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#ifndef CPLUSPLUS_TYPEOFEXPRESSION_H
#define CPLUSPLUS_TYPEOFEXPRESSION_H

#include "CppDocument.h"
#include "LookupContext.h"

#include <ASTfwd.h>
#include <QtCore/QMap>
#include <QtCore/QObject>
#include <QtCore/QString>

namespace CPlusPlus {

class Environment;
class Macro;

class CPLUSPLUS_EXPORT TypeOfExpression
{
public:
    typedef QPair<FullySpecifiedType, Symbol *> Result;

public:
    TypeOfExpression();

    Snapshot snapshot() const;

    /**
     * Sets the documents used to evaluate expressions. Should be set before
     * calling this functor.
     *
     * Also clears the lookup context, so can be used to make sure references
     * to the documents previously used are removed.
     */
    void setSnapshot(const Snapshot &documents);

    enum PreprocessMode {
        NoPreprocess,
        Preprocess
    };

    /**
     * Returns a list of possible fully specified types associated with the
     * given expression.
     *
     * NOTE: The fully specified types only stay valid for as long as this
     * expression evaluator instance still exists, and no new call to evaluate
     * has been made!
     *
     * @param expression        The expression to evaluate.
     * @param document          The document the expression is part of.
     * @param lastVisibleSymbol The last visible symbol in the document.
     */
    QList<Result> operator()(const QString &expression, Document::Ptr document,
                             Symbol *lastVisibleSymbol,
                             PreprocessMode mode = NoPreprocess);

    QString preprocess(const QString &expression, Document::Ptr document) const;

    /**
     * Returns the AST of the last evaluated expression.
     */
    ExpressionAST *ast() const;

    /**
     * Returns the lookup context of the last evaluated expression.
     */
    const LookupContext &lookupContext() const;

    ExpressionAST *expressionAST() const;

private:
    ExpressionAST *extractExpressionAST(Document::Ptr doc) const;
    Document::Ptr documentForExpression(const QString &expression) const;

    void processEnvironment(CPlusPlus::Snapshot documents,
                            CPlusPlus::Document::Ptr doc, CPlusPlus::Environment *env,
                            QSet<QString> *processed) const;

    QString preprocessedExpression(const QString &expression,
                                   CPlusPlus::Snapshot documents,
                                   CPlusPlus::Document::Ptr thisDocument) const;

    Snapshot m_snapshot;
    ExpressionAST *m_ast;
    LookupContext m_lookupContext;
};

} // namespace CPlusPlus

#endif // CPLUSPLUS_TYPEOFEXPRESSION_H