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#pragma once

#include <QChar>
#include <QString>
#include <QVector>

#include <memory>

namespace Haskell {
namespace Internal {

enum class TokenType {
    Variable,
    Constructor,
    Operator,
    OperatorConstructor,
    Whitespace,
    String,
    StringError,
    Char,
    CharError,
    EscapeSequence,
    Integer,
    Float,
    Keyword,
    Special,
    SingleLineComment,
    MultiLineComment,
    Unknown
};

class Token {
public:
    bool isValid() const;

    TokenType type = TokenType::Unknown;
    int startCol = -1;
    int length = -1;
    QStringRef text;

    std::shared_ptr<QString> source; // keep the string ref alive
};

class Tokens : public QVector<Token>
{
public:
    enum class State {
        None = -1,
        StringGap = 0, // gap == two backslashes enclosing only whitespace
        MultiLineCommentGuard // nothing may follow that
    };

    Tokens(std::shared_ptr<QString> source);

    Token tokenAtColumn(int col) const;

    std::shared_ptr<QString> source;
    int state = int(State::None);
};

class HaskellTokenizer
{
public:
    static Tokens tokenize(const QString &line, int startState);
};

} // Internal
} // Haskell