/// <summary>
/// Creates a new Scope instance.
/// </summary>
/// <param name="parentScope"> A reference to the parent scope, or <c>null</c> if this is
/// the global scope. </param>
/// <param name="declaredVariableCount"> The number of variables declared in this scope. </param>
protected Scope(Scope parentScope, int declaredVariableCount)
{
this.ParentScope = parentScope;
this.variables = new Dictionary<string, DeclaredVariable>(declaredVariableCount);
this.CanDeclareVariables = true;
this.ExistsAtRuntime = true;
}
/// <summary>
/// Creates a new VarStatement instance.
/// </summary>
/// <param name="labels"> The labels that are associated with this statement. </param>
/// <param name="scope"> The scope the variables are defined within. </param>
public VarStatement(IList<string> labels, Scope scope)
: base(labels)
{
if (scope == null)
throw new ArgumentNullException("scope");
this.Scope = scope;
this.declarations = new List<VariableDeclaration>(1);
}
/// <summary>
/// Creates a new NameExpression instance.
/// </summary>
/// <param name="scope"> The current scope. </param>
/// <param name="name"> The name of the variable or member that is being referenced. </param>
public NameExpression(Scope scope, string name)
{
if (scope == null)
throw new ArgumentNullException("scope");
if (name == null)
throw new ArgumentNullException("name");
this.Scope = scope;
this.Name = name;
}
/// <summary>
/// Creates a parser that can read the body of a function.
/// </summary>
/// <param name="parser"> The parser for the parent context. </param>
/// <param name="scope"> The function scope. </param>
/// <returns> A new parser. </returns>
private static Parser CreateFunctionBodyParser(Parser parser, Scope scope)
{
var result = (Parser)parser.MemberwiseClone();
result.currentScope = result.initialScope = scope;
result.methodOptimizationHints = new MethodOptimizationHints();
result.context = CodeContext.Function;
result.endToken = PunctuatorToken.RightBrace;
result.DirectivePrologueProcessedCallback = null;
return result;
}
/// <summary>
/// Creates a new declarative scope for use inside a catch statement.
/// </summary>
/// <param name="parentScope"> A reference to the parent scope. Can not be <c>null</c>. </param>
/// <param name="catchVariableName"> The name of the catch variable. </param>
/// <returns> A new DeclarativeScope instance. </returns>
internal static DeclarativeScope CreateCatchScope(Scope parentScope, string catchVariableName)
{
if (parentScope == null)
throw new ArgumentNullException("parentScope", "Catch scopes must have a parent scope.");
if (catchVariableName == null)
throw new ArgumentNullException("catchVariableName");
var result = new DeclarativeScope(parentScope, 0);
result.DeclareVariable(catchVariableName);
result.CanDeclareVariables = false; // Only the catch variable can be declared in this scope.
return result;
}
/// <summary>
/// Creates a new declarative scope for use at runtime.
/// </summary>
/// <param name="parentScope"> A reference to the parent scope. Can not be <c>null</c>. </param>
/// <param name="declaredVariableNames"> The names of variables that were declared in this scope. </param>
/// <returns> A new DeclarativeScope instance. </returns>
public static DeclarativeScope CreateRuntimeScope(Scope parentScope, string[] declaredVariableNames)
{
if (parentScope == null)
throw new ArgumentNullException("parentScope", "Function scopes must have a parent scope.");
if (declaredVariableNames == null)
throw new ArgumentNullException("declaredVariableNames");
var result = new DeclarativeScope(parentScope, declaredVariableNames.Length);
foreach (string variableName in declaredVariableNames)
result.DeclareVariable(variableName);
result.values = new object[result.DeclaredVariableCount];
return result;
}
/// <summary>
/// Creates a new MethodGenerator instance.
/// </summary>
/// <param name="engine"> The script engine. </param>
/// <param name="scope"> The initial scope. </param>
/// <param name="source"> The source of javascript code. </param>
/// <param name="options"> Options that influence the compiler. </param>
protected MethodGenerator(ScriptEngine engine, Scope scope, ScriptSource source, CompilerOptions options)
{
if (engine == null)
throw new ArgumentNullException("engine");
if (scope == null)
throw new ArgumentNullException("scope");
if (source == null)
throw new ArgumentNullException("source");
if (options == null)
throw new ArgumentNullException("options");
this.Engine = engine;
this.InitialScope = scope;
this.Source = source;
this.Options = options;
this.StrictMode = this.Options.ForceStrictMode;
}
/// <summary>
/// Creates a new declarative scope for use inside a function body.
/// </summary>
/// <param name="parentScope"> A reference to the parent scope. Can not be <c>null</c>. </param>
/// <param name="functionName"> The name of the function. Can be empty for an anonymous function. </param>
/// <param name="argumentNames"> The names of each of the function arguments. </param>
/// <returns> A new DeclarativeScope instance. </returns>
internal static DeclarativeScope CreateFunctionScope(Scope parentScope, string functionName, IEnumerable<string> argumentNames)
{
if (parentScope == null)
throw new ArgumentNullException("parentScope", "Function scopes must have a parent scope.");
if (functionName == null)
throw new ArgumentNullException("functionName");
if (argumentNames == null)
throw new ArgumentNullException("argumentNames");
var result = new DeclarativeScope(parentScope, 0);
if (string.IsNullOrEmpty(functionName) == false)
result.DeclareVariable(functionName);
result.DeclareVariable("this");
result.DeclareVariable("arguments");
foreach (var argumentName in argumentNames)
result.DeclareVariable(argumentName);
return result;
}
// INITIALIZATION
//_________________________________________________________________________________________
/// <summary>
/// Creates a Parser instance with the given lexer supplying the tokens.
/// </summary>
/// <param name="engine"> The associated script engine. </param>
/// <param name="lexer"> The lexical analyser that provides the tokens. </param>
/// <param name="initialScope"> The initial variable scope. </param>
/// <param name="options"> Options that influence the compiler. </param>
/// <param name="context"> The context of the code (global, function or eval). </param>
public Parser(ScriptEngine engine, Lexer lexer, Scope initialScope, CompilerOptions options, CodeContext context)
{
if (engine == null)
throw new ArgumentNullException("engine");
if (lexer == null)
throw new ArgumentNullException("lexer");
if (initialScope == null)
throw new ArgumentNullException("initialScope");
this.engine = engine;
this.lexer = lexer;
this.lexer.ParserExpressionState = ParserExpressionState.Literal;
this.currentScope = this.initialScope = initialScope;
this.methodOptimizationHints = new MethodOptimizationHints();
this.options = options;
this.context = context;
this.StrictMode = options.ForceStrictMode;
this.Consume();
}
// EVAL SUPPORT
//_________________________________________________________________________________________
//private class EvalCacheKey
//{
// public string Code;
// public Compiler.Scope Scope;
// public bool StrictMode;
// public override int GetHashCode()
// {
// int bitValue = 1;
// int hashCode = this.Code.GetHashCode();
// var scope = this.Scope;
// do
// {
// if (scope is Compiler.DeclarativeScope)
// hashCode ^= bitValue;
// scope = scope.ParentScope;
// bitValue *= 2;
// } while (scope != null);
// if (this.StrictMode == true)
// hashCode ^= bitValue;
// return hashCode;
// }
// public override bool Equals(object obj)
// {
// if ((obj is EvalCacheKey) == false)
// return false;
// var other = (EvalCacheKey) obj;
// if (this.Code != other.Code ||
// this.StrictMode != other.StrictMode)
// return false;
// var scope1 = this.Scope;
// var scope2 = other.Scope;
// do
// {
// if (scope1.GetType() != scope2.GetType())
// return false;
// scope1 = scope1.ParentScope;
// scope2 = scope2.ParentScope;
// if (scope1 == null && scope2 != null)
// return false;
// if (scope1 != null && scope2 == null)
// return false;
// } while (scope1 != null);
// return true;
// }
//}
//private Dictionary<EvalCacheKey, WeakReference> evalCache =
// new Dictionary<EvalCacheKey, WeakReference>();
/// <summary>
/// Evaluates the given javascript source code and returns the result.
/// </summary>
/// <param name="code"> The source code to evaluate. </param>
/// <param name="scope"> The containing scope. </param>
/// <param name="thisObject"> The value of the "this" keyword in the containing scope. </param>
/// <param name="strictMode"> Indicates whether the eval statement is being called from
/// strict mode code. </param>
/// <returns> The value of the last statement that was executed, or <c>undefined</c> if
/// there were no executed statements. </returns>
internal object Eval(string code, Compiler.Scope scope, object thisObject, bool strictMode)
{
// Check if the cache contains the eval already.
//var key = new EvalCacheKey() { Code = code, Scope = scope, StrictMode = strictMode };
//WeakReference cachedEvalGenRef;
//if (evalCache.TryGetValue(key, out cachedEvalGenRef) == true)
//{
// var cachedEvalGen = (Compiler.EvalMethodGenerator)cachedEvalGenRef.Target;
// if (cachedEvalGen != null)
// {
// // Replace the "this object" before running.
// cachedEvalGen.ThisObject = thisObject;
// // Execute the cached code.
// return ((Compiler.EvalMethodGenerator)cachedEvalGen).Execute();
// }
//}
// Parse the eval string into an AST.
var options = new Compiler.CompilerOptions()
{
ForceStrictMode = strictMode
};
var evalGen = new Jurassic.Compiler.EvalMethodGenerator(
this, // The script engine.
scope, // The scope to run the code in.
new StringScriptSource(code), // The source code to execute.
options, // Options.
thisObject); // The value of the "this" keyword.
// Make sure the eval cache doesn't get too big. TODO: add some sort of LRU strategy?
//if (evalCache.Count > 100)
// evalCache.Clear();
//// Add the eval method generator to the cache.
//evalCache[key] = new WeakReference(evalGen);
// Compile and run the eval code.
return(evalGen.Execute());
}
public ScopeContext(Parser parser)
{
this.parser = parser;
previousLetScope = parser.currentLetScope;
previousVarScope = parser.currentVarScope;
}
/// <summary>
/// Creates a new EvalMethodGenerator instance.
/// </summary>
/// <param name="engine"> The script engine. </param>
/// <param name="parentScope"> The scope of the calling code. </param>
/// <param name="source"> The script code to execute. </param>
/// <param name="options"> Options that influence the compiler. </param>
/// <param name="thisObject"> The value of the "this" keyword in the calling code. </param>
public EvalMethodGenerator(ScriptEngine engine, Scope parentScope, ScriptSource source, CompilerOptions options, object thisObject)
: base(engine, parentScope, source, options)
{
this.ThisObject = thisObject;
}
/// <summary>
/// Creates a new instance of a user-defined function.
/// </summary>
/// <param name="prototype"> The next object in the prototype chain. </param>
/// <param name="name"> The name of the function. </param>
/// <param name="argumentNames"> The names of the arguments. </param>
/// <param name="parentScope"> The scope at the point the function is declared. </param>
/// <param name="bodyText"> The source code for the function body. </param>
/// <param name="generatedMethod"> A delegate which represents the body of the function plus any dependencies. </param>
/// <param name="strictMode"> <c>true</c> if the function body is strict mode; <c>false</c> otherwise. </param>
public UserDefinedFunction(ObjectInstance prototype, string name, IList<string> argumentNames, Scope parentScope, string bodyText, GeneratedMethod generatedMethod, bool strictMode)
: base(prototype)
{
Init(name, argumentNames, parentScope, bodyText, generatedMethod, strictMode, true);
}
/// <summary>
/// Creates a new instance of a user-defined function.
/// </summary>
/// <param name="prototype"> The next object in the prototype chain. </param>
/// <param name="name"> The name of the function. </param>
/// <param name="argumentNames"> The names of the arguments. </param>
/// <param name="parentScope"> The scope at the point the function is declared. </param>
/// <param name="bodyText"> The source code for the function body. </param>
/// <param name="body"> A delegate which represents the body of the function. </param>
/// <param name="strictMode"> <c>true</c> if the function body is strict mode; <c>false</c> otherwise. </param>
internal UserDefinedFunction(ObjectInstance prototype, string name, IList<string> argumentNames, Scope parentScope, string bodyText, FunctionDelegate body, bool strictMode)
: base(prototype)
{
Init(name, argumentNames, parentScope, bodyText, new GeneratedMethod(body, null), strictMode, true);
}
/// <summary>
/// Initializes a user-defined function.
/// </summary>
/// <param name="name"> The name of the function. </param>
/// <param name="argumentNames"> The names of the arguments. </param>
/// <param name="parentScope"> The scope at the point the function is declared. </param>
/// <param name="bodyText"> The source code for the function body. </param>
/// <param name="generatedMethod"> A delegate which represents the body of the function, plus any dependencies. </param>
/// <param name="strictMode"> <c>true</c> if the function body is strict mode; <c>false</c> otherwise. </param>
/// <param name="hasInstancePrototype"> <c>true</c> if the function should have a valid
/// "prototype" property; <c>false</c> if the "prototype" property should be <c>null</c>. </param>
private void Init(string name, IList<string> argumentNames, Scope parentScope, string bodyText, GeneratedMethod generatedMethod, bool strictMode, bool hasInstancePrototype)
{
if (name == null)
throw new ArgumentNullException("name");
if (argumentNames == null)
throw new ArgumentNullException("argumentNames");
if (bodyText == null)
throw new ArgumentNullException("bodyText");
if (generatedMethod == null)
throw new ArgumentNullException("generatedMethod");
if (parentScope == null)
throw new ArgumentNullException("parentScope");
this.ArgumentNames = new System.Collections.ObjectModel.ReadOnlyCollection<string>(argumentNames);
this.BodyText = bodyText;
this.generatedMethod = generatedMethod;
this.body = (FunctionDelegate)this.generatedMethod.GeneratedDelegate;
this.ParentScope = parentScope;
this.StrictMode = strictMode;
// Add function properties.
this.FastSetProperty("name", name);
this.FastSetProperty("length", argumentNames.Count);
// The empty function doesn't have an instance prototype.
if (hasInstancePrototype == true)
{
this.FastSetProperty("prototype", this.Engine.Object.Construct(), PropertyAttributes.Writable);
this.InstancePrototype.FastSetProperty("constructor", this, PropertyAttributes.NonEnumerable);
}
}
/// <summary>
/// Parses a with statement.
/// </summary>
/// <returns> An expression representing the with statement. </returns>
private WithStatement ParseWith()
{
// This statement is not allowed in strict mode.
if (this.StrictMode == true)
throw new JavaScriptException(this.engine, "SyntaxError", "The with statement is not supported in strict mode", this.LineNumber, this.SourcePath);
var result = new WithStatement(this.labelsForCurrentStatement);
// Read past the "with" token.
this.Expect(KeywordToken.With);
// Read a left parenthesis token "(".
this.Expect(PunctuatorToken.LeftParenthesis);
// Keep track of the start of the statement so that source debugging works correctly.
var start = this.PositionAfterWhitespace;
// Read an object reference.
var objectEnvironment = ParseExpression(PunctuatorToken.RightParenthesis);
// Record the portion of the source document that will be highlighted when debugging.
result.SourceSpan = new SourceCodeSpan(start, this.PositionBeforeWhitespace);
// Read a right parenthesis token ")".
this.Expect(PunctuatorToken.RightParenthesis);
// Create a new scope and assign variables within the with statement to the scope.
result.Scope = ObjectScope.CreateWithScope(this.currentScope, objectEnvironment);
this.currentScope = result.Scope;
// Read the body of the with statement.
result.Body = ParseStatement();
// Revert the scope.
this.currentScope = this.currentScope.ParentScope;
return result;
}
///// <summary>
///// Creates a new object scope for use inside a with statement.
///// </summary>
///// <param name="parentScope"> A reference to the parent scope. Can not be <c>null</c>. </param>
///// <param name="scopeObject"> An expression that evaluates to the object to use. </param>
///// <returns> A new ObjectScope instance. </returns>
//public static ObjectScope CreateWithScope(Scope parentScope, Library.ObjectInstance scopeObject)
//{
// if (parentScope == null)
// throw new ArgumentException("With scopes must have a parent scope.");
// return new ObjectScope(parentScope) { ScopeObject = scopeObject, ProvidesImplicitThisValue = true };
//}
/// <summary>
/// Creates a new object scope for use at runtime.
/// </summary>
/// <param name="parentScope"> A reference to the parent scope. Can not be <c>null</c>. </param>
/// <param name="scopeObject"> An expression that evaluates to the object to use. </param>
/// <param name="providesImplicitThisValue"> Indicates whether an implicit "this" value is
/// supplied to function calls in this scope. </param>
/// <param name="canDeclareVariables"> Indicates whether variables can be declared within
/// the scope. </param>
/// <returns> A new ObjectScope instance. </returns>
public static ObjectScope CreateRuntimeScope(Scope parentScope, Library.ObjectInstance scopeObject, bool providesImplicitThisValue, bool canDeclareVariables)
{
return new ObjectScope(parentScope) { ScopeObject = scopeObject, ProvidesImplicitThisValue = providesImplicitThisValue, CanDeclareVariables = canDeclareVariables };
}
/// <summary>
/// Parses a function declaration or a function expression.
/// </summary>
/// <param name="functionType"> The type of function to parse. </param>
/// <param name="parentScope"> The parent scope for the function. </param>
/// <param name="functionName"> The name of the function (can be empty). </param>
/// <returns> A function expression. </returns>
private FunctionExpression ParseFunction(FunctionDeclarationType functionType, Scope parentScope, string functionName)
{
// Read the left parenthesis.
this.Expect(PunctuatorToken.LeftParenthesis);
// Create a new scope and assign variables within the function body to the scope.
bool includeNameInScope = functionType != FunctionDeclarationType.Getter && functionType != FunctionDeclarationType.Setter;
var scope = DeclarativeScope.CreateFunctionScope(parentScope, includeNameInScope ? functionName : string.Empty, null);
// Replace scope and methodOptimizationHints.
var originalScope = this.currentVarScope;
var originalMethodOptimizationHints = this.methodOptimizationHints;
var newMethodOptimizationHints = new MethodOptimizationHints();
this.methodOptimizationHints = newMethodOptimizationHints;
this.currentVarScope = scope;
// Read zero or more arguments.
var arguments = ParseFunctionArguments(PunctuatorToken.RightParenthesis);
// Restore scope and methodOptimizationHints.
this.methodOptimizationHints = originalMethodOptimizationHints;
this.currentVarScope = originalScope;
// Getters must have zero arguments.
if (functionType == FunctionDeclarationType.Getter && arguments.Count != 0)
throw new JavaScriptException(this.engine, ErrorType.SyntaxError, "Getters cannot have arguments", this.LineNumber, this.SourcePath);
// Setters must have one argument.
if (functionType == FunctionDeclarationType.Setter && arguments.Count != 1)
throw new JavaScriptException(this.engine, ErrorType.SyntaxError, "Setters must have a single argument", this.LineNumber, this.SourcePath);
// Read the right parenthesis.
this.Expect(PunctuatorToken.RightParenthesis);
// Record the start of the function body.
var startPosition = this.PositionBeforeWhitespace;
// Since the parser reads one token in advance, start capturing the function body here.
var bodyTextBuilder = new System.Text.StringBuilder();
var originalBodyTextBuilder = this.lexer.InputCaptureStringBuilder;
this.lexer.InputCaptureStringBuilder = bodyTextBuilder;
// Read the start brace.
this.Expect(PunctuatorToken.LeftBrace);
// This context has a nested function.
this.methodOptimizationHints.HasNestedFunction = true;
// Read the function body.
var functionParser = CreateFunctionBodyParser(this, scope, newMethodOptimizationHints);
var body = functionParser.Parse();
// Transfer state back from the function parser.
this.nextToken = functionParser.nextToken;
this.lexer.StrictMode = this.StrictMode;
this.lexer.InputCaptureStringBuilder = originalBodyTextBuilder;
if (originalBodyTextBuilder != null)
originalBodyTextBuilder.Append(bodyTextBuilder);
SourceCodePosition endPosition;
if (functionType == FunctionDeclarationType.Expression)
{
// The end token '}' will be consumed by the parent function.
if (this.nextToken != PunctuatorToken.RightBrace)
throw new JavaScriptException(this.engine, ErrorType.SyntaxError, "Expected '}'", this.LineNumber, this.SourcePath);
// Record the end of the function body.
endPosition = new SourceCodePosition(this.PositionAfterWhitespace.Line, this.PositionAfterWhitespace.Column + 1);
}
else
{
// Consume the '}'.
this.Expect(PunctuatorToken.RightBrace);
// Record the end of the function body.
endPosition = new SourceCodePosition(this.PositionAfterWhitespace.Line, this.PositionAfterWhitespace.Column + 1);
}
// Create a new function expression.
var options = this.options.Clone();
options.ForceStrictMode = functionParser.StrictMode;
var context = new FunctionMethodGenerator(this.engine, scope, functionName,
functionType, arguments,
bodyTextBuilder.ToString(0, bodyTextBuilder.Length - 1), body,
this.SourcePath, options);
context.MethodOptimizationHints = functionParser.methodOptimizationHints;
return new FunctionExpression(context);
}
/// <summary>
/// Sets the current scope and returns an object which can be disposed to restore the
/// previous scope.
/// </summary>
/// <param name="letScope"> The new let scope. </param>
/// <param name="varScope"> The new var scope. </param>
/// <returns> An object which can be disposed to restore the previous scope. </returns>
private ScopeContext CreateScopeContext(Scope letScope, Scope varScope = null)
{
if (letScope == null)
throw new ArgumentNullException("letScope");
var result = new ScopeContext(this);
this.currentLetScope = letScope;
if (varScope != null)
this.currentVarScope = varScope;
return result;
}
/// <summary>
/// Creates a new object scope for use inside a with statement.
/// </summary>
/// <param name="parentScope"> A reference to the parent scope. Can not be <c>null</c>. </param>
/// <param name="scopeObject"> An expression that evaluates to the object to use. </param>
/// <returns> A new ObjectScope instance. </returns>
internal static ObjectScope CreateWithScope(Scope parentScope, Expression scopeObject)
{
if (parentScope == null)
throw new ArgumentException("With scopes must have a parent scope.");
return new ObjectScope(parentScope) { ScopeObjectExpression = scopeObject, ProvidesImplicitThisValue = true, CanDeclareVariables = false };
}
/// <summary>
/// Creates a new Scope instance.
/// </summary>
/// <param name="parentScope"> A reference to the parent scope, or <c>null</c> if this is
/// the global scope. </param>
protected Scope(Scope parentScope)
: this(parentScope, 0)
{
}
/// <summary>
/// Creates a simple variable assignment expression.
/// </summary>
/// <param name="scope"> The scope the variable is defined within. </param>
/// <param name="name"> The name of the variable to set. </param>
/// <param name="value"> The value to set the variable to. </param>
public AssignmentExpression(Scope scope, string name, Expression value)
: base(Operator.Assignment)
{
this.Push(new NameExpression(scope, name));
this.Push(value);
}
// SCOPE HELPERS
//_________________________________________________________________________________________
/// <summary>
/// Sets the initial scope.
/// </summary>
/// <param name="initialScope"> The initial scope </param>
private void SetInitialScope(Scope initialScope)
{
if (initialScope == null)
throw new ArgumentNullException("initialScope");
this.currentLetScope = this.currentVarScope = this.initialScope = initialScope;
}
/// <summary>
/// Creates a parser that can read the body of a function.
/// </summary>
/// <param name="parser"> The parser for the parent context. </param>
/// <param name="scope"> The function scope. </param>
/// <param name="optimizationHints"> Hints about whether optimization is possible. </param>
/// <returns> A new parser. </returns>
private static Parser CreateFunctionBodyParser(Parser parser, Scope scope, MethodOptimizationHints optimizationHints)
{
var result = (Parser)parser.MemberwiseClone();
result.SetInitialScope(scope);
result.methodOptimizationHints = optimizationHints;
result.context = CodeContext.Function;
result.endToken = PunctuatorToken.RightBrace;
return result;
}
/// <summary>
/// Creates a new ObjectScope instance.
/// </summary>
private ObjectScope(Scope parentScope)
: base(parentScope)
{
this.ScopeObjectExpression = null;
this.ProvidesImplicitThisValue = false;
}
/// <summary>
/// Creates a new declarative scope for use inside a strict mode eval statement.
/// </summary>
/// <param name="parentScope"> A reference to the parent scope. Can not be <c>null</c>. </param>
/// <returns> A new DeclarativeScope instance. </returns>
internal static DeclarativeScope CreateEvalScope(Scope parentScope)
{
if (parentScope == null)
throw new ArgumentNullException("parentScope", "Eval scopes must have a parent scope.");
return new DeclarativeScope(parentScope, 0);
}
/// <summary>
/// Parses a try statement.
/// </summary>
/// <returns> A try-catch-finally statement. </returns>
private TryCatchFinallyStatement ParseTry()
{
var result = new TryCatchFinallyStatement(this.labelsForCurrentStatement);
// Consume the try keyword.
this.Expect(KeywordToken.Try);
// Parse the try block.
result.TryBlock = ParseBlock();
// The next token is either 'catch' or 'finally'.
if (this.nextToken == KeywordToken.Catch)
{
// Consume the catch token.
this.Expect(KeywordToken.Catch);
// Read the left parenthesis.
this.Expect(PunctuatorToken.LeftParenthesis);
// Read the name of the variable to assign the exception to.
result.CatchVariableName = this.ExpectIdentifier();
this.ValidateVariableName(result.CatchVariableName);
// Read the right parenthesis.
this.Expect(PunctuatorToken.RightParenthesis);
// Create a new scope for the catch variable.
this.currentScope = result.CatchScope = DeclarativeScope.CreateCatchScope(this.currentScope, result.CatchVariableName);
// Parse the statements inside the catch block.
result.CatchBlock = ParseBlock();
// Revert the scope.
this.currentScope = this.currentScope.ParentScope;
}
if (this.nextToken == KeywordToken.Finally)
{
// Consume the finally token.
this.Expect(KeywordToken.Finally);
// Read the finally statements.
result.FinallyBlock = ParseBlock();
}
// There must be a catch or finally block.
if (result.CatchBlock == null && result.FinallyBlock == null)
throw new JavaScriptException(this.engine, "SyntaxError", "Missing catch or finally after try", this.LineNumber, this.SourcePath);
return result;
}
/// <summary>
/// Creates a new DeclarativeScope instance.
/// </summary>
/// <param name="parentScope"> A reference to the parent scope, or <c>null</c> if this is
/// the global scope. </param>
/// <param name="declaredVariableCount"> The number of variables declared in this scope. </param>
private DeclarativeScope(Scope parentScope, int declaredVariableCount)
: base(parentScope, declaredVariableCount)
{
}
/// <summary>
/// Parses a function declaration or a function expression.
/// </summary>
/// <param name="functionType"> The type of function to parse. </param>
/// <param name="parentScope"> The parent scope for the function. </param>
/// <returns> A function expression. </returns>
private FunctionExpression ParseFunction(FunctionType functionType, Scope parentScope)
{
if (functionType != FunctionType.Getter && functionType != FunctionType.Setter)
{
// Consume the function keyword.
this.Expect(KeywordToken.Function);
}
// Read the function name.
var functionName = string.Empty;
if (functionType == FunctionType.Declaration)
{
functionName = this.ExpectIdentifier();
}
else if (functionType == FunctionType.Expression)
{
// The function name is optional for function expressions.
if (this.nextToken is IdentifierToken)
functionName = this.ExpectIdentifier();
}
else if (functionType == FunctionType.Getter || functionType == FunctionType.Setter)
{
// Getters and setters can have any name that is allowed of a property.
bool wasIdentifier;
functionName = ReadPropertyName(out wasIdentifier);
}
else
throw new ArgumentOutOfRangeException("functionType");
ValidateVariableName(functionName);
// Read the left parenthesis.
this.Expect(PunctuatorToken.LeftParenthesis);
// Read zero or more argument names.
var argumentNames = new List<string>();
// Read the first argument name.
if (this.nextToken != PunctuatorToken.RightParenthesis)
{
var argumentName = this.ExpectIdentifier();
ValidateVariableName(argumentName);
argumentNames.Add(argumentName);
}
while (true)
{
if (this.nextToken == PunctuatorToken.Comma)
{
// Consume the comma.
this.Consume();
// Read and validate the argument name.
var argumentName = this.ExpectIdentifier();
ValidateVariableName(argumentName);
argumentNames.Add(argumentName);
}
else if (this.nextToken == PunctuatorToken.RightParenthesis)
break;
else
throw new JavaScriptException(this.engine, "SyntaxError", "Expected ',' or ')'", this.LineNumber, this.SourcePath);
}
// Getters must have zero arguments.
if (functionType == FunctionType.Getter && argumentNames.Count != 0)
throw new JavaScriptException(this.engine, "SyntaxError", "Getters cannot have arguments", this.LineNumber, this.SourcePath);
// Setters must have one argument.
if (functionType == FunctionType.Setter && argumentNames.Count != 1)
throw new JavaScriptException(this.engine, "SyntaxError", "Setters must have a single argument", this.LineNumber, this.SourcePath);
// Read the right parenthesis.
this.Expect(PunctuatorToken.RightParenthesis);
// Record the start of the function body.
var startPosition = this.PositionBeforeWhitespace;
// Since the parser reads one token in advance, start capturing the function body here.
var bodyTextBuilder = new System.Text.StringBuilder();
var originalBodyTextBuilder = this.lexer.InputCaptureStringBuilder;
this.lexer.InputCaptureStringBuilder = bodyTextBuilder;
// Read the start brace.
this.Expect(PunctuatorToken.LeftBrace);
// This context has a nested function.
this.methodOptimizationHints.HasNestedFunction = true;
// Create a new scope and assign variables within the function body to the scope.
bool includeNameInScope = functionType != FunctionType.Getter && functionType != FunctionType.Setter;
var scope = DeclarativeScope.CreateFunctionScope(parentScope, includeNameInScope ? functionName : string.Empty, argumentNames);
// Read the function body.
var functionParser = Parser.CreateFunctionBodyParser(this, scope);
var body = functionParser.Parse();
// Transfer state back from the function parser.
this.nextToken = functionParser.nextToken;
this.lexer.StrictMode = this.StrictMode;
this.lexer.InputCaptureStringBuilder = originalBodyTextBuilder;
if (originalBodyTextBuilder != null)
originalBodyTextBuilder.Append(bodyTextBuilder);
SourceCodePosition endPosition;
if (functionType == FunctionType.Expression)
{
// The end token '}' will be consumed by the parent function.
if (this.nextToken != PunctuatorToken.RightBrace)
throw new JavaScriptException(this.engine, "SyntaxError", "Expected '}'", this.LineNumber, this.SourcePath);
// Record the end of the function body.
endPosition = new SourceCodePosition(this.PositionAfterWhitespace.Line, this.PositionAfterWhitespace.Column + 1);
}
else
{
// Consume the '}'.
this.Expect(PunctuatorToken.RightBrace);
// Record the end of the function body.
endPosition = new SourceCodePosition(this.PositionAfterWhitespace.Line, this.PositionAfterWhitespace.Column + 1);
}
// Create a new function expression.
var options = this.options.Clone();
options.ForceStrictMode = functionParser.StrictMode;
var context = new FunctionMethodGenerator(this.engine, scope, functionName,
includeNameInScope, argumentNames,
bodyTextBuilder.ToString(0, bodyTextBuilder.Length - 1), body,
this.SourcePath, options);
context.MethodOptimizationHints = functionParser.methodOptimizationHints;
return new FunctionExpression(context);
}