dims_macro

This will allow for easy creation of storage values like distance or mass, as well as preventing adding grams to feet.

The intent is for these values to be kept in-memory as Mass or Length, without having to worry about the unit except for creation of the value, and when accessing it (for display, storage, etc).

IMPORTANT

This is still a Work-In-Progress. Expect rough-edges, but I am working to smooth them out.

System and Unit Creation

These particular systems are already set up already in dims, but you can set up your own systems:

use dims_core::unit_creation::*;
#[macro_use]
use dims_macro;

// You can use this macro to generate a full system.
// It requires a length for use as debug.
measure_system!(name: LengthSystem, debug_unit: FOOT,data_type: f32);
// Allow for conversion between the systems
// Multiple `MultiplyBy` and `DivideBy` traits can be applied for each `MeasureSystem`
impl MultiplyBy<LengthSystem> for LengthSystem {
    type Output = AreaSystem;
}

measure_system!(name: AreaSystem, debug_unit: SQUARE_FOOT,data_type: f32);

impl DivideBy<LengthSystem> for AreaSystem {
    type Output = LengthSystem;
}

measure_system!(name: TemperatureSystem, debug_unit: FAHRENHEIT,data_type: f32);

// Set up some units, now

pub const FAHRENHEIT: UnitSimple<TemperatureSystem> = UnitSimple {
    /// The system is used for compiler warnings, but has no memory impact in production code
    system: PhantomData,
    // Offset is used to change the zero point.  Most of the time, this is zero
    offset: 459.67,
    // Ratio is multiplied to get to the base unit
    ratio: 5.0 / 9.0,
};
pub const CELCIUS: UnitSimple<TemperatureSystem> = UnitSimple {
    system: PhantomData,
    offset: 273.15,
    ratio: 1.0,
};
pub const FOOT: UnitSimple<LengthSystem> = UnitSimple {
    system: PhantomData,
    offset: 0.0,
    ratio: 0.3048,
};
pub const SQUARE_FOOT: UnitSimple<AreaSystem> = UnitSimple {
    system: PhantomData,
    offset: 0.0,
    ratio: 0.09290304,
};

This also contains the si_unit! macro, which will generate a whole set (or individual) SI units with the given info.

TODO: EXAMPLE

MeasureSystem macro

This is used to easily generate a new measuring system with used as:

  measure_system! {name: Mass, debug_unit: GRAM, data_type: f32}

Expands to (with absolute paths):

#[derive(PartialEq, PartialOrd, Eq, Clone, Copy)]
pub struct Mass;
impl MeasureSystem for Mass {
    type N = f32;
    #[cfg(feature = "str")]
    const DEBUG_UNIT: UnitFormat<Self> = GRAM;
}

The DEBUG_UNIT is how the value will be displayed when debugging. This could be how you want to display it, but that should be specified explicitly by consuming code.

Other Notes

Crate options for dims and dims_core

Crate options for dims and dims_macro

• str (default) will utilize UnitFormat and store:

  • abbr: Abbreviated unit name (m or ft)
  • singular: Singular name of a unit (metre or foot)
  • plural: Plural name of the unit (metres or feet)

• std is the default option, and defaults to using the standard library.
  This enables the UnitFormatTrait (as the functions return String), but no_std can still be used with str (see below) to store the unit name info.