Sync from upstream llama.cpp repository

common/unicode.h

@@ -0,0 +1,22 @@
+#pragma once
+
+#include <cstdint>
+#include <string_view>
+
+// UTF-8 parsing utilities for streaming-aware unicode support
+
+struct utf8_parse_result {
+    uint32_t codepoint;      // Decoded codepoint (only valid if status == SUCCESS)
+    size_t bytes_consumed;   // How many bytes this codepoint uses (1-4)
+    enum status { SUCCESS, INCOMPLETE, INVALID } status;
+
+    utf8_parse_result(enum status s, uint32_t cp = 0, size_t bytes = 0)
+        : codepoint(cp), bytes_consumed(bytes), status(s) {}
+};
+
+// Determine the expected length of a UTF-8 sequence from its first byte
+// Returns 0 for invalid first bytes
+size_t utf8_sequence_length(unsigned char first_byte);
+
+// Parse a single UTF-8 codepoint from input
+utf8_parse_result parse_utf8_codepoint(std::string_view input, size_t offset);