/*
*
* ***** BEGIN LICENSE BLOCK *****
* Version: MPL 1.1/GPL 2.0
*
* The contents of this file are subject to the Mozilla Public License Version
* 1.1 (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
* http://www.mozilla.org/MPL/
*
* Software distributed under the License is distributed on an "AS IS" basis,
* WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
* for the specific language governing rights and limitations under the
* License.
*
* The Original Code is Rhino code, released
* May 6, 1999.
*
* The Initial Developer of the Original Code is
* Netscape Communications Corporation.
* Portions created by the Initial Developer are Copyright (C) 1997-1999
* the Initial Developer. All Rights Reserved.
*
* Contributor(s):
* John Lenz
* Google Inc.
*
* Alternatively, the contents of this file may be used under the terms of
* the GNU General Public License Version 2 or later (the "GPL"), in which
* case the provisions of the GPL are applicable instead of those above. If
* you wish to allow use of your version of this file only under the terms of
* the GPL and not to allow others to use your version of this file under the
* MPL, indicate your decision by deleting the provisions above and replacing
* them with the notice and other provisions required by the GPL. If you do
* not delete the provisions above, a recipient may use your version of this
* file under either the MPL or the GPL.
*
* ***** END LICENSE BLOCK ***** */
package com.google.javascript.rhino.jstype;
import com.google.common.collect.ImmutableList;
import com.google.common.collect.Lists;
import com.google.common.collect.Sets;
import com.google.javascript.rhino.Node;
import java.util.List;
import java.util.Set;
/**
* A visitor implementation that enables type substitutions.
*
* @author johnlenz@google.com (John Lenz)
*/
public class ModificationVisitor implements Visitor<JSType> {
private final JSTypeRegistry registry;
private final boolean visitProperties;
private final Set<JSType> seenTypes = Sets.newIdentityHashSet();
public ModificationVisitor(JSTypeRegistry registry, boolean visitProperties) {
this.registry = registry;
this.visitProperties = visitProperties;
}
@Override
public JSType caseNoType(NoType type) {
return type;
}
@Override
public JSType caseEnumElementType(EnumElementType type) {
return type;
}
@Override
public JSType caseAllType() {
return getNativeType(JSTypeNative.ALL_TYPE);
}
@Override
public JSType caseBooleanType() {
return getNativeType(JSTypeNative.BOOLEAN_TYPE);
}
@Override
public JSType caseNoObjectType() {
return getNativeType(JSTypeNative.NO_OBJECT_TYPE);
}
@Override
public JSType caseFunctionType(FunctionType type) {
if (isNativeFunctionType(type)) {
return type;
}
if (!type.isOrdinaryFunction() && !type.isConstructor()) {
return type;
}
boolean changed = false;
JSType beforeThis = type.getTypeOfThis();
JSType afterThis = coerseToThisType(beforeThis.visit(this));
if (beforeThis != afterThis) {
changed = true;
}
JSType beforeReturn = type.getReturnType();
JSType afterReturn = beforeReturn.visit(this);
if (beforeReturn != afterReturn) {
changed = true;
}
FunctionParamBuilder paramBuilder = new FunctionParamBuilder(registry);
for (Node paramNode : type.getParameters()) {
JSType beforeParamType = paramNode.getJSType();
JSType afterParamType = beforeParamType.visit(this);
if (beforeParamType != afterParamType) {
changed = true;
}
if (paramNode.isOptionalArg()) {
paramBuilder.addOptionalParams(afterParamType);
} else if (paramNode.isVarArgs()) {
paramBuilder.addVarArgs(afterParamType);
} else {
paramBuilder.addRequiredParams(afterParamType);
}
}
if (changed) {
FunctionBuilder builder = new FunctionBuilder(registry)
.setIsConstructor(type.isConstructor())
.withParams(paramBuilder)
.withReturnType(afterReturn)
.withTypeOfThis(afterThis)
.withTemplateKeys(
type.getTemplateTypeMap().getUnfilledTemplateKeys());
return builder.build();
}
return type;
}
private JSType coerseToThisType(JSType type) {
return type != null ? type : registry.getNativeObjectType(
JSTypeNative.UNKNOWN_TYPE);
}
@Override
public JSType caseObjectType(ObjectType objType) {
if (!visitProperties
|| objType.isNominalType()
|| objType instanceof ProxyObjectType
|| !objType.isRecordType()) {
return objType;
}
if (seenTypes.contains(objType)) {
return objType;
}
seenTypes.add(objType);
boolean changed = false;
RecordTypeBuilder builder = new RecordTypeBuilder(registry);
for (String prop : objType.getOwnPropertyNames()) {
Node propertyNode = objType.getPropertyNode(prop);
JSType beforeType = objType.getPropertyType(prop);
JSType afterType = beforeType.visit(this);
if (beforeType != afterType) {
changed = true;
}
builder.addProperty(prop, afterType, propertyNode);
}
seenTypes.remove(objType);
if (changed) {
return builder.build();
}
return objType;
}
@Override
public JSType caseTemplatizedType(TemplatizedType type) {
boolean changed = false;
ObjectType beforeBaseType = type.getReferencedType();
ObjectType afterBaseType = ObjectType.cast(beforeBaseType.visit(this));
if (beforeBaseType != afterBaseType) {
changed = true;
}
ImmutableList.Builder<JSType> builder = ImmutableList.builder();
for (JSType beforeTemplateType : type.getTemplateTypes()) {
JSType afterTemplateType = beforeTemplateType.visit(this);
if (beforeTemplateType != afterTemplateType) {
changed = true;
}
builder.add(afterTemplateType);
}
if (changed) {
type = registry.createTemplatizedType(afterBaseType, builder.build());
}
return type;
}
@Override
public JSType caseUnknownType() {
return getNativeType(JSTypeNative.UNKNOWN_TYPE);
}
@Override
public JSType caseNullType() {
return getNativeType(JSTypeNative.NULL_TYPE);
}
@Override
public JSType caseNumberType() {
return getNativeType(JSTypeNative.NUMBER_TYPE);
}
@Override
public JSType caseStringType() {
return getNativeType(JSTypeNative.STRING_TYPE);
}
@Override
public JSType caseVoidType() {
return getNativeType(JSTypeNative.VOID_TYPE);
}
@Override
public JSType caseUnionType(UnionType type) {
boolean changed = false;
List<JSType> results = Lists.newArrayList();
for (JSType alternative : type.getAlternates()) {
JSType replacement = alternative.visit(this);
if (replacement != alternative) {
changed = true;
}
results.add(replacement);
}
if (changed) {
UnionTypeBuilder builder = new UnionTypeBuilder(registry);
for (JSType alternate : results) {
builder.addAlternate(alternate);
}
return builder.build(); // maybe not a union
}
return type;
}
@Override
public JSType caseTemplateType(TemplateType type) {
return type;
}
private JSType getNativeType(JSTypeNative nativeType) {
return registry.getNativeType(nativeType);
}
private boolean isNativeFunctionType(FunctionType type) {
return type.isNativeObjectType();
}
@Override
public JSType caseNamedType(NamedType type) {
// The internals of a named type aren't interesting.
return type;
}
@Override
public JSType caseProxyObjectType(ProxyObjectType type) {
// Be careful not to unwrap a type unless it has changed.
JSType beforeType = type.getReferencedTypeInternal();
JSType replacement = beforeType.visit(this);
if (replacement != beforeType) {
return replacement;
}
return type;
}
}