コード例 #1
0
ファイル: jsparser.cs プロジェクト: nuxleus/ajaxmin
        //---------------------------------------------------------------------------------------
        // ParseSwitchStatement
        //
        //  SwitchStatement :
        //    'switch' '(' Expression ')' '{' CaseBlock '}'
        //
        //  CaseBlock :
        //    CaseList DefaultCaseClause CaseList
        //
        //  CaseList :
        //    <empty> |
        //    CaseClause CaseList
        //
        //  CaseClause :
        //    'case' Expression ':' OptionalStatements
        //
        //  DefaultCaseClause :
        //    <empty> |
        //    'default' ':' OptionalStatements
        //---------------------------------------------------------------------------------------
        private AstNode ParseSwitchStatement()
        {
            Context switchCtx = m_currentToken.Clone();
            AstNode expr = null;
            AstNodeList cases = null;
            m_blockType.Add(BlockType.Switch);
            try
            {
                // read switch(expr)
                GetNextToken();
                if (JSToken.LeftParenthesis != m_currentToken.Token)
                    ReportError(JSError.NoLeftParenthesis);
                GetNextToken();
                m_noSkipTokenSet.Add(NoSkipTokenSet.s_BlockConditionNoSkipTokenSet);
                m_noSkipTokenSet.Add(NoSkipTokenSet.s_SwitchNoSkipTokenSet);
                try
                {
                    expr = ParseExpression();

                    if (JSToken.RightParenthesis != m_currentToken.Token)
                    {
                        ReportError(JSError.NoRightParenthesis);
                    }

                    GetNextToken();
                    if (JSToken.LeftCurly != m_currentToken.Token)
                    {
                        ReportError(JSError.NoLeftCurly);
                    }
                    GetNextToken();

                }
                catch (RecoveryTokenException exc)
                {
                    if (IndexOfToken(NoSkipTokenSet.s_BlockConditionNoSkipTokenSet, exc) == -1
                          && IndexOfToken(NoSkipTokenSet.s_SwitchNoSkipTokenSet, exc) == -1)
                    {
                        // give up
                        exc._partiallyComputedNode = null;
                        throw;
                    }
                    else
                    {
                        if (exc._partiallyComputedNode == null)
                            expr = new ConstantWrapper(true, PrimitiveType.Boolean, CurrentPositionContext(), this);
                        else
                            expr = exc._partiallyComputedNode;

                        if (IndexOfToken(NoSkipTokenSet.s_BlockConditionNoSkipTokenSet, exc) != -1)
                        {
                            if (exc._token == JSToken.RightParenthesis)
                                GetNextToken();

                            if (JSToken.LeftCurly != m_currentToken.Token)
                            {
                                ReportError(JSError.NoLeftCurly);
                            }
                            GetNextToken();
                        }

                    }
                }
                finally
                {
                    m_noSkipTokenSet.Remove(NoSkipTokenSet.s_SwitchNoSkipTokenSet);
                    m_noSkipTokenSet.Remove(NoSkipTokenSet.s_BlockConditionNoSkipTokenSet);
                }

                // parse the switch body
                cases = new AstNodeList(m_currentToken.Clone(), this);
                bool defaultStatement = false;
                m_noSkipTokenSet.Add(NoSkipTokenSet.s_BlockNoSkipTokenSet);
                try
                {
                    while (JSToken.RightCurly != m_currentToken.Token)
                    {
                        SwitchCase caseClause = null;
                        AstNode caseValue = null;
                        Context caseCtx = m_currentToken.Clone();
                        m_noSkipTokenSet.Add(NoSkipTokenSet.s_CaseNoSkipTokenSet);
                        try
                        {
                            if (JSToken.Case == m_currentToken.Token)
                            {
                                // get the case
                                GetNextToken();
                                caseValue = ParseExpression();
                            }
                            else if (JSToken.Default == m_currentToken.Token)
                            {
                                // get the default
                                if (defaultStatement)
                                {
                                    // we report an error but we still accept the default
                                    ReportError(JSError.DupDefault, true);
                                }
                                else
                                {
                                    defaultStatement = true;
                                }
                                GetNextToken();
                            }
                            else
                            {
                                // This is an error, there is no case or default. Assume a default was missing and keep going
                                defaultStatement = true;
                                ReportError(JSError.BadSwitch);
                            }
                            if (JSToken.Colon != m_currentToken.Token)
                            {
                                ReportError(JSError.NoColon);
                            }

                            // read the statements inside the case or default
                            GetNextToken();
                        }
                        catch (RecoveryTokenException exc)
                        {
                            // right now we can only get here for the 'case' statement
                            if (IndexOfToken(NoSkipTokenSet.s_CaseNoSkipTokenSet, exc) == -1)
                            {
                                // ignore the current case or default
                                exc._partiallyComputedNode = null;
                                throw;
                            }
                            else
                            {
                                caseValue = exc._partiallyComputedNode;

                                if (exc._token == JSToken.Colon)
                                {
                                    GetNextToken();
                                }
                            }
                        }
                        finally
                        {
                            m_noSkipTokenSet.Remove(NoSkipTokenSet.s_CaseNoSkipTokenSet);
                        }

                        m_blockType.Add(BlockType.Block);
                        try
                        {
                            Block statements = new Block(m_currentToken.Clone(), this);
                            m_noSkipTokenSet.Add(NoSkipTokenSet.s_SwitchNoSkipTokenSet);
                            m_noSkipTokenSet.Add(NoSkipTokenSet.s_StartStatementNoSkipTokenSet);
                            try
                            {
                                while (JSToken.RightCurly != m_currentToken.Token && JSToken.Case != m_currentToken.Token && JSToken.Default != m_currentToken.Token)
                                {
                                    try
                                    {
                                        // parse a Statement, not a SourceElement
                                        statements.Append(ParseStatement(false));
                                    }
                                    catch (RecoveryTokenException exc)
                                    {
                                        if (exc._partiallyComputedNode != null)
                                        {
                                            statements.Append(exc._partiallyComputedNode);
                                            exc._partiallyComputedNode = null;
                                        }
                                        if (IndexOfToken(NoSkipTokenSet.s_StartStatementNoSkipTokenSet, exc) == -1)
                                        {
                                            throw;
                                        }
                                    }
                                }
                            }
                            catch (RecoveryTokenException exc)
                            {
                                if (IndexOfToken(NoSkipTokenSet.s_SwitchNoSkipTokenSet, exc) == -1)
                                {
                                    caseClause = new SwitchCase(caseCtx, this, caseValue, statements);
                                    cases.Append(caseClause);
                                    throw;
                                }
                            }
                            finally
                            {
                                m_noSkipTokenSet.Remove(NoSkipTokenSet.s_StartStatementNoSkipTokenSet);
                                m_noSkipTokenSet.Remove(NoSkipTokenSet.s_SwitchNoSkipTokenSet);
                            }
                            if (JSToken.RightCurly == m_currentToken.Token)
                            {
                                statements.Context.UpdateWith(m_currentToken);
                            }
                            caseCtx.UpdateWith(statements.Context);
                            caseClause = new SwitchCase(caseCtx, this, caseValue, statements);
                            cases.Append(caseClause);
                        }
                        finally
                        {
                            m_blockType.RemoveAt(m_blockType.Count - 1);
                        }
                    }
                }
                catch (RecoveryTokenException exc)
                {
                    if (IndexOfToken(NoSkipTokenSet.s_BlockNoSkipTokenSet, exc) == -1)
                    {
                        //save what you can a rethrow
                        switchCtx.UpdateWith(CurrentPositionContext());
                        exc._partiallyComputedNode = new Switch(switchCtx, this, expr, cases);
                        throw;
                    }
                }
                finally
                {
                    m_noSkipTokenSet.Remove(NoSkipTokenSet.s_BlockNoSkipTokenSet);
                }
                switchCtx.UpdateWith(m_currentToken);
                GetNextToken();
            }
            finally
            {
                m_blockType.RemoveAt(m_blockType.Count - 1);
            }

            return new Switch(switchCtx, this, expr, cases);
        }