Added FixedSizeListScalar and FixedSizeBinaryScalar (#786)

src/scalar/fixed_size_binary.rs

@@ -0,0 +1,59 @@
+use crate::datatypes::DataType;
+
+use super::Scalar;
+
+#[derive(Debug, Clone, PartialEq)]
+/// The [`Scalar`] implementation of fixed size binary ([`Option<Box<[u8]>>`]).
+pub struct FixedSizeBinaryScalar {
+    value: Option<Box<[u8]>>,
+    data_type: DataType,
+}
+
+impl FixedSizeBinaryScalar {
+    /// Returns a new [`FixedSizeBinaryScalar`].
+    /// # Panics
+    /// iff
+    /// * the `data_type` is not `FixedSizeBinary`
+    /// * the size of child binary is not equal
+    #[inline]
+    pub fn new<P: Into<Vec<u8>>>(data_type: DataType, value: Option<P>) -> Self {
+        assert_eq!(
+            data_type.to_physical_type(),
+            crate::datatypes::PhysicalType::FixedSizeBinary
+        );
+        Self {
+            value: value.map(|x| {
+                let x: Vec<u8> = x.into();
+                assert_eq!(
+                    data_type.to_logical_type(),
+                    &DataType::FixedSizeBinary(x.len())
+                );
+                x.into_boxed_slice()
+            }),
+            data_type,
+        }
+    }
+
+    /// Its value
+    #[inline]
+    pub fn value(&self) -> Option<&[u8]> {
+        self.value.as_ref().map(|x| x.as_ref())
+    }
+}
+
+impl Scalar for FixedSizeBinaryScalar {
+    #[inline]
+    fn as_any(&self) -> &dyn std::any::Any {
+        self
+    }
+
+    #[inline]
+    fn is_valid(&self) -> bool {
+        self.value.is_some()
+    }
+
+    #[inline]
+    fn data_type(&self) -> &DataType {
+        &self.data_type
+    }
+}

src/scalar/fixed_size_list.rs

@@ -0,0 +1,61 @@
+use std::any::Any;
+use std::sync::Arc;
+
+use crate::{array::*, datatypes::DataType};
+
+use super::Scalar;
+
+/// The scalar equivalent of [`FixedSizeListArray`]. Like [`FixedSizeListArray`], this struct holds a dynamically-typed
+/// [`Array`]. The only difference is that this has only one element.
+#[derive(Debug, Clone)]
+pub struct FixedSizeListScalar {
+    values: Option<Arc<dyn Array>>,
+    data_type: DataType,
+}
+
+impl PartialEq for FixedSizeListScalar {
+    fn eq(&self, other: &Self) -> bool {
+        (self.data_type == other.data_type)
+            && (self.values.is_some() == other.values.is_some())
+            && ((self.values.is_none()) | (self.values.as_ref() == other.values.as_ref()))
+    }
+}
+
+impl FixedSizeListScalar {
+    /// returns a new [`FixedSizeListScalar`]
+    /// # Panics
+    /// iff
+    /// * the `data_type` is not `FixedSizeList`
+    /// * the child of the `data_type` is not equal to the `values`
+    /// * the size of child array is not equal
+    #[inline]
+    pub fn new(data_type: DataType, values: Option<Arc<dyn Array>>) -> Self {
+        let (field, size) = FixedSizeListArray::get_child_and_size(&data_type);
+        let inner_data_type = field.data_type();
+        let values = values.map(|x| {
+            assert_eq!(inner_data_type, x.data_type());
+            assert_eq!(size, x.len());
+            x
+        });
+        Self { values, data_type }
+    }
+
+    /// The values of the [`FixedSizeListScalar`]
+    pub fn values(&self) -> Option<&Arc<dyn Array>> {
+        self.values.as_ref()
+    }
+}
+
+impl Scalar for FixedSizeListScalar {
+    fn as_any(&self) -> &dyn Any {
+        self
+    }
+
+    fn is_valid(&self) -> bool {
+        self.values.is_some()
+    }
+
+    fn data_type(&self) -> &DataType {
+        &self.data_type
+    }
+}

src/scalar/mod.rs

@@ -22,6 +22,10 @@ mod null;
 pub use null::*;
 mod struct_;
 pub use struct_::*;
+mod fixed_size_list;
+pub use fixed_size_list::*;
+mod fixed_size_binary;
+pub use fixed_size_binary::*;
 
 /// Trait object declaring an optional value with a [`DataType`].
 /// This strait is often used in APIs that accept multiple scalar types.
@@ -120,8 +124,27 @@ pub fn new_scalar(array: &dyn Array, index: usize) -> Box<dyn Scalar> {
                 Box::new(StructScalar::new(array.data_type().clone(), None))
             }
         }
-        FixedSizeBinary => todo!(),
-        FixedSizeList => todo!(),
+        FixedSizeBinary => {
+            let array = array
+                .as_any()
+                .downcast_ref::<FixedSizeBinaryArray>()
+                .unwrap();
+            let value = if array.is_valid(index) {
+                Some(array.value(index))
+            } else {
+                None
+            };
+            Box::new(FixedSizeBinaryScalar::new(array.data_type().clone(), value))
+        }
+        FixedSizeList => {
+            let array = array.as_any().downcast_ref::<FixedSizeListArray>().unwrap();
+            let value = if array.is_valid(index) {
+                Some(array.value(index).into())
+            } else {
+                None
+            };
+            Box::new(FixedSizeListScalar::new(array.data_type().clone(), value))
+        }
         Union | Map => todo!(),
         Dictionary(key_type) => match_integer_type!(key_type, |$T| {
             let array = array

tests/it/scalar/fixed_size_binary.rs

@@ -0,0 +1,28 @@
+use arrow2::{
+    datatypes::DataType,
+    scalar::{FixedSizeBinaryScalar, Scalar},
+};
+
+#[allow(clippy::eq_op)]
+#[test]
+fn equal() {
+    let a = FixedSizeBinaryScalar::new(DataType::FixedSizeBinary(1), Some("a"));
+    let b = FixedSizeBinaryScalar::new(DataType::FixedSizeBinary(1), None::<&str>);
+    assert_eq!(a, a);
+    assert_eq!(b, b);
+    assert!(a != b);
+    let b = FixedSizeBinaryScalar::new(DataType::FixedSizeBinary(1), Some("b"));
+    assert!(a != b);
+    assert_eq!(b, b);
+}
+
+#[test]
+fn basics() {
+    let a = FixedSizeBinaryScalar::new(DataType::FixedSizeBinary(1), Some("a"));
+
+    assert_eq!(a.value(), Some(b"a".as_ref()));
+    assert_eq!(a.data_type(), &DataType::FixedSizeBinary(1));
+    assert!(a.is_valid());
+
+    let _: &dyn std::any::Any = a.as_any();
+}

tests/it/scalar/fixed_size_list.rs

@@ -0,0 +1,48 @@
+use std::sync::Arc;
+
+use arrow2::{
+    array::{Array, BooleanArray},
+    datatypes::{DataType, Field},
+    scalar::{FixedSizeListScalar, Scalar},
+};
+
+#[allow(clippy::eq_op)]
+#[test]
+fn equal() {
+    let dt = DataType::FixedSizeList(Box::new(Field::new("a", DataType::Boolean, true)), 2);
+    let a = FixedSizeListScalar::new(
+        dt.clone(),
+        Some(Arc::new(BooleanArray::from_slice([true, false])) as Arc<dyn Array>),
+    );
+
+    let b = FixedSizeListScalar::new(dt.clone(), None);
+
+    assert_eq!(a, a);
+    assert_eq!(b, b);
+    assert!(a != b);
+
+    let b = FixedSizeListScalar::new(
+        dt,
+        Some(Arc::new(BooleanArray::from_slice([true, true])) as Arc<dyn Array>),
+    );
+    assert!(a != b);
+    assert_eq!(b, b);
+}
+
+#[test]
+fn basics() {
+    let dt = DataType::FixedSizeList(Box::new(Field::new("a", DataType::Boolean, true)), 2);
+    let a = FixedSizeListScalar::new(
+        dt.clone(),
+        Some(Arc::new(BooleanArray::from_slice([true, false])) as Arc<dyn Array>),
+    );
+
+    assert_eq!(
+        BooleanArray::from_slice([true, false]),
+        a.values().unwrap().as_ref()
+    );
+    assert_eq!(a.data_type(), &dt);
+    assert!(a.is_valid());
+
+    let _: &dyn std::any::Any = a.as_any();
+}

tests/it/scalar/mod.rs

@@ -1,5 +1,7 @@
 mod binary;
 mod boolean;
+mod fixed_size_binary;
+mod fixed_size_list;
 mod list;
 mod null;
 mod primitive;