/// <summary>
/// Is a RuleReturnScope node candidate for the left-hand-side of an in expression?
/// </summary>
/// <param name="lhs">The RuleReturnScope node</param>
/// <param name="cached">The cached result of a former call to this method</param>
/// <returns>True if so, false otherwise</returns>
public bool IsLeftHandSideIn(RuleReturnScope lhs, ref bool? cached)
{
if (cached.HasValue)
{
return cached.Value;
}
bool result = IsLeftHandSideExpression(lhs) && (input.LA(1) == IN);
cached = result;
return result;
}
/// <summary>
/// Is a RuleReturnScope node candidate for the left-hand-side of an assignment expression?
/// </summary>
/// <param name="lhs">The RuleReturnScope node</param>
/// <param name="cached">The cached result of a former call to this method</param>
/// <returns>True if so, false otherwise</returns>
public bool IsLeftHandSideAssign(RuleReturnScope lhs, ref bool? cached)
{
if (cached.HasValue)
{
return cached.Value;
}
bool result;
if (IsLeftHandSideExpression(lhs))
{
switch (input.LA(1))
{
case ASSIGN:
case MULASS:
case DIVASS:
case MODASS:
case ADDASS:
case SUBASS:
case SHLASS:
case SHRASS:
case SHUASS:
case ANDASS:
case XORASS:
case ORASS:
result = true;
break;
default:
result = false;
break;
}
}
else
{
result = false;
}
cached = result;
return result;
}
/// <summary>
/// Is a RuleReturnScope node candidate a left-hand-side expression?
/// </summary>
/// <param name="lhs">The RuleReturnScope node</param>
/// <returns>True if so, false otherwise</returns>
private bool IsLeftHandSideExpression(RuleReturnScope lhs)
{
if (lhs.Tree == null) // e.g. during backtracking
{
return true;
}
else
{
switch (((ITree)lhs.Tree).Type)
{
// primaryExpression
case THIS:
case Identifier:
case NULL:
case TRUE:
case FALSE:
case DecimalLiteral:
case OctalIntegerLiteral:
case HexIntegerLiteral:
case StringLiteral:
case RegularExpressionLiteral:
case ARRAY:
case OBJECT:
case PAREXPR:
// functionExpression
case FUNCTION:
// newExpression
case NEW:
// leftHandSideExpression
case CALL:
case BYFIELD:
case BYINDEX:
return true;
default:
return false;
}
}
}
private bool isLeftHandSideIn(RuleReturnScope lhs, Object[] cached)
{
if (cached[0] != null)
{
return (bool)cached[0];
}
bool result = isLeftHandSideExpression(lhs) && (input.LA(1) == IN);
cached[0] = result;
return result;
}
private bool isLeftHandSideAssign(RuleReturnScope lhs, Object[] cached)
{
if (cached[0] != null)
{
return (bool)cached[0];
}
bool result;
if (isLeftHandSideExpression(lhs))
{
switch (input.LA(1))
{
case ASSIGN:
case MULASS:
case DIVASS:
case MODASS:
case ADDASS:
case SUBASS:
case SHLASS:
case SHRASS:
case SHUASS:
case ANDASS:
case XORASS:
case ORASS:
result = true;
break;
default:
result = false;
break;
}
}
else
{
result = false;
}
cached[0] = result;
return result;
}