Move nextChar to generic class

lib/Encoding/GenericEncoding.php

@@ -43,6 +43,27 @@ trait GenericEncoding {
         $this->posChar = 0;
     }
 
+    /** Retrieve the next character in the string, in UTF-8 encoding
+     *
+     * The returned character may be a replacement character, or the empty string if the end of the string has been reached
+     */
+    public function nextChar(): string {
+        // get the byte at the current position
+        $b = @$this->string[$this->posByte];
+        if ($b === "") {
+            // if the byte is end of input, simply return it
+            return "";
+        } elseif (ord($b) < 0x80) {
+            // if the byte is an ASCII character, simply return it
+            $this->posChar++;
+            $this->posByte++;
+            return $b;
+        } else {
+            // otherwise return the serialization of the code point at the current position
+            return UTF8::encode($this->nextCode());
+        }
+    }
+
     /** Retrieves the next $num characters (in UTF-8 encoding) from the string without advancing the character pointer */
     public function peekChar(int $num = 1): string {
         $out = "";

lib/Encoding/UTF8.php

@@ -12,26 +12,6 @@ class UTF8 implements StatelessEncoding {
     const NAME = "UTF-8";
     const LABELS = ["unicode-1-1-utf-8", "utf-8", "utf8"];
 
-    /** Retrieve the next character in the string, in UTF-8 encoding
-     *
-     * The returned character may be a replacement character, or the empty string if the end of the string has been reached
-     */
-    public function nextChar(): string {
-        // get the byte at the current position
-        $b = @$this->string[$this->posByte];
-        if ($b === "") {
-            return "";
-        } elseif (ord($b) < 0x80) {
-            // if the byte is an ASCII character or end of input, simply return it
-            $this->posChar++;
-            $this->posByte++;
-            return $b;
-        } else {
-            // otherwise return the serialization of the code point at the current position
-            return UTF8::encode($this->nextCode());
-        }
-    }
-
     /** Decodes the next character from the string and returns its code point number
      *
      * If the end of the string has been reached, false is returned