feat(cpp-object-oriented-modular-refactoring): step 11 - source-target-resolver

include/fesa/core/ascii.h

@@ -0,0 +1,28 @@
+#ifndef FESA_CORE_ASCII_H_
+#define FESA_CORE_ASCII_H_
+
+#include <cstdint>
+#include <string_view>
+
+#include "fesa/core/status.h"
+
+namespace fesa {
+
+/// @brief Converts one ASCII uppercase byte to lowercase.
+/// @return The lowercase ASCII byte, or the input byte when it is not A-Z.
+char AsciiLower(char value) noexcept;
+
+/// @brief Compares two byte strings with ASCII-only case folding.
+/// @return True when the strings have equal length and equal ASCII-folded
+/// bytes.
+bool AsciiCaseInsensitiveEquals(std::string_view lhs,
+                                std::string_view rhs) noexcept;
+
+/// @brief Parses a complete positive base-10 source label.
+/// @return The positive label or an input failure for malformed, nonpositive,
+/// or out-of-range text.
+Result<std::int64_t> ParsePositiveSourceLabel(std::string_view text);
+
+}  // namespace fesa
+
+#endif  // FESA_CORE_ASCII_H_