com.google.javascript.jscomp.TypedVar Maven / Gradle / Ivy
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/*
* Copyright 2015 The Closure Compiler Authors.
*
* Licensed under the Apache License, Version 2.0 (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.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.google.javascript.jscomp;
import static com.google.common.base.Preconditions.checkArgument;
import com.google.common.collect.ImmutableSet;
import com.google.common.collect.Sets;
import com.google.javascript.rhino.ErrorReporter;
import com.google.javascript.rhino.Node;
import com.google.javascript.rhino.Token;
import com.google.javascript.rhino.jstype.JSType;
import com.google.javascript.rhino.jstype.StaticTypedRef;
import com.google.javascript.rhino.jstype.StaticTypedSlot;
/**
* {@link AbstractVar} subclass for use with {@link TypedScope}.
*
* Note that this class inherits its {@link #equals} and {@link #hashCode} implementations from
* {@link ScopedName}, which does not include any type information. This is necessary because {@code
* Var}-keyed maps are used across multiple top scopes, but it comes with the caveat that if {@code
* TypedVar} instances are stored in a set, the type information is at risk of disappearing if an
* untyped (or differently typed) var is added for the same symbol.
*/
public class TypedVar extends AbstractVar
implements StaticTypedSlot, StaticTypedRef {
private JSType type;
// The next two fields and the associated methods are only used by
// TypeInference.java. Maybe there is a way to avoid having them in all typed variable instances.
private boolean markedEscaped = false;
private boolean markedAssignedExactlyOnce = false;
/**
* Whether the variable's type has been inferred or is declared. An inferred
* type may change over time (as more code is discovered), whereas a
* declared type is a static contract that must be matched.
*/
private final boolean typeInferred;
// includes nodes that in plain JS semantics are not 'declarations', but that the type system
// & compiler treat as declarations.
private static final ImmutableSet NAME_NODE_TYPES =
Sets.immutableEnumSet(
Token.NAME,
Token.THIS, // `if ('prop' in this) {` creates a TypedVar `this.prop` requiring a node
Token.IMPORT_STAR,
Token.EXPR_RESULT, // implicit variables from goog.provide
Token.EXPORT, // tracks the *default* export
Token.GETPROP,
Token.FUNCTION,
Token.STRING_KEY,
Token.SETTER_DEF,
Token.GETTER_DEF,
Token.MEMBER_FUNCTION_DEF,
Token.MODULE_BODY); // for the implicit exports object in a module
TypedVar(boolean inferred, String name, Node nameNode, JSType type,
TypedScope scope, int index, CompilerInput input) {
super(name, nameNode, scope, index, input, /* implicitGoogNamespaceDefinition= */ null);
if (nameNode != null) {
checkArgument(
NAME_NODE_TYPES.contains(nameNode.getToken()),
"Invalid name node token %s",
nameNode.getToken());
}
this.type = type;
this.typeInferred = inferred;
}
/**
* Gets this variable's type. To know whether this type has been inferred,
* see {@code #isTypeInferred()}.
*/
@Override
public JSType getType() {
return type;
}
void setType(JSType type) {
this.type = type;
}
void resolveType(ErrorReporter errorReporter) {
if (type != null) {
this.type = type.resolve(errorReporter);
}
}
/**
* Returns whether this variable's type is inferred. To get the variable's
* type, see {@link #getType()}.
*/
@Override
public boolean isTypeInferred() {
return typeInferred;
}
public String getInputName() {
if (getInput() == null) {
return "";
}
return getInput().getName();
}
@Override
public String toString() {
return "Var " + getName() + "{" + type + "}";
}
void markEscaped() {
markedEscaped = true;
}
boolean isMarkedEscaped() {
return markedEscaped;
}
void markAssignedExactlyOnce() {
markedAssignedExactlyOnce = true;
}
boolean isMarkedAssignedExactlyOnce() {
return markedAssignedExactlyOnce;
}
}