move empty_record to header

this makes it so we don't need access to the VCF struct in order to make an empty record.
since the header is always available as record.header() then we can create an empty record

src/bcf/header.rs

@@ -34,6 +34,7 @@
 
 use std::ffi;
 use std::os::raw::c_char;
+use std::rc::Rc;
 use std::slice;
 use std::str;
 
@@ -506,6 +507,13 @@ impl HeaderView {
         }
         result
     }
+
+    /// Create an empty record using this header view.
+    ///
+    /// The record can be reused multiple times.
+    pub fn empty_record(&self) -> crate::bcf::Record {
+        crate::bcf::Record::new(Rc::new(self.clone()))
+    }
 }
 
 impl Clone for HeaderView {
@@ -540,3 +548,25 @@ pub enum TagLength {
     Genotypes,
     Variable,
 }
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use crate::bcf::Reader;
+
+    #[test]
+    fn test_header_view_empty_record() {
+        // Open a VCF file to get a HeaderView
+        let vcf = Reader::from_path("test/test_string.vcf").expect("Error opening file");
+        let header_view = vcf.header.clone();
+
+        // Create an empty record from the HeaderView
+        let record = header_view.empty_record();
+        eprintln!("{:?}", record.rid());
+
+        // Verify the record is properly initialized with default/empty values
+        assert_eq!(record.rid(), Some(0)); // No chromosome/contig set
+        assert_eq!(record.pos(), 0); // No position set
+        assert_eq!(record.qual(), 0.0); // No quality score set
+    }
+}

src/bcf/mod.rs

@@ -237,7 +237,7 @@ impl Read for Reader {
 
     /// Return empty record.  Can be reused multiple times.
     fn empty_record(&self) -> Record {
-        Record::new(Rc::clone(&self.header))
+        self.header.empty_record()
     }
 }