3 ms·

If you see units as multiplicative factors: 1.5 USD = 1.5 * USD 65 mph = 65 * mile / hour you can then use simple algebra to solve unit conversion and many o

If you see units as multiplicative factors: 1.5 USD = 1.5 * USD 65 mph = 65 * mile / hour you can then use simple algebra to solve unit conversion and many other common deductive reasoning questions ("how many miles per gallon...?"), relying on the units to guide you to the solution. There's probably a name for this, and it is indeed built into the SI notation (km/h vs mph).

chriswarbo 4y ago
Sounds like https://en.wikipedia.org/wiki/Dimensional_analysis https://en.wikipedia.org/wiki/Dimensional_analysis
mckinney 4y ago
This is already implemented with manifold's unit expressions, but is made richer and more readable via concatenative features. For instance, '1.5 * USD' is not as readable as simply '1.5 USD'. However, unit expressions leverage operators for dimensional arithmetic: Force f = 5 kg * 9.807 m/s/s; // result: 49.035 Newtons Area space = (20ft + 2in) * (37ft + 7.5in); // result: 758 37/48 ft² All unit expressions internally store amounts as SI units, which enables interunit expressions. Length height = 6 ft + 4 cm; // mix SI and US units out.println(height.to(ft)); // display any unit You aren't limited to units. Generally, any concatenative sequence can be implemented. Like ranges: IntegerRange range = 1 to 5; Here the `to` identifier's type implements reactions to Number types to produce range types, which enables: for (int i: 1 to 5) { out.println(i); } See the manifold project's Unit and Science modules: Units: https://github.com/manifold-systems/manifold/tree/master/manifold-deps-parent/manifold-ext#unit-expressions https://github.com/manifold-systems/manifold/tree/master/man... Science: https://github.com/manifold-systems/manifold/tree/master/manifold-deps-parent/manifold-science https://github.com/manifold-systems/manifold/tree/master/man...

3 ms·

If you see units as multiplicative factors: 1.5 USD = 1.5 * USD 65 mph = 65 * mile / hour you can then use simple algebra to solve unit conversion and many o

by opminion 4y ago

chriswarbo 4y ago
Sounds like https://en.wikipedia.org/wiki/Dimensional_analysis https://en.wikipedia.org/wiki/Dimensional_analysis
mckinney 4y ago
This is already implemented with manifold's unit expressions, but is made richer and more readable via concatenative features. For instance, '1.5 * USD' is not as readable as simply '1.5 USD'. However, unit expressions leverage operators for dimensional arithmetic: Force f = 5 kg * 9.807 m/s/s; // result: 49.035 Newtons Area space = (20ft + 2in) * (37ft + 7.5in); // result: 758 37/48 ft² All unit expressions internally store amounts as SI units, which enables interunit expressions. Length height = 6 ft + 4 cm; // mix SI and US units out.println(height.to(ft)); // display any unit You aren't limited to units. Generally, any concatenative sequence can be implemented. Like ranges: IntegerRange range = 1 to 5; Here the `to` identifier's type implements reactions to Number types to produce range types, which enables: for (int i: 1 to 5) { out.println(i); } See the manifold project's Unit and Science modules: Units: https://github.com/manifold-systems/manifold/tree/master/manifold-deps-parent/manifold-ext#unit-expressions https://github.com/manifold-systems/manifold/tree/master/man... Science: https://github.com/manifold-systems/manifold/tree/master/manifold-deps-parent/manifold-science https://github.com/manifold-systems/manifold/tree/master/man...