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;
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];
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;
}