gerrit.simantics Code Review - simantics/platform.git/blob

   1 package org.simantics.scl.compiler.elaboration.java;
   2
   3 import org.simantics.scl.compiler.common.names.Names;
   4 import org.simantics.scl.compiler.elaboration.expressions.EApply;
   5 import org.simantics.scl.compiler.elaboration.expressions.EVariable;
   6 import org.simantics.scl.compiler.elaboration.expressions.Expression;
   7 import org.simantics.scl.compiler.elaboration.expressions.Variable;
   8 import org.simantics.scl.compiler.elaboration.query.compilation.QueryCompilationContext;
   9 import org.simantics.scl.compiler.elaboration.relations.AbstractRelation;
  10 import org.simantics.scl.compiler.types.TVar;
  11 import org.simantics.scl.compiler.types.Type;
  12 import org.simantics.scl.compiler.types.Types;
  13 import org.simantics.scl.compiler.types.kinds.Kinds;
  14
  15 public class OptionalRelation extends AbstractRelation {
  16     public static final OptionalRelation INSTANCE = new OptionalRelation();
  17
  18     private OptionalRelation() {}
  19
  20     private static final TVar A = Types.var(Kinds.STAR);
  21
  22     private static final TVar[] TYPE_VARIABLES = new TVar[] {A};
  23
  24     @Override
  25     public TVar[] getTypeVariables() {
  26         return TYPE_VARIABLES;
  27     }
  28
  29     private static final Type[] PARAMETER_TYPES = new Type[] {A, Types.apply(Types.MAYBE, A)};
  30
  31     @Override
  32     public Type[] getParameterTypes() {
  33         return PARAMETER_TYPES;
  34     }
  35
  36     @Override
  37     public int getPhase() {
  38         return 0;
  39     }
  40
  41     @Override
  42     public double getSelectivity(int boundVariables) {
  43         switch(boundVariables) {
  44         case FF:
  45         case BF: return Double.POSITIVE_INFINITY;
  46         case FB: return 0.95;
  47         case BB: return 0.5;
  48         default: throw new IllegalArgumentException();
  49         }
  50     }
  51
  52     @Override
  53     public int getRequiredVariablesMask() {
  54         return FB;
  55     }
  56
  57     @Override
  58     public void generate(long location,
  59             QueryCompilationContext context,
  60             Type[] typeParameters, Variable[] parameters, int boundVariables) {
  61         switch(boundVariables) {
  62         case FB:
  63             context.iterateMaybe(parameters[0], new EVariable(parameters[1]));
  64             break;
  65         case BB:
  66             context.condition(
  67                     new EApply(
  68                             context.getConstant(Names.Prelude_elemMaybe, typeParameters),
  69                             new Expression[] {
  70                                 new EVariable(parameters[0]),
  71                                 new EVariable(parameters[1])
  72                             }
  73                             ));
  74             break;
  75         default: throw new IllegalArgumentException();
  76         }
  77     }
  78
  79     @Override
  80     public String toString() {
  81         return "Optional";
  82     }
  83 }