Completer.hh

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#ifndef COMPLETER_HH
#define COMPLETER_HH

#include "inline.hh"
#include "span.hh"
#include <string>
#include <string_view>
#include <vector>

namespace openmsx {

class FileContext;
class Interpreter;
class InterpreterOutput;
class TclObject;

class Completer
{
public:
        const std::string& getName() const { return name; }

        virtual std::string help(const std::vector<std::string>& tokens) const = 0;

        virtual void tabCompletion(std::vector<std::string>& tokens) const = 0;

        virtual Interpreter& getInterpreter() const = 0;

        template<typename ITER>
        static void completeString(std::vector<std::string>& tokens,
                                   ITER begin, ITER end,
                                   bool caseSensitive = true);
        template<typename RANGE>
        static void completeString(std::vector<std::string>& tokens,
                                   const RANGE& possibleValues,
                                   bool caseSensitive = true);
        template<typename RANGE>
        static void completeFileName(std::vector<std::string>& tokens,
                                     const FileContext& context,
                                     const RANGE& extra);
        static void completeFileName(std::vector<std::string>& tokens,
                                     const FileContext& context);

        static std::vector<std::string> formatListInColumns(
                const std::vector<std::string_view>& input);

        // helper functions to check the number of arguments
        struct AtLeast { unsigned min; };
        struct Between { unsigned min; unsigned max; };
        struct Prefix { unsigned n; }; // how many items from 'tokens' to show in error
        void checkNumArgs(span<const TclObject> tokens, unsigned exactly, const char* errMessage) const;
        void checkNumArgs(span<const TclObject> tokens, AtLeast atLeast,  const char* errMessage) const;
        void checkNumArgs(span<const TclObject> tokens, Between between,  const char* errMessage) const;
        void checkNumArgs(span<const TclObject> tokens, unsigned exactly, Prefix prefix, const char* errMessage) const;
        void checkNumArgs(span<const TclObject> tokens, AtLeast atLeast,  Prefix prefix, const char* errMessage) const;
        void checkNumArgs(span<const TclObject> tokens, Between between,  Prefix prefix, const char* errMessage) const;

        // should only be called by CommandConsole
        static void setOutput(InterpreterOutput* output_) { output = output_; }

protected:
        explicit Completer(std::string_view name);
        ~Completer() = default;

private:
        static bool equalHead(std::string_view s1, std::string_view s2, bool caseSensitive);
        template<typename ITER>
        static std::vector<std::string_view> filter(
                std::string_view str, ITER begin, ITER end, bool caseSensitive);
        template<typename RANGE>
        static std::vector<std::string_view> filter(
                std::string_view str, const RANGE& range, bool caseSensitive);
        static bool completeImpl(std::string& str, std::vector<std::string_view> matches,
                                 bool caseSensitive);
        static void completeFileNameImpl(std::vector<std::string>& tokens,
                                         const FileContext& context,
                                         std::vector<std::string_view> matches);

        const std::string name;
        static inline InterpreterOutput* output = nullptr;
};


template<typename ITER>
NEVER_INLINE std::vector<std::string_view> Completer::filter(
        std::string_view str, ITER begin, ITER end, bool caseSensitive)
{
        std::vector<std::string_view> result;
        for (auto it = begin; it != end; ++it) {
                if (equalHead(str, *it, caseSensitive)) {
                        result.push_back(*it);
                }
        }
        return result;
}

template<typename RANGE>
inline std::vector<std::string_view> Completer::filter(
        std::string_view str, const RANGE& range, bool caseSensitive)
{
        return filter(str, std::begin(range), std::end(range), caseSensitive);
}

template<typename RANGE>
void Completer::completeString(
        std::vector<std::string>& tokens,
        const RANGE& possibleValues,
        bool caseSensitive)
{
        auto& str = tokens.back();
        if (completeImpl(str,
                         filter(str, possibleValues, caseSensitive),
                         caseSensitive)) {
                tokens.emplace_back();
        }
}

template<typename ITER>
void Completer::completeString(
        std::vector<std::string>& tokens,
        ITER begin, ITER end,
        bool caseSensitive)
{
        auto& str = tokens.back();
        if (completeImpl(str,
                         filter(str, begin, end, caseSensitive),
                         caseSensitive)) {
                tokens.emplace_back();
        }
}

template<typename RANGE>
void Completer::completeFileName(
        std::vector<std::string>& tokens,
        const FileContext& context,
        const RANGE& extra)
{
        completeFileNameImpl(tokens, context, filter(tokens.back(), extra, true));
}

} // namespace openmsx

#endif