AOO410/main/connectivity/source/inc/RowFunctionParser.hxx

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 * 
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 * 
 *   http://www.apache.org/licenses/LICENSE-2.0
 * 
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 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 * 
 *************************************************************/



#ifndef CONNECTIVITY_ROWFUNCTIONPARSER_HXX_INCLUDED
#define CONNECTIVITY_ROWFUNCTIONPARSER_HXX_INCLUDED

#include <sal/config.h>
#ifndef BOOST_SHARED_PTR_HPP_INCLUDED
#include <boost/shared_ptr.hpp>
#endif
#include "FDatabaseMetaDataResultSet.hxx"
#include <vector>
#include "connectivity/dbtoolsdllapi.hxx"

// -------------------------------------------------------------------------
namespace connectivity
{
// -------------------------------------------------------------------------
struct OOO_DLLPUBLIC_DBTOOLS RowEquation
{
	sal_Int32	nOperation;
	ORowSetValueDecoratorRef	nPara[ 3 ];

	RowEquation() :
		nOperation	( 0 )
		{
		}
};

enum ExpressionFunct
{
	FUNC_CONST,

	ENUM_FUNC_EQUATION,

    UNARY_FUNC_COLUMN,
    ENUM_FUNC_AND,
    ENUM_FUNC_OR
};

#define EXPRESSION_FLAG_SUMANGLE_MODE 1

class OOO_DLLPUBLIC_DBTOOLS SAL_NO_VTABLE ExpressionNode
{
public:
    virtual ~ExpressionNode(){}

    /** Operator to calculate function value.

        This method calculates the function value.
	*/
    virtual ORowSetValueDecoratorRef evaluate(const ODatabaseMetaDataResultSet::ORow& _aRow ) const = 0;

    virtual void fill(const ODatabaseMetaDataResultSet::ORow& _aRow ) const = 0;

	/** Operator to retrieve the type of expression node
	*/
	virtual ExpressionFunct getType() const = 0;

	/** Operator to retrieve the ms version of expression
	*/
	virtual ODatabaseMetaDataResultSet::ORow fillNode(
		std::vector< RowEquation >& rEquations, ExpressionNode* pOptionalArg, sal_uInt32 nFlags ) = 0;
};
typedef ::boost::shared_ptr< ExpressionNode > ExpressionNodeSharedPtr;

/** This exception is thrown, when the arithmetic expression
    parser failed to parse a string.
    */
struct OOO_DLLPUBLIC_DBTOOLS ParseError
{
    ParseError() {}
    ParseError( const char* ) {}
};

class OOO_DLLPUBLIC_DBTOOLS FunctionParser
{
public:

    /** Parse a string
        
        The following grammar is accepted by this method:
        <code>
		
		number_digit = '0'|'1'|'2'|'3'|'4'|'5'|'6'|'7'|'8'|'9'

		number = number number_digit | number_digit

		equal_function = '='
		ternary_function = 'if'

		string_reference = 'a-z,A-Z,0-9' ' '
		modifier_reference = '$' '0-9' ' '
					  
		basic_expression = 
			number |
            string_reference |
            additive_expression equal_function additive_expression |
            unary_function '(' number_digit ')'
			ternary_function '(' additive_expression ',' additive_expression ',
					           ' additive_expression ')' | '(' additive_expression ')'

        </code> 

        @param rFunction
        The string to parse

        @throws ParseError if an invalid expression is given.

        @return the generated function object.
       */

    static ExpressionNodeSharedPtr parseFunction( const ::rtl::OUString& _sFunction);

private:
    // disabled constructor/destructor, since this is 
    // supposed to be a singleton
    FunctionParser();

    // default: disabled copy/assignment
    FunctionParser(const FunctionParser&);
    FunctionParser& operator=( const FunctionParser& );
};

// -------------------------------------------------------------------------
} // namespace connectivity
// -------------------------------------------------------------------------
#endif /* CONNECTIVITY_ROWFUNCTIONPARSER_HXX_INCLUDED */