//---------------------------------------------------------------------------------------
// ParseLeftHandSideExpression
//
// LeftHandSideExpression :
// PrimaryExpression Accessor |
// 'new' LeftHandSideExpression |
// FunctionExpression
//
// PrimaryExpression :
// 'this' |
// Identifier |
// Literal |
// '(' Expression ')'
//
// FunctionExpression :
// 'function' OptionalFuncName '(' FormalParameterList ')' { FunctionBody }
//
// OptionalFuncName :
// <empty> |
// Identifier
//---------------------------------------------------------------------------------------
private AstNode ParseLeftHandSideExpression(bool isMinus)
{
AstNode ast = null;
bool isFunction = false;
List<Context> newContexts = null;
TryItAgain:
// new expression
while (JSToken.New == m_currentToken.Token)
{
if (null == newContexts)
newContexts = new List<Context>(4);
newContexts.Add(m_currentToken.Clone());
GetNextToken();
}
JSToken token = m_currentToken.Token;
switch (token)
{
// primary expression
case JSToken.Identifier:
ast = new Lookup(m_scanner.GetIdentifier(), m_currentToken.Clone(), this);
break;
case JSToken.ConditionalCommentStart:
// skip past the start to the next token
GetNextToken();
if (m_currentToken.Token == JSToken.PreprocessorConstant)
{
// we have /*@id
ast = new ConstantWrapperPP(m_currentToken.Code, true, m_currentToken.Clone(), this);
GetNextToken();
if (m_currentToken.Token == JSToken.ConditionalCommentEnd)
{
// skip past the closing comment
GetNextToken();
}
else
{
// we ONLY support /*@id@*/ in expressions right now. If there's not
// a closing comment after the ID, then we don't support it.
// throw an error, skip to the end of the comment, then ignore it and start
// looking for the next token.
m_currentToken.HandleError(JSError.ConditionalCompilationTooComplex);
// skip to end of conditional comment
while (m_currentToken.Token != JSToken.EndOfFile && m_currentToken.Token != JSToken.ConditionalCommentEnd)
{
GetNextToken();
}
GetNextToken();
goto TryItAgain;
}
}
else if (m_currentToken.Token == JSToken.ConditionalCommentEnd)
{
// empty conditional comment! Ignore.
GetNextToken();
goto TryItAgain;
}
else
{
// we DON'T have "/*@IDENT". We only support "/*@IDENT @*/", so since this isn't
// and id, throw the error, skip to the end of the comment, and ignore it
// by looping back and looking for the NEXT token.
m_currentToken.HandleError(JSError.ConditionalCompilationTooComplex);
// skip to end of conditional comment
while (m_currentToken.Token != JSToken.EndOfFile && m_currentToken.Token != JSToken.ConditionalCommentEnd)
{
GetNextToken();
}
GetNextToken();
goto TryItAgain;
}
break;
case JSToken.This:
ast = new ThisLiteral(m_currentToken.Clone(), this);
break;
case JSToken.StringLiteral:
ast = new ConstantWrapper(m_scanner.StringLiteral, PrimitiveType.String, m_currentToken.Clone(), this);
break;
case JSToken.IntegerLiteral:
case JSToken.NumericLiteral:
{
Context numericContext = m_currentToken.Clone();
double doubleValue;
if (ConvertNumericLiteralToDouble(m_currentToken.Code, (token == JSToken.IntegerLiteral), out doubleValue))
{
// conversion worked fine
// check for some boundary conditions
if (doubleValue == double.MaxValue)
{
ReportError(JSError.NumericMaximum, numericContext, true);
}
else if (isMinus && -doubleValue == double.MinValue)
{
ReportError(JSError.NumericMinimum, numericContext, true);
}
// create the constant wrapper from the value
ast = new ConstantWrapper(doubleValue, PrimitiveType.Number, numericContext, this);
}
else
{
// check to see if we went overflow
if (double.IsInfinity(doubleValue))
{
ReportError(JSError.NumericOverflow, numericContext, true);
}
// regardless, we're going to create a special constant wrapper
// that simply echos the input as-is
ast = new ConstantWrapper(m_currentToken.Code, PrimitiveType.Other, numericContext, this);
}
break;
}
case JSToken.True:
ast = new ConstantWrapper(true, PrimitiveType.Boolean, m_currentToken.Clone(), this);
break;
case JSToken.False:
ast = new ConstantWrapper(false, PrimitiveType.Boolean, m_currentToken.Clone(), this);
break;
case JSToken.Null:
ast = new ConstantWrapper(null, PrimitiveType.Null, m_currentToken.Clone(), this);
break;
case JSToken.PreprocessorConstant:
ast = new ConstantWrapperPP(m_currentToken.Code, false, m_currentToken.Clone(), this);
break;
case JSToken.DivideAssign:
// normally this token is not allowed on the left-hand side of an expression.
// BUT, this might be the start of a regular expression that begins with an equals sign!
// we need to test to see if we can parse a regular expression, and if not, THEN
// we can fail the parse.
case JSToken.Divide:
// could it be a regexp?
String source = m_scanner.ScanRegExp();
if (source != null)
{
// parse the flags (if any)
String flags = m_scanner.ScanRegExpFlags();
// create the literal
ast = new RegExpLiteral(source, flags, m_currentToken.Clone(), this);
break;
}
goto default;
// expression
case JSToken.LeftParenthesis:
{
// save the current context reference
Context openParenContext = m_currentToken.Clone();
GetNextToken();
m_noSkipTokenSet.Add(NoSkipTokenSet.s_ParenExpressionNoSkipToken);
try
{
// parse an expression
ast = ParseExpression();
// update the expression's context with the context of the open paren
ast.Context.UpdateWith(openParenContext);
if (JSToken.RightParenthesis != m_currentToken.Token)
{
ReportError(JSError.NoRightParenthesis);
}
else
{
// add the closing paren to the expression context
ast.Context.UpdateWith(m_currentToken);
}
}
catch (RecoveryTokenException exc)
{
if (IndexOfToken(NoSkipTokenSet.s_ParenExpressionNoSkipToken, exc) == -1)
throw;
else
ast = exc._partiallyComputedNode;
}
finally
{
m_noSkipTokenSet.Remove(NoSkipTokenSet.s_ParenExpressionNoSkipToken);
}
if (ast == null) //this can only happen when catching the exception and nothing was sent up by the caller
SkipTokensAndThrow();
}
break;
// array initializer
case JSToken.LeftBracket:
Context listCtx = m_currentToken.Clone();
AstNodeList list = new AstNodeList(m_currentToken.Clone(), this);
GetNextToken();
while (JSToken.RightBracket != m_currentToken.Token)
{
if (JSToken.Comma != m_currentToken.Token)
{
m_noSkipTokenSet.Add(NoSkipTokenSet.s_ArrayInitNoSkipTokenSet);
try
{
list.Append(ParseExpression(true));
if (JSToken.Comma != m_currentToken.Token)
{
if (JSToken.RightBracket != m_currentToken.Token)
ReportError(JSError.NoRightBracket);
break;
}
else
{
// we have a comma -- skip it
GetNextToken();
// if the next token is the closing brackets, then we need to
// add a missing value to the array because we end in a comma and
// we need to keep it for cross-platform compat.
// TECHNICALLY, that puts an extra item into the array for most modern browsers, but not ALL.
if (m_currentToken.Token == JSToken.RightBracket)
{
list.Append(new ConstantWrapper(Missing.Value, PrimitiveType.Other, m_currentToken.Clone(), this));
}
}
}
catch (RecoveryTokenException exc)
{
if (exc._partiallyComputedNode != null)
list.Append(exc._partiallyComputedNode);
if (IndexOfToken(NoSkipTokenSet.s_ArrayInitNoSkipTokenSet, exc) == -1)
{
listCtx.UpdateWith(CurrentPositionContext());
exc._partiallyComputedNode = new ArrayLiteral(listCtx, this, list);
throw;
}
else
{
if (JSToken.RightBracket == m_currentToken.Token)
break;
}
}
finally
{
m_noSkipTokenSet.Remove(NoSkipTokenSet.s_ArrayInitNoSkipTokenSet);
}
}
else
{
// comma -- missing array item in the list
list.Append(new ConstantWrapper(Missing.Value, PrimitiveType.Other, m_currentToken.Clone(), this));
// skip over the comma
GetNextToken();
// if the next token is the closing brace, then we end with a comma -- and we need to
// add ANOTHER missing value to make sure this last comma doesn't get left off.
// TECHNICALLY, that puts an extra item into the array for most modern browsers, but not ALL.
if (m_currentToken.Token == JSToken.RightBracket)
{
list.Append(new ConstantWrapper(Missing.Value, PrimitiveType.Other, m_currentToken.Clone(), this));
}
}
}
listCtx.UpdateWith(m_currentToken);
ast = new ArrayLiteral(listCtx, this, list);
break;
// object initializer
case JSToken.LeftCurly:
Context objCtx = m_currentToken.Clone();
GetNextToken();
// we're going to keep the keys and values in separate lists, but make sure
// that the indexes correlate (keyList[n] is associated with valueList[n])
List<ObjectLiteralField> keyList = new List<ObjectLiteralField>();
List<AstNode> valueList = new List<AstNode>();
if (JSToken.RightCurly != m_currentToken.Token)
{
for (; ; )
{
ObjectLiteralField field = null;
AstNode value = null;
bool getterSetter = false;
string ident;
switch (m_currentToken.Token)
{
case JSToken.Identifier:
field = new ObjectLiteralField(m_scanner.GetIdentifier(), PrimitiveType.String, m_currentToken.Clone(), this);
break;
case JSToken.StringLiteral:
field = new ObjectLiteralField(m_scanner.StringLiteral, PrimitiveType.String, m_currentToken.Clone(), this);
break;
case JSToken.IntegerLiteral:
case JSToken.NumericLiteral:
{
double doubleValue;
if (ConvertNumericLiteralToDouble(m_currentToken.Code, (m_currentToken.Token == JSToken.IntegerLiteral), out doubleValue))
{
// conversion worked fine
field = new ObjectLiteralField(
doubleValue,
PrimitiveType.Number,
m_currentToken.Clone(),
this
);
}
else
{
// something went wrong and we're not sure the string representation in the source is
// going to convert to a numeric value well
if (double.IsInfinity(doubleValue))
{
ReportError(JSError.NumericOverflow, m_currentToken.Clone(), true);
}
// use the source as the field name, not the numeric value
field = new ObjectLiteralField(
m_currentToken.Code,
PrimitiveType.Other,
m_currentToken.Clone(),
this);
}
break;
}
case JSToken.Get:
case JSToken.Set:
if (m_scanner.PeekToken() == JSToken.Colon)
{
// the field is either "get" or "set" and isn't the special Mozilla getter/setter
field = new ObjectLiteralField(m_currentToken.Code, PrimitiveType.String, m_currentToken.Clone(), this);
}
else
{
// ecma-script get/set property construct
getterSetter = true;
bool isGet = (m_currentToken.Token == JSToken.Get);
value = ParseFunction(
(JSToken.Get == m_currentToken.Token ? FunctionType.Getter : FunctionType.Setter),
m_currentToken.Clone()
);
FunctionObject funcExpr = value as FunctionObject;
if (funcExpr != null)
{
// getter/setter is just the literal name with a get/set flag
field = new GetterSetter(
funcExpr.Name,
isGet,
funcExpr.IdContext.Clone(),
this
);
}
else
{
ReportError(JSError.FunctionExpressionExpected);
}
}
break;
default:
// NOT: identifier, string, number, or getter/setter.
// see if it's a token that COULD be an identifier.
ident = JSKeyword.CanBeIdentifier(m_currentToken.Token);
if (ident != null)
{
// don't throw a warning -- it's okay to have a keyword that
// can be an identifier here.
field = new ObjectLiteralField(ident, PrimitiveType.String, m_currentToken.Clone(), this);
}
else
{
ReportError(JSError.NoMemberIdentifier);
field = new ObjectLiteralField("_#Missing_Field#_" + s_cDummyName++, PrimitiveType.String, CurrentPositionContext(), this);
}
break;
}
if (field != null)
{
if (!getterSetter)
{
GetNextToken();
}
m_noSkipTokenSet.Add(NoSkipTokenSet.s_ObjectInitNoSkipTokenSet);
try
{
if (!getterSetter)
{
// get the value
if (JSToken.Colon != m_currentToken.Token)
{
ReportError(JSError.NoColon, true);
value = ParseExpression(true);
}
else
{
GetNextToken();
value = ParseExpression(true);
}
}
// put the pair into the list of fields
keyList.Add(field);
valueList.Add(value);
if (JSToken.RightCurly == m_currentToken.Token)
break;
else
{
if (JSToken.Comma == m_currentToken.Token)
{
// skip the comma
GetNextToken();
// if the next token is the right-curly brace, then we ended
// the list with a comma, which is perfectly fine
if (m_currentToken.Token == JSToken.RightCurly)
{
break;
}
}
else
{
if (m_scanner.GotEndOfLine)
{
ReportError(JSError.NoRightCurly);
}
else
ReportError(JSError.NoComma, true);
SkipTokensAndThrow();
}
}
}
catch (RecoveryTokenException exc)
{
if (exc._partiallyComputedNode != null)
{
// the problem was in ParseExpression trying to determine value
value = exc._partiallyComputedNode;
keyList.Add(field);
valueList.Add(value);
}
if (IndexOfToken(NoSkipTokenSet.s_ObjectInitNoSkipTokenSet, exc) == -1)
{
exc._partiallyComputedNode = new ObjectLiteral(objCtx, this, keyList.ToArray(), valueList.ToArray());
throw;
}
else
{
if (JSToken.Comma == m_currentToken.Token)
GetNextToken();
if (JSToken.RightCurly == m_currentToken.Token)
break;
}
}
finally
{
m_noSkipTokenSet.Remove(NoSkipTokenSet.s_ObjectInitNoSkipTokenSet);
}
}
}
}
objCtx.UpdateWith(m_currentToken);
ast = new ObjectLiteral(objCtx, this, keyList.ToArray(), valueList.ToArray());
break;
// function expression
case JSToken.Function:
ast = ParseFunction(FunctionType.Expression, m_currentToken.Clone());
isFunction = true;
break;
case JSToken.AspNetBlock:
ast = ParseAspNetBlock(consumeSemicolonIfPossible: false);
break;
default:
string identifier = JSKeyword.CanBeIdentifier(m_currentToken.Token);
if (null != identifier)
{
ast = new Lookup(identifier, m_currentToken.Clone(), this);
}
else
{
ReportError(JSError.ExpressionExpected);
SkipTokensAndThrow();
}
break;
}
// can be a CallExpression, that is, followed by '.' or '(' or '['
if (!isFunction)
GetNextToken();
return MemberExpression(ast, newContexts);
}
public void Visit(ThisLiteral node)
{
ReportError(node);
}
public override void Visit(ThisLiteral node)
{
// we're going to look for the first FunctionScope on the stack
FunctionScope functionScope = null;
// get the current scope
ActivationObject activationObject = ScopeStack.Peek();
do
{
functionScope = activationObject as FunctionScope;
if (functionScope != null)
{
// found it -- break out of the loop
break;
}
// otherwise go up the chain
activationObject = activationObject.Parent;
} while (activationObject != null);
// if we found one....
if (functionScope != null)
{
// add this object to the list of thisliterals
functionScope.AddThisLiteral(node);
}
}
public void Visit(ThisLiteral node)
{
// invalid! ignore
IsValid = false;
}
public void Visit(ThisLiteral node)
{
// this literal, so we don't care
}
internal void AddThisLiteral(ThisLiteral thisLiteral)
{
if (m_thisLiterals == null)
{
m_thisLiterals = new List<ThisLiteral>();
}
m_thisLiterals.Add(thisLiteral);
}
public void Visit(ThisLiteral node)
{
// we're good
}
public override void Visit(ThisLiteral node)
{
// same logic for most nodes
TypicalHandler(node);
}