valentina/src/libs/vpatterndb/calculator.cpp

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/************************************************************************
**
** @file calculator.cpp
** @author Roman Telezhynskyi <dismine(at)gmail.com>
** @date November 15, 2013
**
** @brief
** @copyright
** This source code is part of the Valentine project, a pattern making
** program, whose allow create and modeling patterns of clothing.
** Copyright (C) 2013-2015 Valentina project
** <https://bitbucket.org/dismine/valentina> All Rights Reserved.
**
** Valentina is free software: you can redistribute it and/or modify
** it under the terms of the GNU General Public License as published by
** the Free Software Foundation, either version 3 of the License, or
** (at your option) any later version.
**
** Valentina is distributed in the hope that it will be useful,
** but WITHOUT ANY WARRANTY; without even the implied warranty of
** MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
** GNU General Public License for more details.
**
** You should have received a copy of the GNU General Public License
** along with Valentina. If not, see <http://www.gnu.org/licenses/>.
**
*************************************************************************/
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#include "calculator.h"
#include <QStaticStringData>
#include <QStringData>
#include <QStringDataPtr>
#include <QStringList>
#include "../vmisc/def.h"
#include "../qmuparser/qmuparsererror.h"
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//---------------------------------------------------------------------------------------------------------------------
/**
* @brief Calculator class wraper for QMuParser. Make easy initialization math parser.
*
* This constructor hide initialization variables, operators, character sets.
* Use this constuctor for evaluation formula. All formulas must be converted to internal look.
* Example:
*
* const QString formula = qApp->FormulaFromUser(edit->text());
* Calculator *cal = new Calculator(data, patternType);
* const qreal result = cal->EvalFormula(data->PlainVariables(), formula);
* delete cal;
*
*/
Calculator::Calculator()
:QmuFormulaBase()
{
InitCharSets();
setAllowSubexpressions(false);//Only one expression per time
SetSepForEval();
}
//---------------------------------------------------------------------------------------------------------------------
/**
* @brief eval calculate formula.
*
* First we try eval expression without adding variables. If it fail, we take tokens from expression and add variables
* to parser and try again.
*
* @param formula string of formula.
* @return value of formula.
*/
qreal Calculator::EvalFormula(const QHash<QString, qreal *> &vars, const QString &formula)
{
// Parser doesn't know any variable on this stage. So, we just use variable factory that for each unknown variable
// set value to 0.
SetVarFactory(AddVariable, this);
SetSepForEval();//Reset separators options
SetExpr(formula);
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qreal result = 0;
result = Eval();
QMap<int, QString> tokens = this->GetTokens();
// Remove "-" from tokens list if exist. If don't do that unary minus operation will broken.
RemoveAll(tokens, QStringLiteral("-"));
for (int i = 0; i < builInFunctions.size(); ++i)
{
if (tokens.isEmpty())
{
break;
}
RemoveAll(tokens, builInFunctions.at(i));
}
if (tokens.isEmpty())
{
return result; // We have found only numbers in expression.
}
// Add variables to parser because we have deal with expression with variables.
InitVariables(vars, tokens, formula);
return Eval();
}
//---------------------------------------------------------------------------------------------------------------------
/**
* @brief Calculator::InitVariables add variables to parser.
*
* For optimization purpose we try don't add variables that we don't need.
*
* @param vars list of variables.
* @param tokens all tokens (measurements names, variables with lengths) that parser have found in expression.
* @param formula expression, need for throwing better error message.
*/
void Calculator::InitVariables(const QHash<QString, qreal *> &vars, const QMap<int, QString> &tokens,
const QString &formula)
{
QMap<int, QString>::const_iterator i = tokens.constBegin();
while (i != tokens.constEnd())
{
bool found = false;
if (vars.contains(i.value()))
{
DefineVar(i.value(), vars.value(i.value()));
found = true;
}
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if (found == false && builInFunctions.contains(i.value()))
{// We have found built-in function
found = true;
}
if (found == false)
{
throw qmu::QmuParserError (qmu::ecUNASSIGNABLE_TOKEN, i.value(), formula, i.key());
}
++i;
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}
}