From 29abea07d460bc203e98fdb9d322e7e24e3ffc20 Mon Sep 17 00:00:00 2001
From: Paul Masurel <paul.masurel@gmail.com>
Date: Sun, 14 Aug 2016 10:26:56 +0900
Subject: [PATCH] Refactoring

---
 src/postings/mod.rs                           |  2 -
 .../daat_multiterm_scorer.rs}                 | 53 ++++++++++-------
 src/query/mod.rs                              | 17 ++++--
 src/query/multi_term_accumulator.rs           |  4 ++
 src/query/multi_term_explainer.rs             | 36 ------------
 src/query/multi_term_query.rs                 | 19 +++---
 src/query/multi_term_scorer.rs                | 11 ----
 src/query/scorer.rs                           |  6 +-
 src/query/similarity.rs                       |  8 +++
 src/query/similarity_explainer.rs             | 48 +++++++++++++++
 src/query/tfidf.rs                            | 58 +++++++++----------
 src/schema/schema.rs                          |  9 ---
 12 files changed, 144 insertions(+), 127 deletions(-)
 rename src/{postings/union_postings.rs => query/daat_multiterm_scorer.rs} (81%)
 create mode 100644 src/query/multi_term_accumulator.rs
 delete mode 100644 src/query/multi_term_explainer.rs
 delete mode 100644 src/query/multi_term_scorer.rs
 create mode 100644 src/query/similarity.rs
 create mode 100644 src/query/similarity_explainer.rs

diff --git a/src/postings/mod.rs b/src/postings/mod.rs
index 7480bd129..c4d55bd0f 100644
--- a/src/postings/mod.rs
+++ b/src/postings/mod.rs
@@ -9,13 +9,11 @@ mod segment_postings;
 mod intersection;
 mod offset_postings;
 mod freq_handler;
-mod union_postings;
 mod docset;
 mod scored_docset;
 mod segment_postings_option;
 
 pub use self::docset::{SkipResult, DocSet};
-pub use self::union_postings::UnionPostings;
 pub use self::offset_postings::OffsetPostings;
 pub use self::recorder::{Recorder, NothingRecorder, TermFrequencyRecorder, TFAndPositionRecorder};
 pub use self::serializer::PostingsSerializer;
diff --git a/src/postings/union_postings.rs b/src/query/daat_multiterm_scorer.rs
similarity index 81%
rename from src/postings/union_postings.rs
rename to src/query/daat_multiterm_scorer.rs
index 59f96ffed..60b132579 100644
--- a/src/postings/union_postings.rs
+++ b/src/query/daat_multiterm_scorer.rs
@@ -2,10 +2,13 @@ use DocId;
 use postings::{Postings, DocSet};
 use std::cmp::Ordering;
 use std::collections::BinaryHeap;
-use query::MultiTermAccumulator; 
+use query::MultiTermAccumulator;
+use query::Similarity; 
 use fastfield::U32FastFieldReader;
 use query::Occur;
 use std::iter;
+use super::Scorer;
+use Score;
 
 #[derive(Eq, PartialEq)]
 struct HeapItem(DocId, u32);
@@ -55,27 +58,27 @@ impl Filter {
     }
 }
 
-pub struct UnionPostings<TPostings: Postings, TAccumulator: MultiTermAccumulator> {
+pub struct DAATMultiTermScorer<TPostings: Postings, TAccumulator: MultiTermAccumulator> {
     fieldnorm_readers: Vec<U32FastFieldReader>,
     postings: Vec<TPostings>,
     term_frequencies: Vec<u32>,
     queue: BinaryHeap<HeapItem>,
     doc: DocId,
-    scorer: TAccumulator,
+    similarity: TAccumulator,
     filter: Filter,
 }
 
 
 
-impl<TPostings: Postings, TAccumulator: MultiTermAccumulator> UnionPostings<TPostings, TAccumulator> {
+impl<TPostings: Postings, TAccumulator: MultiTermAccumulator> DAATMultiTermScorer<TPostings, TAccumulator> {
     
     fn new_non_empty(
         
         fieldnorm_readers: Vec<U32FastFieldReader>,
         postings: Vec<TPostings>,
-        scorer: TAccumulator,
+        similarity: TAccumulator,
         filter: Filter
-    ) -> UnionPostings<TPostings, TAccumulator> {
+    ) -> DAATMultiTermScorer<TPostings, TAccumulator> {
         let mut term_frequencies: Vec<u32> = iter::repeat(0u32).take(postings.len()).collect();
         let heap_items: Vec<HeapItem> = postings
             .iter()
@@ -88,18 +91,18 @@ impl<TPostings: Postings, TAccumulator: MultiTermAccumulator> UnionPostings<TPos
                 HeapItem(doc, ord as u32)
             })
             .collect();
-        UnionPostings {
+        DAATMultiTermScorer {
             fieldnorm_readers: fieldnorm_readers,
             postings: postings,
             term_frequencies: term_frequencies,
             queue: BinaryHeap::from(heap_items),
             doc: 0,
-            scorer: scorer,
+            similarity: similarity,
             filter: filter
         }
     }
     
-    pub fn new(postings_and_fieldnorms: Vec<(Occur, TPostings, U32FastFieldReader)>, scorer: TAccumulator) -> UnionPostings<TPostings, TAccumulator> {      
+    pub fn new(postings_and_fieldnorms: Vec<(Occur, TPostings, U32FastFieldReader)>, similarity: TAccumulator) -> DAATMultiTermScorer<TPostings, TAccumulator> {      
         let mut postings = Vec::new();
         let mut fieldnorm_readers = Vec::new();
         let mut occurs = Vec::new();
@@ -111,12 +114,12 @@ impl<TPostings: Postings, TAccumulator: MultiTermAccumulator> UnionPostings<TPos
             }
         }
         let filter = Filter::new(&occurs);
-        UnionPostings::new_non_empty(fieldnorm_readers, postings, scorer, filter)
+        DAATMultiTermScorer::new_non_empty(fieldnorm_readers, postings, similarity, filter)
     }
 
 
     pub fn scorer(&self,) -> &TAccumulator {
-        &self.scorer
+        &self.similarity
     }
 
     fn advance_head(&mut self,) {
@@ -138,11 +141,17 @@ impl<TPostings: Postings, TAccumulator: MultiTermAccumulator> UnionPostings<TPos
 
 }
 
-impl<TPostings: Postings, TAccumulator: MultiTermAccumulator> DocSet for UnionPostings<TPostings, TAccumulator> {
+impl<TPostings: Postings, TSimilarity: Similarity> Scorer for DAATMultiTermScorer<TPostings, TSimilarity> {
+    fn score(&self,) -> Score {
+        self.similarity.score()
+    }
+} 
+
+impl<TPostings: Postings, TAccumulator: MultiTermAccumulator> DocSet for DAATMultiTermScorer<TPostings, TAccumulator> {
     
     fn advance(&mut self,) -> bool {
         loop {
-            self.scorer.clear();
+            self.similarity.clear();
             let mut ord_bitset = 0u64;
             match self.queue.peek() {
                 Some(&HeapItem(doc, ord)) => {
@@ -150,7 +159,7 @@ impl<TPostings: Postings, TAccumulator: MultiTermAccumulator> DocSet for UnionPo
                     let ord: usize = ord as usize;
                     let fieldnorm = self.get_field_norm(ord, doc);
                     let tf = self.term_frequencies[ord];
-                    self.scorer.update(ord, tf, fieldnorm);
+                    self.similarity.update(ord, tf, fieldnorm);
                     ord_bitset |= 1 << ord;  
                 }
                 None => {
@@ -168,7 +177,7 @@ impl<TPostings: Postings, TAccumulator: MultiTermAccumulator> DocSet for UnionPo
                             let peek_ord: usize = peek_ord as usize;
                             let peek_tf = self.term_frequencies[peek_ord];
                             let peek_fieldnorm = self.get_field_norm(peek_ord, peek_doc);
-                            self.scorer.update(peek_ord, peek_tf, peek_fieldnorm);
+                            self.similarity.update(peek_ord, peek_tf, peek_fieldnorm);
                             ord_bitset |= 1 << peek_ord;
                         }
                     }
@@ -193,7 +202,7 @@ mod tests {
     
     use super::*;
     use postings::{DocSet, VecPostings};
-    use query::TfIdfScorer;
+    use query::TfIdf;
     use query::Scorer;
     use directory::ReadOnlySource;
     use directory::SharedVec;
@@ -225,21 +234,21 @@ mod tests {
         let right_fieldnorms = create_u32_fastfieldreader(Field(2), vec!(15,25,35));   
         let left = VecPostings::from(vec!(1, 2, 3));
         let right = VecPostings::from(vec!(1, 3, 8));
-        let multi_term_scorer = TfIdfScorer::new(vec!(0f32, 1f32, 2f32), vec!(1f32, 4f32));
-        let mut union = UnionPostings::new(
+        let tfidf = TfIdf::new(vec!(0f32, 1f32, 2f32), vec!(1f32, 4f32));
+        let mut union = DAATMultiTermScorer::new(
             vec!(
                 (Occur::Should, left, left_fieldnorms),
                 (Occur::Should, right, right_fieldnorms),
             ),
-            multi_term_scorer
+            tfidf
         );
         assert_eq!(union.next(), Some(1u32));
-        assert!(abs_diff(union.scorer().score(), 2.182179f32) < 0.001);
+        assert!(abs_diff(union.score(), 2.182179f32) < 0.001);
         assert_eq!(union.next(), Some(2u32));
-        assert!(abs_diff(union.scorer().score(), 0.2236068) < 0.001f32);
+        assert!(abs_diff(union.score(), 0.2236068) < 0.001f32);
         assert_eq!(union.next(), Some(3u32));
         assert_eq!(union.next(), Some(8u32));
-        assert!(abs_diff(union.scorer().score(), 0.8944272f32) < 0.001f32);
+        assert!(abs_diff(union.score(), 0.8944272f32) < 0.001f32);
         assert!(!union.advance());
     }
 
diff --git a/src/query/mod.rs b/src/query/mod.rs
index 09c6d463e..7c482b66e 100644
--- a/src/query/mod.rs
+++ b/src/query/mod.rs
@@ -1,21 +1,26 @@
 mod query;
 mod multi_term_query;
-mod multi_term_scorer;
-mod multi_term_explainer;
+mod multi_term_accumulator;
+mod similarity_explainer;
 mod scorer;
 mod query_parser;
 mod explanation;
 mod tfidf;
 mod occur;
+mod daat_multiterm_scorer;
+mod similarity;
+
+pub use self::similarity::Similarity;
+
+pub use self::daat_multiterm_scorer::DAATMultiTermScorer;
 
 pub use self::occur::Occur;
 pub use self::query::Query;
 pub use self::multi_term_query::MultiTermQuery;
-pub use self::multi_term_scorer::MultiTermScorer;
-pub use self::multi_term_explainer::MultiTermExplainer;
-pub use self::tfidf::TfIdfScorer;
+pub use self::similarity_explainer::SimilarityExplainer;
+pub use self::tfidf::TfIdf;
 
 pub use self::scorer::Scorer;
 pub use self::query_parser::QueryParser;
 pub use self::explanation::Explanation;
-pub use self::multi_term_scorer::MultiTermAccumulator;
+pub use self::multi_term_accumulator::MultiTermAccumulator;
diff --git a/src/query/multi_term_accumulator.rs b/src/query/multi_term_accumulator.rs
new file mode 100644
index 000000000..6685b1673
--- /dev/null
+++ b/src/query/multi_term_accumulator.rs
@@ -0,0 +1,4 @@
+pub trait MultiTermAccumulator {
+    fn update(&mut self, term_ord: usize, term_freq: u32, fieldnorm: u32);
+    fn clear(&mut self,);
+}
diff --git a/src/query/multi_term_explainer.rs b/src/query/multi_term_explainer.rs
deleted file mode 100644
index 453e1561e..000000000
--- a/src/query/multi_term_explainer.rs
+++ /dev/null
@@ -1,36 +0,0 @@
-use super::MultiTermAccumulator;
-use super::MultiTermScorer;
-use super::Explanation;
-
-pub struct MultiTermExplainer<TScorer: MultiTermScorer + Sized> {
-    scorer: TScorer,
-    vals: Vec<(usize, u32, u32)>,
-}
-
-impl<TScorer: MultiTermScorer + Sized> MultiTermExplainer<TScorer> {
-    pub fn explain_score(&self,) -> Explanation {
-        self.scorer.explain(&self.vals)
-    }
-}
-
-impl<TScorer: MultiTermScorer + Sized> From<TScorer> for MultiTermExplainer<TScorer> {
-    fn from(multi_term_scorer: TScorer) -> MultiTermExplainer<TScorer> {
-        MultiTermExplainer {
-            scorer: multi_term_scorer,
-            vals: Vec::new(),
-        }
-    }
-}
-
-impl<TScorer: MultiTermScorer + Sized> MultiTermAccumulator for MultiTermExplainer<TScorer> {
-    fn update(&mut self, term_ord: usize, term_freq: u32, fieldnorm: u32) {
-        self.vals.push((term_ord, term_freq, fieldnorm));
-        self.scorer.update(term_ord, term_freq, fieldnorm);
-    }
-    
-    fn clear(&mut self,) {
-        self.vals.clear();
-        self.scorer.clear();
-    }
-}
-
diff --git a/src/query/multi_term_query.rs b/src/query/multi_term_query.rs
index ed2378561..48da22d1e 100644
--- a/src/query/multi_term_query.rs
+++ b/src/query/multi_term_query.rs
@@ -8,11 +8,10 @@ use core::searcher::Searcher;
 use collector::Collector;
 use SegmentLocalId;
 use core::SegmentReader;
-use query::MultiTermExplainer;
+use query::SimilarityExplainer;
 use postings::SegmentPostings;
-use postings::UnionPostings;
 use postings::DocSet;
-use query::TfIdfScorer;
+use query::TfIdf;
 use postings::SkipResult;
 use ScoredDoc;
 use query::Scorer;
@@ -21,6 +20,7 @@ use DocAddress;
 use query::Explanation;
 use query::occur::Occur;
 use postings::SegmentPostingsOption;
+use query::DAATMultiTermScorer;
 
 
 #[derive(Eq, PartialEq, Debug)]
@@ -30,13 +30,12 @@ pub struct MultiTermQuery {
 
 
 impl MultiTermQuery {
-
     
     pub fn num_terms(&self,) -> usize {
         self.occur_terms.len()
     } 
     
-    fn scorer(&self, searcher: &Searcher) -> TfIdfScorer {
+    fn scorer(&self, searcher: &Searcher) -> TfIdf {
         let num_terms = self.num_terms();
         let num_docs = searcher.num_docs() as f32;
         let idfs: Vec<f32> = self.occur_terms
@@ -59,7 +58,7 @@ impl MultiTermQuery {
             .iter()
             .map(|&(_, ref term)| format!("{:?}", &term))
             .collect();
-        let mut tfidf_scorer = TfIdfScorer::new(query_coords, idfs);
+        let mut tfidf_scorer = TfIdf::new(query_coords, idfs);
         tfidf_scorer.set_term_names(term_names);
         tfidf_scorer
     }
@@ -68,7 +67,7 @@ impl MultiTermQuery {
             &'b self,
             reader: &'b SegmentReader,
             multi_term_scorer: TScorer,
-            mut timer: OpenTimer<'a>) -> Result<UnionPostings<SegmentPostings, TScorer>> {
+            mut timer: OpenTimer<'a>) -> Result<DAATMultiTermScorer<SegmentPostings, TScorer>> {
         let mut postings_and_fieldnorms = Vec::with_capacity(self.num_terms());
         {
             let mut decode_timer = timer.open("decode_all");
@@ -88,7 +87,7 @@ impl MultiTermQuery {
             // TODO putting the SHOULD at the end of the list should push the limit.
             return Err(Error::InvalidArgument(String::from("Limit of 64 terms was exceeded.")));
         }
-        Ok(UnionPostings::new(postings_and_fieldnorms, multi_term_scorer))
+        Ok(DAATMultiTermScorer::new(postings_and_fieldnorms, multi_term_scorer))
     }
 }
 
@@ -120,7 +119,7 @@ impl Query for MultiTermQuery {
         searcher: &Searcher,
         doc_address: &DocAddress) -> Result<Explanation> {
             let segment_reader = &searcher.segments()[doc_address.segment_ord() as usize];
-            let multi_term_scorer = MultiTermExplainer::from(self.scorer(searcher));
+            let multi_term_scorer = SimilarityExplainer::from(self.scorer(searcher));
             let mut timer_tree = TimerTree::new();
             let mut postings = try!(
                 self.search_segment(
@@ -164,7 +163,7 @@ impl Query for MultiTermQuery {
                 {
                     let _collection_timer = segment_search_timer.open("collection");
                     while postings.advance() {
-                        let scored_doc = ScoredDoc(postings.scorer().score(), postings.doc());
+                        let scored_doc = ScoredDoc(postings.score(), postings.doc());
                         collector.collect(scored_doc);
                     }
                 }
diff --git a/src/query/multi_term_scorer.rs b/src/query/multi_term_scorer.rs
deleted file mode 100644
index 00e5ecb5e..000000000
--- a/src/query/multi_term_scorer.rs
+++ /dev/null
@@ -1,11 +0,0 @@
-use query::Scorer;
-use query::Explanation;
-
-pub trait MultiTermAccumulator {
-    fn update(&mut self, term_ord: usize, term_freq: u32, fieldnorm: u32);
-    fn clear(&mut self,);
-}
-
-pub trait MultiTermScorer: Scorer + MultiTermAccumulator {
-    fn explain(&self, vals: &Vec<(usize, u32, u32)>) -> Explanation;
-}
diff --git a/src/query/scorer.rs b/src/query/scorer.rs
index 78b58cf36..36a91cd01 100644
--- a/src/query/scorer.rs
+++ b/src/query/scorer.rs
@@ -1,3 +1,7 @@
-pub trait Scorer {
+use DocSet;
+
+pub trait Scorer: DocSet {
     fn score(&self,) -> f32;
 } 
+
+
diff --git a/src/query/similarity.rs b/src/query/similarity.rs
new file mode 100644
index 000000000..b911cd435
--- /dev/null
+++ b/src/query/similarity.rs
@@ -0,0 +1,8 @@
+use Score;
+use query::Explanation;
+use query::MultiTermAccumulator;
+
+pub trait Similarity: MultiTermAccumulator {
+    fn score(&self, ) -> Score;
+    fn explain(&self, vals: &Vec<(usize, u32, u32)>) -> Explanation;
+}
\ No newline at end of file
diff --git a/src/query/similarity_explainer.rs b/src/query/similarity_explainer.rs
new file mode 100644
index 000000000..19588e329
--- /dev/null
+++ b/src/query/similarity_explainer.rs
@@ -0,0 +1,48 @@
+use Score;
+use super::MultiTermAccumulator;
+use super::Similarity;
+use super::Explanation;
+
+pub struct SimilarityExplainer<TSimilarity: Similarity + Sized> {
+    scorer: TSimilarity,
+    vals: Vec<(usize, u32, u32)>,
+}
+
+impl<TSimilarity: Similarity + Sized> SimilarityExplainer<TSimilarity> {
+    pub fn explain_score(&self,) -> Explanation {
+        self.scorer.explain(&self.vals)
+    }
+}
+
+impl<TSimilarity: Similarity + Sized> From<TSimilarity> for SimilarityExplainer<TSimilarity> {
+    fn from(multi_term_scorer: TSimilarity) -> SimilarityExplainer<TSimilarity> {
+        SimilarityExplainer {
+            scorer: multi_term_scorer,
+            vals: Vec::new(),
+        }
+    }
+}
+
+impl<TSimilarity: Similarity + Sized> MultiTermAccumulator for SimilarityExplainer<TSimilarity> {
+    fn update(&mut self, term_ord: usize, term_freq: u32, fieldnorm: u32) {
+        self.vals.push((term_ord, term_freq, fieldnorm));
+        self.scorer.update(term_ord, term_freq, fieldnorm);
+    }
+    
+    fn clear(&mut self,) {
+        self.vals.clear();
+        self.scorer.clear();
+    }
+}
+
+
+impl<TSimilarity: Similarity + Sized> Similarity for SimilarityExplainer<TSimilarity> {
+    
+    fn score(&self,) -> Score {
+        self.scorer.score()
+    } 
+    
+    fn explain(&self, vals: &Vec<(usize, u32, u32)>) -> Explanation {
+        self.scorer.explain(vals)
+    }
+}
diff --git a/src/query/tfidf.rs b/src/query/tfidf.rs
index 6dd2b9f58..3f978ac78 100644
--- a/src/query/tfidf.rs
+++ b/src/query/tfidf.rs
@@ -1,10 +1,10 @@
+use Score;
 use super::MultiTermAccumulator;
-use super::Scorer;
-use super::MultiTermScorer;
 use super::Explanation;
+use super::Similarity;
 
 #[derive(Clone)]
-pub struct TfIdfScorer {
+pub struct TfIdf {
     coords: Vec<f32>,
     idf: Vec<f32>,
     score: f32,
@@ -12,7 +12,7 @@ pub struct TfIdfScorer {
     term_names: Option<Vec<String>>, //< only here for explain
 }
 
-impl MultiTermAccumulator for TfIdfScorer {
+impl MultiTermAccumulator for TfIdf {
     
     #[inline(always)]
     fn update(&mut self, term_ord: usize, term_freq: u32, fieldnorm: u32) {
@@ -28,9 +28,9 @@ impl MultiTermAccumulator for TfIdfScorer {
     }
 }
 
-impl TfIdfScorer {
-    pub fn new(coords: Vec<f32>, idf: Vec<f32>) -> TfIdfScorer {
-        TfIdfScorer {
+impl TfIdf {
+    pub fn new(coords: Vec<f32>, idf: Vec<f32>) -> TfIdf {
+        TfIdf {
             coords: coords,
             idf: idf,
             score: 0f32,
@@ -61,14 +61,12 @@ impl TfIdfScorer {
     }
 }
 
-impl Scorer for TfIdfScorer {
+impl Similarity for TfIdf {
     #[inline(always)]
-    fn score(&self, ) -> f32 {
+    fn score(&self, ) -> Score {
         self.score * self.coord()
     }
-}
-
-impl MultiTermScorer for TfIdfScorer {
+    
     fn explain(&self, vals: &Vec<(usize, u32, u32)>) -> Explanation {
         let score = self.score();
         let mut explanation = Explanation::with_val(score);
@@ -89,41 +87,41 @@ impl MultiTermScorer for TfIdfScorer {
 
 
 
+
 #[cfg(test)]
 mod tests {
     
     use super::*;
-    use query::Scorer;
     use query::MultiTermAccumulator;
-            
+    use query::Similarity;
+    
     fn abs_diff(left: f32, right: f32) -> f32 {
         (right - left).abs()
     }  
 
     #[test]
-    pub fn test_multiterm_scorer() {
-        let mut tfidf_scorer = TfIdfScorer::new(vec!(0f32, 1f32, 2f32), vec!(1f32, 4f32));
+    pub fn test_tfidf() {
+        let mut tfidf = TfIdf::new(vec!(0f32, 1f32, 2f32), vec!(1f32, 4f32));
         {
-            tfidf_scorer.update(0, 1, 1);
-            assert!(abs_diff(tfidf_scorer.score(), 1f32) < 0.001f32);
-            tfidf_scorer.clear();
-            
+            tfidf.update(0, 1, 1);
+            assert!(abs_diff(tfidf.score(), 1f32) < 0.001f32);
+            tfidf.clear();
         }
         {
-            tfidf_scorer.update(1, 1, 1);
-            assert_eq!(tfidf_scorer.score(), 4f32);    
-            tfidf_scorer.clear();
+            tfidf.update(1, 1, 1);
+            assert_eq!(tfidf.score(), 4f32);    
+            tfidf.clear();
         }
         {
-            tfidf_scorer.update(0, 2, 1);
-            assert!(abs_diff(tfidf_scorer.score(), 1.4142135) < 0.001f32);          
-            tfidf_scorer.clear();
+            tfidf.update(0, 2, 1);
+            assert!(abs_diff(tfidf.score(), 1.4142135) < 0.001f32);          
+            tfidf.clear();
         }
         {
-            tfidf_scorer.update(0, 1, 1);
-            tfidf_scorer.update(1, 1, 1);
-            assert_eq!(tfidf_scorer.score(), 10f32);    
-            tfidf_scorer.clear();
+            tfidf.update(0, 1, 1);
+            tfidf.update(1, 1, 1);
+            assert_eq!(tfidf.score(), 10f32);    
+            tfidf.clear();
         }
 
 
diff --git a/src/schema/schema.rs b/src/schema/schema.rs
index dd459dc56..10b9807ef 100644
--- a/src/schema/schema.rs
+++ b/src/schema/schema.rs
@@ -22,20 +22,11 @@ use super::*;
 /// ```
 /// use tantivy::schema::*;
 ///
-/// fn create_schema() -> Schema {
 ///   let mut schema = Schema::new();
-///   let str_fieldtype = TextOptions::new();
 ///   let id_field = schema.add_text_field("id", STRING);
-///   let url_field = schema.add_text_field("url", STRING);
-///   let body_field = schema.add_text_field("body", TEXT);
-///   let id_field = schema.add_text_field("id", STRING);
-///   let url_field = schema.add_text_field("url", STRING);
 ///   let title_field = schema.add_text_field("title", TEXT);
 ///   let body_field = schema.add_text_field("body", TEXT);
-///   schema
-/// }
 ///
-/// let schema = create_schema();
 /// ```
 #[derive(Clone, Debug)]
 pub struct Schema {