eval method
Evaluate this expression in the context of row (column name -> value).
Implementation
@override
Object? eval(Map<String, Object?> row) {
final v = value.eval(row);
final l = low.eval(row);
final h = high.eval(row);
if (v == null || l == null || h == null) return null;
final inRange = BinaryExpr._cmp(v, l) >= 0 && BinaryExpr._cmp(v, h) <= 0;
return negated ? !inRange : inRange;
}