bundles/org.simantics.scl.compiler/src/org/simantics/scl/compiler/types/util/TypeComparator.java

   1 package org.simantics.scl.compiler.types.util;
   2
   3 import java.util.Comparator;
   4
   5 import org.simantics.scl.compiler.types.TApply;
   6 import org.simantics.scl.compiler.types.TCon;
   7 import org.simantics.scl.compiler.types.TFun;
   8 import org.simantics.scl.compiler.types.TPred;
   9 import org.simantics.scl.compiler.types.TUnion;
  10 import org.simantics.scl.compiler.types.Type;
  11 import org.simantics.scl.compiler.types.Types;
  12
  13 public enum TypeComparator implements Comparator<Type> {
  14     INSTANCE;
  15
  16     @Override
  17     public int compare(Type t1, Type t2) {
  18         t1 = Types.canonical(t1);
  19         t2 = Types.canonical(t2);
  20         int id1 = t1.getClassId();
  21         int id2 = t2.getClassId();
  22         if(id1 < id2)
  23             return -1;
  24         if(id1 > id2)
  25             return 1;
  26         int cur;
  27         switch(id1) {
  28         case Type.APPLY_ID: {
  29             TApply p1 = (TApply)t1;
  30             TApply p2 = (TApply)t2;
  31             cur = compare(p1.function, p2.function);
  32             if(cur != 0)
  33                 return cur;
  34             return compare(p1.parameter, p2.parameter);
  35         }
  36         case Type.CON_ID:
  37             return TConComparator.INSTANCE.compare((TCon)t1, (TCon)t2);
  38         case Type.FORALL_ID:
  39             return 0; // TODO hard to compare
  40         case Type.PRED_ID: {
  41             TPred p1 = (TPred)t1;
  42             TPred p2 = (TPred)t2;
  43             cur = TConComparator.INSTANCE.compare(p1.typeClass, p2.typeClass);
  44             if(cur != 0)
  45                 return cur;
  46             cur = p1.parameters.length - p2.parameters.length;
  47             if(cur != 0)
  48                 return cur;
  49             for(int i=0;i<p1.parameters.length;++i) {
  50                 cur = compare(p1.parameters[i], p2.parameters[i]);
  51                 if(cur != 0)
  52                     return cur;
  53             }
  54             return 0;
  55         }
  56         case Type.FUN_ID: {
  57             TFun p1 = (TFun)t1;
  58             TFun p2 = (TFun)t2;
  59             cur = compare(p1.domain, p2.domain);
  60             if(cur != 0)
  61                 return cur;
  62             cur = compare(p1.range, p2.range);
  63             if(cur != 0)
  64                 return cur;
  65             return compare(p1.effect, p2.effect);
  66         }
  67         case Type.UNION_ID: {
  68             TUnion p1 = (TUnion)t1;
  69             TUnion p2 = (TUnion)t2;
  70             cur = p1.effects.length - p2.effects.length;
  71             if(cur != 0)
  72                 return cur;
  73             return 0; // TODO
  74         }
  75         case Type.METAVAR_ID:
  76             return 0; // cannot compare
  77         case Type.VAR_ID:
  78             return 0; // cannot compare
  79         default:
  80             throw new IllegalArgumentException();
  81         }
  82     }
  83
  84 }