Completer.hh

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#ifndef COMPLETER_HH
#define COMPLETER_HH
 
#include "inline.hh"
 
#include <concepts>
#include <span>
#include <string>
#include <string_view>
#include <vector>
 
namespace openmsx {
 
class FileContext;
class Interpreter;
class InterpreterOutput;
class TclObject;
 
class Completer
{
public:
        Completer(const Completer&) = delete;
        Completer& operator=(const Completer&) = delete;
 
        [[nodiscard]] const std::string& getName() const { return theName; }
 
        [[nodiscard]] virtual std::string help(std::span<const TclObject> tokens) const = 0;
 
        virtual void tabCompletion(std::vector<std::string>& tokens) const = 0;
 
        [[nodiscard]] 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,
                                   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(
                std::span<const 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(std::span<const TclObject> tokens, unsigned exactly, const char* errMessage) const;
        void checkNumArgs(std::span<const TclObject> tokens, AtLeast atLeast,  const char* errMessage) const;
        void checkNumArgs(std::span<const TclObject> tokens, Between between,  const char* errMessage) const;
        void checkNumArgs(std::span<const TclObject> tokens, unsigned exactly, Prefix prefix, const char* errMessage) const;
        void checkNumArgs(std::span<const TclObject> tokens, AtLeast atLeast,  Prefix prefix, const char* errMessage) const;
        void checkNumArgs(std::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:
        template<typename String>
                requires(!std::same_as<Completer, std::remove_cvref_t<String>>) // don't block copy-constructor
        explicit Completer(String&& name_)
                : theName(std::forward<String>(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, 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 theName;
        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, 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,
        RANGE&& possibleValues,
        bool caseSensitive)
{
        auto& str = tokens.back();
        if (completeImpl(str,
                         filter(str, std::forward<RANGE>(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