1.1 --- a/src/share/classes/com/sun/tools/javac/code/Type.java Tue Sep 25 11:55:34 2012 +0100
1.2 +++ b/src/share/classes/com/sun/tools/javac/code/Type.java Tue Sep 25 11:56:46 2012 +0100
1.3 @@ -30,6 +30,10 @@
1.4 import com.sun.tools.javac.util.*;
1.5 import com.sun.tools.javac.code.Symbol.*;
1.6
1.7 +import java.util.EnumMap;
1.8 +import java.util.EnumSet;
1.9 +import java.util.Map;
1.10 +import java.util.Set;
1.11 import javax.lang.model.type.*;
1.12
1.13 import static com.sun.tools.javac.code.Flags.*;
1.14 @@ -1168,22 +1172,55 @@
1.15 }
1.16 }
1.17
1.18 - /** A class for instantiatable variables, for use during type
1.19 - * inference.
1.20 + /** A class for inference variables, for use during method/diamond type
1.21 + * inference. An inference variable has upper/lower bounds and a set
1.22 + * of equality constraints. Such bounds are set during subtyping, type-containment,
1.23 + * type-equality checks, when the types being tested contain inference variables.
1.24 + * A change listener can be attached to an inference variable, to receive notifications
1.25 + * whenever the bounds of an inference variable change.
1.26 */
1.27 public static class UndetVar extends DelegatedType {
1.28 - public List<Type> lobounds = List.nil();
1.29 - public List<Type> hibounds = List.nil();
1.30 - public List<Type> eq = List.nil();
1.31 +
1.32 + /** Inference variable change listener. The listener method is called
1.33 + * whenever a change to the inference variable's bounds occurs
1.34 + */
1.35 + public interface UndetVarListener {
1.36 + /** called when some inference variable bounds (of given kinds ibs) change */
1.37 + void varChanged(UndetVar uv, Set<InferenceBound> ibs);
1.38 + }
1.39 +
1.40 + /**
1.41 + * Inference variable bound kinds
1.42 + */
1.43 + public enum InferenceBound {
1.44 + /** upper bounds */
1.45 + UPPER,
1.46 + /** lower bounds */
1.47 + LOWER,
1.48 + /** equality constraints */
1.49 + EQ;
1.50 + }
1.51 +
1.52 + /** inference variable bounds */
1.53 + private Map<InferenceBound, List<Type>> bounds;
1.54 +
1.55 + /** inference variable's inferred type (set from Infer.java) */
1.56 public Type inst = null;
1.57
1.58 + /** inference variable's change listener */
1.59 + public UndetVarListener listener = null;
1.60 +
1.61 @Override
1.62 public <R,S> R accept(Type.Visitor<R,S> v, S s) {
1.63 return v.visitUndetVar(this, s);
1.64 }
1.65
1.66 - public UndetVar(Type origin) {
1.67 + public UndetVar(TypeVar origin, Types types) {
1.68 super(UNDETVAR, origin);
1.69 + bounds = new EnumMap<InferenceBound, List<Type>>(InferenceBound.class);
1.70 + bounds.put(InferenceBound.UPPER, types.getBounds(origin));
1.71 + bounds.put(InferenceBound.LOWER, List.<Type>nil());
1.72 + bounds.put(InferenceBound.EQ, List.<Type>nil());
1.73 }
1.74
1.75 public String toString() {
1.76 @@ -1195,6 +1232,48 @@
1.77 if (inst != null) return inst.baseType();
1.78 else return this;
1.79 }
1.80 +
1.81 + /** get all bounds of a given kind */
1.82 + public List<Type> getBounds(InferenceBound ib) {
1.83 + return bounds.get(ib);
1.84 + }
1.85 +
1.86 + /** add a bound of a given kind - this might trigger listener notification */
1.87 + public void addBound(InferenceBound ib, Type bound, Types types) {
1.88 + List<Type> prevBounds = bounds.get(ib);
1.89 + for (Type b : prevBounds) {
1.90 + if (types.isSameType(b, bound)) {
1.91 + return;
1.92 + }
1.93 + }
1.94 + bounds.put(ib, prevBounds.prepend(bound));
1.95 + notifyChange(EnumSet.of(ib));
1.96 + }
1.97 +
1.98 + /** replace types in all bounds - this might trigger listener notification */
1.99 + public void substBounds(List<Type> from, List<Type> to, Types types) {
1.100 + EnumSet<InferenceBound> changed = EnumSet.noneOf(InferenceBound.class);
1.101 + Map<InferenceBound, List<Type>> bounds2 = new EnumMap<InferenceBound, List<Type>>(InferenceBound.class);
1.102 + for (Map.Entry<InferenceBound, List<Type>> _entry : bounds.entrySet()) {
1.103 + InferenceBound ib = _entry.getKey();
1.104 + List<Type> prevBounds = _entry.getValue();
1.105 + List<Type> newBounds = types.subst(prevBounds, from, to);
1.106 + bounds2.put(ib, newBounds);
1.107 + if (prevBounds != newBounds) {
1.108 + changed.add(ib);
1.109 + }
1.110 + }
1.111 + if (!changed.isEmpty()) {
1.112 + bounds = bounds2;
1.113 + notifyChange(changed);
1.114 + }
1.115 + }
1.116 +
1.117 + private void notifyChange(EnumSet<InferenceBound> ibs) {
1.118 + if (listener != null) {
1.119 + listener.varChanged(this, ibs);
1.120 + }
1.121 + }
1.122 }
1.123
1.124 /** Represents VOID or NONE.
