ParseReferenceNode.h

/* -*- mode: c++; indent-tabs-mode: nil -*- */
/*
    ParseReferenceNode.h
 
    Qore Programming Language
 
    Copyright (C) 2003 - 2022 Qore Technologies, s.r.o.
 
    Permission is hereby granted, free of charge, to any person obtaining a
    copy of this software and associated documentation files (the "Software"),
    to deal in the Software without restriction, including without limitation
    the rights to use, copy, modify, merge, publish, distribute, sublicense,
    and/or sell copies of the Software, and to permit persons to whom the
    Software is furnished to do so, subject to the following conditions:
 
    The above copyright notice and this permission notice shall be included in
    all copies or substantial portions of the Software.
 
    THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
    IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
    FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
    AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
    LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
    FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
    DEALINGS IN THE SOFTWARE.
 
    Note that the Qore library is released under a choice of three open-source
    licenses: MIT (as above), LGPL 2+, or GPL 2+; see README-LICENSE for more
    information.
*/
 
#ifndef _QORE_INTERN_PARSEREFERENCENODE_H
#define _QORE_INTERN_PARSEREFERENCENODE_H
 
#include "qore/intern/ParseNode.h"
 
class IntermediateParseReferenceNode;
 
class ParseReferenceNode : public ParseNode {
public:
 
    DLLLOCAL ParseReferenceNode(const QoreProgramLocation* loc, QoreValue exp,
            const QoreTypeInfo* typeInfo = referenceTypeInfo) : ParseNode(loc, NT_PARSEREFERENCE, true, false),
            lvexp(exp), typeInfo(typeInfo) {
    }
 
 
    DLLLOCAL virtual int getAsString(QoreString& str, int foff, ExceptionSink* xsink) const {
        str.sprintf("parse reference expression (%p)", this);
        return 0;
    }
 
 
    DLLLOCAL virtual QoreString* getAsString(bool &del, int foff, class ExceptionSink* xsink) const {
        del = true;
        QoreString* rv = new QoreString();
        getAsString(*rv, foff, xsink);
        return rv;
    }
 
    DLLLOCAL virtual const char* getTypeName() const {
        return "reference to lvalue";
    }
 
    DLLLOCAL virtual const QoreTypeInfo* getTypeInfo() const {
        return typeInfo;
    }
 
    // returns an intermediate reference for use with the background operator
    DLLLOCAL IntermediateParseReferenceNode* evalToIntermediate(ExceptionSink* xsink) const;
 
    // returns a runtime reference
    DLLLOCAL virtual ReferenceNode* evalToRef(ExceptionSink* xsink) const;
 
protected:
    QoreValue lvexp;
    const QoreTypeInfo* typeInfo;
 
    DLLLOCAL ~ParseReferenceNode() {
        lvexp.discard(nullptr);
    }
 
    // returns a runtime reference (ReferenceNode)
    DLLLOCAL virtual QoreValue evalImpl(bool& needs_deref, ExceptionSink* xsink) const {
        return evalToRef(xsink);
    }
 
    DLLLOCAL QoreValue doPartialEval(QoreValue n, QoreObject*& self, const void*& lvalue_id,
            const qore_class_private*& qc, ExceptionSink* xsink) const;
 
    DLLLOCAL virtual int parseInitImpl(QoreValue& val, QoreParseContext& parse_context);
};
 
class IntermediateParseReferenceNode : public ParseReferenceNode {
protected:
    QoreObject* self;
    const void* lvalue_id;
    const qore_class_private* cls;
 
    DLLLOCAL virtual bool derefImpl(ExceptionSink* xsink) {
        lvexp.discard(xsink);
        lvexp = QoreValue();
        return true;
    }
 
public:
    DLLLOCAL IntermediateParseReferenceNode(const QoreProgramLocation* loc, QoreValue exp,
            const QoreTypeInfo* typeInfo, QoreObject* o, const void* lvid, const qore_class_private* n_cls);
 
    // returns a runtime reference
    DLLLOCAL virtual ReferenceNode* evalToRef(ExceptionSink* xsink) const {
        return new ReferenceNode(lvexp.refSelf(), typeInfo, self, lvalue_id, cls);
    }
};
 
#endif // _QORE_INTERN_PARSEREFERENCENODE_H