script.hh

#pragma once
 
#include <clingo/control.hh>
#include <clingo/core.hh>
#include <clingo/symbol.hh>
 
#include <clingo/script.h>
 
namespace Clingo {
 
 
class Script {
  public:
    Script() = default;
    Script(Script &&other) = delete;
    virtual ~Script() = default;
 
    void execute(std::string_view code) { do_execute(code); }
 
    auto call(Library &lib, std::string_view name, SymbolSpan arguments) -> SymbolVector {
        return do_call(lib, name, arguments);
    }
 
    auto callable(std::string_view name, size_t arguments) -> bool { return do_callable(name, arguments); }
 
    void main(Library &lib, const Control &ctl) { do_main(lib, ctl); }
 
    auto name() -> std::string_view { return do_name(); }
 
    auto version() -> std::string_view { return do_version(); }
 
  private:
    virtual void do_execute(std::string_view code) = 0;
    virtual auto do_call(Library &lib, std::string_view name, SymbolSpan arguments) -> SymbolVector = 0;
    virtual auto do_callable(std::string_view name, size_t arguments) -> bool = 0;
    virtual void do_main(Library &lib, const Control &ctl) = 0;
    virtual auto do_name() -> std::string_view = 0;
    virtual auto do_version() -> std::string_view = 0;
};
 
 
namespace Detail {
 
static constexpr clingo_script_t c_script = {
    [](char const *code, size_t size, void *data) -> bool {
        CLINGO_TRY {
            static_cast<Script *>(data)->execute(std::string_view{code, size});
        }
        CLINGO_CATCH;
    },
    [](clingo_lib_t *lib, [[maybe_unused]] clingo_location_t const *loc, char const *name, size_t name_size,
       clingo_symbol_t const *arguments, size_t arguments_size, clingo_symbol_callback_t symbol_callback,
       void *symbol_callback_data, void *data) -> bool {
        CLINGO_TRY {
            auto &self = *static_cast<Script *>(data);
            auto args = transform(arguments, std::next(arguments, static_cast<std::ptrdiff_t>(arguments_size)),
                                  [](auto sym) { return Symbol{sym, true}; });
            auto cpp_lib = Library{lib, true};
            auto syms = self.call(cpp_lib, {name, name_size}, args);
            auto const *c_syms = c_cast(syms.data());
            return symbol_callback(c_syms, syms.size(), symbol_callback_data);
        }
        CLINGO_CATCH;
    },
    [](char const *name, size_t size, size_t arguments, bool *result, void *data) -> bool {
        CLINGO_TRY {
            auto &self = *static_cast<Script *>(data);
            *result = self.callable({name, size}, arguments);
        }
        CLINGO_CATCH;
    },
    [](clingo_lib_t *lib, clingo_control_t *control, void *data) -> bool {
        CLINGO_TRY {
            auto &self = *static_cast<Script *>(data);
            auto cpp_lib = Library{lib, true};
            auto cpp_ctl = Control{control, true};
            self.main(cpp_lib, cpp_ctl);
        }
        CLINGO_CATCH;
    },
    [](void *data, clingo_string_t *name) {
        auto &self = *static_cast<Script *>(data);
        auto str = self.name();
        name->data = str.data();
        name->size = str.size();
    },
    [](void *data, clingo_string_t *version) {
        auto &self = *static_cast<Script *>(data);
        auto str = self.name();
        version->data = str.data();
        version->size = str.size();
    },
    [](void *data) { std::ignore = std::unique_ptr<Script>(static_cast<Script *>(data)); },
};
 
} // namespace Detail
 
template <std::derived_from<Script> T> auto register_script(Library const &lib, std::unique_ptr<T> script) -> T & {
    auto &res = *script;
    Detail::handle_error(clingo_script_register(c_cast(lib), &Detail::c_script, script.release()));
    return res;
}
 
} // namespace Clingo