add parse and stringify

2025-06-22 19:53:49 +08:00
parent ab8d74efe6
commit 28ff7008a8
9 changed files with 347 additions and 9 deletions
--- a/src/yycc/string/stringify.hpp
+++ b/src/yycc/string/stringify.hpp
@ -0,0 +1,92 @@
+#pragma once
+#include "../string.hpp"
+#include "reinterpret.hpp"
+#include <array>
+#include <charconv>
+#include <stdexcept>
+#include <type_traits>
+
+#define NS_YYCC_STRING ::yycc::string
+#define NS_YYCC_STRING_REINTERPRET ::yycc::string::reinterpret
+
+namespace yycc::string::stringify {
+
+    // Developer Notes:
+    // Reference: https://en.cppreference.com/w/cpp/utility/to_chars
+    // Default float precision = 6 is gotten from: https://en.cppreference.com/w/c/io/fprintf
+
+    inline constexpr size_t STRINGIFY_BUFFER_SIZE = 64u;
+    using StringifyBuffer = std::array<NS_YYCC_STRING::u8char, STRINGIFY_BUFFER_SIZE>;
+
+    /**
+     * @brief Return the string representation of given floating point value.
+     * @tparam T The type derived from floating point type.
+     * @param[in] num The value need to get string representation.
+     * @param[in] fmt The floating point format used when getting string representation.
+     * @param[in] precision The floating point precision used when getting string representation.
+     * @return The string representation of given value.
+    */
+    template<typename T, std::enable_if_t<std::is_floating_point_v<T>, int> = 0>
+    NS_YYCC_STRING::u8string stringify(T num,
+                                       std::chars_format fmt = std::chars_format::general,
+                                       int precision = 6) {
+        namespace reinterpret = NS_YYCC_STRING_REINTERPRET;
+        StringifyBuffer buffer;
+        auto [ptr, ec] = std::to_chars(reinterpret::as_ordinary(buffer.data()),
+                                       reinterpret::as_ordinary(buffer.data() + buffer.size()),
+                                       num,
+                                       fmt,
+                                       precision);
+        if (ec == std::errc()) {
+            return NS_YYCC_STRING::u8string(buffer.data(),
+                                            reinterpret::as_utf8(ptr) - buffer.data());
+        } else if (ec == std::errc::value_too_large) {
+            // Too short buffer. This should not happened
+            throw std::out_of_range("stringify() buffer is not sufficient.");
+        } else {
+            // Unreachable
+            throw std::runtime_error("unreachable code.");
+        }
+    }
+    /**
+     * @brief Return the string representation of given integral value.
+     * @tparam T The type derived from integral type except bool type.
+     * @param[in] num The value need to get string representation.
+     * @param[in] base Integer base used when getting string representation: a value between 2 and 36 (inclusive).
+     * @return The string representation of given value.
+    */
+    template<typename T, std::enable_if_t<std::is_integral_v<T> && !std::is_same_v<T, bool>, int> = 0>
+    NS_YYCC_STRING::u8string stringify(T num, int base = 10) {
+        namespace reinterpret = NS_YYCC_STRING_REINTERPRET;
+        StringifyBuffer buffer;
+        auto [ptr, ec] = std::to_chars(reinterpret::as_ordinary(buffer.data()),
+                                       reinterpret::as_ordinary(buffer.data() + buffer.size()),
+                                       num,
+                                       base);
+        if (ec == std::errc()) {
+            return NS_YYCC_STRING::u8string(buffer.data(),
+                                            reinterpret::as_utf8(ptr) - buffer.data());
+        } else if (ec == std::errc::value_too_large) {
+            // Too short buffer. This should not happened
+            throw std::out_of_range("stringify() buffer is not sufficient.");
+        } else {
+            // Unreachable
+            throw std::runtime_error("unreachable code.");
+        }
+    }
+    /**
+     * @brief Return the string representation of given bool value.
+     * @tparam T The type derived from bool type.
+     * @param[in] num The value need to get string representation.
+     * @return The string representation of given value ("true" or "false").
+    */
+    template<typename T, std::enable_if_t<std::is_same_v<T, bool>, int> = 0>
+    NS_YYCC_STRING::u8string stringify(T num) {
+        if (num) return NS_YYCC_STRING::u8string(YYCC_U8("true"));
+        else return NS_YYCC_STRING::u8string(YYCC_U8("false"));
+    }
+
+} // namespace yycc::string::stringify
+
+#undef NS_YYCC_STRING_REINTERPRET
+#undef NS_YYCC_STRING