#ifndef SCRIPT_ENGINE_H
#define SCRIPT_ENGINE_H

#include "number.h"
#include "expression.h"

#include <bu/hash.h>
#include <bu/list.h>
#include <bu/string.h>
#include <bu/signals.h>

namespace Bu
{
    class Stream;
}
class Expression;

class ScriptEngine
{
private:
    typedef Bu::Hash<Bu::String, Number> VarHash;
    typedef Bu::List<Number> NumStack;

public:
    ScriptEngine();
    virtual ~ScriptEngine();

    void exec( const Bu::String &sExpr );
    void exec( Bu::Stream &sInput );
    void exec( Expression *pExpr );

    bool isRunning() const { return bRunning; }

public:
    Bu::Signal1<void, const class Number &> sigNumResult;
    Bu::Signal1<void, const Bu::String &> sigError;
    Bu::Signal1<void, const Bu::String &> sigMessage;

private:
    void command( Expression::iterator &i );

private:
    VarHash hVarState;
    bool bRunning;
};

#endif