Use LanguageTag inside of Literal

Allows to normalize language tags case and fixes language tagged string SPARQL lookyp

lib/src/model/literal.rs

@@ -1,3 +1,4 @@
+use crate::model::language_tag::LanguageTag;
 use crate::model::named_node::NamedNode;
 use crate::model::vocab::rdf;
 use crate::model::vocab::xsd;
@@ -18,6 +19,7 @@ use std::option::Option;
 /// The default string formatter is returning a N-Triples, Turtle and SPARQL compatible representation:
 /// ```
 /// use rudf::model::Literal;
+/// use rudf::model::LanguageTag;
 /// use rudf::model::vocab::xsd;
 ///
 /// assert_eq!(
@@ -32,7 +34,7 @@ use std::option::Option;
 ///
 /// assert_eq!(
 ///     "\"foo\"@en",
-///     Literal::new_language_tagged_literal("foo", "en").to_string()
+///     Literal::new_language_tagged_literal("foo", LanguageTag::parse("en").unwrap()).to_string()
 /// );
 /// ```
 #[derive(Eq, PartialEq, Ord, PartialOrd, Debug, Clone, Hash)]
@@ -41,7 +43,10 @@ pub struct Literal(LiteralContent);
 #[derive(PartialEq, Eq, Ord, PartialOrd, Debug, Clone, Hash)]
 enum LiteralContent {
     String(String),
-    LanguageTaggedString { value: String, language: String },
+    LanguageTaggedString {
+        value: String,
+        language: LanguageTag,
+    },
     Boolean(bool),
     Float(OrderedFloat<f32>),
     Double(OrderedFloat<f64>),
@@ -51,7 +56,10 @@ enum LiteralContent {
     NaiveTime(NaiveTime),
     DateTime(DateTime<FixedOffset>),
     NaiveDateTime(NaiveDateTime),
-    TypedLiteral { value: String, datatype: NamedNode },
+    TypedLiteral {
+        value: String,
+        datatype: NamedNode,
+    },
 }
 
 impl Literal {
@@ -131,7 +139,7 @@ impl Literal {
     /// Builds a RDF [language-tagged string](https://www.w3.org/TR/rdf11-concepts/#dfn-language-tagged-string)
     pub fn new_language_tagged_literal(
         value: impl Into<String>,
-        language: impl Into<String>,
+        language: impl Into<LanguageTag>,
     ) -> Self {
         Literal(LiteralContent::LanguageTaggedString {
             value: value.into(),
@@ -159,7 +167,7 @@ impl Literal {
 
     /// The literal [language tag](https://www.w3.org/TR/rdf11-concepts/#dfn-language-tag) if it is a [language-tagged string](https://www.w3.org/TR/rdf11-concepts/#dfn-language-tagged-string).
     /// Language tags are defined by the [BCP47](https://tools.ietf.org/html/bcp47).
-    pub fn language(&self) -> Option<&str> {
+    pub fn language(&self) -> Option<&LanguageTag> {
         match self.0 {
             LiteralContent::LanguageTaggedString { ref language, .. } => Some(language),
             _ => None,

lib/src/model/mod.rs

@@ -14,6 +14,7 @@ pub use crate::model::blank_node::BlankNode;
 pub use crate::model::dataset::Dataset;
 pub use crate::model::dataset::Graph;
 pub use crate::model::dataset::NamedGraph;
+pub use crate::model::language_tag::LanguageTag;
 pub use crate::model::literal::Literal;
 pub use crate::model::named_node::NamedNode;
 pub use crate::model::triple::NamedOrBlankNode;

lib/src/rio/ntriples/ntriples_grammar.rustpeg

@@ -37,8 +37,11 @@ literal -> Literal =
 
 
 //[144s]
-LANGTAG -> &'input str = "@" l:$([a-zA-Z]+ ("-" [a-zA-Z0-9]+)*) {
-    l
+LANGTAG -> LanguageTag = "@" l:$([a-zA-Z]+ ("-" [a-zA-Z0-9]+)*) {?
+    match LanguageTag::parse(&l) {
+        Ok(langtag) => Ok(langtag),
+        Err(error) => Err("language tag parsing failed")
+    }
 }
 
 //[7]

lib/src/rio/turtle/turtle_grammar.rustpeg

@@ -185,8 +185,11 @@ BLANK_NODE_LABEL -> &'input str = "_:" b:$(([0-9] / PN_CHARS_U) PN_CHARS* ("."+
 }
 
 //[144s]
-LANGTAG -> &'input str = "@" l:$([a-zA-Z]+ ("-" [a-zA-Z0-9]+)*) {
-    l
+LANGTAG -> LanguageTag = "@" l:$([a-zA-Z]+ ("-" [a-zA-Z0-9]+)*) {?
+    match LanguageTag::parse(&l) {
+        Ok(langtag) => Ok(langtag),
+        Err(error) => Err("language tag parsing failed")
+    }
 }
 
 //[19]

lib/src/rio/xml.rs

@@ -1,7 +1,6 @@
 //! Implementation of [RDF XML](https://www.w3.org/TR/rdf-syntax-grammar/) syntax
 
 use crate::model::vocab::rdf;
-use crate::model::Triple;
 use crate::model::*;
 use crate::Result;
 use failure::format_err;
@@ -82,18 +81,18 @@ enum RdfXmlState {
     },
     RDF {
         base_uri: Option<Url>,
-        language: String,
+        language: Option<LanguageTag>,
     },
     NodeElt {
         base_uri: Option<Url>,
-        language: String,
+        language: Option<LanguageTag>,
         subject: NamedOrBlankNode,
     },
     PropertyElt {
         //Resource, Literal or Empty property element
         uri: Url,
         base_uri: Option<Url>,
-        language: String,
+        language: Option<LanguageTag>,
         subject: NamedOrBlankNode,
         object: Option<NamedOrBlankNode>,
         id_attr: Option<NamedNode>,
@@ -102,7 +101,7 @@ enum RdfXmlState {
     ParseTypeCollectionPropertyElt {
         uri: NamedNode,
         base_uri: Option<Url>,
-        language: String,
+        language: Option<LanguageTag>,
         subject: NamedOrBlankNode,
         id_attr: Option<NamedNode>,
     },
@@ -120,13 +119,13 @@ impl RdfXmlState {
         }
     }
 
-    fn language(&self) -> &str {
+    fn language(&self) -> Option<&LanguageTag> {
         match self {
-            RdfXmlState::Doc { .. } => "",
-            RdfXmlState::RDF { language, .. } => language,
-            RdfXmlState::NodeElt { language, .. } => language,
-            RdfXmlState::PropertyElt { language, .. } => language,
-            RdfXmlState::ParseTypeCollectionPropertyElt { language, .. } => language,
+            RdfXmlState::Doc { .. } => None,
+            RdfXmlState::RDF { language, .. } => language.as_ref(),
+            RdfXmlState::NodeElt { language, .. } => language.as_ref(),
+            RdfXmlState::PropertyElt { language, .. } => language.as_ref(),
+            RdfXmlState::ParseTypeCollectionPropertyElt { language, .. } => language.as_ref(),
         }
     }
 }
@@ -193,10 +192,10 @@ impl<R: BufRead> RdfXmlIterator<R> {
         let uri = self.resolve_tag_name(event.name())?;
 
         //We read attributes
-        let mut language = String::default();
+        let mut language = None;
         let mut base_uri = None;
         if let Some(current_state) = self.state.last() {
-            language = current_state.language().to_string();
+            language = current_state.language().cloned();
             base_uri = current_state.base_uri().clone();
         }
         let mut id_attr = None;
@@ -212,7 +211,9 @@ impl<R: BufRead> RdfXmlIterator<R> {
             let attribute = attribute?;
             match attribute.key {
                 b"xml:lang" => {
-                    language = attribute.unescape_and_decode_value(&self.reader)?;
+                    language = Some(LanguageTag::parse(
+                        &attribute.unescape_and_decode_value(&self.reader)?,
+                    )?);
                 }
                 b"xml:base" => {
                     base_uri = Some(self.resolve_uri(&attribute.unescaped_value()?, &None)?)
@@ -434,7 +435,7 @@ impl<R: BufRead> RdfXmlIterator<R> {
         &mut self,
         uri: NamedNode,
         base_uri: Option<Url>,
-        language: String,
+        language: Option<LanguageTag>,
         id_attr: Option<NamedNode>,
         node_id_attr: Option<BlankNode>,
         about_attr: Option<NamedNode>,
@@ -474,7 +475,7 @@ impl<R: BufRead> RdfXmlIterator<R> {
         &mut self,
         uri: NamedNode,
         base_uri: Option<Url>,
-        language: String,
+        language: Option<LanguageTag>,
         subject: NamedOrBlankNode,
         id_attr: Option<NamedNode>,
     ) -> RdfXmlState {
@@ -544,13 +545,18 @@ impl<R: BufRead> RdfXmlIterator<R> {
         Ok(())
     }
 
-    fn new_literal(&self, text: String, language: String, datatype: Option<NamedNode>) -> Literal {
+    fn new_literal(
+        &self,
+        text: String,
+        language: Option<LanguageTag>,
+        datatype: Option<NamedNode>,
+    ) -> Literal {
         if let Some(datatype) = datatype {
             Literal::new_typed_literal(text, datatype)
-        } else if language.is_empty() {
-            Literal::new_simple_literal(text)
-        } else {
+        } else if let Some(language) = language {
             Literal::new_language_tagged_literal(text, language)
+        } else {
+            Literal::new_simple_literal(text)
         }
     }
 
@@ -581,16 +587,16 @@ impl<R: BufRead> RdfXmlIterator<R> {
         &mut self,
         subject: &NamedOrBlankNode,
         literal_attributes: Vec<(NamedNode, String)>,
-        language: &str,
+        language: &Option<LanguageTag>,
     ) {
         for (literal_predicate, literal_value) in literal_attributes {
             self.triples_cache.push(Triple::new(
                 subject.clone(),
                 literal_predicate,
-                if language.is_empty() {
-                    Literal::new_simple_literal(literal_value)
+                if let Some(language) = language {
+                    Literal::new_language_tagged_literal(literal_value, language.clone())
                 } else {
-                    Literal::new_language_tagged_literal(literal_value, language)
+                    Literal::new_simple_literal(literal_value)
                 },
             ));
         }

lib/src/sparql/sparql_grammar.rustpeg

@@ -949,8 +949,11 @@ VAR1 -> &'input str = '?' v:$(VARNAME) { v }
 VAR2 -> &'input str = '$' v:$(VARNAME) { v }
 
 //[145]
-LANGTAG -> &'input str = "@" l:$([a-zA-Z]+ ("-" [a-zA-Z0-9]+)*) {
-    l
+LANGTAG -> LanguageTag = "@" l:$([a-zA-Z]+ ("-" [a-zA-Z0-9]+)*) {?
+    match LanguageTag::parse(&l) {
+        Ok(langtag) => Ok(langtag),
+        Err(error) => Err("language tag parsing failed")
+    }
 }
 
 //[146]

lib/src/sparql/xml_results.rs

@@ -81,7 +81,7 @@ pub fn write_xml_results<W: Write>(results: QueryResult<'_>, sink: W) -> Result<
                             Term::Literal(literal) => {
                                 let mut literal_tag = BytesStart::borrowed_name(b"literal");
                                 if let Some(language) = literal.language() {
-                                    literal_tag.push_attribute(("xml:lang", language));
+                                    literal_tag.push_attribute(("xml:lang", language.as_str()));
                                 } else if !literal.is_plain() {
                                     literal_tag
                                         .push_attribute(("datatype", literal.datatype().as_str()));
@@ -336,8 +336,11 @@ impl<R: BufRead> Iterator for ResultsIterator<R> {
                                 if let Ok(attr) = attr {
                                     if attr.key == b"xml:lang" {
                                         match attr.unescape_and_decode_value(&self.reader) {
+                                            Ok(val) => match LanguageTag::parse(&val) {
                                                 Ok(val) => lang = Some(val),
                                                 Err(error) => return Some(Err(error.into())),
+                                            },
+                                            Err(error) => return Some(Err(error.into())),
                                         }
                                     } else if attr.key == b"datatype" {
                                         match attr.unescaped_value() {
@@ -429,7 +432,7 @@ impl<R: BufRead> Iterator for ResultsIterator<R> {
 
 fn build_literal(
     value: impl Into<String>,
-    lang: &Option<String>,
+    lang: &Option<LanguageTag>,
     datatype: &Option<NamedNode>,
 ) -> Literal {
     match datatype {

lib/src/store/memory.rs

@@ -1,3 +1,4 @@
+use crate::model::LanguageTag;
 use crate::store::encoded::*;
 use crate::store::numeric_encoder::*;
 use crate::utils::MutexPoisonError;
@@ -81,6 +82,10 @@ impl StringStore for MemoryStore {
     fn get_url(&self, id: u64) -> Result<Url> {
         self.string_store.get_url(id)
     }
+
+    fn get_language_tag(&self, id: u64) -> Result<LanguageTag> {
+        self.string_store.get_language_tag(id)
+    }
 }
 
 impl EncodedQuadsStore for MemoryStore {

lib/src/store/numeric_encoder.rs

@@ -13,7 +13,6 @@ use std::io::Read;
 use std::io::Write;
 use std::ops::Deref;
 use std::str;
-use std::str::FromStr;
 use std::sync::RwLock;
 use url::Url;
 use uuid::Uuid;
@@ -36,6 +35,7 @@ pub trait StringStore {
     fn insert_str(&self, value: &str) -> Result<u64>;
     fn get_str(&self, id: u64) -> Result<Self::StringType>;
     fn get_url(&self, id: u64) -> Result<Url>;
+    fn get_language_tag(&self, id: u64) -> Result<LanguageTag>;
 
     /// Should be called when the bytes store is created
     fn set_first_strings(&self) -> Result<()> {
@@ -74,6 +74,10 @@ impl<'a, S: StringStore> StringStore for &'a S {
     fn get_url(&self, id: u64) -> Result<Url> {
         (*self).get_url(id)
     }
+
+    fn get_language_tag(&self, id: u64) -> Result<LanguageTag> {
+        (*self).get_language_tag(id)
+    }
 }
 
 pub struct MemoryStringStore {
@@ -120,7 +124,16 @@ impl StringStore for MemoryStringStore {
         if id2str.len() as u64 <= id {
             Err(format_err!("value not found in the dictionary"))
         } else {
-            Ok(Url::from_str(&id2str[id as usize])?)
+            Ok(Url::parse(&id2str[id as usize])?)
+        }
+    }
+
+    fn get_language_tag(&self, id: u64) -> Result<LanguageTag> {
+        let id2str = self.id2str.read().map_err(MutexPoisonError::from)?;
+        if id2str.len() as u64 <= id {
+            Err(format_err!("value not found in the dictionary"))
+        } else {
+            Ok(LanguageTag::parse(&id2str[id as usize])?)
         }
     }
 }
@@ -586,16 +599,10 @@ impl<S: StringStore> Encoder<S> {
     }
 
     pub fn encode_literal(&self, literal: &Literal) -> Result<EncodedTerm> {
-        Ok(if literal.is_plain() {
-            if let Some(language) = literal.language() {
+        Ok(if let Some(language) = literal.language() {
             EncodedTerm::LangStringLiteral {
                 value_id: self.string_store.insert_str(&literal.value())?,
-                    language_id: self.string_store.insert_str(language)?,
-                }
-            } else {
-                EncodedTerm::StringLiteral {
-                    value_id: self.string_store.insert_str(&literal.value())?,
-                }
+                language_id: self.string_store.insert_str(language.as_str())?,
             }
         } else if literal.is_string() {
             EncodedTerm::StringLiteral {
@@ -711,7 +718,7 @@ impl<S: StringStore> Encoder<S> {
                 language_id,
             } => Ok(Literal::new_language_tagged_literal(
                 self.string_store.get_str(value_id)?,
-                self.string_store.get_str(language_id)?,
+                self.string_store.get_language_tag(language_id)?,
             )
             .into()),
             EncodedTerm::TypedLiteral {
@@ -787,6 +794,8 @@ impl<S: StringStore + Default> Default for Encoder<S> {
 
 #[test]
 fn test_encoding() {
+    use std::str::FromStr;
+
     let encoder: Encoder<MemoryStringStore> = Encoder::default();
     let terms: Vec<Term> = vec![
         NamedNode::from_str("http://foo.com").unwrap().into(),
@@ -798,7 +807,7 @@ fn test_encoding() {
         Literal::from(1.2).into(),
         Literal::from(1).into(),
         Literal::from("foo").into(),
-        Literal::new_language_tagged_literal("foo", "fr").into(),
+        Literal::new_language_tagged_literal("foo", LanguageTag::parse("fr").unwrap()).into(),
     ];
     for term in terms {
         let encoded = encoder.encode_term(&term).unwrap();

lib/src/store/rocksdb.rs

@@ -1,3 +1,4 @@
+use crate::model::LanguageTag;
 use crate::store::encoded::EncodedQuadsStore;
 use crate::store::encoded::StoreDataset;
 use crate::store::numeric_encoder::*;
@@ -17,7 +18,6 @@ use std::io::Cursor;
 use std::ops::Deref;
 use std::path::Path;
 use std::str;
-use std::str::FromStr;
 use std::sync::Mutex;
 use url::Url;
 
@@ -120,7 +120,11 @@ impl StringStore for RocksDbStore {
     }
 
     fn get_url(&self, id: u64) -> Result<Url> {
-        Ok(Url::from_str(&self.get_str(id)?)?)
+        Ok(Url::parse(&self.get_str(id)?)?)
+    }
+
+    fn get_language_tag(&self, id: u64) -> Result<LanguageTag> {
+        Ok(LanguageTag::parse(&self.get_str(id)?)?)
     }
 }
 

lib/tests/sparql_test_cases.rs

@@ -168,16 +168,6 @@ fn sparql_w3c_query_evaluation_testsuite() {
         NamedNode::from_str(
             "http://www.w3.org/2001/sw/DataAccess/tests/data-r2/optional-filter/manifest#dawg-optional-filter-005-not-simplified",
         ).unwrap(),
-        //Case insensitive language tag comparison
-        NamedNode::from_str(
-            "http://www.w3.org/2001/sw/DataAccess/tests/data-r2/expr-builtin/manifest#lang-case-insensitive-eq",
-        ).unwrap(),
-        NamedNode::from_str(
-            "http://www.w3.org/2001/sw/DataAccess/tests/data-r2/expr-builtin/manifest#lang-case-insensitive-ne",
-        ).unwrap(),
-        NamedNode::from_str(
-            "http://www.w3.org/2001/sw/DataAccess/tests/data-r2/expr-builtin/manifest#dawg-lang-3",
-        ).unwrap(),
         //DATATYPE("foo"@en) returns rdf:langString in SPARQL 1.1
         NamedNode::from_str(
             "http://www.w3.org/2001/sw/DataAccess/tests/data-r2/expr-builtin/manifest#dawg-datatype-2",

python/src/lib.rs

@@ -87,7 +87,10 @@ py_class!(class Literal |py| {
 
     def __new__(_cls, value: String, language: Option<String> = None, datatype: Option<NamedNode> = None) -> PyResult<Literal> {
         Literal::create_instance(py, match language {
-            Some(language) => model::Literal::new_language_tagged_literal(value, language),
+            Some(language) => {
+                let language = model::LanguageTag::parse(&language).map_err(|error| new_value_error(py, &error.into()))?;
+                model::Literal::new_language_tagged_literal(value, language)
+            },
             None => match datatype {
                 Some(datatype) => model::Literal::new_typed_literal(value, datatype.inner(py).clone()),
                 None => model::Literal::new_simple_literal(value)
@@ -100,7 +103,7 @@ py_class!(class Literal |py| {
     }
 
     def language(&self) -> PyResult<Option<String>> {
-        Ok(self.inner(py).language().map(|l| l.to_string()))
+        Ok(self.inner(py).language().map(|l| l.as_str().to_string()))
     }
 
     def datatype(&self) -> PyResult<NamedNode> {