/// <summary>
/// Creates a new FunctionMethodGenerator instance.
/// </summary>
/// <param name="scope"> The function scope. </param>
/// <param name="functionName"> The name of the function. </param>
/// <param name="declarationType"> Indicates how the function was declared. </param>
/// <param name="arguments"> The names and default values of the arguments. </param>
/// <param name="bodyText"> The source code of the function. </param>
/// <param name="body"> The root of the abstract syntax tree for the body of the function. </param>
/// <param name="scriptPath"> The URL or file system path that the script was sourced from. </param>
/// <param name="span"> The extent of the function in the source code. </param>
/// <param name="options"> Options that influence the compiler. </param>
public FunctionMethodGenerator(DeclarativeScope scope, string functionName, FunctionDeclarationType declarationType,
IList <FunctionArgument> arguments, string bodyText, Statement body, string scriptPath, SourceCodeSpan span,
CompilerOptions options)
: base(scope, new DummyScriptSource(scriptPath), options)
{
this.Name = functionName;
this.DeclarationType = declarationType;
this.Arguments = arguments;
this.BodyRoot = body;
this.BodyText = bodyText;
Validate(span.StartLine, scriptPath);
}
/// <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);
}
