pub fn rescale_decimal<I: DecimalType, O: DecimalType>(
value: I::Native,
input_precision: u8,
input_scale: i8,
output_precision: u8,
output_scale: i8,
) -> Option<O::Native>where
I::Native: DecimalCast + ArrowNativeTypeOp,
O::Native: DecimalCast + ArrowNativeTypeOp,Expand description
Rescales a decimal value from (input_precision, input_scale) to
(output_precision, output_scale) and returns the converted number when it fits
within the output precision.
The function first validates that the requested precision and scale are supported for both the source and destination decimal types. It then either upscales (multiplying by an appropriate power of ten) or downscales (dividing with rounding) the input value. When the scaling factor exceeds the precision table of the destination type, the value is treated as an overflow for upscaling, or rounded to zero for downscaling (as any possible result would be zero at the requested scale).
This mirrors the column-oriented helpers of decimal casting but operates on a single value (row-level) instead of an entire array.
Returns None if the value cannot be represented with the requested precision.