connectivity/source/inc/RowFunctionParser.hxx

   1 /* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
   2 /*
   3  * This file is part of the LibreOffice project.
   4  *
   5  * This Source Code Form is subject to the terms of the Mozilla Public
   6  * License, v. 2.0. If a copy of the MPL was not distributed with this
   7  * file, You can obtain one at http://mozilla.org/MPL/2.0/.
   8  *
   9  * This file incorporates work covered by the following license notice:
  10  *
  11  *   Licensed to the Apache Software Foundation (ASF) under one or more
  12  *   contributor license agreements. See the NOTICE file distributed
  13  *   with this work for additional information regarding copyright
  14  *   ownership. The ASF licenses this file to you under the Apache
  15  *   License, Version 2.0 (the "License"); you may not use this file
  16  *   except in compliance with the License. You may obtain a copy of
  17  *   the License at http://www.apache.org/licenses/LICENSE-2.0 .
  18  */
  19
  20 #pragma once
  21
  22 #include <sal/config.h>
  23 #include "FDatabaseMetaDataResultSet.hxx"
  24 #include <connectivity/dbtoolsdllapi.hxx>
  25 #include <memory>
  26
  27 namespace connectivity
  28 {
  29 enum class ExpressionFunct
  30 {
  31     Equation,
  32     And,
  33     Or
  34 };
  35
  36 #define EXPRESSION_FLAG_SUMANGLE_MODE 1
  37
  38 class OOO_DLLPUBLIC_DBTOOLS SAL_NO_VTABLE ExpressionNode
  39 {
  40 public:
  41     virtual ~ExpressionNode() {}
  42
  43     /** Operator to calculate function value.
  44
  45         This method calculates the function value.
  46     */
  47     virtual ORowSetValueDecoratorRef
  48     evaluate(const ODatabaseMetaDataResultSet::ORow& _aRow) const = 0;
  49
  50     virtual void fill(const ODatabaseMetaDataResultSet::ORow& _aRow) const = 0;
  51 };
  52
  53 /** This exception is thrown, when the arithmetic expression
  54     parser failed to parse a string.
  55     */
  56 struct OOO_DLLPUBLIC_DBTOOLS ParseError
  57 {
  58     ParseError(const char*) {}
  59 };
  60
  61 class FunctionParser
  62 {
  63 public:
  64     /** Parse a string
  65
  66         The following grammar is accepted by this method:
  67         <code>
  68
  69         number_digit = '0'|'1'|'2'|'3'|'4'|'5'|'6'|'7'|'8'|'9'
  70
  71         number = number number_digit | number_digit
  72
  73         equal_function = '='
  74         ternary_function = 'if'
  75
  76         string_reference = 'a-z,A-Z,0-9' ' '
  77         modifier_reference = '$' '0-9' ' '
  78
  79         basic_expression =
  80             number |
  81             string_reference |
  82             additive_expression equal_function additive_expression |
  83             unary_function '(' number_digit ')'
  84             ternary_function '(' additive_expression ',' additive_expression ',
  85                                ' additive_expression ')' | '(' additive_expression ')'
  86
  87         </code>
  88
  89         @param rFunction
  90         The string to parse
  91
  92         @throws ParseError if an invalid expression is given.
  93
  94         @return the generated function object.
  95        */
  96
  97     static std::shared_ptr<ExpressionNode> const& parseFunction(const OUString& _sFunction);
  98
  99 private:
 100     // disabled constructor/destructor, since this is
 101     // supposed to be a singleton
 102     FunctionParser() = delete;
 103     FunctionParser(const FunctionParser&) = delete;
 104     FunctionParser& operator=(const FunctionParser&) = delete;
 105 };
 106
 107 } // namespace connectivity
 108
 109 /* vim:set shiftwidth=4 softtabstop=4 expandtab: */