X-Git-Url: https://gerrit.simantics.org/r/gitweb?p=simantics%2Fplatform.git;a=blobdiff_plain;f=bundles%2Forg.simantics.scl.compiler%2Fsrc%2Forg%2Fsimantics%2Fscl%2Fcompiler%2Finternal%2Felaboration%2Fconstraints%2FConstraintEnvironment.java;h=72aa1ea9e09e627c441125cfb16048c91d0d7993;hp=ba982b1c6ab14c8fe886e318e471e42d4af54594;hb=a8758de5bc19e5adb3f618d3038743a164f09912;hpb=12d9af17384d960b75d58c3935d2b7b46d93e87b

diff --git a/bundles/org.simantics.scl.compiler/src/org/simantics/scl/compiler/internal/elaboration/constraints/ConstraintEnvironment.java b/bundles/org.simantics.scl.compiler/src/org/simantics/scl/compiler/internal/elaboration/constraints/ConstraintEnvironment.java
index ba982b1c6..72aa1ea9e 100644
--- a/bundles/org.simantics.scl.compiler/src/org/simantics/scl/compiler/internal/elaboration/constraints/ConstraintEnvironment.java
+++ b/bundles/org.simantics.scl.compiler/src/org/simantics/scl/compiler/internal/elaboration/constraints/ConstraintEnvironment.java
@@ -1,5 +1,7 @@
 package org.simantics.scl.compiler.internal.elaboration.constraints;
 
+import java.util.ArrayList;
+
 import org.simantics.scl.compiler.common.exceptions.InternalCompilerError;
 import org.simantics.scl.compiler.constants.ClassConstant;
 import org.simantics.scl.compiler.constants.StringConstant;
@@ -92,19 +94,25 @@ public class ConstraintEnvironment {
             else if(parameter instanceof TUnion) {
                 TUnion union = (TUnion)parameter;
                 
-                /*TPred[] demands = new TPred[union.effects.length];
-                for(int i=0;i<union.effects.length;++i)
-                    demands[i] = Types.pred(Types.TYPEABLE, union.effects[i]);*/
                 if(union.effects.length == 0)
-                return new Reduction(
+                    return new Reduction(
                             new EConstant(Builtins.INSTANCE.getValue("TPure")),
                             Type.EMPTY_ARRAY,
                             TPred.EMPTY_ARRAY);
+                else if(union.effects.length == 2) {
+                    return new Reduction(
+                            new EConstant(Builtins.INSTANCE.getValue("TUnion2")),
+                            Type.EMPTY_ARRAY, new TPred[] {
+                                Types.pred(Types.TYPEABLE, union.effects[0]),
+                                Types.pred(Types.TYPEABLE, union.effects[1])
+                            });
+                }
             }
         }
         
         // Standard case
-        THashMap<TVar, Type> substitution = new THashMap<TVar, Type>(); 
+        THashMap<TVar, Type> substitution = new THashMap<TVar, Type>();
+        ArrayList<Reduction> reductions = new ArrayList<Reduction>(1); 
         for(TypeClassInstance inst : environment.getInstances(constraint.typeClass)) {
             if(Types.match(inst.instance, constraint, substitution)) {
                 TPred[] demands = new TPred[inst.context.length];
@@ -118,10 +126,15 @@ public class ConstraintEnvironment {
                         parameter = inst.generatorParameters[i]; // TODO Is this correct?
                     parameters[i] = parameter;
                 }
-                return new Reduction(new ELiteral(inst.generator), parameters, demands);
+                reductions.add(new Reduction(new ELiteral(inst.generator), parameters, demands));
             }
-            else
-                substitution.clear();
+            substitution.clear();
+        }
+        //System.out.println(constraint.typeClass + " -> " + reductions.size());
+        if(reductions.size() == 1)
+            return reductions.get(0);
+        else if(reductions.size() > 1) {
+            throw new InternalCompilerError("Found more than one matching instances for " + constraint.typeClass + ".");
         }
         return null;
     }