@Override
public boolean test(Type arg1, Type arg2) {
boolean hasStringOp =
types.isSameType(arg1, syms.stringType) || types.isSameType(arg2, syms.stringType);
boolean hasVoidOp = arg1.hasTag(TypeTag.VOID) || arg2.hasTag(TypeTag.VOID);
return hasStringOp && !hasVoidOp;
}
/**
* This routine applies following mappings: - if input type is primitive, apply numeric
* promotion - if input type is either 'void', 'null' or 'String' leave it untouched - otherwise
* return 'Object'
*/
private Type stringPromotion(Type t) {
if (t.isPrimitive()) {
return unaryPromotion(t);
} else if (t.hasTag(TypeTag.VOID)
|| t.hasTag(TypeTag.BOT)
|| types.isSameType(t, syms.stringType)) {
return t;
} else if (t.hasTag(TypeTag.TYPEVAR)) {
return stringPromotion(t.getUpperBound());
} else {
return syms.objectType;
}
}
/**
* Returns the upper bound of a type if it has one, or the type itself if not. Correctly handles
* wildcards and capture variables.
*/
public static Type getUpperBound(Type type, Types types) {
if (type.hasTag(TypeTag.WILDCARD)) {
return types.wildUpperBound(type);
}
if (type.hasTag(TypeTag.TYPEVAR) && ((TypeVar) type).isCaptured()) {
return types.cvarUpperBound(type);
}
if (type.getUpperBound() != null) {
return type.getUpperBound();
}
// concrete type, e.g. java.lang.String, or a case we haven't considered
return type;
}
/**
* Perform binary promotion of a pair of types; this routine implements JLS 5.6.2. If the input
* types are not supported by unary promotion, if such types are identical to a type C, then C is
* returned, otherwise Object is returned.
*/
Type binaryPromotion(Type t1, Type t2) {
Type unboxedT1 = types.unboxedTypeOrType(t1);
Type unboxedT2 = types.unboxedTypeOrType(t2);
if (unboxedT1.isNumeric() && unboxedT2.isNumeric()) {
if (unboxedT1.hasTag(TypeTag.DOUBLE) || unboxedT2.hasTag(TypeTag.DOUBLE)) {
return syms.doubleType;
} else if (unboxedT1.hasTag(TypeTag.FLOAT) || unboxedT2.hasTag(TypeTag.FLOAT)) {
return syms.floatType;
} else if (unboxedT1.hasTag(TypeTag.LONG) || unboxedT2.hasTag(TypeTag.LONG)) {
return syms.longType;
} else {
return syms.intType;
}
} else if (types.isSameType(unboxedT1, unboxedT2)) {
return unboxedT1;
} else {
return syms.objectType;
}
}
