update: enhance `PyCases` wrapper

src/core_ffi/CMakeLists.txt

@@ -15,7 +15,7 @@ if (KLSK_PYTHON_FFI)
         py_ffi/binder.cc
         py_ffi/wrapper/short_code.cc
         py_ffi/wrapper/common_codec.cc
-        py_ffi/wrapper/py_cases.cc
+        py_ffi/wrapper/cases.cc
         py_ffi/wrapper/py_group_union.cc
         py_ffi/wrapper/py_group.cc
     )

src/core_ffi/py_ffi/binder.cc

@@ -8,15 +8,19 @@
 #include "py_cases.h"
 #include "py_group.h"
 
+#include "py_exception.h"
+
 namespace py = pybind11;
 
 using klotski::ffi::PyCases;
-using klotski::ffi::PyCasesIter;
+//using klotski::ffi::PyCasesIter;
 
-using klotski::ffi::PyCodecExp;
+//using klotski::ffi::PyCodecExp;
 using klotski::ffi::PyShortCode;
 using klotski::ffi::PyCommonCode;
 
+using klotski::ffi::PyExc_CodecError;
+
 using klotski::ffi::PyGroup;
 using klotski::ffi::PyGroupUnion;
 
@@ -90,20 +94,24 @@ static PyCases all_cases() {
 }
 
 PYBIND11_MODULE(klotski, m) {
-    py::register_exception<PyCodecExp>(m, "CodecExp", PyExc_ValueError);
+//    py::register_exception<PyCodecExp>(m, "CodecExp", PyExc_ValueError);
+    py::register_exception<PyExc_CodecError>(m, "CodecError", PyExc_ValueError);
 
     m.def("all_cases", &all_cases);
     m.def("group_demo", &group_demo);
 
-    py::class_<PyCases>(m, "PyCases")
+    auto py_cases = py::class_<PyCases>(m, "Cases")
         .def("size", &PyCases::size)
-        .def("__iter__", [](const PyCases &self) {
-            return PyCasesIter(self);
-        }, py::keep_alive<0, 1>());
+        .def("__iter__", &PyCases::common_codes, py::keep_alive<0, 1>())
+        .def("short_codes", &PyCases::short_codes, py::keep_alive<0, 1>());
+
+    py::class_<PyCases::ShortCodeIter>(py_cases, "ShortCodeIter")
+            .def("__iter__", [](PyCases::ShortCodeIter &it) -> PyCases::ShortCodeIter& { return it; })
+            .def("__next__", &PyCases::ShortCodeIter::next);
 
-    py::class_<PyCasesIter>(m, "PyCasesIter")
-            .def("__iter__", [](PyCasesIter &it) -> PyCasesIter& { return it; })
-            .def("__next__", &PyCasesIter::next);
+    py::class_<PyCases::CommonCodeIter>(py_cases, "CommonCodeIter")
+            .def("__iter__", [](PyCases::CommonCodeIter &it) -> PyCases::CommonCodeIter& { return it; })
+            .def("__next__", &PyCases::CommonCodeIter::next);
 
     bind_short_code(m);
     bind_common_code(m);

src/core_ffi/py_ffi/include/py_cases.h

@@ -2,128 +2,82 @@
 
 #pragma once
 
-#include <iostream>
-
 #include <variant>
 
-#include "ranges/ranges.h"
-
 #include "py_common_code.h"
+#include "ranges/ranges.h"
 
 namespace klotski::ffi {
 
-using klotski::cases::RangesUnion;
-
-//class PyCases {
-//public:
-//    PyCases() = delete;
-//
-//    PyCases(PyCases &&cases) noexcept : real_data_(std::move(cases.real_data_)), data_(real_data_) {
-//        std::cout << "PyCases(PyCases &&) called" << std::endl;
-//        std::cout << "real_data / data_ref -> " << &real_data_ << " " << &data_ << std::endl;
-//    }
-//
-//    PyCases(const PyCases &cases) : real_data_(cases.real_data_), data_(real_data_) {
-//        std::cout << "PyCases(const PyCases &) called" << std::endl;
-//        std::cout << "real_data / data_ref -> " << &real_data_ << " " << &data_ << std::endl;
-//    }
-//
-//    PyCases& operator==(PyCases &&cases) {
-//        std::cout << "PyCases& operator==(PyCases &&) called" << std::endl;
-//        if (this != &cases) {
-//            real_data_ = std::move(cases.real_data_);
-//        }
-//        std::cout << "real_data / data_ref -> " << &real_data_ << " " << &data_ << std::endl;
-//        return *this;
-//    }
-//
-//    PyCases& operator==(const PyCases &&cases) {
-//        std::cout << "PyCases& operator==(const PyCases &&) called" << std::endl;
-//        if (this != &cases) {
-//            real_data_ = cases.real_data_;
-//        }
-//        std::cout << "real_data / data_ref -> " << &real_data_ << " " << &data_ << std::endl;
-//        return *this;
-//    }
-//
-//    [[nodiscard]] size_t size() const;
-//
-//    static PyCases from(RangesUnion &&data);
-//
-//    static PyCases from_ref(const RangesUnion &data);
-//
-//    [[nodiscard]] const RangesUnion& data_ref() const;
-//
-//private:
-//    explicit PyCases(RangesUnion &&data) : real_data_(std::move(data)), data_(real_data_) {
-//        std::cout << "PyCases init from r-value" << std::endl;
-//        std::cout << "real_data / data_ref -> " << &real_data_ << " " << &data_ << std::endl;
-//    }
-//
-//    explicit PyCases(const RangesUnion &data) : data_(data) {
-//        std::cout << "PyCases init from l-value" << std::endl;
-//    }
-//
-//    RangesUnion real_data_;
-//    const RangesUnion &data_;
-//};
+using cases::RangesUnion;
 
 class PyCases {
 public:
-    using Cases = RangesUnion;
-    using CasesRef = std::reference_wrapper<const Cases>;
+    PyCases() = delete;
 
-    static PyCases from(RangesUnion &&data) {
-        return PyCases(std::move(data));
-    }
+    // ------------------------------------------------------------------------------------- //
 
-    static PyCases from_ref(const RangesUnion &data) {
-        return PyCases(data);
-    }
+    class CommonCodeIter {
+    public:
+        PyCommonCode next();
+        explicit CommonCodeIter(const RangesUnion &data);
 
-    [[nodiscard]] size_t size() const;
+    private:
+        uint8_t head_ {0};
+        uint32_t index_ {0};
+        const RangesUnion &data_;
+    };
 
-    [[nodiscard]] const Cases& ref() const {
+    class ShortCodeIter {
+    public:
+        PyShortCode next();
+        explicit ShortCodeIter(CommonCodeIter iter);
 
-        // if (std::holds_alternative<Cases>(data_)) {
-        //     return std::get<Cases>(data_);
-        // } else {
-        //     return std::get<CasesRef>(data_);
-        // }
+    private:
+        CommonCodeIter iter_;
+    };
 
-        return std::visit([]<typename T>(T &&arg) -> const Cases& {
-            if constexpr (std::is_same_v<std::decay_t<T>, Cases>) {
-                return arg;
-            } else {
-                return arg.get();
-            }
-        }, data_);
-    }
+    // ------------------------------------------------------------------------------------- //
 
-private:
-    std::variant<Cases, CasesRef> data_;
+    /// Constructing from rvalue.
+    static PyCases from(RangesUnion &&data) noexcept;
 
-    explicit PyCases(const RangesUnion &data) : data_(std::cref(data)) {
-        std::cout << "PyCases(const RangesUnion &) called" << std::endl;
-        std::cout << "variant data index: " << data_.index() << std::endl;
-    }
+    /// Constructing from longer-lived reference.
+    static PyCases from_ref(const RangesUnion &data) noexcept;
 
-    explicit PyCases(RangesUnion &&data) : data_(std::move(data)) {
-        std::cout << "PyCases(RangesUnion &&) called" << std::endl;
-        std::cout << "variant data index: " << data_.index() << std::endl;
-    }
-};
+    // ------------------------------------------------------------------------------------- //
 
-class PyCasesIter {
-public:
-    explicit PyCasesIter(const PyCases &data) : data_(data) {}
+    /// Get the number of cases.
+    [[nodiscard]] size_t size() const;
 
-    PyCommonCode next();
+    /// Get ShortCode iterator of cases.
+    [[nodiscard]] ShortCodeIter short_codes() const;
+
+    /// Get CommonCode iterator of cases.
+    [[nodiscard]] CommonCodeIter common_codes() const;
+
+    /// Get the CommonCode of the specified index.
+    [[nodiscard]] PyCommonCode operator[](size_t index) const;
+
+    // ------------------------------------------------------------------------------------- //
+
+    // TODO: add len / repr
 
 private:
-    uint64_t head_ {0};
-    size_t index_ {0};
-    const PyCases &data_;
+    explicit PyCases(RangesUnion &&data);
+    explicit PyCases(const RangesUnion &data);
+
+    // ------------------------------------------------------------------------------------- //
+
+    /// Get const reference of the cases data.
+    [[nodiscard]] const RangesUnion& data_ref() const noexcept;
+
+    /// Stores actual cases data or its references.
+    std::variant<RangesUnion, std::reference_wrapper<const RangesUnion>> data_;
+
+    // ------------------------------------------------------------------------------------- //
 };
 
+// TODO: allow compare
+
 } // namespace klotski::ffi

src/core_ffi/py_ffi/include/py_exps.h

@@ -4,19 +4,19 @@
 
 namespace klotski::ffi {
 
-class PyCodecExp final : std::exception {
-public:
-    explicit PyCodecExp(const std::string_view &msg) : msg_(msg) {}
-
-    ~PyCodecExp() override = default;
-
-    [[nodiscard]] const char* what() const noexcept override {
-        return msg_.c_str();
-    }
-
-private:
-    std::string msg_;
-};
+//class PyCodecExp final : std::exception {
+//public:
+//    explicit PyCodecExp(const std::string_view &msg) : msg_(msg) {}
+//
+//    ~PyCodecExp() override = default;
+//
+//    [[nodiscard]] const char* what() const noexcept override {
+//        return msg_.c_str();
+//    }
+//
+//private:
+//    std::string msg_;
+//};
 
 class PyGroupExp final : std::exception {
 public:

src/core_ffi/py_ffi/wrapper/cases.cc

@@ -0,0 +1,98 @@
+#include <pybind11/pybind11.h>
+
+#include "include/py_cases.h"
+
+namespace py = pybind11;
+
+using namespace klotski::ffi;
+
+using ShortCodeIter = PyCases::ShortCodeIter;
+using CommonCodeIter = PyCases::CommonCodeIter;
+
+// ----------------------------------------------------------------------------------------- //
+
+CommonCodeIter::CommonCodeIter(const RangesUnion &data) : data_(data) {}
+
+ShortCodeIter::ShortCodeIter(PyCases::CommonCodeIter iter) : iter_(iter) {}
+
+PyShortCode ShortCodeIter::next() {
+    return iter_.next().short_code();
+}
+
+PyCommonCode CommonCodeIter::next() {
+    while (head_ < 16) {
+        const auto &ranges = data_[head_];
+        if (index_ < ranges.size()) {
+            auto code = (static_cast<uint64_t>(head_) << 32) | ranges[index_++];
+            return std::bit_cast<PyCommonCode>(code);
+        }
+        ++head_;
+        index_ = 0;
+    }
+    throw py::stop_iteration();
+}
+
+// ----------------------------------------------------------------------------------------- //
+
+size_t PyCases::size() const {
+    size_t num = 0;
+    for (const auto &x : data_ref()) { // TODO: fetch from RangesUnion.size()
+        num += x.size();
+    }
+    return num;
+}
+
+auto PyCases::short_codes() const -> ShortCodeIter {
+    return ShortCodeIter(common_codes());
+}
+
+auto PyCases::common_codes() const -> CommonCodeIter {
+    return CommonCodeIter(data_ref());
+}
+
+PyCommonCode PyCases::operator[](size_t index) const {
+
+    if (index >= size()) {
+        throw py::index_error("cases index out of range");
+    }
+
+    uint64_t head = 0;
+    for (;;) {
+        if (index >= data_ref()[head].size()) {
+            index -= data_ref()[head].size();
+            ++head;
+        } else {
+            break;
+        }
+    }
+    uint32_t range = data_ref()[head][index];
+
+    // TODO: fetch from RangesUnion[]
+    const auto code = CommonCode::unsafe_create(head << 32 | range);
+    return std::bit_cast<PyCommonCode>(code);
+}
+
+// ----------------------------------------------------------------------------------------- //
+
+PyCases PyCases::from(RangesUnion &&data) noexcept {
+    return PyCases(std::move(data));
+}
+
+PyCases PyCases::from_ref(const RangesUnion &data) noexcept {
+    return PyCases(data);
+}
+
+const RangesUnion& PyCases::data_ref() const noexcept {
+    return std::visit([]<typename T>(T &&arg) -> const RangesUnion& {
+        if constexpr (std::is_same_v<std::decay_t<T>, RangesUnion>) {
+            return arg;
+        } else {
+            return arg.get();
+        }
+    }, data_);
+}
+
+PyCases::PyCases(RangesUnion &&data) : data_(std::move(data)) {}
+PyCases::PyCases(const RangesUnion &data) : data_(std::cref(data)) {}
+
+// ----------------------------------------------------------------------------------------- //

src/core_ffi/py_ffi/wrapper/py_cases.cc

@@ -1,44 +0,0 @@
-#include <pybind11/pybind11.h>
-
-#include "include/py_cases.h"
-
-namespace py = pybind11;
-
-using klotski::ffi::PyCases;
-using klotski::ffi::PyCasesIter;
-using klotski::ffi::PyCommonCode;
-
-using klotski::cases::RangesUnion;
-
-size_t PyCases::size() const {
-    size_t num = 0;
-    for (const auto &x : ref()) {
-        num += x.size();
-    }
-    return num;
-}
-
-//PyCases PyCases::from(RangesUnion &&data) {
-//    return PyCases(std::move(data));
-//}
-//
-//PyCases PyCases::from_ref(const RangesUnion &data) {
-//    return PyCases(data);
-//}
-//
-//const RangesUnion& PyCases::data_ref() const {
-//    return data_;
-//}
-
-PyCommonCode PyCasesIter::next() {
-    while (head_ < 16) {
-        const auto &ranges = data_.ref()[head_];
-        if (index_ < ranges.size()) {
-            auto code = (head_ << 32) | ranges[index_++];
-            return std::bit_cast<PyCommonCode>(code);
-        }
-        ++head_;
-        index_ = 0;
-    }
-    throw py::stop_iteration();
-}