/*
* Copyright 2012, the Dart project authors.
*
* Licensed under the Eclipse Public License v1.0 (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.eclipse.org/legal/epl-v10.html
*
* 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.dart.engine.ast;
import com.google.dart.engine.AnalysisEngine;
import com.google.dart.engine.element.ClassElement;
import com.google.dart.engine.element.Element;
import com.google.dart.engine.element.ExecutableElement;
import com.google.dart.engine.element.FunctionTypeAliasElement;
import com.google.dart.engine.element.LocalVariableElement;
import com.google.dart.engine.element.ParameterElement;
import com.google.dart.engine.element.TypeParameterElement;
import com.google.dart.engine.element.VariableElement;
import com.google.dart.engine.internal.element.AuxiliaryElements;
import com.google.dart.engine.scanner.Token;
import com.google.dart.engine.scanner.TokenType;
/**
* Instances of the class {@code SimpleIdentifier} represent a simple identifier.
*
* <pre>
* simpleIdentifier ::=
* initialCharacter internalCharacter*
*
* initialCharacter ::= '_' | '$' | letter
*
* internalCharacter ::= '_' | '$' | letter | digit
* </pre>
*
* @coverage dart.engine.ast
*/
public class SimpleIdentifier extends Identifier {
/**
* The token representing the identifier.
*/
private Token token;
/**
* The element associated with this identifier based on static type information, or {@code null}
* if the AST structure has not been resolved or if this identifier could not be resolved.
*/
private Element staticElement;
/**
* The element associated with this identifier based on propagated type information, or
* {@code null} if the AST structure has not been resolved or if this identifier could not be
* resolved.
*/
private Element propagatedElement;
/**
* If this expression is both in a getter and setter context, the {@link AuxiliaryElements} will
* be set to hold onto the static and propagated information. The auxiliary element will hold onto
* the elements from the getter context.
*/
private AuxiliaryElements auxiliaryElements = null;
/**
* Initialize a newly created identifier.
*
* @param token the token representing the identifier
*/
public SimpleIdentifier(Token token) {
this.token = token;
}
@Override
public <R> R accept(AstVisitor<R> visitor) {
return visitor.visitSimpleIdentifier(this);
}
/**
* Get the auxiliary elements, this will be {@code null} if the node is not in a getter and setter
* context, or if it is not yet fully resolved.
*/
public AuxiliaryElements getAuxiliaryElements() {
return auxiliaryElements;
}
@Override
public Token getBeginToken() {
return token;
}
@Override
public Element getBestElement() {
if (propagatedElement == null) {
return staticElement;
}
return propagatedElement;
}
@Override
public Token getEndToken() {
return token;
}
@Override
public String getName() {
return token.getLexeme();
}
@Override
public int getPrecedence() {
return 16;
}
@Override
public Element getPropagatedElement() {
return propagatedElement;
}
@Override
public Element getStaticElement() {
return staticElement;
}
/**
* Return the token representing the identifier.
*
* @return the token representing the identifier
*/
public Token getToken() {
return token;
}
/**
* Return {@code true} if this identifier is the name being declared in a declaration.
*
* @return {@code true} if this identifier is the name being declared in a declaration
*/
public boolean inDeclarationContext() {
AstNode parent = getParent();
if (parent instanceof CatchClause) {
CatchClause clause = (CatchClause) parent;
return this == clause.getExceptionParameter() || this == clause.getStackTraceParameter();
} else if (parent instanceof ClassDeclaration) {
return this == ((ClassDeclaration) parent).getName();
} else if (parent instanceof ClassTypeAlias) {
return this == ((ClassTypeAlias) parent).getName();
} else if (parent instanceof ConstructorDeclaration) {
return this == ((ConstructorDeclaration) parent).getName();
} else if (parent instanceof DeclaredIdentifier) {
return this == ((DeclaredIdentifier) parent).getIdentifier();
} else if (parent instanceof EnumDeclaration) {
return this == ((EnumDeclaration) parent).getName();
} else if (parent instanceof EnumConstantDeclaration) {
return this == ((EnumConstantDeclaration) parent).getName();
} else if (parent instanceof FunctionDeclaration) {
return this == ((FunctionDeclaration) parent).getName();
} else if (parent instanceof FunctionTypeAlias) {
return this == ((FunctionTypeAlias) parent).getName();
} else if (parent instanceof ImportDirective) {
return this == ((ImportDirective) parent).getPrefix();
} else if (parent instanceof Label) {
return this == ((Label) parent).getLabel()
&& (parent.getParent() instanceof LabeledStatement);
} else if (parent instanceof MethodDeclaration) {
return this == ((MethodDeclaration) parent).getName();
} else if (parent instanceof FunctionTypedFormalParameter
|| parent instanceof SimpleFormalParameter) {
return this == ((NormalFormalParameter) parent).getIdentifier();
} else if (parent instanceof TypeParameter) {
return this == ((TypeParameter) parent).getName();
} else if (parent instanceof VariableDeclaration) {
return this == ((VariableDeclaration) parent).getName();
}
return false;
}
/**
* Return {@code true} if this expression is computing a right-hand value.
* <p>
* Note that {@link #inGetterContext()} and {@link #inSetterContext()} are not opposites, nor are
* they mutually exclusive. In other words, it is possible for both methods to return {@code true}
* when invoked on the same node.
*
* @return {@code true} if this expression is in a context where a getter will be invoked
*/
public boolean inGetterContext() {
AstNode parent = getParent();
AstNode target = this;
// skip prefix
if (parent instanceof PrefixedIdentifier) {
PrefixedIdentifier prefixed = (PrefixedIdentifier) parent;
if (prefixed.getPrefix() == this) {
return true;
}
parent = prefixed.getParent();
target = prefixed;
} else if (parent instanceof PropertyAccess) {
PropertyAccess access = (PropertyAccess) parent;
if (access.getTarget() == this) {
return true;
}
parent = access.getParent();
target = access;
}
// skip label
if (parent instanceof Label) {
return false;
}
// analyze usage
if (parent instanceof AssignmentExpression) {
AssignmentExpression expr = (AssignmentExpression) parent;
if (expr.getLeftHandSide() == target && expr.getOperator().getType() == TokenType.EQ) {
return false;
}
}
return true;
}
/**
* Return {@code true} if this expression is computing a left-hand value.
* <p>
* Note that {@link #inGetterContext()} and {@link #inSetterContext()} are not opposites, nor are
* they mutually exclusive. In other words, it is possible for both methods to return {@code true}
* when invoked on the same node.
*
* @return {@code true} if this expression is in a context where a setter will be invoked
*/
public boolean inSetterContext() {
AstNode parent = getParent();
AstNode target = this;
// skip prefix
if (parent instanceof PrefixedIdentifier) {
PrefixedIdentifier prefixed = (PrefixedIdentifier) parent;
// if this is the prefix, then return false
if (prefixed.getPrefix() == this) {
return false;
}
parent = prefixed.getParent();
target = prefixed;
} else if (parent instanceof PropertyAccess) {
PropertyAccess access = (PropertyAccess) parent;
if (access.getTarget() == this) {
return false;
}
parent = access.getParent();
target = access;
}
// analyze usage
if (parent instanceof PrefixExpression) {
return ((PrefixExpression) parent).getOperator().getType().isIncrementOperator();
} else if (parent instanceof PostfixExpression) {
return true;
} else if (parent instanceof AssignmentExpression) {
return ((AssignmentExpression) parent).getLeftHandSide() == target;
}
return false;
}
/**
* Returns {@code true} if this identifier is the "name" part of a prefixed identifier or a method
* invocation.
*
* @return {@code true} if this identifier is the "name" part of a prefixed identifier or a method
* invocation
*/
public boolean isQualified() {
AstNode parent = getParent();
if (parent instanceof PrefixedIdentifier) {
return ((PrefixedIdentifier) parent).getIdentifier() == this;
}
if (parent instanceof PropertyAccess) {
return ((PropertyAccess) parent).getPropertyName() == this;
}
if (parent instanceof MethodInvocation) {
MethodInvocation invocation = (MethodInvocation) parent;
return invocation.getMethodName() == this && invocation.getRealTarget() != null;
}
return false;
}
@Override
public boolean isSynthetic() {
return token.isSynthetic();
}
/**
* Set the auxiliary elements.
*/
public void setAuxiliaryElements(AuxiliaryElements auxiliaryElements) {
this.auxiliaryElements = auxiliaryElements;
}
/**
* Set the element associated with this identifier based on propagated type information to the
* given element.
*
* @param element the element to be associated with this identifier
*/
public void setPropagatedElement(Element element) {
propagatedElement = validateElement(element);
}
/**
* Set the element associated with this identifier based on static type information to the given
* element.
*
* @param element the element to be associated with this identifier
*/
public void setStaticElement(Element element) {
staticElement = validateElement(element);
}
/**
* Set the token representing the identifier to the given token.
*
* @param token the token representing the literal
*/
public void setToken(Token token) {
this.token = token;
}
@Override
public void visitChildren(AstVisitor<?> visitor) {
// There are no children to visit.
}
/**
* Return the given element if it is valid, or report the problem and return {@code null} if it is
* not appropriate.
*
* @param parent the parent of the element, used for reporting when there is a problem
* @param isValid {@code true} if the element is appropriate
* @param element the element to be associated with this identifier
* @return the element to be associated with this identifier
*/
private Element returnOrReportElement(AstNode parent, boolean isValid, Element element) {
if (!isValid) {
AnalysisEngine.getInstance().getLogger().logInformation(
"Internal error: attempting to set the name of a " + parent.getClass().getName()
+ " to a " + element.getClass().getName(),
new Exception());
return null;
}
return element;
}
/**
* Return the given element if it is an appropriate element based on the parent of this
* identifier, or {@code null} if it is not appropriate.
*
* @param element the element to be associated with this identifier
* @return the element to be associated with this identifier
*/
private Element validateElement(Element element) {
if (element == null) {
return null;
}
AstNode parent = getParent();
if (parent instanceof ClassDeclaration && ((ClassDeclaration) parent).getName() == this) {
return returnOrReportElement(parent, element instanceof ClassElement, element);
} else if (parent instanceof ClassTypeAlias && ((ClassTypeAlias) parent).getName() == this) {
return returnOrReportElement(parent, element instanceof ClassElement, element);
} else if (parent instanceof DeclaredIdentifier
&& ((DeclaredIdentifier) parent).getIdentifier() == this) {
return returnOrReportElement(parent, element instanceof LocalVariableElement, element);
} else if (parent instanceof FormalParameter
&& ((FormalParameter) parent).getIdentifier() == this) {
return returnOrReportElement(parent, element instanceof ParameterElement, element);
} else if (parent instanceof FunctionDeclaration
&& ((FunctionDeclaration) parent).getName() == this) {
return returnOrReportElement(parent, element instanceof ExecutableElement, element);
} else if (parent instanceof FunctionTypeAlias
&& ((FunctionTypeAlias) parent).getName() == this) {
return returnOrReportElement(parent, element instanceof FunctionTypeAliasElement, element);
} else if (parent instanceof MethodDeclaration
&& ((MethodDeclaration) parent).getName() == this) {
return returnOrReportElement(parent, element instanceof ExecutableElement, element);
} else if (parent instanceof TypeParameter && ((TypeParameter) parent).getName() == this) {
return returnOrReportElement(parent, element instanceof TypeParameterElement, element);
} else if (parent instanceof VariableDeclaration
&& ((VariableDeclaration) parent).getName() == this) {
return returnOrReportElement(parent, element instanceof VariableElement, element);
}
return element;
}
}