bundles/org.simantics.scl.compiler/src/org/simantics/scl/compiler/elaboration/java/EqRelation.java

   1 package org.simantics.scl.compiler.elaboration.java;
   2
   3 import org.simantics.scl.compiler.elaboration.expressions.EVariable;
   4 import org.simantics.scl.compiler.elaboration.expressions.Variable;
   5 import org.simantics.scl.compiler.elaboration.query.compilation.QueryCompilationContext;
   6 import org.simantics.scl.compiler.elaboration.relations.AbstractRelation;
   7 import org.simantics.scl.compiler.types.TVar;
   8 import org.simantics.scl.compiler.types.Type;
   9 import org.simantics.scl.compiler.types.Types;
  10 import org.simantics.scl.compiler.types.kinds.Kinds;
  11
  12 public class EqRelation extends AbstractRelation {
  13     public static final EqRelation INSTANCE = new EqRelation();
  14
  15     private EqRelation() {}
  16
  17     private static final TVar A = Types.var(Kinds.STAR);
  18
  19     private static final TVar[] TYPE_VARIABLES = new TVar[] {A};
  20
  21     @Override
  22     public TVar[] getTypeVariables() {
  23         return TYPE_VARIABLES;
  24     }
  25
  26     private static final Type[] PARAMETER_TYPES = new Type[] {A, A};
  27
  28     @Override
  29     public Type[] getParameterTypes() {
  30         return PARAMETER_TYPES;
  31     }
  32
  33     @Override
  34     public int getPhase() {
  35         return 0;
  36     }
  37
  38     @Override
  39     public double getSelectivity(int boundVariables) {
  40         switch(boundVariables) {
  41         case FF: return Double.POSITIVE_INFINITY;
  42         case BF:
  43         case FB: return 1.0;
  44         case BB: return 0.1;
  45         default: throw new IllegalArgumentException();
  46         }
  47     }
  48
  49     @Override
  50     public int getRequiredVariablesMask() {
  51         return FF;
  52     }
  53
  54     @Override
  55     public void generate(long location,
  56             QueryCompilationContext context,
  57             Type[] typeParameters, Variable[] parameters, int boundVariables) {
  58         switch(boundVariables) {
  59         case BF:
  60             context.let(parameters[1], new EVariable(parameters[0]));
  61             break;
  62         case FB:
  63             context.let(parameters[0], new EVariable(parameters[1]));
  64             break;
  65         case BB:
  66             context.equalityCondition(location,
  67                         new EVariable(parameters[0]),
  68                         new EVariable(parameters[1]));
  69             break;
  70         default: throw new IllegalArgumentException();
  71         }
  72     }
  73
  74     @Override
  75     public String toString() {
  76         return "=";
  77     }
  78
  79     @Override
  80     public Type getEnforceEffect() {
  81         return Types.NO_EFFECTS;
  82     }
  83
  84     @Override
  85     public Type getQueryEffect() {
  86         return Types.NO_EFFECTS;
  87     }
  88 }