add AsRef, expose object and array iter on Value (#2207)

add AsRef
expose object and array iter
add to_json on Document

examples/date_time_field.rs

@@ -4,7 +4,7 @@
 
 use tantivy::collector::TopDocs;
 use tantivy::query::QueryParser;
-use tantivy::schema::{DateOptions, OwnedValue, Schema, INDEXED, STORED, STRING};
+use tantivy::schema::{DateOptions, Document, OwnedValue, Schema, INDEXED, STORED, STRING};
 use tantivy::{Index, IndexWriter, TantivyDocument};
 
 fn main() -> tantivy::Result<()> {

src/indexer/segment_writer.rs

@@ -494,7 +494,8 @@ mod tests {
     use crate::query::PhraseQuery;
     use crate::schema::document::Value;
     use crate::schema::{
-        IndexRecordOption, Schema, TextFieldIndexing, TextOptions, Type, STORED, STRING, TEXT,
+        Document, IndexRecordOption, Schema, TextFieldIndexing, TextOptions, Type, STORED, STRING,
+        TEXT,
     };
     use crate::store::{Compressor, StoreReader, StoreWriter};
     use crate::time::format_description::well_known::Rfc3339;

src/schema/document/default_doc_type.rs

@@ -195,14 +195,6 @@ impl TantivyDocument {
         Ok(document)
     }
 
-    /// Encode the schema in JSON.
-    ///
-    /// Encoding a document cannot fail.
-    pub fn to_json(&self, schema: &Schema) -> String {
-        serde_json::to_string(&self.to_named_doc(schema))
-            .expect("doc encoding failed. This is a bug")
-    }
-
     /// Build a document object from a json-object.
     pub fn parse_json(schema: &Schema, doc_json: &str) -> Result<TantivyDocument, DocParsingError> {
         let json_obj: Map<String, serde_json::Value> =

src/schema/document/mod.rs

@@ -235,6 +235,14 @@ pub trait Document: DocumentDeserialize + Send + Sync + 'static {
         }
         NamedFieldDocument(field_map)
     }
+
+    /// Encode the doc in JSON.
+    ///
+    /// Encoding a document cannot fail.
+    fn to_json(&self, schema: &Schema) -> String {
+        serde_json::to_string(&self.to_named_doc(schema))
+            .expect("doc encoding failed. This is a bug")
+    }
 }
 
 /// A single field value.
@@ -357,6 +365,26 @@ pub trait Value<'a>: Send + Sync + Debug {
         }
     }
 
+    #[inline]
+    /// Returns the iterator over the array if the Value is an array.
+    fn as_array(&self) -> Option<Self::ArrayIter> {
+        if let ReferenceValue::Array(val) = self.as_value() {
+            Some(val)
+        } else {
+            None
+        }
+    }
+
+    #[inline]
+    /// Returns the iterator over the object if the Value is an object.
+    fn as_object(&self) -> Option<Self::ObjectIter> {
+        if let ReferenceValue::Object(val) = self.as_value() {
+            Some(val)
+        } else {
+            None
+        }
+    }
+
     #[inline]
     /// Returns true if the Value is an array.
     fn is_array(&self) -> bool {

src/schema/field_type.rs

@@ -535,7 +535,9 @@ mod tests {
 
     use super::FieldType;
     use crate::schema::field_type::ValueParsingError;
-    use crate::schema::{NumericOptions, OwnedValue, Schema, TextOptions, Type, COERCE, INDEXED};
+    use crate::schema::{
+        Document, NumericOptions, OwnedValue, Schema, TextOptions, Type, COERCE, INDEXED,
+    };
     use crate::time::{Date, Month, PrimitiveDateTime, Time};
     use crate::tokenizer::{PreTokenizedString, Token};
     use crate::{DateTime, TantivyDocument};

src/schema/value.rs

@@ -49,6 +49,13 @@ pub enum OwnedValue {
     IpAddr(Ipv6Addr),
 }
 
+impl AsRef<OwnedValue> for OwnedValue {
+    #[inline]
+    fn as_ref(&self) -> &OwnedValue {
+        self
+    }
+}
+
 impl<'a> Value<'a> for &'a OwnedValue {
     type ChildValue = Self;
     type ArrayIter = ArrayIter<'a>;
@@ -441,11 +448,11 @@ impl<'a> Iterator for ObjectMapIter<'a> {
 
 #[cfg(test)]
 mod tests {
-    use super::OwnedValue;
+    use super::*;
     use crate::schema::{BytesOptions, Schema};
     use crate::time::format_description::well_known::Rfc3339;
     use crate::time::OffsetDateTime;
-    use crate::{DateTime, TantivyDocument};
+    use crate::{DateTime, Document, TantivyDocument};
 
     #[test]
     fn test_parse_bytes_doc() {