--- /dev/null
+// Get the identifier of a HTML square from its numeric coordinates o.x,o.y.
+function getSquareId(o)
+{
+ // NOTE: a separator is required to allow any size of board
+ return "sq-" + o.x + "-" + o.y;
+}
+
+// Inverse function
+function getSquareFromId(id)
+{
+ const idParts = id.split('-');
+ return [parseInt(idParts[1]), parseInt(idParts[2])];
+}