Remove forgotten code.

src/core/segment_reader.rs

@@ -310,7 +310,7 @@ impl SegmentReader {
     }
 
     /// Returns an iterator that will iterate over the alive document ids
-    pub fn doc_ids_alive<'a>(&'a self) -> impl Iterator<Item = DocId> + 'a {
+    pub fn doc_ids_alive(&self) -> impl Iterator<Item = DocId> + '_ {
         (0u32..self.max_doc).filter(move |doc| !self.is_deleted(*doc))
     }
 

src/indexer/segment_writer.rs

@@ -11,7 +11,8 @@ use crate::schema::Schema;
 use crate::schema::Term;
 use crate::schema::Value;
 use crate::schema::{Field, FieldEntry};
-use crate::tokenizer::{BoxTokenStream, PreTokenizedStream};
+use crate::tokenizer::PreTokenizedStream;
+use crate::tokenizer::TokenStream;
 use crate::tokenizer::{FacetTokenizer, TextAnalyzer};
 use crate::tokenizer::{TokenStreamChain, Tokenizer};
 use crate::Opstamp;
@@ -141,13 +142,13 @@ impl SegmentWriter {
             }
             let (term_buffer, multifield_postings) =
                 (&mut self.term_buffer, &mut self.multifield_postings);
-            match *field_entry.field_type() {
+            match field_entry.field_type() {
                 FieldType::HierarchicalFacet => {
                     term_buffer.set_field(field);
                     let facets =
                         field_values
                             .iter()
-                            .flat_map(|field_value| match *field_value.value() {
+                            .flat_map(|field_value| match field_value.value() {
                                 Value::Facet(ref facet) => Some(facet.encoded_str()),
                                 _ => {
                                     panic!("Expected hierarchical facet");
@@ -172,37 +173,38 @@ impl SegmentWriter {
                     }
                 }
                 FieldType::Str(_) => {
-                    let mut token_streams: Vec<BoxTokenStream> = vec![];
-                    let mut offsets = vec![];
+                    let mut streams_with_offsets = vec![];
                     let mut total_offset = 0;
 
                     for field_value in field_values {
                         match field_value.value() {
                             Value::PreTokStr(tok_str) => {
-                                offsets.push(total_offset);
+                                streams_with_offsets.push((
+                                    Box::new(PreTokenizedStream::from(tok_str.clone()))
+                                        as Box<dyn TokenStream>,
+                                    total_offset,
+                                ));
                                 if let Some(last_token) = tok_str.tokens.last() {
                                     total_offset += last_token.offset_to;
                                 }
-                                token_streams
-                                    .push(PreTokenizedStream::from(tok_str.clone()).into());
                             }
                             Value::Str(ref text) => {
                                 if let Some(ref mut tokenizer) =
                                     self.tokenizers[field.field_id() as usize]
                                 {
-                                    offsets.push(total_offset);
+                                    streams_with_offsets
+                                        .push((tokenizer.token_stream(text), total_offset));
                                     total_offset += text.len();
-                                    token_streams.push(tokenizer.token_stream(text));
                                 }
                             }
                             _ => (),
                         }
                     }
 
-                    let num_tokens = if token_streams.is_empty() {
+                    let num_tokens = if streams_with_offsets.is_empty() {
                         0
                     } else {
-                        let mut token_stream = TokenStreamChain::new(offsets, token_streams);
+                        let mut token_stream = TokenStreamChain::new(streams_with_offsets);
                         multifield_postings.index_text(
                             doc_id,
                             field,

src/positions/reader.rs

@@ -132,7 +132,7 @@ impl PositionReader {
             "offset arguments should be increasing."
         );
         let delta_to_block_offset = offset as i64 - self.block_offset as i64;
-        if delta_to_block_offset < 0 || delta_to_block_offset >= 128 {
+        if !(0..128).contains(&delta_to_block_offset) {
             // The first position is not within the first block.
             // We need to decompress the first block.
             let delta_to_anchor_offset = offset - self.anchor_offset;

src/postings/block_search.rs

@@ -109,9 +109,9 @@ impl BlockSearcher {
     /// The results should be equivalent to
     /// ```compile_fail
     /// block[..]
-    //       .iter()
-    //       .take_while(|&&val| val < target)
-    //       .count()
+    ///       .iter()
+    ///       .take_while(|&&val| val < target)
+    ///       .count()
     /// ```
     ///
     /// The `start` argument is just used to hint that the response is

src/store/index/skip_index.rs

@@ -35,11 +35,11 @@ struct Layer {
 }
 
 impl Layer {
-    fn cursor<'a>(&'a self) -> impl Iterator<Item = Checkpoint> + 'a {
+    fn cursor(&self) -> impl Iterator<Item = Checkpoint> + '_ {
         self.cursor_at_offset(0u64)
     }
 
-    fn cursor_at_offset<'a>(&'a self, start_offset: u64) -> impl Iterator<Item = Checkpoint> + 'a {
+    fn cursor_at_offset(&self, start_offset: u64) -> impl Iterator<Item = Checkpoint> + '_ {
         let data = &self.data.as_slice();
         LayerCursor {
             remaining: &data[start_offset as usize..],
@@ -59,7 +59,7 @@ pub struct SkipIndex {
 }
 
 impl SkipIndex {
-    pub(crate) fn checkpoints<'a>(&'a self) -> impl Iterator<Item = Checkpoint> + 'a {
+    pub(crate) fn checkpoints(&self) -> impl Iterator<Item = Checkpoint> + '_ {
         self.layers
             .last()
             .into_iter()

src/store/reader.rs

@@ -46,7 +46,7 @@ impl StoreReader {
         })
     }
 
-    pub(crate) fn block_checkpoints<'a>(&'a self) -> impl Iterator<Item = Checkpoint> + 'a {
+    pub(crate) fn block_checkpoints(&self) -> impl Iterator<Item = Checkpoint> + '_ {
         self.skip_index.checkpoints()
     }
 

src/tokenizer/alphanum_only.rs

@@ -19,7 +19,7 @@
 //! // the "emoji" is dropped because its not an alphanum
 //! assert!(stream.next().is_none());
 //! ```
-use super::{BoxTokenStream, Token, TokenFilter, TokenStream};
+use super::{Token, TokenFilter, TokenStream};
 
 /// `TokenFilter` that removes all tokens that contain non
 /// ascii alphanumeric characters.
@@ -27,7 +27,7 @@ use super::{BoxTokenStream, Token, TokenFilter, TokenStream};
 pub struct AlphaNumOnlyFilter;
 
 pub struct AlphaNumOnlyFilterStream<'a> {
-    tail: BoxTokenStream<'a>,
+    tail: Box<dyn TokenStream + 'a>,
 }
 
 impl<'a> AlphaNumOnlyFilterStream<'a> {
@@ -37,8 +37,8 @@ impl<'a> AlphaNumOnlyFilterStream<'a> {
 }
 
 impl TokenFilter for AlphaNumOnlyFilter {
-    fn transform<'a>(&self, token_stream: BoxTokenStream<'a>) -> BoxTokenStream<'a> {
-        BoxTokenStream::from(AlphaNumOnlyFilterStream { tail: token_stream })
+    fn transform<'a>(&self, token_stream: Box<dyn TokenStream + 'a>) -> Box<dyn TokenStream + 'a> {
+        Box::new(AlphaNumOnlyFilterStream { tail: token_stream })
     }
 }
 

src/tokenizer/ascii_folding_filter.rs

@@ -1,4 +1,4 @@
-use super::{BoxTokenStream, Token, TokenFilter, TokenStream};
+use super::{Token, TokenFilter, TokenStream};
 use std::mem;
 
 /// This class converts alphabetic, numeric, and symbolic Unicode characters
@@ -8,8 +8,8 @@ use std::mem;
 pub struct AsciiFoldingFilter;
 
 impl TokenFilter for AsciiFoldingFilter {
-    fn transform<'a>(&self, token_stream: BoxTokenStream<'a>) -> BoxTokenStream<'a> {
-        From::from(AsciiFoldingFilterTokenStream {
+    fn transform<'a>(&self, token_stream: Box<dyn TokenStream + 'a>) -> Box<dyn TokenStream + 'a> {
+        Box::new(AsciiFoldingFilterTokenStream {
             tail: token_stream,
             buffer: String::with_capacity(100),
         })
@@ -18,7 +18,7 @@ impl TokenFilter for AsciiFoldingFilter {
 
 pub struct AsciiFoldingFilterTokenStream<'a> {
     buffer: String,
-    tail: BoxTokenStream<'a>,
+    tail: Box<dyn TokenStream + 'a>,
 }
 
 impl<'a> TokenStream for AsciiFoldingFilterTokenStream<'a> {

src/tokenizer/facet_tokenizer.rs

@@ -1,4 +1,4 @@
-use super::{BoxTokenStream, Token, TokenStream, Tokenizer};
+use super::{Token, TokenStream, Tokenizer};
 use crate::schema::FACET_SEP_BYTE;
 
 /// The `FacetTokenizer` process a `Facet` binary representation
@@ -26,13 +26,12 @@ pub struct FacetTokenStream<'a> {
 }
 
 impl Tokenizer for FacetTokenizer {
-    fn token_stream<'a>(&self, text: &'a str) -> BoxTokenStream<'a> {
-        FacetTokenStream {
+    fn token_stream<'a>(&self, text: &'a str) -> Box<dyn TokenStream + 'a> {
+        Box::new(FacetTokenStream {
             text,
             state: State::RootFacetNotEmitted, //< pos is the first char that has not been processed yet.
             token: Token::default(),
-        }
-        .into()
+        })
     }
 }
 

src/tokenizer/lower_caser.rs

@@ -1,10 +1,9 @@
 use super::{Token, TokenFilter, TokenStream};
-use crate::tokenizer::BoxTokenStream;
 use std::mem;
 
 impl TokenFilter for LowerCaser {
-    fn transform<'a>(&self, token_stream: BoxTokenStream<'a>) -> BoxTokenStream<'a> {
-        BoxTokenStream::from(LowerCaserTokenStream {
+    fn transform<'a>(&self, token_stream: Box<dyn TokenStream + 'a>) -> Box<dyn TokenStream + 'a> {
+        Box::new(LowerCaserTokenStream {
             tail: token_stream,
             buffer: String::with_capacity(100),
         })
@@ -17,7 +16,7 @@ pub struct LowerCaser;
 
 pub struct LowerCaserTokenStream<'a> {
     buffer: String,
-    tail: BoxTokenStream<'a>,
+    tail: Box<dyn TokenStream + 'a>,
 }
 
 // writes a lowercased version of text into output.

src/tokenizer/mod.rs

@@ -145,9 +145,7 @@ pub use self::stop_word_filter::StopWordFilter;
 pub(crate) use self::token_stream_chain::TokenStreamChain;
 
 pub use self::tokenized_string::{PreTokenizedStream, PreTokenizedString};
-pub use self::tokenizer::{
-    BoxTokenFilter, BoxTokenStream, TextAnalyzer, Token, TokenFilter, TokenStream, Tokenizer,
-};
+pub use self::tokenizer::{TextAnalyzer, Token, TokenFilter, TokenStream, Tokenizer};
 
 pub use self::tokenizer_manager::TokenizerManager;
 

src/tokenizer/ngram_tokenizer.rs

@@ -1,5 +1,4 @@
 use super::{Token, TokenStream, Tokenizer};
-use crate::tokenizer::BoxTokenStream;
 
 /// Tokenize the text by splitting words into n-grams of the given size(s)
 ///
@@ -131,8 +130,8 @@ pub struct NgramTokenStream<'a> {
 }
 
 impl Tokenizer for NgramTokenizer {
-    fn token_stream<'a>(&self, text: &'a str) -> BoxTokenStream<'a> {
-        From::from(NgramTokenStream {
+    fn token_stream<'a>(&self, text: &'a str) -> Box<dyn TokenStream + 'a> {
+        Box::new(NgramTokenStream {
             ngram_charidx_iterator: StutteringIterator::new(
                 CodepointFrontiers::for_str(text),
                 self.min_gram,
@@ -308,9 +307,9 @@ mod tests {
     use super::StutteringIterator;
     use crate::tokenizer::tests::assert_token;
     use crate::tokenizer::tokenizer::Tokenizer;
-    use crate::tokenizer::{BoxTokenStream, Token};
+    use crate::tokenizer::{Token, TokenStream};
 
-    fn test_helper(mut tokenizer: BoxTokenStream) -> Vec<Token> {
+    fn test_helper(mut tokenizer: Box<dyn TokenStream>) -> Vec<Token> {
         let mut tokens: Vec<Token> = vec![];
         tokenizer.process(&mut |token: &Token| tokens.push(token.clone()));
         tokens

src/tokenizer/raw_tokenizer.rs

@@ -1,5 +1,4 @@
 use super::{Token, TokenStream, Tokenizer};
-use crate::tokenizer::BoxTokenStream;
 
 /// For each value of the field, emit a single unprocessed token.
 #[derive(Clone)]
@@ -11,7 +10,7 @@ pub struct RawTokenStream {
 }
 
 impl Tokenizer for RawTokenizer {
-    fn token_stream<'a>(&self, text: &'a str) -> BoxTokenStream<'a> {
+    fn token_stream<'a>(&self, text: &'a str) -> Box<dyn TokenStream + 'a> {
         let token = Token {
             offset_from: 0,
             offset_to: text.len(),
@@ -19,11 +18,10 @@ impl Tokenizer for RawTokenizer {
             text: text.to_string(),
             position_length: 1,
         };
-        RawTokenStream {
+        Box::new(RawTokenStream {
             token,
             has_token: true,
-        }
-        .into()
+        })
     }
 }
 

src/tokenizer/remove_long.rs

@@ -13,7 +13,6 @@
 //! ```
 //!
 use super::{Token, TokenFilter, TokenStream};
-use crate::tokenizer::BoxTokenStream;
 
 /// `RemoveLongFilter` removes tokens that are longer
 /// than a given number of bytes (in UTF-8 representation).
@@ -39,8 +38,8 @@ impl<'a> RemoveLongFilterStream<'a> {
 }
 
 impl TokenFilter for RemoveLongFilter {
-    fn transform<'a>(&self, token_stream: BoxTokenStream<'a>) -> BoxTokenStream<'a> {
-        BoxTokenStream::from(RemoveLongFilterStream {
+    fn transform<'a>(&self, token_stream: Box<dyn TokenStream + 'a>) -> Box<dyn TokenStream + 'a> {
+        Box::new(RemoveLongFilterStream {
             token_length_limit: self.length_limit,
             tail: token_stream,
         })
@@ -49,7 +48,7 @@ impl TokenFilter for RemoveLongFilter {
 
 pub struct RemoveLongFilterStream<'a> {
     token_length_limit: usize,
-    tail: BoxTokenStream<'a>,
+    tail: Box<dyn TokenStream + 'a>,
 }
 
 impl<'a> TokenStream for RemoveLongFilterStream<'a> {

src/tokenizer/simple_tokenizer.rs

@@ -1,4 +1,3 @@
-use super::BoxTokenStream;
 use super::{Token, TokenStream, Tokenizer};
 use std::str::CharIndices;
 
@@ -13,8 +12,8 @@ pub struct SimpleTokenStream<'a> {
 }
 
 impl Tokenizer for SimpleTokenizer {
-    fn token_stream<'a>(&self, text: &'a str) -> BoxTokenStream<'a> {
-        BoxTokenStream::from(SimpleTokenStream {
+    fn token_stream<'a>(&self, text: &'a str) -> Box<dyn TokenStream + 'a> {
+        Box::new(SimpleTokenStream {
             text,
             chars: text.char_indices(),
             token: Token::default(),

src/tokenizer/stemmer.rs

@@ -1,5 +1,4 @@
 use super::{Token, TokenFilter, TokenStream};
-use crate::tokenizer::BoxTokenStream;
 use rust_stemmers::{self, Algorithm};
 use serde::{Deserialize, Serialize};
 
@@ -78,9 +77,9 @@ impl Default for Stemmer {
 }
 
 impl TokenFilter for Stemmer {
-    fn transform<'a>(&self, token_stream: BoxTokenStream<'a>) -> BoxTokenStream<'a> {
+    fn transform<'a>(&self, token_stream: Box<dyn TokenStream + 'a>) -> Box<dyn TokenStream + 'a> {
         let inner_stemmer = rust_stemmers::Stemmer::create(self.stemmer_algorithm);
-        BoxTokenStream::from(StemmerTokenStream {
+        Box::new(StemmerTokenStream {
             tail: token_stream,
             stemmer: inner_stemmer,
         })
@@ -88,7 +87,7 @@ impl TokenFilter for Stemmer {
 }
 
 pub struct StemmerTokenStream<'a> {
-    tail: BoxTokenStream<'a>,
+    tail: Box<dyn TokenStream + 'a>,
     stemmer: rust_stemmers::Stemmer,
 }
 

src/tokenizer/stop_word_filter.rs

@@ -11,7 +11,6 @@
 //! assert!(stream.next().is_none());
 //! ```
 use super::{Token, TokenFilter, TokenStream};
-use crate::tokenizer::BoxTokenStream;
 use fnv::FnvHasher;
 use std::collections::HashSet;
 use std::hash::BuildHasherDefault;
@@ -51,12 +50,12 @@ impl StopWordFilter {
 
 pub struct StopWordFilterStream<'a> {
     words: StopWordHashSet,
-    tail: BoxTokenStream<'a>,
+    tail: Box<dyn TokenStream + 'a>,
 }
 
 impl TokenFilter for StopWordFilter {
-    fn transform<'a>(&self, token_stream: BoxTokenStream<'a>) -> BoxTokenStream<'a> {
-        BoxTokenStream::from(StopWordFilterStream {
+    fn transform<'a>(&self, token_stream: Box<dyn TokenStream + 'a>) -> Box<dyn TokenStream + 'a> {
+        Box::new(StopWordFilterStream {
             words: self.words.clone(),
             tail: token_stream,
         })

src/tokenizer/token_stream_chain.rs

@@ -1,11 +1,9 @@
-use crate::tokenizer::{BoxTokenStream, Token, TokenStream};
-use std::ops::DerefMut;
+use crate::tokenizer::{Token, TokenStream};
 
 const POSITION_GAP: usize = 2;
 
 pub(crate) struct TokenStreamChain<'a> {
-    offsets: Vec<usize>,
-    token_streams: Vec<BoxTokenStream<'a>>,
+    streams_with_offsets: Vec<(Box<dyn TokenStream + 'a>, usize)>,
     position_shift: usize,
     stream_idx: usize,
     token: Token,
@@ -13,13 +11,11 @@ pub(crate) struct TokenStreamChain<'a> {
 
 impl<'a> TokenStreamChain<'a> {
     pub fn new(
-        offsets: Vec<usize>,
-        token_streams: Vec<BoxTokenStream<'a>>,
+        streams_with_offsets: Vec<(Box<dyn TokenStream + 'a>, usize)>,
     ) -> TokenStreamChain<'a> {
         TokenStreamChain {
-            offsets,
+            streams_with_offsets,
             stream_idx: 0,
-            token_streams,
             position_shift: 0,
             token: Token::default(),
         }
@@ -28,11 +24,10 @@ impl<'a> TokenStreamChain<'a> {
 
 impl<'a> TokenStream for TokenStreamChain<'a> {
     fn advance(&mut self) -> bool {
-        while self.stream_idx < self.token_streams.len() {
-            let token_stream = self.token_streams[self.stream_idx].deref_mut();
+        while self.stream_idx < self.streams_with_offsets.len() {
+            let (ref mut token_stream, offset_offset) = self.streams_with_offsets[self.stream_idx];
             if token_stream.advance() {
                 let token = token_stream.token();
-                let offset_offset = self.offsets[self.stream_idx];
                 self.token.offset_from = token.offset_from + offset_offset;
                 self.token.offset_to = token.offset_to + offset_offset;
                 self.token.position = token.position + self.position_shift;
@@ -49,7 +44,7 @@ impl<'a> TokenStream for TokenStreamChain<'a> {
 
     fn token(&self) -> &Token {
         assert!(
-            self.stream_idx <= self.token_streams.len(),
+            self.stream_idx <= self.streams_with_offsets.len(),
             "You called .token(), after the end of the token stream has been reached"
         );
         &self.token
@@ -57,7 +52,7 @@ impl<'a> TokenStream for TokenStreamChain<'a> {
 
     fn token_mut(&mut self) -> &mut Token {
         assert!(
-            self.stream_idx <= self.token_streams.len(),
+            self.stream_idx <= self.streams_with_offsets.len(),
             "You called .token(), after the end of the token stream has been reached"
         );
         &mut self.token
@@ -73,10 +68,10 @@ mod tests {
     #[test]
     fn test_chain_first_emits_no_tokens() {
         let token_streams = vec![
-            SimpleTokenizer.token_stream(""),
-            SimpleTokenizer.token_stream("hello world"),
+            (SimpleTokenizer.token_stream(""), 0),
+            (SimpleTokenizer.token_stream("hello world"), 0),
         ];
-        let mut token_chain = TokenStreamChain::new(vec![0, 0], token_streams);
+        let mut token_chain = TokenStreamChain::new(token_streams);
 
         assert!(token_chain.advance());
         assert_eq!(token_chain.token().text, "hello");

src/tokenizer/tokenized_string.rs

@@ -1,4 +1,4 @@
-use crate::tokenizer::{BoxTokenStream, Token, TokenStream, TokenStreamChain};
+use crate::tokenizer::{Token, TokenStream, TokenStreamChain};
 use serde::{Deserialize, Serialize};
 use std::cmp::Ordering;
 
@@ -42,24 +42,23 @@ impl PreTokenizedStream {
     /// Creates a TokenStream from PreTokenizedString array
     pub fn chain_tokenized_strings<'a>(
         tok_strings: &'a [&'a PreTokenizedString],
-    ) -> BoxTokenStream {
+    ) -> Box<dyn TokenStream> {
         if tok_strings.len() == 1 {
-            PreTokenizedStream::from((*tok_strings[0]).clone()).into()
+            Box::new(PreTokenizedStream::from(tok_strings[0].to_owned()))
         } else {
-            let mut offsets = vec![];
+            let mut streams_with_offsets = vec![];
             let mut total_offset = 0;
             for &tok_string in tok_strings {
-                offsets.push(total_offset);
+                streams_with_offsets.push((
+                    Box::new(PreTokenizedStream::from(tok_string.to_owned()))
+                        as Box<dyn TokenStream>,
+                    total_offset,
+                ));
                 if let Some(last_token) = tok_string.tokens.last() {
                     total_offset += last_token.offset_to;
                 }
             }
-            // TODO remove the string cloning.
-            let token_streams: Vec<BoxTokenStream<'static>> = tok_strings
-                .iter()
-                .map(|&tok_string| PreTokenizedStream::from((*tok_string).clone()).into())
-                .collect();
-            TokenStreamChain::new(offsets, token_streams).into()
+            Box::new(TokenStreamChain::new(streams_with_offsets))
         }
     }
 }

src/tokenizer/tokenizer.rs

@@ -2,8 +2,6 @@ use crate::tokenizer::TokenStreamChain;
 use serde::{Deserialize, Serialize};
 /// The tokenizer module contains all of the tools used to process
 /// text in `tantivy`.
-use std::borrow::{Borrow, BorrowMut};
-use std::ops::{Deref, DerefMut};
 
 /// Token
 #[derive(Debug, Clone, Serialize, Deserialize, Eq, PartialEq)]
@@ -40,7 +38,7 @@ impl Default for Token {
 /// It simply wraps a `Tokenizer` and a list of `TokenFilter` that are applied sequentially.
 pub struct TextAnalyzer {
     tokenizer: Box<dyn Tokenizer>,
-    token_filters: Vec<BoxTokenFilter>,
+    token_filters: Vec<Box<dyn TokenFilter>>,
 }
 
 impl<T: Tokenizer> From<T> for TextAnalyzer {
@@ -50,11 +48,14 @@ impl<T: Tokenizer> From<T> for TextAnalyzer {
 }
 
 impl TextAnalyzer {
-    /// Creates a new `TextAnalyzer` given a tokenizer and a vector of `BoxTokenFilter`.
+    /// Creates a new `TextAnalyzer` given a tokenizer and a vector of `Box<dyn TokenFilter>`.
     ///
     /// When creating a `TextAnalyzer` from a `Tokenizer` alone, prefer using
     /// `TextAnalyzer::from(tokenizer)`.
-    pub fn new<T: Tokenizer>(tokenizer: T, token_filters: Vec<BoxTokenFilter>) -> TextAnalyzer {
+    pub fn new<T: Tokenizer>(
+        tokenizer: T,
+        token_filters: Vec<Box<dyn TokenFilter>>,
+    ) -> TextAnalyzer {
         TextAnalyzer {
             tokenizer: Box::new(tokenizer),
             token_filters,
@@ -77,8 +78,8 @@ impl TextAnalyzer {
     ///     .filter(Stemmer::default());
     /// ```
     ///
-    pub fn filter<F: Into<BoxTokenFilter>>(mut self, token_filter: F) -> Self {
-        self.token_filters.push(token_filter.into());
+    pub fn filter<F: TokenFilter>(mut self, token_filter: F) -> Self {
+        self.token_filters.push(Box::new(token_filter));
         self
     }
 
@@ -87,28 +88,19 @@ impl TextAnalyzer {
     /// The resulting `BoxTokenStream` is equivalent to what would be obtained if the &str were
     /// one concatenated `&str`, with an artificial position gap of `2` between the different fields
     /// to prevent accidental `PhraseQuery` to match accross two terms.
-    pub fn token_stream_texts<'a>(&self, texts: &'a [&'a str]) -> BoxTokenStream<'a> {
-        assert!(!texts.is_empty());
-        if texts.len() == 1 {
-            self.token_stream(texts[0])
-        } else {
-            let mut offsets = vec![];
-            let mut total_offset = 0;
-            for &text in texts {
-                offsets.push(total_offset);
-                total_offset += text.len();
-            }
-            let token_streams: Vec<BoxTokenStream<'a>> = texts
-                .iter()
-                .cloned()
-                .map(|text| self.token_stream(text))
-                .collect();
-            From::from(TokenStreamChain::new(offsets, token_streams))
+    pub fn token_stream_texts<'a>(&self, texts: &'a [&str]) -> Box<dyn TokenStream + 'a> {
+        debug_assert!(!texts.is_empty());
+        let mut streams_with_offsets = vec![];
+        let mut total_offset = 0;
+        for &text in texts {
+            streams_with_offsets.push((self.token_stream(text), total_offset));
+            total_offset += text.len();
         }
+        Box::new(TokenStreamChain::new(streams_with_offsets))
     }
 
     /// Creates a token stream for a given `str`.
-    pub fn token_stream<'a>(&self, text: &'a str) -> BoxTokenStream<'a> {
+    pub fn token_stream<'a>(&self, text: &'a str) -> Box<dyn TokenStream + 'a> {
         let mut token_stream = self.tokenizer.token_stream(text);
         for token_filter in &self.token_filters {
             token_stream = token_filter.transform(token_stream);
@@ -140,7 +132,7 @@ impl Clone for TextAnalyzer {
 /// This API may change to use associated types.
 pub trait Tokenizer: 'static + Send + Sync + TokenizerClone {
     /// Creates a token stream for a given `str`.
-    fn token_stream<'a>(&self, text: &'a str) -> BoxTokenStream<'a>;
+    fn token_stream<'a>(&self, text: &'a str) -> Box<dyn TokenStream + 'a>;
 }
 
 pub trait TokenizerClone {
@@ -153,69 +145,6 @@ impl<T: Tokenizer + Clone> TokenizerClone for T {
     }
 }
 
-impl<'a> TokenStream for Box<dyn TokenStream + 'a> {
-    fn advance(&mut self) -> bool {
-        let token_stream: &mut dyn TokenStream = self.borrow_mut();
-        token_stream.advance()
-    }
-
-    fn token<'b>(&'b self) -> &'b Token {
-        let token_stream: &'b (dyn TokenStream + 'a) = self.borrow();
-        token_stream.token()
-    }
-
-    fn token_mut<'b>(&'b mut self) -> &'b mut Token {
-        let token_stream: &'b mut (dyn TokenStream + 'a) = self.borrow_mut();
-        token_stream.token_mut()
-    }
-}
-
-/// Simple wrapper of `Box<dyn TokenStream + 'a>`.
-///
-/// See `TokenStream` for more information.
-pub struct BoxTokenStream<'a>(Box<dyn TokenStream + 'a>);
-
-impl<'a, T> From<T> for BoxTokenStream<'a>
-where
-    T: TokenStream + 'a,
-{
-    fn from(token_stream: T) -> BoxTokenStream<'a> {
-        BoxTokenStream(Box::new(token_stream))
-    }
-}
-
-impl<'a> Deref for BoxTokenStream<'a> {
-    type Target = dyn TokenStream + 'a;
-
-    fn deref(&self) -> &Self::Target {
-        &*self.0
-    }
-}
-impl<'a> DerefMut for BoxTokenStream<'a> {
-    fn deref_mut(&mut self) -> &mut Self::Target {
-        &mut *self.0
-    }
-}
-
-/// Simple wrapper of `Box<dyn TokenFilter + 'a>`.
-///
-/// See `TokenStream` for more information.
-pub struct BoxTokenFilter(Box<dyn TokenFilter>);
-
-impl Deref for BoxTokenFilter {
-    type Target = dyn TokenFilter;
-
-    fn deref(&self) -> &dyn TokenFilter {
-        &*self.0
-    }
-}
-
-impl<T: TokenFilter> From<T> for BoxTokenFilter {
-    fn from(tokenizer: T) -> BoxTokenFilter {
-        BoxTokenFilter(Box::new(tokenizer))
-    }
-}
-
 /// `TokenStream` is the result of the tokenization.
 ///
 /// It consists consumable stream of `Token`s.
@@ -295,18 +224,18 @@ pub trait TokenStream {
 }
 
 pub trait TokenFilterClone {
-    fn box_clone(&self) -> BoxTokenFilter;
+    fn box_clone(&self) -> Box<dyn TokenFilter>;
 }
 
 /// Trait for the pluggable components of `Tokenizer`s.
 pub trait TokenFilter: 'static + Send + Sync + TokenFilterClone {
     /// Wraps a token stream and returns the modified one.
-    fn transform<'a>(&self, token_stream: BoxTokenStream<'a>) -> BoxTokenStream<'a>;
+    fn transform<'a>(&self, token_stream: Box<dyn TokenStream + 'a>) -> Box<dyn TokenStream + 'a>;
 }
 
 impl<T: TokenFilter + Clone> TokenFilterClone for T {
-    fn box_clone(&self) -> BoxTokenFilter {
-        BoxTokenFilter::from(self.clone())
+    fn box_clone(&self) -> Box<dyn TokenFilter> {
+        Box::new(self.clone())
     }
 }