Enum ScalarValue

pub enum ScalarValue {
    Null,
    Boolean(Option<bool>),
    Float16(Option<f16>),
    Float32(Option<f32>),
    Float64(Option<f64>),
    Decimal128(Option<i128>, u8, i8),
    Decimal256(Option<i256>, u8, i8),
    Int8(Option<i8>),
    Int16(Option<i16>),
    Int32(Option<i32>),
    Int64(Option<i64>),
    UInt8(Option<u8>),
    UInt16(Option<u16>),
    UInt32(Option<u32>),
    UInt64(Option<u64>),
    Utf8(Option<String>),
    Utf8View(Option<String>),
    LargeUtf8(Option<String>),
    Binary(Option<Vec<u8>>),
    BinaryView(Option<Vec<u8>>),
    FixedSizeBinary(i32, Option<Vec<u8>>),
    LargeBinary(Option<Vec<u8>>),
    FixedSizeList(Arc<FixedSizeListArray>),
    List(Arc<ListArray>),
    LargeList(Arc<LargeListArray>),
    Struct(Arc<StructArray>),
    Map(Arc<MapArray>),
    Date32(Option<i32>),
    Date64(Option<i64>),
    Time32Second(Option<i32>),
    Time32Millisecond(Option<i32>),
    Time64Microsecond(Option<i64>),
    Time64Nanosecond(Option<i64>),
    TimestampSecond(Option<i64>, Option<Arc<str>>),
    TimestampMillisecond(Option<i64>, Option<Arc<str>>),
    TimestampMicrosecond(Option<i64>, Option<Arc<str>>),
    TimestampNanosecond(Option<i64>, Option<Arc<str>>),
    IntervalYearMonth(Option<i32>),
    IntervalDayTime(Option<IntervalDayTime>),
    IntervalMonthDayNano(Option<IntervalMonthDayNano>),
    DurationSecond(Option<i64>),
    DurationMillisecond(Option<i64>),
    DurationMicrosecond(Option<i64>),
    DurationNanosecond(Option<i64>),
    Union(Option<(i8, Box<ScalarValue>)>, UnionFields, UnionMode),
    Dictionary(Box<DataType>, Box<ScalarValue>),
}

A dynamically typed, nullable single value.

While an arrow Array) stores one or more values of the same type, in a single column, a ScalarValue stores a single value of a single type, the equivalent of 1 row and one column.

 ┌────────┐
 │ value1 │
 │ value2 │                  ┌────────┐
 │ value3 │                  │ value2 │
 │  ...   │                  └────────┘
 │ valueN │
 └────────┘

   Array                     ScalarValue

stores multiple,             stores a single,
possibly null, values of     possible null, value
the same type

Performance

In general, performance will be better using arrow Arrays rather than ScalarValue, as it is far more efficient to process multiple values at once (vectorized processing).

Example

// Create single scalar value for an Int32 value
let s1 = ScalarValue::Int32(Some(10));

// You can also create values using the From impl:
let s2 = ScalarValue::from(10i32);
assert_eq!(s1, s2);

Null Handling

ScalarValue represents null values in the same way as Arrow. Nulls are “typed” in the sense that a null value in an Int32Array is different from a null value in a Float64Array, and is different from the values in a NullArray.

// You can create a 'null' Int32 value directly:
let s1 = ScalarValue::Int32(None);

// You can also create a null value for a given datatype:
let s2 = ScalarValue::try_from(&DataType::Int32)?;
assert_eq!(s1, s2);

// Note that this is DIFFERENT than a `ScalarValue::Null`
let s3 = ScalarValue::Null;
assert_ne!(s1, s3);

Nested Types

List / LargeList / FixedSizeList / Struct / Map are represented as a single element array of the corresponding type.

Example: Creating ScalarValue::Struct using ScalarStructBuilder

// Build a struct like: {a: 1, b: "foo"}
let field_a = Field::new("a", DataType::Int32, false);
let field_b = Field::new("b", DataType::Utf8, false);

let s1 = ScalarStructBuilder::new()
   .with_scalar(field_a, ScalarValue::from(1i32))
   .with_scalar(field_b, ScalarValue::from("foo"))
   .build();

Example: Creating a null ScalarValue::Struct using ScalarStructBuilder

// Build a struct representing a NULL value
let fields = vec![
    Field::new("a", DataType::Int32, false),
    Field::new("b", DataType::Utf8, false),
];

let s1 = ScalarStructBuilder::new_null(fields);

Example: Creating ScalarValue::Struct directly

// Build a struct like: {a: 1, b: "foo"}
// Field description
let fields = Fields::from(vec![
  Field::new("a", DataType::Int32, false),
  Field::new("b", DataType::Utf8, false),
]);
// one row arrays for each field
let arrays: Vec<ArrayRef> = vec![
  Arc::new(Int32Array::from(vec![1])),
  Arc::new(StringArray::from(vec!["foo"])),
];
// no nulls for this array
let nulls = None;
let arr = StructArray::new(fields, arrays, nulls);

// Create a ScalarValue::Struct directly
let s1 = ScalarValue::Struct(Arc::new(arr));

Further Reading

See datatypes for details on datatypes and the format for the definitive reference.

Variants

Null

represents DataType::Null (castable to/from any other type)

Boolean(Option<bool>)

true or false value

Float16(Option<f16>)

16bit float

Float32(Option<f32>)

32bit float

Float64(Option<f64>)

64bit float

Decimal128(Option<i128>, u8, i8)

128bit decimal, using the i128 to represent the decimal, precision scale

Decimal256(Option<i256>, u8, i8)

256bit decimal, using the i256 to represent the decimal, precision scale

Int8(Option<i8>)

signed 8bit int

Int16(Option<i16>)

signed 16bit int

Int32(Option<i32>)

signed 32bit int

Int64(Option<i64>)

signed 64bit int

UInt8(Option<u8>)

unsigned 8bit int

UInt16(Option<u16>)

unsigned 16bit int

UInt32(Option<u32>)

unsigned 32bit int

UInt64(Option<u64>)

unsigned 64bit int

Utf8(Option<String>)

utf-8 encoded string.

Utf8View(Option<String>)

utf-8 encoded string but from view types.

LargeUtf8(Option<String>)

utf-8 encoded string representing a LargeString’s arrow type.

Binary(Option<Vec<u8>>)

binary

BinaryView(Option<Vec<u8>>)

binary but from view types.

FixedSizeBinary(i32, Option<Vec<u8>>)

fixed size binary

LargeBinary(Option<Vec<u8>>)

large binary

FixedSizeList(Arc<FixedSizeListArray>)

Fixed size list scalar.

The array must be a FixedSizeListArray with length 1.

List(Arc<ListArray>)

Represents a single element of a ListArray as an ArrayRef

The array must be a ListArray with length 1.

LargeList(Arc<LargeListArray>)

The array must be a LargeListArray with length 1.

Struct(Arc<StructArray>)

Represents a single element StructArray as an ArrayRef. See ScalarValue for examples of how to create instances of this type.

Map(Arc<MapArray>)

Represents a single element MapArray as an ArrayRef.

Date32(Option<i32>)

Date stored as a signed 32bit int days since UNIX epoch 1970-01-01

Date64(Option<i64>)

Date stored as a signed 64bit int milliseconds since UNIX epoch 1970-01-01

Time32Second(Option<i32>)

Time stored as a signed 32bit int as seconds since midnight

Time32Millisecond(Option<i32>)

Time stored as a signed 32bit int as milliseconds since midnight

Time64Microsecond(Option<i64>)

Time stored as a signed 64bit int as microseconds since midnight

Time64Nanosecond(Option<i64>)

Time stored as a signed 64bit int as nanoseconds since midnight

TimestampSecond(Option<i64>, Option<Arc<str>>)

Timestamp Second

TimestampMillisecond(Option<i64>, Option<Arc<str>>)

Timestamp Milliseconds

TimestampMicrosecond(Option<i64>, Option<Arc<str>>)

Timestamp Microseconds

TimestampNanosecond(Option<i64>, Option<Arc<str>>)

Timestamp Nanoseconds

IntervalYearMonth(Option<i32>)

Number of elapsed whole months

IntervalDayTime(Option<IntervalDayTime>)

Number of elapsed days and milliseconds (no leap seconds) stored as 2 contiguous 32-bit signed integers

IntervalMonthDayNano(Option<IntervalMonthDayNano>)

A triple of the number of elapsed months, days, and nanoseconds. Months and days are encoded as 32-bit signed integers. Nanoseconds is encoded as a 64-bit signed integer (no leap seconds).

DurationSecond(Option<i64>)

Duration in seconds

DurationMillisecond(Option<i64>)

Duration in milliseconds

DurationMicrosecond(Option<i64>)

Duration in microseconds

DurationNanosecond(Option<i64>)

Duration in nanoseconds

Union(Option<(i8, Box<ScalarValue>)>, UnionFields, UnionMode)

A nested datatype that can represent slots of differing types. Components: .0: a tuple of union type_id and the single value held by this Scalar .1: the list of fields, zero-to-one of which will by set in .0 .2: the physical storage of the source/destination UnionArray from which this Scalar came

Dictionary(Box<DataType>, Box<ScalarValue>)

Dictionary type: index type and value

Implementations

impl ScalarValue

pub fn new_primitive<T: ArrowPrimitiveType>( a: Option<T::Native>, d: &DataType, ) -> Result<Self>

Create a Result<ScalarValue> with the provided value and datatype

Panics

Panics if d is not compatible with T

pub fn try_new_decimal128(value: i128, precision: u8, scale: i8) -> Result<Self>

Create a decimal Scalar from value/precision and scale.

pub fn new_utf8(val: impl Into<String>) -> Self

Returns a ScalarValue::Utf8 representing val

pub fn new_utf8view(val: impl Into<String>) -> Self

Returns a ScalarValue::Utf8View representing val

pub fn new_interval_ym(years: i32, months: i32) -> Self

Returns a ScalarValue::IntervalYearMonth representing years years and months months

pub fn new_interval_dt(days: i32, millis: i32) -> Self

Returns a ScalarValue::IntervalDayTime representing days days and millis milliseconds

pub fn new_interval_mdn(months: i32, days: i32, nanos: i64) -> Self

Returns a ScalarValue::IntervalMonthDayNano representing months months and days days, and nanos nanoseconds

pub fn new_timestamp<T: ArrowTimestampType>( value: Option<i64>, tz_opt: Option<Arc<str>>, ) -> Self

Returns a ScalarValue representing value and tz_opt timezone

pub fn new_pi(datatype: &DataType) -> Result<ScalarValue>

Returns a ScalarValue representing PI

pub fn new_pi_upper(datatype: &DataType) -> Result<ScalarValue>

Returns a ScalarValue representing PI’s upper bound

pub fn new_negative_pi_lower(datatype: &DataType) -> Result<ScalarValue>

Returns a ScalarValue representing -PI’s lower bound

pub fn new_frac_pi_2_upper(datatype: &DataType) -> Result<ScalarValue>

Returns a ScalarValue representing FRAC_PI_2’s upper bound

pub fn new_neg_frac_pi_2_lower(datatype: &DataType) -> Result<ScalarValue>

pub fn new_negative_pi(datatype: &DataType) -> Result<ScalarValue>

Returns a ScalarValue representing -PI

pub fn new_frac_pi_2(datatype: &DataType) -> Result<ScalarValue>

Returns a ScalarValue representing PI/2

pub fn new_neg_frac_pi_2(datatype: &DataType) -> Result<ScalarValue>

Returns a ScalarValue representing -PI/2

pub fn new_infinity(datatype: &DataType) -> Result<ScalarValue>

Returns a ScalarValue representing infinity

pub fn new_neg_infinity(datatype: &DataType) -> Result<ScalarValue>

Returns a ScalarValue representing negative infinity

pub fn new_zero(datatype: &DataType) -> Result<ScalarValue>

Create a zero value in the given type.

pub fn new_one(datatype: &DataType) -> Result<ScalarValue>

Create an one value in the given type.

pub fn new_negative_one(datatype: &DataType) -> Result<ScalarValue>

Create a negative one value in the given type.

pub fn new_ten(datatype: &DataType) -> Result<ScalarValue>

pub fn data_type(&self) -> DataType

return the DataType of this ScalarValue

pub fn arithmetic_negate(&self) -> Result<Self>

Calculate arithmetic negation for a scalar value

pub fn add<T: Borrow<ScalarValue>>(&self, other: T) -> Result<ScalarValue>

Wrapping addition of ScalarValue

NB: operating on ScalarValue directly is not efficient, performance sensitive code should operate on Arrays directly, using vectorized array kernels

pub fn add_checked<T: Borrow<ScalarValue>>( &self, other: T, ) -> Result<ScalarValue>

Checked addition of ScalarValue

NB: operating on ScalarValue directly is not efficient, performance sensitive code should operate on Arrays directly, using vectorized array kernels

pub fn sub<T: Borrow<ScalarValue>>(&self, other: T) -> Result<ScalarValue>

Wrapping subtraction of ScalarValue

NB: operating on ScalarValue directly is not efficient, performance sensitive code should operate on Arrays directly, using vectorized array kernels

pub fn sub_checked<T: Borrow<ScalarValue>>( &self, other: T, ) -> Result<ScalarValue>

Checked subtraction of ScalarValue

NB: operating on ScalarValue directly is not efficient, performance sensitive code should operate on Arrays directly, using vectorized array kernels

pub fn mul<T: Borrow<ScalarValue>>(&self, other: T) -> Result<ScalarValue>

Wrapping multiplication of ScalarValue

NB: operating on ScalarValue directly is not efficient, performance sensitive code should operate on Arrays directly, using vectorized array kernels.

pub fn mul_checked<T: Borrow<ScalarValue>>( &self, other: T, ) -> Result<ScalarValue>

Checked multiplication of ScalarValue

NB: operating on ScalarValue directly is not efficient, performance sensitive code should operate on Arrays directly, using vectorized array kernels.

pub fn div<T: Borrow<ScalarValue>>(&self, other: T) -> Result<ScalarValue>

Performs lhs / rhs

Overflow or division by zero will result in an error, with exception to floating point numbers, which instead follow the IEEE 754 rules.

NB: operating on ScalarValue directly is not efficient, performance sensitive code should operate on Arrays directly, using vectorized array kernels.

pub fn rem<T: Borrow<ScalarValue>>(&self, other: T) -> Result<ScalarValue>

Performs lhs % rhs

Overflow or division by zero will result in an error, with exception to floating point numbers, which instead follow the IEEE 754 rules.

NB: operating on ScalarValue directly is not efficient, performance sensitive code should operate on Arrays directly, using vectorized array kernels.

pub fn is_unsigned(&self) -> bool

pub fn is_null(&self) -> bool

whether this value is null or not.

pub fn distance(&self, other: &ScalarValue) -> Option<usize>

Absolute distance between two numeric values (of the same type). This method will return None if either one of the arguments are null. It might also return None if the resulting distance is greater than usize::MAX. If the type is a float, then the distance will be rounded to the nearest integer.

Note: the datatype itself must support subtraction.

pub fn to_array(&self) -> Result<ArrayRef>

Converts a scalar value into an 1-row array.

Errors

Errors if the ScalarValue cannot be converted into a 1-row array

pub fn to_scalar(&self) -> Result<Scalar<ArrayRef>>

Converts a scalar into an arrow Scalar (which implements the Datum interface).

This can be used to call arrow compute kernels such as lt

Errors

Errors if the ScalarValue cannot be converted into a 1-row array

Example

use datafusion_common::ScalarValue;
use arrow::array::{BooleanArray, Int32Array};

let arr = Int32Array::from(vec![Some(1), None, Some(10)]);
let five = ScalarValue::Int32(Some(5));

let result = arrow::compute::kernels::cmp::lt(
  &arr,
  &five.to_scalar().unwrap(),
).unwrap();

let expected = BooleanArray::from(vec![
    Some(true),
    None,
    Some(false)
  ]
);

assert_eq!(&result, &expected);

pub fn iter_to_array( scalars: impl IntoIterator<Item = ScalarValue>, ) -> Result<ArrayRef>

Converts an iterator of references ScalarValue into an ArrayRef corresponding to those values. For example, an iterator of ScalarValue::Int32 would be converted to an Int32Array.

Returns an error if the iterator is empty or if the ScalarValues are not all the same type

Panics

Panics if self is a dictionary with invalid key type

Example

use datafusion_common::ScalarValue;
use arrow::array::{ArrayRef, BooleanArray};

let scalars = vec![
  ScalarValue::Boolean(Some(true)),
  ScalarValue::Boolean(None),
  ScalarValue::Boolean(Some(false)),
];

// Build an Array from the list of ScalarValues
let array = ScalarValue::iter_to_array(scalars.into_iter())
  .unwrap();

let expected: ArrayRef = std::sync::Arc::new(
  BooleanArray::from(vec![
    Some(true),
    None,
    Some(false)
  ]
));

assert_eq!(&array, &expected);

pub fn new_list( values: &[ScalarValue], data_type: &DataType, nullable: bool, ) -> Arc<ListArray>

Converts Vec<ScalarValue> where each element has type corresponding to data_type, to a single element ListArray.

Example

use datafusion_common::ScalarValue;
use arrow::array::{ListArray, Int32Array};
use arrow::datatypes::{DataType, Int32Type};
use datafusion_common::cast::as_list_array;

let scalars = vec![
   ScalarValue::Int32(Some(1)),
   ScalarValue::Int32(None),
   ScalarValue::Int32(Some(2))
];

let result = ScalarValue::new_list(&scalars, &DataType::Int32, true);

let expected = ListArray::from_iter_primitive::<Int32Type, _, _>(
    vec![
       Some(vec![Some(1), None, Some(2)])
    ]);

assert_eq!(*result, expected);

pub fn new_list_nullable( values: &[ScalarValue], data_type: &DataType, ) -> Arc<ListArray>

Same as ScalarValue::new_list but with nullable set to true.

pub fn new_null_list( data_type: DataType, nullable: bool, null_len: usize, ) -> Self

Create ListArray with Null with specific data type

• new_null_list(i32, nullable, 1): ListArray[NULL]

pub fn new_list_from_iter( values: impl IntoIterator<Item = ScalarValue> + ExactSizeIterator, data_type: &DataType, nullable: bool, ) -> Arc<ListArray>

Converts IntoIterator<Item = ScalarValue> where each element has type corresponding to data_type, to a ListArray.

Example

use datafusion_common::ScalarValue;
use arrow::array::{ListArray, Int32Array};
use arrow::datatypes::{DataType, Int32Type};
use datafusion_common::cast::as_list_array;

let scalars = vec![
   ScalarValue::Int32(Some(1)),
   ScalarValue::Int32(None),
   ScalarValue::Int32(Some(2))
];

let result = ScalarValue::new_list_from_iter(scalars.into_iter(), &DataType::Int32, true);

let expected = ListArray::from_iter_primitive::<Int32Type, _, _>(
    vec![
       Some(vec![Some(1), None, Some(2)])
    ]);

assert_eq!(*result, expected);

pub fn new_large_list( values: &[ScalarValue], data_type: &DataType, ) -> Arc<LargeListArray>

Converts Vec<ScalarValue> where each element has type corresponding to data_type, to a LargeListArray.

Example

use datafusion_common::ScalarValue;
use arrow::array::{LargeListArray, Int32Array};
use arrow::datatypes::{DataType, Int32Type};
use datafusion_common::cast::as_large_list_array;

let scalars = vec![
   ScalarValue::Int32(Some(1)),
   ScalarValue::Int32(None),
   ScalarValue::Int32(Some(2))
];

let result = ScalarValue::new_large_list(&scalars, &DataType::Int32);

let expected = LargeListArray::from_iter_primitive::<Int32Type, _, _>(
    vec![
       Some(vec![Some(1), None, Some(2)])
    ]);

assert_eq!(*result, expected);

pub fn to_array_of_size(&self, size: usize) -> Result<ArrayRef>

Converts a scalar value into an array of size rows.

Errors

Errors if self is

• a decimal that fails be converted to a decimal array of size
• a Fixedsizelist that fails to be concatenated into an array of size
• a List that fails to be concatenated into an array of size
• a Dictionary that fails be converted to a dictionary array of size

pub fn convert_array_to_scalar_vec(array: &dyn Array) -> Result<Vec<Vec<Self>>>

Retrieve ScalarValue for each row in array

Example 1: Array (ScalarValue::Int32)

use datafusion_common::ScalarValue;
use arrow::array::ListArray;
use arrow::datatypes::{DataType, Int32Type};

// Equivalent to [[1,2,3], [4,5]]
let list_arr = ListArray::from_iter_primitive::<Int32Type, _, _>(vec![
   Some(vec![Some(1), Some(2), Some(3)]),
   Some(vec![Some(4), Some(5)])
]);

// Convert the array into Scalar Values for each row
let scalar_vec = ScalarValue::convert_array_to_scalar_vec(&list_arr).unwrap();

let expected = vec![
vec![
    ScalarValue::Int32(Some(1)),
    ScalarValue::Int32(Some(2)),
    ScalarValue::Int32(Some(3)),
],
vec![
   ScalarValue::Int32(Some(4)),
   ScalarValue::Int32(Some(5)),
],
];

assert_eq!(scalar_vec, expected);

Example 2: Nested array (ScalarValue::List)

use datafusion_common::ScalarValue;
use arrow::array::ListArray;
use arrow::datatypes::{DataType, Int32Type};
use datafusion_common::utils::array_into_list_array_nullable;
use std::sync::Arc;

let list_arr = ListArray::from_iter_primitive::<Int32Type, _, _>(vec![
   Some(vec![Some(1), Some(2), Some(3)]),
   Some(vec![Some(4), Some(5)])
]);

// Wrap into another layer of list, we got nested array as [ [[1,2,3], [4,5]] ]
let list_arr = array_into_list_array_nullable(Arc::new(list_arr));

// Convert the array into Scalar Values for each row, we got 1D arrays in this example
let scalar_vec = ScalarValue::convert_array_to_scalar_vec(&list_arr).unwrap();

let l1 = ListArray::from_iter_primitive::<Int32Type, _, _>(vec![
    Some(vec![Some(1), Some(2), Some(3)]),
]);
let l2 = ListArray::from_iter_primitive::<Int32Type, _, _>(vec![
    Some(vec![Some(4), Some(5)]),
]);

let expected = vec![
  vec![
    ScalarValue::List(Arc::new(l1)),
    ScalarValue::List(Arc::new(l2)),
  ],
];

assert_eq!(scalar_vec, expected);

pub fn raw_data(&self) -> Result<ArrayRef>

Get raw data (inner array) inside ScalarValue

pub fn try_from_array(array: &dyn Array, index: usize) -> Result<Self>

Converts a value in array at index into a ScalarValue

pub fn try_from_string(value: String, target_type: &DataType) -> Result<Self>

Try to parse value into a ScalarValue of type target_type

pub fn cast_to(&self, target_type: &DataType) -> Result<Self>

Try to cast this value to a ScalarValue of type data_type

pub fn cast_to_with_options( &self, target_type: &DataType, cast_options: &CastOptions<'static>, ) -> Result<Self>

Try to cast this value to a ScalarValue of type data_type with CastOptions

pub fn eq_array(&self, array: &ArrayRef, index: usize) -> Result<bool>

Compares a single row of array @ index for equality with self, in an optimized fashion.

This method implements an optimized version of:

    let arr_scalar = Self::try_from_array(array, index).unwrap();
    arr_scalar.eq(self)

Performance note: the arrow compute kernels should be preferred over this function if at all possible as they can be vectorized and are generally much faster.

This function has a few narrow usescases such as hash table key comparisons where comparing a single row at a time is necessary.

Errors

Errors if

• it fails to downcast array to the data type of self
• self is a Struct

Panics

Panics if self is a dictionary with invalid key type

pub fn size(&self) -> usize

Estimate size if bytes including Self. For values with internal containers such as String includes the allocated size (capacity) rather than the current length (len)

pub fn size_of_vec(vec: &Vec<Self>) -> usize

Estimates size of Vec in bytes.

Includes the size of the Vec container itself.

pub fn size_of_vec_deque(vec_deque: &VecDeque<Self>) -> usize

Estimates size of VecDeque in bytes.

Includes the size of the VecDeque container itself.

pub fn size_of_hashset<S>(set: &HashSet<Self, S>) -> usize

Estimates size of HashSet in bytes.

Includes the size of the HashSet container itself.

Trait Implementations

impl Clone for ScalarValue

fn clone(&self) -> ScalarValue

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for ScalarValue

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Display for ScalarValue

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl From<&str> for ScalarValue

fn from(value: &str) -> Self

Converts to this type from the input type.

impl From<Option<&str>> for ScalarValue

fn from(value: Option<&str>) -> Self

Converts to this type from the input type.

impl From<Option<bool>> for ScalarValue

fn from(value: Option<bool>) -> Self

Converts to this type from the input type.

impl From<Option<f32>> for ScalarValue

fn from(value: Option<f32>) -> Self

Converts to this type from the input type.

impl From<Option<f64>> for ScalarValue

fn from(value: Option<f64>) -> Self

Converts to this type from the input type.

impl From<Option<i16>> for ScalarValue

fn from(value: Option<i16>) -> Self

Converts to this type from the input type.

impl From<Option<i32>> for ScalarValue

fn from(value: Option<i32>) -> Self

Converts to this type from the input type.

impl From<Option<i64>> for ScalarValue

fn from(value: Option<i64>) -> Self

Converts to this type from the input type.

impl From<Option<i8>> for ScalarValue

fn from(value: Option<i8>) -> Self

Converts to this type from the input type.

impl From<Option<u16>> for ScalarValue

fn from(value: Option<u16>) -> Self

Converts to this type from the input type.

impl From<Option<u32>> for ScalarValue

fn from(value: Option<u32>) -> Self

Converts to this type from the input type.

impl From<Option<u64>> for ScalarValue

fn from(value: Option<u64>) -> Self

Converts to this type from the input type.

impl From<Option<u8>> for ScalarValue

fn from(value: Option<u8>) -> Self

Converts to this type from the input type.

impl From<String> for ScalarValue

fn from(value: String) -> Self

Converts to this type from the input type.

impl From<Vec<(&str, ScalarValue)>> for ScalarValue

Wrapper to create ScalarValue::Struct for convenience

fn from(value: Vec<(&str, ScalarValue)>) -> Self

Converts to this type from the input type.

impl From<bool> for ScalarValue

fn from(value: bool) -> Self

Converts to this type from the input type.

impl From<f32> for ScalarValue

fn from(value: f32) -> Self

Converts to this type from the input type.

impl From<f64> for ScalarValue

fn from(value: f64) -> Self

Converts to this type from the input type.

impl From<i16> for ScalarValue

fn from(value: i16) -> Self

Converts to this type from the input type.

impl From<i32> for ScalarValue

fn from(value: i32) -> Self

Converts to this type from the input type.

impl From<i64> for ScalarValue

fn from(value: i64) -> Self

Converts to this type from the input type.

impl From<i8> for ScalarValue

fn from(value: i8) -> Self

Converts to this type from the input type.

impl From<u16> for ScalarValue

fn from(value: u16) -> Self

Converts to this type from the input type.

impl From<u32> for ScalarValue

fn from(value: u32) -> Self

Converts to this type from the input type.

impl From<u64> for ScalarValue

fn from(value: u64) -> Self

Converts to this type from the input type.

impl From<u8> for ScalarValue

fn from(value: u8) -> Self

Converts to this type from the input type.

impl FromStr for ScalarValue

type Err = Infallible

The associated error which can be returned from parsing.

fn from_str(s: &str) -> Result<Self, Self::Err>

Parses a string s to return a value of this type.

impl Hash for ScalarValue

fn hash<H: Hasher>(&self, state: &mut H)

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H)

where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher.

impl PartialEq for ScalarValue

fn eq(&self, other: &Self) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl PartialOrd for ScalarValue

fn partial_cmp(&self, other: &Self) -> Option<Ordering>

This method returns an ordering between self and other values if one exists.

fn lt(&self, other: &Rhs) -> bool

Tests less than (for self and other) and is used by the < operator.

fn le(&self, other: &Rhs) -> bool

Tests less than or equal to (for self and other) and is used by the <= operator.

fn gt(&self, other: &Rhs) -> bool

Tests greater than (for self and other) and is used by the > operator.

fn ge(&self, other: &Rhs) -> bool

Tests greater than or equal to (for self and other) and is used by the >= operator.

impl TryFrom<&DataType> for ScalarValue

fn try_from(data_type: &DataType) -> Result<Self>

Create a Null instance of ScalarValue for this datatype

type Error = DataFusionError

The type returned in the event of a conversion error.

impl TryFrom<DataType> for ScalarValue

fn try_from(datatype: DataType) -> Result<Self>

Create a Null instance of ScalarValue for this datatype

type Error = DataFusionError

The type returned in the event of a conversion error.

impl TryFrom<ScalarValue> for bool

type Error = DataFusionError

The type returned in the event of a conversion error.

fn try_from(value: ScalarValue) -> Result<Self>

Performs the conversion.

impl TryFrom<ScalarValue> for f32

type Error = DataFusionError

The type returned in the event of a conversion error.

fn try_from(value: ScalarValue) -> Result<Self>

Performs the conversion.

impl TryFrom<ScalarValue> for f64

type Error = DataFusionError

The type returned in the event of a conversion error.

fn try_from(value: ScalarValue) -> Result<Self>

Performs the conversion.

impl TryFrom<ScalarValue> for i128

type Error = DataFusionError

The type returned in the event of a conversion error.

fn try_from(value: ScalarValue) -> Result<Self>

Performs the conversion.

impl TryFrom<ScalarValue> for i16

type Error = DataFusionError

The type returned in the event of a conversion error.

fn try_from(value: ScalarValue) -> Result<Self>

Performs the conversion.

impl TryFrom<ScalarValue> for i256

type Error = DataFusionError

The type returned in the event of a conversion error.

fn try_from(value: ScalarValue) -> Result<Self>

Performs the conversion.

impl TryFrom<ScalarValue> for i32

type Error = DataFusionError

The type returned in the event of a conversion error.

fn try_from(value: ScalarValue) -> Result<Self>

Performs the conversion.

impl TryFrom<ScalarValue> for i64

type Error = DataFusionError

The type returned in the event of a conversion error.

fn try_from(value: ScalarValue) -> Result<Self>

Performs the conversion.

impl TryFrom<ScalarValue> for i8

type Error = DataFusionError

The type returned in the event of a conversion error.

fn try_from(value: ScalarValue) -> Result<Self>

Performs the conversion.

impl TryFrom<ScalarValue> for u16

type Error = DataFusionError

The type returned in the event of a conversion error.

fn try_from(value: ScalarValue) -> Result<Self>

Performs the conversion.

impl TryFrom<ScalarValue> for u32

type Error = DataFusionError

The type returned in the event of a conversion error.

fn try_from(value: ScalarValue) -> Result<Self>

Performs the conversion.

impl TryFrom<ScalarValue> for u64

type Error = DataFusionError

The type returned in the event of a conversion error.

fn try_from(value: ScalarValue) -> Result<Self>

Performs the conversion.

impl TryFrom<ScalarValue> for u8

type Error = DataFusionError

The type returned in the event of a conversion error.

fn try_from(value: ScalarValue) -> Result<Self>

Performs the conversion.

impl Eq for ScalarValue