Trait DecimalType 

pub trait DecimalType:
    'static
    + Send
    + Sync
    + ArrowPrimitiveType
    + DecimalTypeSealed
where
    Self::Native: DecimalNativeType,
{
    const BYTE_LENGTH: usize;
    const MAX_PRECISION: u8;
    const MAX_SCALE: i8;
    const MAX_FOR_EACH_PRECISION: &'static [Self::Native];
    const TYPE_CONSTRUCTOR: fn(u8, i8) -> DataType;
    const DEFAULT_TYPE: DataType;
    const PREFIX: &'static str;

    // Required methods
    fn validate_decimal_precision(
        value: Self::Native,
        precision: u8,
        scale: i8,
    ) -> Result<(), ArrowError>;
    fn is_valid_decimal_precision(value: Self::Native, precision: u8) -> bool;

    // Provided method
    fn format_decimal(value: Self::Native, _precision: u8, scale: i8) -> String { ... }
}

A trait over the decimal types, used by PrimitiveArray to provide a generic implementation across the various decimal types

Implemented by Decimal32Type, Decimal64Type, Decimal128Type and Decimal256Type for Decimal32Array, Decimal64Array, Decimal128Array and Decimal256Array respectively

Required Associated Constants

const BYTE_LENGTH: usize

Width of the type

const MAX_PRECISION: u8

Maximum number of significant digits

const MAX_SCALE: i8

Maximum no of digits after the decimal point (note the scale can be negative)

const MAX_FOR_EACH_PRECISION: &'static [Self::Native]

The maximum value for each precision in 0..=MAX_PRECISION: [0, 9, 99, …]

const TYPE_CONSTRUCTOR: fn(u8, i8) -> DataType

fn to create its DataType

const DEFAULT_TYPE: DataType

Default values for DataType

const PREFIX: &'static str

“Decimal32”, “Decimal64”, “Decimal128” or “Decimal256”, for use in error messages

Required Methods

fn validate_decimal_precision( value: Self::Native, precision: u8, scale: i8, ) -> Result<(), ArrowError>

Validates that value contains no more than precision decimal digits

fn is_valid_decimal_precision(value: Self::Native, precision: u8) -> bool

Determines whether value contains no more than precision decimal digits

Provided Methods

fn format_decimal(value: Self::Native, _precision: u8, scale: i8) -> String

Formats value with scale fractional digits. The value is always formatted in full: precision is ignored and retained for API compatibility.

Dyn Compatibility

This trait is not dyn compatible.

In older versions of Rust, dyn compatibility was called "object safety".

Implementors

impl DecimalType for Decimal32Type

const BYTE_LENGTH: usize = 4

const MAX_PRECISION: u8 = DECIMAL32_MAX_PRECISION

const MAX_SCALE: i8 = DECIMAL32_MAX_SCALE

const MAX_FOR_EACH_PRECISION: &'static [i32]

const TYPE_CONSTRUCTOR: fn(u8, i8) -> DataType = DataType::Decimal32

const DEFAULT_TYPE: DataType

const PREFIX: &'static str = "Decimal32"

impl DecimalType for Decimal64Type

const BYTE_LENGTH: usize = 8

const MAX_PRECISION: u8 = DECIMAL64_MAX_PRECISION

const MAX_SCALE: i8 = DECIMAL64_MAX_SCALE

const MAX_FOR_EACH_PRECISION: &'static [i64]

const TYPE_CONSTRUCTOR: fn(u8, i8) -> DataType = DataType::Decimal64

const DEFAULT_TYPE: DataType

const PREFIX: &'static str = "Decimal64"

impl DecimalType for Decimal128Type

const BYTE_LENGTH: usize = 16

const MAX_PRECISION: u8 = DECIMAL128_MAX_PRECISION

const MAX_SCALE: i8 = DECIMAL128_MAX_SCALE

const MAX_FOR_EACH_PRECISION: &'static [i128]

const TYPE_CONSTRUCTOR: fn(u8, i8) -> DataType = DataType::Decimal128

const DEFAULT_TYPE: DataType

const PREFIX: &'static str = "Decimal128"

impl DecimalType for Decimal256Type

const BYTE_LENGTH: usize = 32

const MAX_PRECISION: u8 = DECIMAL256_MAX_PRECISION

const MAX_SCALE: i8 = DECIMAL256_MAX_SCALE

const MAX_FOR_EACH_PRECISION: &'static [i256]

const TYPE_CONSTRUCTOR: fn(u8, i8) -> DataType = DataType::Decimal256

const DEFAULT_TYPE: DataType

const PREFIX: &'static str = "Decimal256"