Changes required for python binding (#610)

src/collector/top_score_collector.rs

@@ -13,6 +13,7 @@ use crate::Result;
 use crate::Score;
 use crate::SegmentLocalId;
 use crate::SegmentReader;
+use std::fmt;
 
 /// The Top Score Collector keeps track of the K documents
 /// sorted by their score.
@@ -68,6 +69,12 @@ use crate::SegmentReader;
 /// ```
 pub struct TopDocs(TopCollector<Score>);
 
+impl fmt::Debug for TopDocs {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        write!(f, "TopDocs({})", self.0.limit())
+    }
+}
+
 impl TopDocs {
     /// Creates a top score collector, with a number of documents equal to "limit".
     ///

src/lib.rs

@@ -171,16 +171,16 @@ pub use self::snippet::{Snippet, SnippetGenerator};
 mod docset;
 pub use self::docset::{DocSet, SkipResult};
 
+pub use crate::common::{f64_to_u64, i64_to_u64, u64_to_f64, u64_to_i64};
 pub use crate::core::SegmentComponent;
 pub use crate::core::{Index, IndexMeta, Searcher, Segment, SegmentId, SegmentMeta};
 pub use crate::core::{InvertedIndexReader, SegmentReader};
 pub use crate::directory::Directory;
 pub use crate::indexer::IndexWriter;
 pub use crate::postings::Postings;
+pub use crate::reader::LeasedItem;
 pub use crate::schema::{Document, Term};
 
-pub use crate::common::{i64_to_u64, u64_to_i64, f64_to_u64, u64_to_f64};
-
 /// Expose the current version of tantivy, as well
 /// whether it was compiled with the simd compression.
 pub fn version() -> &'static str {
@@ -849,7 +849,8 @@ mod tests {
         let index = Index::create_in_ram(schema);
         let mut index_writer = index.writer_with_num_threads(1, 50_000_000).unwrap();
         {
-            let document = doc!(fast_field_unsigned => 4u64, fast_field_signed=>4i64, fast_field_float=>4f64);
+            let document =
+                doc!(fast_field_unsigned => 4u64, fast_field_signed=>4i64, fast_field_float=>4f64);
             index_writer.add_document(document);
             index_writer.commit().unwrap();
         }

src/query/query_parser/query_parser.rs

@@ -18,42 +18,56 @@ use crate::schema::{FieldType, Term};
 use crate::tokenizer::TokenizerManager;
 use combine::Parser;
 use std::borrow::Cow;
-use std::num::{ParseIntError, ParseFloatError};
+use std::num::{ParseFloatError, ParseIntError};
 use std::ops::Bound;
 use std::str::FromStr;
 
 /// Possible error that may happen when parsing a query.
-#[derive(Debug, PartialEq, Eq)]
+#[derive(Debug, PartialEq, Eq, Fail)]
 pub enum QueryParserError {
     /// Error in the query syntax
+    #[fail(display = "Syntax Error")]
     SyntaxError,
     /// `FieldDoesNotExist(field_name: String)`
     /// The query references a field that is not in the schema
+    #[fail(display = "File does not exists: '{:?}'", _0)]
     FieldDoesNotExist(String),
     /// The query contains a term for a `u64` or `i64`-field, but the value
     /// is neither.
+    #[fail(display = "Expected a valid integer: '{:?}'", _0)]
     ExpectedInt(ParseIntError),
     /// The query contains a term for a `f64`-field, but the value
     /// is not a f64.
+    #[fail(display = "Invalid query: Only excluding terms given")]
     ExpectedFloat(ParseFloatError),
     /// It is forbidden queries that are only "excluding". (e.g. -title:pop)
+    #[fail(display = "Invalid query: Only excluding terms given")]
     AllButQueryForbidden,
     /// If no default field is declared, running a query without any
     /// field specified is forbbidden.
+    #[fail(display = "No default field declared and no field specified in query")]
     NoDefaultFieldDeclared,
     /// The field searched for is not declared
     /// as indexed in the schema.
+    #[fail(display = "The field '{:?}' is not declared as indexed", _0)]
     FieldNotIndexed(String),
     /// A phrase query was requested for a field that does not
     /// have any positions indexed.
+    #[fail(display = "The field '{:?}' does not have positions indexed", _0)]
     FieldDoesNotHavePositionsIndexed(String),
     /// The tokenizer for the given field is unknown
     /// The two argument strings are the name of the field, the name of the tokenizer
+    #[fail(
+        display = "The tokenizer '{:?}' for the field '{:?}' is unknown",
+        _0, _1
+    )]
     UnknownTokenizer(String, String),
     /// The query contains a range query with a phrase as one of the bounds.
     /// Only terms can be used as bounds.
+    #[fail(display = "A range query cannot have a phrase as one of the bounds")]
     RangeMustNotHavePhrase,
     /// The format for the date field is not RFC 3339 compliant.
+    #[fail(display = "The date field has an invalid format")]
     DateFormatError(chrono::ParseError),
 }
 

src/reader/mod.rs

@@ -1,6 +1,7 @@
 mod pool;
 
-use self::pool::{LeasedItem, Pool};
+pub use self::pool::LeasedItem;
+use self::pool::Pool;
 use crate::core::Segment;
 use crate::directory::Directory;
 use crate::directory::WatchHandle;

src/reader/pool.rs

@@ -123,6 +123,10 @@ impl<T> Pool<T> {
     }
 }
 
+/// A LeasedItem holds an object borrowed from a Pool.
+///
+/// Upon drop, the object is automatically returned
+/// into the pool.
 pub struct LeasedItem<T> {
     gen_item: Option<GenerationItem<T>>,
     recycle_queue: Arc<Queue<GenerationItem<T>>>,

src/schema/schema.rs

@@ -360,13 +360,16 @@ impl<'de> Deserialize<'de> for Schema {
 
 /// Error that may happen when deserializing
 /// a document from JSON.
-#[derive(Debug)]
+#[derive(Debug, Fail)]
 pub enum DocParsingError {
     /// The payload given is not valid JSON.
+    #[fail(display = "The provided string is not valid JSON")]
     NotJSON(String),
     /// One of the value node could not be parsed.
+    #[fail(display = "The field '{:?}' could not be parsed: {:?}", _0, _1)]
     ValueError(String, ValueParsingError),
     /// The json-document contains a field that is not declared in the schema.
+    #[fail(display = "The json-document contains an unknown field: {:?}", _0)]
     NoSuchFieldInSchema(String),
 }