Jasper is a port of Kiwi for developing GUIs in haxe.

var x = new Variable("x");
var y = new Variable("y");
var solver = new Solver();

solver.addConstraint(x <= y);
solver.addConstraint(y == x + 3.0);
solver.addConstraint((x == 10.0) | Strength.WEAK);
solver.addConstraint((y == 10.0) | Strength.WEAK);

solver.updateVariables();

trace("x = " + x.m_value); // x = 10
trace("y = " + y.m_value); // y = 13

The motivation to develop Jasper was to port a cassowary implementation to haxe. There were already two projects but one was not completely typed and the other did not use operator overloading for easy constraint creation. Jasper's goal is to be completely typed and also use the same operators for constraint development as the c++ implementation.

https://github.com/nucleic/kiwi

https://github.com/alexbirkett/kiwi-java

https://github.com/Tw1ddle/haxe-kiwi

https://github.com/underscorediscovery/cassowary-hx

Jasper is MIT licensed.