schcont.hpp

Go to the documentation of this file.

// +-------------------------------------------------------------------------+
// |               I__n__t__e__L__i__b           0.6.10 development          |
// | Copyright (c) Andrey Vikt. Stolyarov <crocodil_AT_croco.net> 2000-2007. |
// |                                                                         |
// | This is free software. The library part is available under              |
// |                               GNU LESSER GENERAL PUBLIC LICENSE v.2.1.  |
// | GNU LGPL v2.1 is found in docs/gnu_gpl2.txt,  or at  http://www.gnu.org |
// |     Please see also docs/readme.txt and visit http://www.intelib.org    |
// |                                                                         |
// | !!! THERE IS NO WARRANTY OF ANY KIND, NEITHER EXPRESSED NOR IMPLIED !!! |
// +-------------------------------------------------------------------------+




#ifndef INTELIB_SCHCONT_HPP_SENTRY
#define INTELIB_SCHCONT_HPP_SENTRY

#include "../sexpress/sexpress.hpp"
#include "../sexpress/iexcept.hpp"
#include "../sexpress/sbindtbl.hpp"
#include "../sexpress/gensref.hpp"
#include "../genlisp/conteval.hpp"
#include "scheme.hpp"


class SchExpressionSymbol;

class SchExpressionContext;

class IntelibX_scheme_not_a_context : public IntelibX {
public:
    IntelibX_scheme_not_a_context(SReference a_param);
};

typedef GenericSReference<SchExpressionContext, IntelibX_scheme_not_a_context> 
    SchContextRef;


class SchExpressionContext : public SExpression {  
    SchContextRef prev;
    IntelibBindTable tbl;
public:
    static IntelibTypeId TypeId;

    SchExpressionContext(); 
    SchExpressionContext(SchContextRef a_prev); 
protected:
    ~SchExpressionContext();    

public:
    void AddBinding(const SchExpressionSymbol *symb, const SReference& val);

    SReference* GetBinding(const SchExpressionSymbol *symb) const;

    SReference* ProvideBinding(const SchExpressionSymbol *symb);

    SReference GetAllSymbols() const;

#if INTELIB_TEXT_REPRESENTATIONS == 1
    virtual class SString TextRepresentation() const;
#endif
};



class SchemeContinuation : public IntelibContinuation {
public:
    SchemeContinuation() : IntelibContinuation()
        { PTheFalseValue = PTheSchemeBooleanFalse; }

    SchemeContinuation(const SchemeContinuation &other, bool b)
        : IntelibContinuation(other, b)
        { PTheFalseValue = PTheSchemeBooleanFalse; }

    ~SchemeContinuation() {}

    enum CustomInstructions { case_check = max_command - 1 };

    SchContextRef GetContext() const
        { return IntelibContinuation::GetContext(); }

    void SetContext(const SchContextRef& context)
        { IntelibContinuation::SetContext(context); }

private:
    virtual void JustEvaluate(const SReference& expr);
    virtual void CustomCommand(int opcode, const SReference& param);

    void CaseCheck(const SReference& expr);

    void EvaluateForm(SExpressionCons *form);
    SReference& GetSymbolValue(SchExpressionSymbol *sym) const;
};

class IntelibX_scheme_symbol_has_no_value : public IntelibX {
public:
    IntelibX_scheme_symbol_has_no_value(SReference a_param);
};

#endif

---