Crate staticfraction [−] [src]
Static fractions are generalized fixed-point numbers. They can scale a compactly stored (eg. u8 typed) mantissa to any fractional range expressible by a fraction of a more expressive (eg. u32) fraction.
They are useful not only for accessing stored sensor data without manually following the operations to convert them into a standard unit, but should also be usable in APIs of embedded systems, especially where measurements are post-processed in a fashion known at compile time, which can then be simplified by the compiler.
For example, when a check like
if get_system_voltage() < 3.1 { prinln!("Undervoltage warning!"); }
should finally be optimizable at compile time into an integer comparison against the value read from a hardware device without the user of the API having to know the constants involved explicitly.
A note on generic names: The S parameter always indicates with which data
type the numerator is *s*tored. The C parameter always indicates with
which data type *c*alculations happen, which is also the type of the stored
denominator. The D parameter indicates the
StaticFractionDescription that holds the
numerator scaling and the denominator.
Structs
| StaticFraction |
Stored numeric datum that is, for all mathematical operations, seen under the transformation described by D. |
Traits
| HasOverflowingMul | |
| StaticFractionDescription |
Description of transformation parameters |