Struct VariantDecimal4 

pub struct VariantDecimal4 {
    integer: i32,
    scale: u8,
}

Represents a 4-byte decimal value in the Variant format.

This struct stores a decimal number using a 32-bit signed integer for the coefficient and an 8-bit unsigned integer for the scale (number of decimal places). Its precision is limited to 9 digits.

For valid precision and scale values, see the Variant specification: https://github.com/apache/parquet-format/blob/87f2c8bf77eefb4c43d0ebaeea1778bd28ac3609/VariantEncoding.md?plain=1#L418-L420

Example: Create a VariantDecimal4

// Create a value representing the decimal 123.4567
let decimal = VariantDecimal4::try_new(1234567, 4).expect("Failed to create decimal");

Fields

integer: i32

scale: u8

Implementations

impl VariantDecimal4

pub const MAX_PRECISION: u8 = 9u8

Maximum number of significant digits (9 for 4-byte decimals)

impl VariantDecimal4

pub fn try_new(integer: i32, scale: u8) -> Result<Self, ArrowError>

Attempts to create a new instance of this decimal type, failing if the value is too wide or the scale is too large.

pub fn integer(&self) -> i32

Returns the unscaled integer value of the decimal.

For example, if the decimal is 123.45, this will return 12345.

pub fn scale(&self) -> u8

Returns the scale of the decimal (how many digits after the decimal point).

For example, if the decimal is 123.45, this will return 2.

Trait Implementations

impl Clone for VariantDecimal4

fn clone(&self) -> VariantDecimal4

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for VariantDecimal4

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

Formats the value using the given formatter.

impl Display for VariantDecimal4

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

Formats the value using the given formatter.

impl From<VariantDecimal4> for Variant<'_, '_>

fn from(value: VariantDecimal4) -> Self

Converts to this type from the input type.

impl From<VariantDecimal4> for VariantDecimal16

fn from(decimal: VariantDecimal4) -> Self

Converts to this type from the input type.

impl From<VariantDecimal4> for VariantDecimal8

fn from(decimal: VariantDecimal4) -> Self

Converts to this type from the input type.

impl PartialEq for VariantDecimal4

fn eq(&self, other: &VariantDecimal4) -> 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 TryFrom<VariantDecimal16> for VariantDecimal4

type Error = ArrowError

The type returned in the event of a conversion error.

fn try_from(decimal: VariantDecimal16) -> Result<Self, ArrowError>

Performs the conversion.

impl TryFrom<VariantDecimal8> for VariantDecimal4

type Error = ArrowError

The type returned in the event of a conversion error.

fn try_from(decimal: VariantDecimal8) -> Result<Self, ArrowError>

Performs the conversion.

impl TryFrom<i32> for VariantDecimal4

type Error = ArrowError

The type returned in the event of a conversion error.

fn try_from(integer: i32) -> Result<Self, ArrowError>

Performs the conversion.

impl VariantDecimalType for VariantDecimal4

const MAX_PRECISION: u8 = 9u8

Maximum number of significant digits this decimal type can represent (9, 18, or 38)

const MAX_UNSCALED_VALUE: i32 = 999_999_999i32

The largest positive unscaled value that fits in Self::MAX_PRECISION digits.

type Native = i32

The underlying signed integer type (i32, i64, or i128)

fn try_new(integer: i32, scale: u8) -> Result<Self, ArrowError>

Creates a new decimal value from the given unscaled integer and scale, failing if the integer’s width, or the requested scale, exceeds MAX_PRECISION.

fn try_new_with_signed_scale( integer: i32, scale: i8, ) -> Result<Self, ArrowError>

Attempts to convert an unscaled arrow decimal value to the indicated variant decimal type.

fn integer(&self) -> i32

Returns the unscaled integer value

fn scale(&self) -> u8

Returns the scale (number of digits after the decimal point)

fn is_valid_precision_and_scale(precision: &u8, scale: &i8) -> bool

True if the given precision and scale are valid for this variant decimal type.

impl Copy for VariantDecimal4

impl StructuralPartialEq for VariantDecimal4