int n = jjtGetNumChildren() ;
53 if ( n != 1 )
54 throw new QueryException("Q_UnaryMinus: Wrong number of children: "+n) ;
55 expr = (Expr)jjtGetChild(0) ;
56 }
57
58
61 public boolean isApply() { return true ; }
62 public String getFun() { return super.constructURI(this.getClass().getName()) ; }
63 public int argCount() { return 1; }
64 public Expression getArg(int i)
65 {
66 if ( i == 0 && expr instanceof Expression )
67 return (Expression)expr ;
68 return null;
69 }
70
71 public String asInfixString() { return QueryPrintUtils.asInfixString1(expr, printName, opSymbol) ; }
72
73 public String asPrefixString() { return QueryPrintUtils.asPrefixString(expr, null, printName, opSymbol) ; }
74
75 public void print(PrintWriter pw, int level) { QueryPrintUtils.print(pw, expr, null, printName, opSymbol, level) ; }
76
77 public String toString() { return asInfixString() ; }
78 }
79
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