Expand description
§Fixed-point math, for any static or dynamic precision in any base.
Differences from floating-point:
- exact results, except where explicitly rounded
- supports rounding in any base, such as decimal
- simpler interface (no NaN, infinities)
- better performance
- more compact storage for some value ranges
- unnormalized, so sigfigs of result can be determined by sigfigs of inputs
Differences from bignums:
- if you know the “shape” of your inputs/calculations, the statically typed fixed-points can be more efficient
- XeN is optimized for values that fit in a relatively small range
§Dynamic precision? Isn’t that floating point?
Technically yes, but the Xe API is much simpler than typical floating point; it’s designed for applications like working with a collection of values that are known to be fixed-precision decimal of the same type, but the number of decimal places won’t be known until runtime.