/*
* 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.element.CompilationUnitElement;
import com.google.dart.engine.scanner.Token;
import com.google.dart.engine.scanner.TokenType;
import com.google.dart.engine.utilities.source.LineInfo;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
/**
* Instances of the class {@code CompilationUnit} represent a compilation unit.
* <p>
* While the grammar restricts the order of the directives and declarations within a compilation
* unit, this class does not enforce those restrictions. In particular, the children of a
* compilation unit will be visited in lexical order even if lexical order does not conform to the
* restrictions of the grammar.
*
* <pre>
* compilationUnit ::=
* directives declarations
*
* directives ::=
* {@link ScriptTag scriptTag}? {@link LibraryDirective libraryDirective}? namespaceDirective* {@link PartDirective partDirective}*
* | {@link PartOfDirective partOfDirective}
*
* namespaceDirective ::=
* {@link ImportDirective importDirective}
* | {@link ExportDirective exportDirective}
*
* declarations ::=
* {@link CompilationUnitMember compilationUnitMember}*
* </pre>
*
* @coverage dart.engine.ast
*/
public class CompilationUnit extends AstNode {
/**
* The first token in the token stream that was parsed to form this compilation unit.
*/
private Token beginToken;
/**
* The script tag at the beginning of the compilation unit, or {@code null} if there is no script
* tag in this compilation unit.
*/
private ScriptTag scriptTag;
/**
* The directives contained in this compilation unit.
*/
private NodeList<Directive> directives = new NodeList<Directive>(this);
/**
* The declarations contained in this compilation unit.
*/
private NodeList<CompilationUnitMember> declarations = new NodeList<CompilationUnitMember>(this);
/**
* The last token in the token stream that was parsed to form this compilation unit. This token
* should always have a type of {@link TokenType.EOF}.
*/
private Token endToken;
/**
* The element associated with this compilation unit, or {@code null} if the AST structure has not
* been resolved.
*/
private CompilationUnitElement element;
/**
* The line information for this compilation unit.
*/
private LineInfo lineInfo;
/**
* Initialize a newly created compilation unit to have the given directives and declarations.
*
* @param beginToken the first token in the token stream
* @param scriptTag the script tag at the beginning of the compilation unit
* @param directives the directives contained in this compilation unit
* @param declarations the declarations contained in this compilation unit
* @param endToken the last token in the token stream
*/
public CompilationUnit(Token beginToken, ScriptTag scriptTag, List<Directive> directives,
List<CompilationUnitMember> declarations, Token endToken) {
this.beginToken = beginToken;
this.scriptTag = becomeParentOf(scriptTag);
this.directives.addAll(directives);
this.declarations.addAll(declarations);
this.endToken = endToken;
}
@Override
public <R> R accept(AstVisitor<R> visitor) {
return visitor.visitCompilationUnit(this);
}
@Override
public Token getBeginToken() {
return beginToken;
}
/**
* Return the declarations contained in this compilation unit.
*
* @return the declarations contained in this compilation unit
*/
public NodeList<CompilationUnitMember> getDeclarations() {
return declarations;
}
/**
* Return the directives contained in this compilation unit.
*
* @return the directives contained in this compilation unit
*/
public NodeList<Directive> getDirectives() {
return directives;
}
/**
* Return the element associated with this compilation unit, or {@code null} if the AST structure
* has not been resolved.
*
* @return the element associated with this compilation unit
*/
public CompilationUnitElement getElement() {
return element;
}
@Override
public Token getEndToken() {
return endToken;
}
@Override
public int getLength() {
Token endToken = getEndToken();
if (endToken == null) {
return 0;
}
return endToken.getOffset() + endToken.getLength();
}
/**
* Return the line information for this compilation unit.
*
* @return the line information for this compilation unit
*/
public LineInfo getLineInfo() {
return lineInfo;
}
@Override
public int getOffset() {
return 0;
}
/**
* Return the script tag at the beginning of the compilation unit, or {@code null} if there is no
* script tag in this compilation unit.
*
* @return the script tag at the beginning of the compilation unit
*/
public ScriptTag getScriptTag() {
return scriptTag;
}
/**
* Set the element associated with this compilation unit to the given element.
*
* @param element the element associated with this compilation unit
*/
public void setElement(CompilationUnitElement element) {
this.element = element;
}
/**
* Set the line information for this compilation unit to the given line information.
*
* @param errors the line information to associate with this compilation unit
*/
public void setLineInfo(LineInfo lineInfo) {
this.lineInfo = lineInfo;
}
/**
* Set the script tag at the beginning of the compilation unit to the given script tag.
*
* @param scriptTag the script tag at the beginning of the compilation unit
*/
public void setScriptTag(ScriptTag scriptTag) {
this.scriptTag = becomeParentOf(scriptTag);
}
@Override
public void visitChildren(AstVisitor<?> visitor) {
safelyVisitChild(scriptTag, visitor);
if (directivesAreBeforeDeclarations()) {
directives.accept(visitor);
declarations.accept(visitor);
} else {
for (AstNode child : getSortedDirectivesAndDeclarations()) {
child.accept(visitor);
}
}
}
/**
* Return {@code true} if all of the directives are lexically before any declarations.
*
* @return {@code true} if all of the directives are lexically before any declarations
*/
private boolean directivesAreBeforeDeclarations() {
if (directives.isEmpty() || declarations.isEmpty()) {
return true;
}
Directive lastDirective = directives.get(directives.size() - 1);
CompilationUnitMember firstDeclaration = declarations.get(0);
return lastDirective.getOffset() < firstDeclaration.getOffset();
}
/**
* Return an array containing all of the directives and declarations in this compilation unit,
* sorted in lexical order.
*
* @return the directives and declarations in this compilation unit in the order in which they
* appeared in the original source
*/
private AstNode[] getSortedDirectivesAndDeclarations() {
ArrayList<AstNode> childList = new ArrayList<AstNode>();
childList.addAll(directives);
childList.addAll(declarations);
AstNode[] children = childList.toArray(new AstNode[childList.size()]);
Arrays.sort(children, AstNode.LEXICAL_ORDER);
return children;
}
}