mathexpression.h

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#pragma once
 
/*+
________________________________________________________________________
 
 (C) dGB Beheer B.V.; (LICENSE) http://opendtect.org/OpendTect_license.txt
 Author:        Kristofer Tingdahl
 Date:          10-12-1999
 RCS:           $Id$
________________________________________________________________________
 
-*/
 
#include "generalmod.h"
#include "bufstringset.h"
 
 
namespace Math
{
 
mExpClass(General) Expression
{
public:
 
    virtual double      getValue() const                = 0;
 
    virtual int         nrVariables() const;
    virtual const char* fullVariableExpression(int) const;
    virtual void        setVariableValue(int,double);
 
                        // recursive "out" or "this" excluded
    int                 nrUniqueVarNames() const
                        { return varnms_.size(); }
    const char*         uniqueVarName( int idx ) const
                        { return varnms_.get(idx).buf(); }
    int                 indexOfUnVarName( const char* nm ) const
                        { return varnms_.indexOf( nm ); }
    int                 firstOccurVarName(const char*) const;
 
    enum VarType        { Variable, Constant, Recursive };
    VarType             getType(int varidx) const;
    int                 getConstIdx(int varidx) const;
 
    bool                isRecursive() const
                        { return isrecursive_; }
 
    virtual Expression* clone() const = 0;
 
    virtual             ~Expression();
 
    const char*         type() const;
    void                dump( BufferString& str ) const { doDump(str,0); }
 
protected:
 
                        Expression(int nrinputs);
 
    int                 nrInputs() const { return inputs_.size(); }
    bool                setInput( int, Expression* );
    void                copyInput( Expression* target ) const;
 
    void                addIfOK(const char*);
 
    ObjectSet<TypeSet<int> > variableobj_;
    ObjectSet<TypeSet<int> > variablenr_;
    ObjectSet<Expression> inputs_;
    BufferStringSet     varnms_;
    bool                isrecursive_;
 
    friend class        ExpressionParser;
 
    void                doDump(BufferString&,int nrtabs) const;
    virtual void        dumpSpecifics(BufferString&,int nrtabs) const   {}
 
};
 
 
mExpClass(General) ExpressionParser
{
public:
 
                        ExpressionParser( const char* str=0,
                                          bool inputsareseries=true )
                            : inp_(str), abswarn_(false)
                            , inputsareseries_(inputsareseries) {}
 
    void                setInput( const char* s ) { inp_ = s; }
    Expression*         parse() const;
 
    static BufferString varNameOf(const char* fullvarnm,int* shift=0);
    static Expression::VarType varTypeOf(const char*);
    static int          constIdxOf(const char*);
 
    const char*         errMsg() const          { return errmsg_; }
    bool                foundOldAbs() const     { return abswarn_; }
 
protected:
 
    BufferString        inp_;
    const bool          inputsareseries_;
    mutable BufferString errmsg_;
    mutable bool        abswarn_;
 
    Expression*         parse(const char*) const;
 
    bool                findOuterParens(char*,int,Expression*&) const;
    bool                findOuterAbs(char*,int,Expression*&) const;
    bool                findQMarkOper(char*,int,Expression*&) const;
    bool                findAndOrOr(char*,int,Expression*&) const;
    bool                findInequality(char*,int,Expression*&) const;
    bool                findPlusAndMinus(char*,int,Expression*&) const;
    bool                findOtherOper(BufferString&,int,Expression*&) const;
    bool                findVariable(char*,int,Expression*&) const;
    bool                findMathFunction(BufferString&,int,
                                         Expression*&) const;
    bool                findStatsFunction(BufferString&,int,
                                          Expression*&) const;
 
};
 
 
mExpClass(General) ExpressionOperatorDesc
{
public:
                        ExpressionOperatorDesc( const char* s,
                                        const char* d, bool isop, int n )
                            : symbol_(s), desc_(d)
                            , isoperator_(isop), nrargs_(n)     {}
 
    const char*         symbol_; // can have spaces, e.g. "? :"
    const char*         desc_;
    bool                isoperator_; 
    int                 nrargs_; 
};
 
 
mExpClass(General) ExpressionOperatorDescGroup
{
public:
 
    BufferString                        name_;
    ObjectSet<ExpressionOperatorDesc>   opers_;
 
    static const ObjectSet<const ExpressionOperatorDescGroup>& supported();
 
};
 
} // namespace Math