@Override
public JSType getLeastSupertype(JSType that) {
if (!that.isUnknownType() && !that.isUnionType()) {
for (JSType alternate : alternatesWithoutStucturalTyping) {
if (!alternate.isUnknownType() && that.isSubtype(alternate)) {
return this;
}
}
}
return getLeastSupertype(this, that);
}
@Override
public String toDebugHashCodeString() {
if (this == registry.getNativeType(JSTypeNative.FUNCTION_INSTANCE_TYPE)) {
return super.toDebugHashCodeString();
}
StringBuilder b = new StringBuilder(32);
b.append("function (");
int paramNum = call.parameters.getChildCount();
boolean hasKnownTypeOfThis = !typeOfThis.isUnknownType();
if (hasKnownTypeOfThis) {
b.append("this:");
b.append(getDebugHashCodeStringOf(typeOfThis));
}
if (paramNum > 0) {
if (hasKnownTypeOfThis) {
b.append(", ");
}
Node p = call.parameters.getFirstChild();
b.append(getDebugHashCodeStringOf(p.getJSType()));
p = p.getNext();
while (p != null) {
b.append(", ");
b.append(getDebugHashCodeStringOf(p.getJSType()));
p = p.getNext();
}
}
b.append(")");
b.append(": ");
b.append(getDebugHashCodeStringOf(call.returnType));
return b.toString();
}
@Override
public JSType collapseUnion() {
JSType currentValue = null;
ObjectType currentCommonSuper = null;
for (JSType a : alternatesWithoutStucturalTyping) {
if (a.isUnknownType()) {
return getNativeType(JSTypeNative.UNKNOWN_TYPE);
}
ObjectType obj = a.toObjectType();
if (obj == null) {
if (currentValue == null && currentCommonSuper == null) {
// If obj is not an object, then it must be a value.
currentValue = a;
} else {
// Multiple values and objects will always collapse to the ALL_TYPE.
return getNativeType(JSTypeNative.ALL_TYPE);
}
} else if (currentValue != null) {
// Values and objects will always collapse to the ALL_TYPE.
return getNativeType(JSTypeNative.ALL_TYPE);
} else if (currentCommonSuper == null) {
currentCommonSuper = obj;
} else {
currentCommonSuper = registry.findCommonSuperObject(currentCommonSuper, obj);
}
}
return currentCommonSuper;
}
@Override
public boolean isUnknownType() {
for (JSType t : alternatesWithoutStucturalTyping) {
if (t.isUnknownType()) {
return true;
}
}
return false;
}
/**
* Returns a more restricted union type than {@code this} one, in which all subtypes of {@code
* type} have been removed.
*
* <p>Examples:
*
* <ul>
* <li>{@code (number,string)} restricted by {@code number} is {@code string}
* <li>{@code (null, EvalError, URIError)} restricted by {@code Error} is {@code null}
* </ul>
*
* @param type the supertype of the types to remove from this union type
*/
public JSType getRestrictedUnion(JSType type) {
UnionTypeBuilder restricted = new UnionTypeBuilder(registry);
for (JSType t : alternatesWithoutStucturalTyping) {
// Keep all unknown/unresolved types.
if (t.isUnknownType() || t.isNoResolvedType() || !t.isSubtype(type)) {
restricted.addAlternate(t);
}
}
return restricted.build();
}
@Override
public TernaryValue testForEquality(JSType that) {
TernaryValue result = super.testForEquality(that);
if (result != null) {
return result;
}
if (that.isUnknownType()
|| that.isSubtype(getNativeType(JSTypeNative.OBJECT_NUMBER_STRING_BOOLEAN))) {
return UNKNOWN;
}
return FALSE;
}
@Override
protected boolean isSubtype(JSType that, ImplCache implicitImplCache) {
// unknown
if (that.isUnknownType()) {
return true;
}
// all type
if (that.isAllType()) {
return true;
}
for (JSType element : alternatesWithoutStucturalTyping) {
if (!element.isSubtype(that, implicitImplCache)) {
return false;
}
}
return true;
}
/**
* Resolves a named type by looking up its first component in the scope, and subsequent components
* as properties. The scope must have been fully parsed and a symbol table constructed.
*/
private void resolveViaProperties(ErrorReporter reporter, StaticTypedScope<JSType> enclosing) {
JSType value = lookupViaProperties(reporter, enclosing);
// last component of the chain
if (value != null && value.isFunctionType() && (value.isConstructor() || value.isInterface())) {
FunctionType functionType = value.toMaybeFunctionType();
setReferencedAndResolvedType(functionType.getInstanceType(), reporter);
} else if (value != null && value.isNoObjectType()) {
setReferencedAndResolvedType(
registry.getNativeObjectType(JSTypeNative.NO_OBJECT_TYPE), reporter);
} else if (value instanceof EnumType) {
setReferencedAndResolvedType(((EnumType) value).getElementsType(), reporter);
} else {
// We've been running into issues where people forward-declare
// non-named types. (This is legitimate...our dependency management
// code doubles as our forward-declaration code.)
//
// So if the type does resolve to an actual value, but it's not named,
// then don't respect the forward declaration.
handleUnresolvedType(reporter, value == null || value.isUnknownType());
}
}
/** Adds an alternate to the union type under construction. Returns this for easy chaining. */
public UnionTypeBuilder addAlternate(JSType alternate, boolean isStructural) {
// build() returns the bottom type by default, so we can
// just bail out early here.
if (alternate.isNoType()) {
return this;
}
isAllType = isAllType || alternate.isAllType();
containsVoidType = containsVoidType || alternate.isVoidType();
boolean isAlternateUnknown = alternate instanceof UnknownType;
isNativeUnknownType = isNativeUnknownType || isAlternateUnknown;
if (isAlternateUnknown) {
areAllUnknownsChecked = areAllUnknownsChecked && alternate.isCheckedUnknownType();
}
if (!isAllType && !isNativeUnknownType) {
if (alternate.isUnionType()) {
UnionType union = alternate.toMaybeUnionType();
for (JSType unionAlt : union.getAlternatesWithoutStructuralTyping()) {
addAlternate(unionAlt);
}
} else {
if (alternates.size() > maxUnionSize) {
return this;
}
// Function types are special, because they have their
// own bizarre sub-lattice. See the comments on
// FunctionType#supAndInf helper and above at functionTypePosition.
if (alternate.isFunctionType() && functionTypePosition != -1) {
// See the comments on functionTypePosition above.
FunctionType other = alternates.get(functionTypePosition).toMaybeFunctionType();
FunctionType supremum = alternate.toMaybeFunctionType().supAndInfHelper(other, true);
alternates.set(functionTypePosition, supremum);
result = null;
return this;
}
// Look through the alternates we've got so far,
// and check if any of them are duplicates of
// one another.
int currentIndex = 0;
Iterator<JSType> it = alternates.iterator();
while (it.hasNext()) {
boolean removeCurrent = false;
JSType current = it.next();
// Unknown and NoResolved types may just be names that haven't
// been resolved yet. So keep these in the union, and just use
// equality checking for simple de-duping.
if (alternate.isUnknownType()
|| current.isUnknownType()
|| alternate.isNoResolvedType()
|| current.isNoResolvedType()
|| alternate.hasAnyTemplateTypes()
|| current.hasAnyTemplateTypes()) {
if (alternate.isEquivalentTo(current, isStructural)) {
// Alternate is unnecessary.
return this;
}
} else {
// Because "Foo" and "Foo.<?>" are roughly equivalent
// templatized types, special care is needed when building the
// union. For example:
// Object is consider a subtype of Object.<string>
// but we want to leave "Object" not "Object.<string>" when
// building the subtype.
//
if (alternate.isTemplatizedType() || current.isTemplatizedType()) {
// Cases:
// 1) alternate:Array.<string> and current:Object ==> Object
// 2) alternate:Array.<string> and current:Array ==> Array
// 3) alternate:Object.<string> and
// current:Array ==> Array|Object.<string>
// 4) alternate:Object and current:Array.<string> ==> Object
// 5) alternate:Array and current:Array.<string> ==> Array
// 6) alternate:Array and
// current:Object.<string> ==> Array|Object.<string>
// 7) alternate:Array.<string> and
// current:Array.<number> ==> Array.<?>
// 8) alternate:Array.<string> and
// current:Array.<string> ==> Array.<string>
// 9) alternate:Array.<string> and
// current:Object.<string> ==> Object.<string>|Array.<string>
if (!current.isTemplatizedType()) {
if (isSubtype(alternate, current, isStructural)) {
// case 1, 2
return this;
}
// case 3: leave current, add alternate
} else if (!alternate.isTemplatizedType()) {
if (isSubtype(current, alternate, isStructural)) {
// case 4, 5
removeCurrent = true;
}
// case 6: leave current, add alternate
} else {
Preconditions.checkState(
current.isTemplatizedType() && alternate.isTemplatizedType());
TemplatizedType templatizedAlternate = alternate.toMaybeTemplatizedType();
TemplatizedType templatizedCurrent = current.toMaybeTemplatizedType();
if (templatizedCurrent.wrapsSameRawType(templatizedAlternate)) {
if (alternate
.getTemplateTypeMap()
.checkEquivalenceHelper(
current.getTemplateTypeMap(),
EquivalenceMethod.IDENTITY,
SubtypingMode.NORMAL)) {
// case 8
return this;
} else {
// TODO(johnlenz): should we leave both types?
// case 7: add a merged alternate
// We currently merge to the templatized types to "unknown"
// which is equivalent to the raw type.
JSType merged = templatizedCurrent.getReferencedObjTypeInternal();
return addAlternate(merged);
}
}
// case 9: leave current, add alternate
}
// Otherwise leave both templatized types.
} else if (isSubtype(alternate, current, isStructural)) {
// Alternate is unnecessary.
return this;
} else if (isSubtype(current, alternate, isStructural)) {
// Alternate makes current obsolete
removeCurrent = true;
}
}
if (removeCurrent) {
it.remove();
if (currentIndex == functionTypePosition) {
functionTypePosition = -1;
} else if (currentIndex < functionTypePosition) {
functionTypePosition--;
currentIndex--;
}
}
currentIndex++;
}
if (alternate.isFunctionType()) {
// See the comments on functionTypePosition above.
Preconditions.checkState(functionTypePosition == -1);
functionTypePosition = alternates.size();
}
alternates.add(alternate);
result = null; // invalidate the memoized result
}
} else {
result = null;
}
return this;
}