diff --git a/lib/src/sparql/eval.rs b/lib/src/sparql/eval.rs
index 9946f029..ac2edfbf 100644
--- a/lib/src/sparql/eval.rs
+++ b/lib/src/sparql/eval.rs
@@ -11,7 +11,6 @@ use num_traits::identities::Zero;
 use num_traits::FromPrimitive;
 use num_traits::One;
 use num_traits::ToPrimitive;
-use ordered_float::OrderedFloat;
 use regex::RegexBuilder;
 use rust_decimal::Decimal;
 use std::cmp::Ordering;
@@ -639,13 +638,10 @@ impl<'a, S: StoreConnection + 'a> SimpleEvaluator<S> {
             }
             PlanExpression::BooleanCast(e) => match self.eval_expression(e, tuple)? {
                 EncodedTerm::BooleanLiteral(value) => Some(value.into()),
-                EncodedTerm::StringLiteral { value_id } => {
-                    match &*self.dataset.get_str(value_id).ok()?? {
-                        "true" | "1" => Some(true.into()),
-                        "false" | "0" => Some(false.into()),
-                        _ => None,
-                    }
-                }
+                EncodedTerm::StringLiteral { value_id } => self
+                    .dataset
+                    .encoder()
+                    .encode_boolean_str(&*self.dataset.get_str(value_id).ok()??),
                 _ => None,
             },
             PlanExpression::DoubleCast(e) => match self.eval_expression(e, tuple)? {
@@ -656,9 +652,10 @@ impl<'a, S: StoreConnection + 'a> SimpleEvaluator<S> {
                 EncodedTerm::BooleanLiteral(value) => {
                     Some(if value { 1. as f64 } else { 0. }.into())
                 }
-                EncodedTerm::StringLiteral { value_id } => Some(EncodedTerm::DoubleLiteral(
-                    OrderedFloat(self.dataset.get_str(value_id).ok()??.parse().ok()?),
-                )),
+                EncodedTerm::StringLiteral { value_id } => self
+                    .dataset
+                    .encoder()
+                    .encode_double_str(&*self.dataset.get_str(value_id).ok()??),
                 _ => None,
             },
             PlanExpression::FloatCast(e) => match self.eval_expression(e, tuple)? {
@@ -669,9 +666,10 @@ impl<'a, S: StoreConnection + 'a> SimpleEvaluator<S> {
                 EncodedTerm::BooleanLiteral(value) => {
                     Some(if value { 1. as f32 } else { 0. }.into())
                 }
-                EncodedTerm::StringLiteral { value_id } => Some(EncodedTerm::FloatLiteral(
-                    OrderedFloat(self.dataset.get_str(value_id).ok()??.parse().ok()?),
-                )),
+                EncodedTerm::StringLiteral { value_id } => self
+                    .dataset
+                    .encoder()
+                    .encode_float_str(&*self.dataset.get_str(value_id).ok()??),
                 _ => None,
             },
             PlanExpression::IntegerCast(e) => match self.eval_expression(e, tuple)? {
@@ -680,9 +678,10 @@ impl<'a, S: StoreConnection + 'a> SimpleEvaluator<S> {
                 EncodedTerm::IntegerLiteral(value) => Some(value.to_i128()?.into()),
                 EncodedTerm::DecimalLiteral(value) => Some(value.to_i128()?.into()),
                 EncodedTerm::BooleanLiteral(value) => Some(if value { 1 } else { 0 }.into()),
-                EncodedTerm::StringLiteral { value_id } => Some(EncodedTerm::IntegerLiteral(
-                    self.dataset.get_str(value_id).ok()??.parse().ok()?,
-                )),
+                EncodedTerm::StringLiteral { value_id } => self
+                    .dataset
+                    .encoder()
+                    .encode_integer_str(&*self.dataset.get_str(value_id).ok()??),
                 _ => None,
             },
             PlanExpression::DecimalCast(e) => match self.eval_expression(e, tuple)? {
@@ -698,43 +697,40 @@ impl<'a, S: StoreConnection + 'a> SimpleEvaluator<S> {
                     }
                     .into(),
                 ),
-                EncodedTerm::StringLiteral { value_id } => Some(EncodedTerm::DecimalLiteral(
-                    self.dataset.get_str(value_id).ok()??.parse().ok()?,
-                )),
+                EncodedTerm::StringLiteral { value_id } => self
+                    .dataset
+                    .encoder()
+                    .encode_decimal_str(&*self.dataset.get_str(value_id).ok()??),
                 _ => None,
             },
             PlanExpression::DateCast(e) => match self.eval_expression(e, tuple)? {
+                EncodedTerm::DateLiteral(value) => Some(value.into()),
                 EncodedTerm::NaiveDateLiteral(value) => Some(value.into()),
-                EncodedTerm::DateTimeLiteral(value) => Some(value.date().naive_utc().into()), //TODO: use date with timezone
+                EncodedTerm::DateTimeLiteral(value) => Some(value.date().into()),
                 EncodedTerm::NaiveDateTimeLiteral(value) => Some(value.date().into()),
-                EncodedTerm::StringLiteral { value_id } => {
-                    let value = self.dataset.get_str(value_id).ok()??;
-                    Some(NaiveDate::parse_from_str(&value, "%Y-%m-%d").ok()?.into())
-                }
+                EncodedTerm::StringLiteral { value_id } => self
+                    .dataset
+                    .encoder()
+                    .encode_date_str(&*self.dataset.get_str(value_id).ok()??),
                 _ => None,
             },
             PlanExpression::TimeCast(e) => match self.eval_expression(e, tuple)? {
                 EncodedTerm::NaiveTimeLiteral(value) => Some(value.into()),
                 EncodedTerm::DateTimeLiteral(value) => Some(value.time().into()),
                 EncodedTerm::NaiveDateTimeLiteral(value) => Some(value.time().into()),
-                EncodedTerm::StringLiteral { value_id } => {
-                    let value = self.dataset.get_str(value_id).ok()??;
-                    Some(NaiveTime::parse_from_str(&value, "%H:%M:%S").ok()?.into())
-                }
+                EncodedTerm::StringLiteral { value_id } => self
+                    .dataset
+                    .encoder()
+                    .encode_time_str(&*self.dataset.get_str(value_id).ok()??),
                 _ => None,
             },
             PlanExpression::DateTimeCast(e) => match self.eval_expression(e, tuple)? {
                 EncodedTerm::DateTimeLiteral(value) => Some(value.into()),
                 EncodedTerm::NaiveDateTimeLiteral(value) => Some(value.into()),
-                EncodedTerm::StringLiteral { value_id } => {
-                    let value = self.dataset.get_str(value_id).ok()??;
-                    Some(match DateTime::parse_from_rfc3339(&value) {
-                        Ok(value) => value.into(),
-                        Err(_) => NaiveDateTime::parse_from_str(&value, "%Y-%m-%dT%H:%M:%S")
-                            .ok()?
-                            .into(),
-                    })
-                }
+                EncodedTerm::StringLiteral { value_id } => self
+                    .dataset
+                    .encoder()
+                    .encode_date_time_str(&*self.dataset.get_str(value_id).ok()??),
                 _ => None,
             },
             PlanExpression::StringCast(e) => Some(EncodedTerm::StringLiteral {
@@ -1514,9 +1510,8 @@ fn get_triple_template_value(
         TripleTemplateValue::Constant(term) => Some(*term),
         TripleTemplateValue::Variable(v) => get_tuple_value(*v, tuple),
         TripleTemplateValue::BlankNode(id) => {
-            //TODO use resize_with
-            while *id >= tuple.len() {
-                bnodes.push(BlankNode::default())
+            if *id >= tuple.len() {
+                bnodes.resize_with(*id, BlankNode::default)
             }
             tuple[*id]
         }
diff --git a/lib/src/store/mod.rs b/lib/src/store/mod.rs
index 435eb72a..49c5ed15 100644
--- a/lib/src/store/mod.rs
+++ b/lib/src/store/mod.rs
@@ -175,7 +175,6 @@ impl<S: StoreConnection> StoreRepositoryConnection<S> {
     where
         P::Error: Send + Sync + 'static,
     {
-        //TODO: handle errors
         let mut bnode_map = HashMap::default();
         let encoder = self.inner.encoder();
         let graph_name = if let Some(graph_name) = to_graph_name {
@@ -194,7 +193,6 @@ impl<S: StoreConnection> StoreRepositoryConnection<S> {
     where
         P::Error: Send + Sync + 'static,
     {
-        //TODO: handle errors
         let mut bnode_map = HashMap::default();
         let encoder = self.inner.encoder();
         parser.parse_all(&mut move |q| {
diff --git a/lib/src/store/numeric_encoder.rs b/lib/src/store/numeric_encoder.rs
index d2886458..a96ba476 100644
--- a/lib/src/store/numeric_encoder.rs
+++ b/lib/src/store/numeric_encoder.rs
@@ -684,113 +684,45 @@ impl<S: StringStore> Encoder<S> {
                     }?,
                 }
             }
-            rio::Literal::Typed { value, datatype } => match datatype.iri {
-                "http://www.w3.org/2001/XMLSchema#boolean" => match value {
-                    "true" | "1" => EncodedTerm::BooleanLiteral(true),
-                    "false" | "0" => EncodedTerm::BooleanLiteral(false),
-                    _ => EncodedTerm::TypedLiteral {
+            rio::Literal::Typed { value, datatype } => {
+                match match datatype.iri {
+                    "http://www.w3.org/2001/XMLSchema#boolean" => self.encode_boolean_str(value),
+                    "http://www.w3.org/2001/XMLSchema#string" => Some(EncodedTerm::StringLiteral {
                         value_id: self.string_store.insert_str(value)?,
-                        datatype_id: XSD_BOOLEAN_ID,
-                    },
-                },
-                "http://www.w3.org/2001/XMLSchema#string" => EncodedTerm::StringLiteral {
-                    value_id: self.string_store.insert_str(value)?,
-                },
-                "http://www.w3.org/2001/XMLSchema#float" => match value.parse() {
-                    Ok(value) => EncodedTerm::FloatLiteral(OrderedFloat(value)),
-                    Err(_) => EncodedTerm::TypedLiteral {
-                        value_id: self.string_store.insert_str(value)?,
-                        datatype_id: XSD_FLOAT_ID,
-                    },
-                },
-                "http://www.w3.org/2001/XMLSchema#double" => match value.parse() {
-                    Ok(value) => EncodedTerm::DoubleLiteral(OrderedFloat(value)),
-                    Err(_) => EncodedTerm::TypedLiteral {
-                        value_id: self.string_store.insert_str(value)?,
-                        datatype_id: XSD_DOUBLE_ID,
-                    },
-                },
-                "http://www.w3.org/2001/XMLSchema#integer"
-                | "http://www.w3.org/2001/XMLSchema#byte"
-                | "http://www.w3.org/2001/XMLSchema#short"
-                | "http://www.w3.org/2001/XMLSchema#int"
-                | "http://www.w3.org/2001/XMLSchema#long"
-                | "http://www.w3.org/2001/XMLSchema#unsignedByte"
-                | "http://www.w3.org/2001/XMLSchema#unsignedShort"
-                | "http://www.w3.org/2001/XMLSchema#unsignedInt"
-                | "http://www.w3.org/2001/XMLSchema#unsignedLong"
-                | "http://www.w3.org/2001/XMLSchema#positiveInteger"
-                | "http://www.w3.org/2001/XMLSchema#negativeInteger"
-                | "http://www.w3.org/2001/XMLSchema#nonPositiveInteger"
-                | "http://www.w3.org/2001/XMLSchema#nonNegativeInteger" => match value.parse() {
-                    Ok(value) => EncodedTerm::IntegerLiteral(value),
-                    Err(_) => EncodedTerm::TypedLiteral {
+                    }),
+                    "http://www.w3.org/2001/XMLSchema#float" => self.encode_float_str(value),
+                    "http://www.w3.org/2001/XMLSchema#double" => self.encode_double_str(value),
+                    "http://www.w3.org/2001/XMLSchema#integer"
+                    | "http://www.w3.org/2001/XMLSchema#byte"
+                    | "http://www.w3.org/2001/XMLSchema#short"
+                    | "http://www.w3.org/2001/XMLSchema#int"
+                    | "http://www.w3.org/2001/XMLSchema#long"
+                    | "http://www.w3.org/2001/XMLSchema#unsignedByte"
+                    | "http://www.w3.org/2001/XMLSchema#unsignedShort"
+                    | "http://www.w3.org/2001/XMLSchema#unsignedInt"
+                    | "http://www.w3.org/2001/XMLSchema#unsignedLong"
+                    | "http://www.w3.org/2001/XMLSchema#positiveInteger"
+                    | "http://www.w3.org/2001/XMLSchema#negativeInteger"
+                    | "http://www.w3.org/2001/XMLSchema#nonPositiveInteger"
+                    | "http://www.w3.org/2001/XMLSchema#nonNegativeInteger" => {
+                        self.encode_integer_str(value)
+                    }
+                    "http://www.w3.org/2001/XMLSchema#decimal" => self.encode_decimal_str(value),
+                    "http://www.w3.org/2001/XMLSchema#date" => self.encode_date_str(value),
+                    "http://www.w3.org/2001/XMLSchema#time" => self.encode_time_str(value),
+                    "http://www.w3.org/2001/XMLSchema#dateTime"
+                    | "http://www.w3.org/2001/XMLSchema#dateTimeStamp" => {
+                        self.encode_date_time_str(value)
+                    }
+                    _ => None,
+                } {
+                    Some(v) => v,
+                    None => EncodedTerm::TypedLiteral {
                         value_id: self.string_store.insert_str(value)?,
                         datatype_id: self.string_store.insert_str(datatype.iri)?,
                     },
-                },
-                "http://www.w3.org/2001/XMLSchema#decimal" => match value.parse() {
-                    Ok(value) => EncodedTerm::DecimalLiteral(value),
-                    Err(_) => EncodedTerm::TypedLiteral {
-                        value_id: self.string_store.insert_str(value)?,
-                        datatype_id: XSD_DECIMAL_ID,
-                    },
-                },
-                "http://www.w3.org/2001/XMLSchema#date" => {
-                    let mut parsed = Parsed::new();
-                    match parse(&mut parsed, &value, StrftimeItems::new("%Y-%m-%d%:z")).and_then(
-                        |_| {
-                            Ok(Date::from_utc(
-                                parsed.to_naive_date()?,
-                                parsed.to_fixed_offset()?,
-                            ))
-                        },
-                    ) {
-                        Ok(value) => EncodedTerm::DateLiteral(value),
-                        Err(_) => match NaiveDate::parse_from_str(&value, "%Y-%m-%dZ") {
-                            Ok(value) => EncodedTerm::DateLiteral(Date::from_utc(
-                                value,
-                                FixedOffset::east(0),
-                            )),
-                            Err(_) => match NaiveDate::parse_from_str(&value, "%Y-%m-%d") {
-                                Ok(value) => EncodedTerm::NaiveDateLiteral(value),
-                                Err(_) => EncodedTerm::TypedLiteral {
-                                    value_id: self.string_store.insert_str(value)?,
-                                    datatype_id: XSD_DATE_ID,
-                                },
-                            },
-                        },
-                    }
-                }
-                "http://www.w3.org/2001/XMLSchema#time" => {
-                    match NaiveTime::parse_from_str(&value, "%H:%M:%S") {
-                        Ok(value) => EncodedTerm::NaiveTimeLiteral(value),
-                        Err(_) => EncodedTerm::TypedLiteral {
-                            value_id: self.string_store.insert_str(value)?,
-                            datatype_id: XSD_TIME_ID,
-                        },
-                    }
-                }
-                "http://www.w3.org/2001/XMLSchema#dateTime"
-                | "http://www.w3.org/2001/XMLSchema#dateTimeStamp" => {
-                    match DateTime::parse_from_rfc3339(&value) {
-                        Ok(value) => EncodedTerm::DateTimeLiteral(value),
-                        Err(_) => {
-                            match NaiveDateTime::parse_from_str(&value, "%Y-%m-%dT%H:%M:%S") {
-                                Ok(value) => EncodedTerm::NaiveDateTimeLiteral(value),
-                                Err(_) => EncodedTerm::TypedLiteral {
-                                    value_id: self.string_store.insert_str(value)?,
-                                    datatype_id: XSD_DATE_TIME_ID,
-                                },
-                            }
-                        }
-                    }
                 }
-                _ => EncodedTerm::TypedLiteral {
-                    value_id: self.string_store.insert_str(value)?,
-                    datatype_id: self.string_store.insert_str(datatype.iri)?,
-                },
-            },
+            }
         })
     }
 
@@ -849,6 +781,72 @@ impl<S: StringStore> Encoder<S> {
         })
     }
 
+    pub fn encode_boolean_str(&self, value: &str) -> Option<EncodedTerm> {
+        match value {
+            "true" | "1" => Some(EncodedTerm::BooleanLiteral(true)),
+            "false" | "0" => Some(EncodedTerm::BooleanLiteral(false)),
+            _ => None,
+        }
+    }
+
+    pub fn encode_float_str(&self, value: &str) -> Option<EncodedTerm> {
+        value
+            .parse()
+            .map(|value| EncodedTerm::FloatLiteral(OrderedFloat(value)))
+            .ok()
+    }
+
+    pub fn encode_double_str(&self, value: &str) -> Option<EncodedTerm> {
+        value
+            .parse()
+            .map(|value| EncodedTerm::DoubleLiteral(OrderedFloat(value)))
+            .ok()
+    }
+
+    pub fn encode_integer_str(&self, value: &str) -> Option<EncodedTerm> {
+        value.parse().map(EncodedTerm::IntegerLiteral).ok()
+    }
+
+    pub fn encode_decimal_str(&self, value: &str) -> Option<EncodedTerm> {
+        value.parse().map(EncodedTerm::DecimalLiteral).ok()
+    }
+
+    pub fn encode_date_str(&self, value: &str) -> Option<EncodedTerm> {
+        let mut parsed = Parsed::new();
+        match parse(&mut parsed, &value, StrftimeItems::new("%Y-%m-%d%:z")).and_then(|_| {
+            Ok(Date::from_utc(
+                parsed.to_naive_date()?,
+                parsed.to_fixed_offset()?,
+            ))
+        }) {
+            Ok(value) => Some(EncodedTerm::DateLiteral(value)),
+            Err(_) => match NaiveDate::parse_from_str(&value, "%Y-%m-%dZ") {
+                Ok(value) => Some(EncodedTerm::DateLiteral(Date::from_utc(
+                    value,
+                    FixedOffset::east(0),
+                ))),
+                Err(_) => NaiveDate::parse_from_str(&value, "%Y-%m-%d")
+                    .map(EncodedTerm::NaiveDateLiteral)
+                    .ok(),
+            },
+        }
+    }
+
+    pub fn encode_time_str(&self, value: &str) -> Option<EncodedTerm> {
+        NaiveTime::parse_from_str(&value, "%H:%M:%S")
+            .map(EncodedTerm::NaiveTimeLiteral)
+            .ok()
+    }
+
+    pub fn encode_date_time_str(&self, value: &str) -> Option<EncodedTerm> {
+        match DateTime::parse_from_rfc3339(&value) {
+            Ok(value) => Some(EncodedTerm::DateTimeLiteral(value)),
+            Err(_) => NaiveDateTime::parse_from_str(&value, "%Y-%m-%dT%H:%M:%S")
+                .map(EncodedTerm::NaiveDateTimeLiteral)
+                .ok(),
+        }
+    }
+
     pub fn decode_term(&self, encoded: EncodedTerm) -> Result<Term> {
         match encoded {
             EncodedTerm::DefaultGraph => {