Btw, there was a bug in (define-decoder :utf-32) and (define-code-point-counter :utf-32) <br><br>At the beginning of that macros, the code that checks for  BOM:<br><br>(case (,getter seq 0 4) ...<br><br>I suppose there must be &quot;start&quot;(as in utf-16 decoder/code-point-counter), not &quot;0&quot;, in this form?<br>
<br>If so, that bug is in my code also.<br>And so, this line in &quot;make-bom-check-form&quot; local function of &quot;define-ucs&quot; macro:<br><br>(case (,,getter ,,src 0 ,&#39;,bytes :ne)<br><br>should be replaced by this line:<br>
<br>(case (,,getter ,,src ,,start ,&#39;,bytes :ne)<br>