bam/reader: Remove UnmappedRecords iterator

This is replaced by an `impl Trait`. Use `impl Iterator<Item =
io::Result<Record>>` instead.

noodles-bam/CHANGELOG.md

@@ -21,6 +21,13 @@
     It's possible for a chunk to include mapped records, which are subsequently
     filtered out, but they do require the associated header to decode.
 
+### Removed
+
+  * bam/reader: Remove `UnmappedRecords` iterator.
+
+    This is replaced by an `impl Trait`. Use `impl Iterator<Item =
+    io::Result<Record>>` instead.
+
 ## 0.43.0 - 2023-08-24
 
 ### Added

noodles-bam/src/indexed_reader.rs

@@ -11,8 +11,6 @@ use noodles_core::Region;
 use noodles_csi as csi;
 use noodles_sam::{self as sam, alignment::Record};
 
-use crate::reader::UnmappedRecords;
-
 use super::{
     lazy,
     reader::{LazyRecords, Query, Records},
@@ -107,7 +105,7 @@ where
     pub fn query_unmapped<'r>(
         &'r mut self,
         header: &'r sam::Header,
-    ) -> io::Result<UnmappedRecords<'r, R>> {
+    ) -> io::Result<impl Iterator<Item = io::Result<Record>> + 'r> {
         self.inner.query_unmapped(header, &self.index)
     }
 }

noodles-bam/src/reader.rs

@@ -6,12 +6,8 @@ mod lazy_records;
 pub(crate) mod query;
 mod record;
 mod records;
-mod unmapped_records;
 
-pub use self::{
-    builder::Builder, lazy_records::LazyRecords, query::Query, records::Records,
-    unmapped_records::UnmappedRecords,
-};
+pub use self::{builder::Builder, lazy_records::LazyRecords, query::Query, records::Records};
 
 use std::{
     ffi::CStr,
@@ -376,22 +372,27 @@ where
     ///
     /// for result in query {
     ///     let record = result?;
-    ///     println!("{:?}", record);
+    ///     // ...
     /// }
     /// # Ok::<(), io::Error>(())
     /// ```
     pub fn query_unmapped<'r>(
         &'r mut self,
         header: &'r sam::Header,
         index: &csi::Index,
-    ) -> io::Result<UnmappedRecords<'r, R>> {
+    ) -> io::Result<impl Iterator<Item = io::Result<Record>> + 'r> {
         if let Some(pos) = index.first_record_in_last_linear_bin_start_position() {
             self.seek(pos)?;
         } else {
             self.seek_to_first_record()?;
         }
 
-        Ok(UnmappedRecords::new(self, header))
+        Ok(self.records(header).filter(|result| {
+            result
+                .as_ref()
+                .map(|record| record.flags().is_unmapped())
+                .unwrap_or(true)
+        }))
     }
 }