Resolve some clippys, format (#1144)

* cargo +nightly clippy --fix -Z unstable-options

examples/custom_collector.rs

@@ -86,12 +86,10 @@ impl Collector for StatsCollector {
 
     fn merge_fruits(&self, segment_stats: Vec<Option<Stats>>) -> tantivy::Result<Option<Stats>> {
         let mut stats = Stats::default();
-        for segment_stats_opt in segment_stats {
-            if let Some(segment_stats) = segment_stats_opt {
-                stats.count += segment_stats.count;
-                stats.sum += segment_stats.sum;
-                stats.squared_sum += segment_stats.squared_sum;
-            }
+        for segment_stats in segment_stats.into_iter().flatten() {
+            stats.count += segment_stats.count;
+            stats.sum += segment_stats.sum;
+            stats.squared_sum += segment_stats.squared_sum;
         }
         Ok(stats.non_zero_count())
     }

src/core/index.rs

@@ -535,7 +535,7 @@ impl Index {
 
         let mut damaged_files = HashSet::new();
         for path in active_existing_files {
-            if !self.directory.validate_checksum(&path)? {
+            if !self.directory.validate_checksum(path)? {
                 damaged_files.insert((*path).clone());
             }
         }

src/fastfield/serializer/mod.rs

@@ -105,9 +105,7 @@ impl CompositeFastFieldSerializer {
             &fastfield_accessor,
             &mut estimations,
         );
-        if let Some(broken_estimation) = estimations
-            .iter()
-            .find(|estimation| estimation.0 == f32::NAN)
+        if let Some(broken_estimation) = estimations.iter().find(|estimation| estimation.0.is_nan())
         {
             warn!(
                 "broken estimation for fast field codec {}",

src/functional_test.rs

@@ -141,7 +141,7 @@ const LOREM: &str = "Doc Lorem ipsum dolor sit amet, consectetur adipiscing elit
 fn get_text() -> String {
     use rand::seq::SliceRandom;
     let mut rng = thread_rng();
-    let tokens: Vec<_> = LOREM.split(" ").collect();
+    let tokens: Vec<_> = LOREM.split(' ').collect();
     let random_val = rng.gen_range(0..20);
 
     (0..random_val)

src/indexer/merger.rs

@@ -150,7 +150,7 @@ impl TermOrdinalMapping {
             .iter()
             .flat_map(|term_ordinals| term_ordinals.iter().cloned().max())
             .max()
-            .unwrap_or_else(TermOrdinal::default)
+            .unwrap_or_default()
     }
 }
 
@@ -966,7 +966,7 @@ impl IndexMerger {
                 doc_id_and_positions.sort_unstable_by_key(|&(doc_id, _, _)| doc_id);
 
                 for (doc_id, term_freq, positions) in &doc_id_and_positions {
-                    let delta_positions = delta_computer.compute_delta(&positions);
+                    let delta_positions = delta_computer.compute_delta(positions);
                     field_serializer.write_doc(*doc_id, *term_freq, delta_positions);
                 }
                 doc_id_and_positions.clear();

src/indexer/merger_sorted_index_test.rs

@@ -260,9 +260,7 @@ mod tests {
             let fallback_bitset = DeleteBitSet::for_test(&[0], 100);
             assert_eq!(
                 postings.doc_freq_given_deletes(
-                    segment_reader
-                        .delete_bitset()
-                        .unwrap_or_else(|| &&fallback_bitset)
+                    segment_reader.delete_bitset().unwrap_or(&fallback_bitset)
                 ),
                 2
             );
@@ -341,9 +339,7 @@ mod tests {
             let fallback_bitset = DeleteBitSet::for_test(&[0], 100);
             assert_eq!(
                 postings.doc_freq_given_deletes(
-                    segment_reader
-                        .delete_bitset()
-                        .unwrap_or_else(|| &&fallback_bitset)
+                    segment_reader.delete_bitset().unwrap_or(&fallback_bitset)
                 ),
                 2
             );
@@ -453,9 +449,7 @@ mod tests {
             let fallback_bitset = DeleteBitSet::for_test(&[0], 100);
             assert_eq!(
                 postings.doc_freq_given_deletes(
-                    segment_reader
-                        .delete_bitset()
-                        .unwrap_or_else(|| &&fallback_bitset)
+                    segment_reader.delete_bitset().unwrap_or(&fallback_bitset)
                 ),
                 2
             );

src/postings/block_segment_postings.rs

@@ -209,7 +209,7 @@ impl BlockSegmentPostings {
     #[inline]
     pub(crate) fn full_block(&self) -> &[DocId; COMPRESSION_BLOCK_SIZE] {
         debug_assert!(self.block_is_loaded());
-        &self.doc_decoder.full_output()
+        self.doc_decoder.full_output()
     }
 
     /// Return the document at index `idx` of the block.

src/postings/serializer.rs

@@ -443,10 +443,8 @@ impl<W: Write> PostingsSerializer<W> {
             let skip_data = self.skip_write.data();
             VInt(skip_data.len() as u64).serialize(&mut self.output_write)?;
             self.output_write.write_all(skip_data)?;
-            self.output_write.write_all(&self.postings_write[..])?;
-        } else {
-            self.output_write.write_all(&self.postings_write[..])?;
         }
+        self.output_write.write_all(&self.postings_write[..])?;
         self.skip_write.clear();
         self.postings_write.clear();
         self.bm25_weight = None;

src/query/automaton_weight.rs

@@ -121,10 +121,7 @@ mod tests {
         }
 
         fn is_match(&self, state: &Self::State) -> bool {
-            match *state {
-                State::AfterA => true,
-                _ => false,
-            }
+            matches!(*state, State::AfterA)
         }
 
         fn accept(&self, state: &Self::State, byte: u8) -> Self::State {

src/query/boolean_query/mod.rs

@@ -310,7 +310,7 @@ mod tests {
         ));
         let query = BooleanQuery::from(vec![(Occur::Should, term_a), (Occur::Should, term_b)]);
         let explanation = query.explain(&searcher, DocAddress::new(0, 0u32))?;
-        assert_nearly_equals!(explanation.value(), 0.6931472);
+        assert_nearly_equals!(explanation.value(), std::f32::consts::LN_2);
         Ok(())
     }
 }

src/schema/mod.rs

@@ -157,7 +157,7 @@ pub use self::int_options::IntOptions;
 /// A field name can be any character, must have at least one character
 /// and must not start with a `-`.
 pub fn is_valid_field_name(field_name: &str) -> bool {
-    field_name.len() > 0 && !field_name.starts_with('-')
+    !field_name.is_empty() && !field_name.starts_with('-')
 }
 
 #[cfg(test)]