feat(api)!: the two enum lists are spans over the tables

CHANGELOG.md

@@ -16,6 +16,10 @@ The release run heads these entries with the version and opens a fresh
 
 ## Unreleased
 
+- **Breaking**: `all_file_types()` and `all_text_encodings()` return a
+  `std::span` over the library's tables instead of a `std::vector`, like the
+  other table lookups. The bindings still hand out a list.
+
 - `HtmlConfig::editing_scope` narrows the document view's editor to edits
   inside one paragraph (`paragraph`); the page refuses the rest with the new
   `ErrorCode::edit_out_of_scope` (1010, `outOfScope`). Bound in every binding.

apple/src/ODROdr.mm

@@ -55,7 +55,7 @@ + (NSString *)identification {
 + (NSArray<NSNumber *> *)allFileTypes {
   return guarded_value(
       [&]() -> NSArray<NSNumber *> * {
-        const std::vector<odr::FileType> types = odr::all_file_types();
+        const std::span<const odr::FileType> types = odr::all_file_types();
         NSMutableArray<NSNumber *> *const result =
             [NSMutableArray arrayWithCapacity:types.size()];
         for (const odr::FileType type : types) {
@@ -149,7 +149,7 @@ + (ODRFileTypeCapabilities *)capabilitiesForFileType:(ODRFileType)type {
 + (NSArray<NSNumber *> *)allTextEncodings {
   return guarded_value(
       [&]() -> NSArray<NSNumber *> * {
-        const std::vector<odr::TextEncoding> encodings =
+        const std::span<const odr::TextEncoding> encodings =
             odr::all_text_encodings();
         NSMutableArray<NSNumber *> *const result =
             [NSMutableArray arrayWithCapacity:encodings.size()];

python/src/bind_core.cpp

@@ -63,10 +63,22 @@ void odr_python::bind_core(py::module_ &m) {
 }
 
 void odr_python::bind_functions(py::module_ &m) {
-  m.def("all_file_types", &odr::all_file_types,
-        "Every file type this library knows about.");
-  m.def("all_text_encodings", &odr::all_text_encodings,
-        "Every text encoding the library knows about, excluding `unknown`.");
+  // pybind11 has no caster for a span
+  m.def(
+      "all_file_types",
+      [] {
+        const auto types = odr::all_file_types();
+        return std::vector<odr::FileType>(types.begin(), types.end());
+      },
+      "Every file type this library knows about.");
+  m.def(
+      "all_text_encodings",
+      [] {
+        const auto encodings = odr::all_text_encodings();
+        return std::vector<odr::TextEncoding>(encodings.begin(),
+                                              encodings.end());
+      },
+      "Every text encoding the library knows about, excluding `unknown`.");
   m.def(
       "text_encoding_to_string",
       [](const odr::TextEncoding encoding) {

src/odr/internal/csv/PLAN.md

@@ -75,7 +75,7 @@ fails when an alias is claimed twice.
 enum class TextEncoding { unknown, utf8, utf16le, utf16be, utf32le, utf32be,
                           windows_1252, iso_8859_1, iso_8859_15, shift_jis, … };
 
-std::vector<TextEncoding> all_text_encodings();
+std::span<const TextEncoding> all_text_encodings() noexcept;
 std::string text_encoding_to_string(TextEncoding);
 TextEncoding text_encoding_by_name(std::string_view) noexcept;  // unknown if none
 std::span<const std::string_view> text_encoding_names(TextEncoding) noexcept;

src/odr/internal/encoding/text_encoding_table.cpp

@@ -4,6 +4,7 @@
 
 #include <algorithm>
 #include <array>
+#include <cstddef>
 #include <string>
 
 namespace odr::internal::encoding {
@@ -133,12 +134,24 @@ std::string normalize(const std::string_view name) {
   return result;
 }
 
+constexpr auto encodings_column = [] {
+  std::array<TextEncoding, table.size()> result{};
+  for (std::size_t i = 0; i < table.size(); ++i) {
+    result[i] = table[i].encoding;
+  }
+  return result;
+}();
+
 } // namespace
 
 std::span<const text_encoding_table::Row> text_encoding_table::rows() noexcept {
   return table;
 }
 
+std::span<const TextEncoding> text_encoding_table::encodings() noexcept {
+  return encodings_column;
+}
+
 const text_encoding_table::Row *
 text_encoding_table::find(const TextEncoding encoding) noexcept {
   const auto it = std::ranges::find(table, encoding, &Row::encoding);

src/odr/internal/encoding/text_encoding_table.hpp

@@ -16,6 +16,8 @@ struct Row final {
 
 /// The whole table, one row per @ref TextEncoding, in declaration order.
 [[nodiscard]] std::span<const Row> rows() noexcept;
+/// The encoding column of @ref rows.
+[[nodiscard]] std::span<const TextEncoding> encodings() noexcept;
 
 /// The row for @p encoding, or `nullptr` if there is none.
 [[nodiscard]] const Row *find(TextEncoding encoding) noexcept;

src/odr/internal/file_type_table.cpp

@@ -2,6 +2,7 @@
 
 #include <algorithm>
 #include <array>
+#include <cstddef>
 
 namespace odr::internal {
 
@@ -831,12 +832,24 @@ const Row *find_by_alias(const std::string_view needle,
   return it == std::ranges::end(table) ? nullptr : &*it;
 }
 
+constexpr auto types_column = [] {
+  std::array<FileType, table.size()> result{};
+  for (std::size_t i = 0; i < table.size(); ++i) {
+    result[i] = table[i].type;
+  }
+  return result;
+}();
+
 } // namespace
 
 std::span<const file_type_table::Row> file_type_table::rows() noexcept {
   return table;
 }
 
+std::span<const FileType> file_type_table::types() noexcept {
+  return types_column;
+}
+
 const file_type_table::Row *
 file_type_table::find(const FileType type) noexcept {
   const auto it = std::ranges::find(table, type, &Row::type);

src/odr/internal/file_type_table.hpp

@@ -20,6 +20,8 @@ struct Row final {
 
 /// The whole table, one row per @ref FileType, in declaration order.
 [[nodiscard]] std::span<const Row> rows() noexcept;
+/// The type column of @ref rows.
+[[nodiscard]] std::span<const FileType> types() noexcept;
 
 /// The row for @p type, or `nullptr` if there is none.
 [[nodiscard]] const Row *find(FileType type) noexcept;

src/odr/odr.cpp

@@ -11,8 +11,6 @@
 #include <odr/internal/open_strategy.hpp>
 #include <odr/internal/project_info.hpp>
 
-#include <algorithm>
-#include <iterator>
 #include <span>
 #include <string_view>
 
@@ -40,11 +38,8 @@ std::string odr::identify() noexcept {
          (is_dirty() ? " [dirty]" : "") + (is_debug() ? " [debug]" : "");
 }
 
-std::vector<odr::FileType> odr::all_file_types() {
-  std::vector<FileType> result;
-  result.reserve(table::rows().size());
-  std::ranges::transform(table::rows(), std::back_inserter(result), &Row::type);
-  return result;
+std::span<const odr::FileType> odr::all_file_types() noexcept {
+  return table::types();
 }
 
 odr::FileType
@@ -152,12 +147,8 @@ odr::capabilities_by_file_type(const FileType type) noexcept {
   return row == nullptr ? FileTypeCapabilities{} : row->capabilities;
 }
 
-std::vector<odr::TextEncoding> odr::all_text_encodings() {
-  std::vector<TextEncoding> result;
-  result.reserve(encoding_table::rows().size());
-  std::ranges::transform(encoding_table::rows(), std::back_inserter(result),
-                         &EncodingRow::encoding);
-  return result;
+std::span<const odr::TextEncoding> odr::all_text_encodings() noexcept {
+  return encoding_table::encodings();
 }
 
 std::string_view odr::text_encoding_to_string(const TextEncoding encoding) {

src/odr/odr.hpp

@@ -23,7 +23,7 @@ namespace odr {
 
 /// Every file type this library knows about, in declaration order, including
 /// @ref FileType::unknown.
-[[nodiscard]] std::vector<FileType> all_file_types();
+[[nodiscard]] std::span<const FileType> all_file_types() noexcept;
 
 /// The file type for a file extension, @ref FileType::unknown if none.
 [[nodiscard]] FileType
@@ -66,7 +66,7 @@ capabilities_by_file_type(FileType type) noexcept;
 
 /// Every text encoding this library knows about, in declaration order,
 /// excluding @ref TextEncoding::unknown.
-[[nodiscard]] std::vector<TextEncoding> all_text_encodings();
+[[nodiscard]] std::span<const TextEncoding> all_text_encodings() noexcept;
 
 /// The text encoding's canonical name, a label a browser accepts.
 /// @throws UnsupportedTextEncoding for @ref TextEncoding::unknown.

test/src/odr_test.cpp

@@ -11,6 +11,7 @@
 #include <algorithm>
 #include <optional>
 #include <set>
+#include <span>
 #include <sstream>
 #include <string>
 #include <string_view>
@@ -115,9 +116,9 @@ TEST(odr, a_named_file_in_memory_is_offered_its_type) {
 
 TEST(FileTypeTable, covers_every_file_type_exactly_once) {
   const std::vector<FileType> expected = every_file_type();
-  const std::vector<FileType> actual = all_file_types();
+  const std::span<const FileType> actual = all_file_types();
 
-  EXPECT_EQ(actual, expected);
+  EXPECT_TRUE(std::ranges::equal(actual, expected));
 
   for (const FileType type : expected) {
     EXPECT_NE(file_type_to_string(type), "unnamed")