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koffice/kspread/formula.h

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/* This file is part of the KDE project
Copyright (C) 2003,2004 Ariya Hidayat <ariya@kde.org>
This library is free software; you can redistribute it and/or
modify it under the terms of the GNU Library General Public
License as published by the Free Software Foundation; either
version 2 of the License.
This library 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
Library General Public License for more details.
You should have received a copy of the GNU Library General Public License
along with this library; see the file COPYING.LIB. If not, write to
the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
* Boston, MA 02110-1301, USA.
*/
#ifndef KSPREAD_FORMULA
#define KSPREAD_FORMULA
#include <tqstring.h>
#include <tqvaluevector.h>
class KLocale;
namespace KSpread
{
class Cell;
class Sheet;
class Value;
/**
* Token
*/
class Token
{
public:
/**
* token types
*/
enum Type
{
Unknown = 0, ///< unknown type
Boolean, ///< True, False (also i18n-ized)
Integer, ///< 14, 3, 1977
Float, ///< 3.141592, 1e10, 5.9e-7
String, ///< "KOffice", "The quick brown fox..."
Operator, ///< +, *, /, -
Cell, ///< $A$1, F4, Sheet2!B5, 'Sales Forecast'!Sum
Range, ///< C1:C100
Identifier ///< function name or named area
};
/**
* operator types
*/
enum Op
{
InvalidOp = 0, ///< invalid operator
Plus, ///< + (addition)
Minus, ///< - (substraction, negation)
Asterisk, ///< * (multiplication)
Slash, ///< / (division)
Caret, ///< ^ (power)
LeftPar, ///< (
RightPar, ///< )
Comma, ///< ,
Semicolon, ///< ; (argument separator)
Ampersand, ///< & (string concat)
Equal, ///< =
NotEqual, ///< <>
Less, ///< <
Greater, ///< >
LessEqual, ///< <=
GreaterEqual, ///< >=
Percent ///< %
};
/**
* Creates a token.
*/
Token( Type type = Unknown, const TQString& text = TQString(), int pos = -1 );
static const Token null;
Token( const Token& );
Token& operator=( const Token& );
/**
* Returns type of the token.
*/
Type type() const { return m_type; }
/**
* Returns text associated with the token.
*
* If you want to obtain meaningful value of this token, instead of
* text(), you might use asInteger(), asFloat(), asString(), sheetName(),
* etc.
*/
TQString text() const { return m_text; }
int pos() const { return m_pos; };
/**
* Returns true if token is a boolean token.
*/
bool isBoolean() const { return m_type == Boolean; }
/**
* Returns true if token is a integer token.
*/
bool isInteger() const { return m_type == Integer; }
/**
* Returns true if token is a floating-point token.
*/
bool isFloat() const { return m_type == Float; }
/**
* Returns true if token is either integer or floating-point token.
*/
bool isNumber() const { return (m_type == Integer) || (m_type == Float); }
/**
* Returns true if token is a string token.
*/
bool isString() const { return m_type == String; }
/**
* Returns true if token is an operator token.
*/
bool isOperator() const { return m_type == Operator; }
/**
* Returns true if token is a cell reference token.
*/
bool isCell() const { return m_type == Cell; }
/**
* Returns true if token is a range reference token.
*/
bool isRange() const { return m_type == Range; }
/**
* Returns true if token is an identifier.
*/
bool isIdentifier() const { return m_type == Identifier; }
/**
* Returns boolean value for an boolean token.
* For any other type of token, return value is undefined.
*/
bool asBoolean() const;
/**
* Returns integer value for an integer token.
* For any other type of token, returns 0.
*/
long asInteger() const;
/**
* Returns floating-point value for a floating-point token.
* For any other type of token, returns 0.0.
*/
double asFloat() const;
/**
* Returns string value for a string token.
* For any other type of token, it returns TQString().
*
* Note that token text for a string token still has leading and trailing
* double-quotes, i.e for "KOffice", text() return "KOffice"
* (with the quotes, 9 characters) while asString() only return KOffice
* (without quotes, 7 characters).
*/
TQString asString() const;
/**
* Returns operator value for an operator token.
* For any other type of token, returns Token::InvalidOp.
*/
Op asOperator() const;
/**
* Returns sheet name in a cell reference token.
* For any other type of token, it returns TQString().
*
* If the cell reference doesn't specify sheet name, an empty string
* is returned. As example, for "Sheet1!B3" , sheetName() returns
* "Sheet1" while for "A2" sheetName() returns "".
*
* When sheet name contains quotes (as if the name has spaces) like
* in "'Sales Forecast'!F4", sheetName() returns the name
* without the quotes, i.e "Sales Forecast" in this case.
*/
TQString sheetName() const;
/**
* Returns a short description of the token.
* Should be used only to assist debugging.
*/
TQString description() const;
protected:
Type m_type;
TQString m_text;
int m_pos;
};
/**
* Class Tokens represents array of tokens.
*
*/
class Tokens: public TQValueVector<Token>
{
public:
Tokens(): TQValueVector<Token>(), m_valid(true) {};
bool valid() const { return m_valid; }
void setValid( bool v ){ m_valid = v; }
protected:
bool m_valid;
};
/**
* Class Formula encapsulates a formula for a cell.
*
* A Formula is a equations which perform calculations on values in the cells
* and sheets. Every formula must start with an equal sign (=).
*
*
*/
class Formula
{
public:
/**
* Creates a formula. It must be owned by a sheet, and optionally sheet.
*/
Formula (Sheet *sheet, Cell *cell = 0);
/**
* Creates a formula that is not owned by any sheet.
* This might be useful in some cases.
*/
Formula();
/**
* Destroys the formula.
*/
~Formula();
/**
* Returns the cell which owns this formula.
*/
Sheet* sheet() const;
/**
* Returns the cell which owns this formula.
*/
Cell* cell() const;
/**
* Sets the expression for this formula.
*/
void setExpression( const TQString& expr );
/**
* Gets the expression of this formula.
*/
TQString expression() const;
/**
* Clears everything, makes as like a newly constructed formula.
*/
void clear();
/**
* Returns true if the specified expression is valid, i.e. it contains
* no parsing error.
* Empty formula (i.e. without expression) is always invalid.
*/
bool isValid() const;
/**
* Returns list of tokens associated with this formula. This has nothing to
* with the formula evaluation but might be useful, e.g. for syntax
* highlight or similar features.
* If the formula contains error, the returned tokens is invalid.
*/
Tokens tokens() const;
/**
* Evaluates the formula and returns the result.
*/
Value eval() const;
/**
* Given an expression, this function separates it into tokens.
* If the expression contains error (e.g. unknown operator, string no terminated)
* this function returns tokens which is not valid.
*/
Tokens scan( const TQString& expr, KLocale* locale = 0 ) const;
TQString dump() const;
protected:
void compile( const Tokens& tokens ) const;
/**
* helper function: return true for valid named area
*/
bool isNamedArea( const TQString& expr ) const;
private:
class Private;
Private *d;
// no copy or assign
Formula( const Formula& );
Formula& operator=( const Formula& );
};
/**
* Dumps the formula, should be used only to assist debugging.
*/
TQTextStream& operator<<( TQTextStream& ts, Formula formula );
/**
* helper function: return operator of given token text
* e.g. "*" yields Operator::Asterisk, and so on
*/
Token::Op matchOperator( const TQString& text );
/**
* helper function: return true for valid identifier character
*/
bool isIdentifier( TQChar ch );
} // namespace KSpread
#endif // KSPREAD_FORMULA