#skypyblue

Implementation of the SkyBlue constraint solver in Python.

Tested with Python2.7, Python3.x and Pypy.

Usage

Base Classes

ConstraintSystem, Variable, Method, Constraint, Strength

from skypyblue.models import ConstraintSystem, Variable, Method, Constraint, Strength

cs = ConstraintSystem()

v1 = Variable("v1", 1, cs)
v2 = Variable("v2", 2, cs)
m1 = Method([v1], [v2], lambda v1: v1)

m2 = Method([v2], [v2], lambda v2: v2)

constraint = Constraint(
  lambda v1, v2: v1 == v2,
  Strength.STRONG,
  [v1, v2], [m1, m2])

cs.add_constraint(constraint)

v1.get_value() # => 1
v2.get_value() # => 1

ConstraintFactory

from skypyblue.models import ConstraintSystem, Variable, ConstraintFactory, Strength

cs = ConstraintSystem()

v1 = Variable("v1", 1, cs)
v2 = Variable("v2", 2, cs)
constraint = ConstraintFactory.equality_constraint(v1, v2, Strength.STRONG)

cs.add_constraint(constraint)

v1.get_value() # => 1
v2.get_value() # => 1

Graphical Demo - requires pygame package, only Python2.7 and Python3.x

cd examples
python midpoint_example.py

Testing

cd tests
python testrunner.py

Performance

Benchmark does two tests: chain and projection test. It runs python implementation of DeltaBlue first and then our implementation. Parameters for the benchmark script: python benchmark.py #rounds #warmups #constraints

cd tests/performance
python benchmark.py 5 15 200

Numbers

All times are in ms.

Chain	python2	python3	pypy	Projection	python2	python3	pypy
Delta Blue	24	26	0		13	16	6
	26	26	1		15	16	3
	27	26	1		15	18	3
	25	25	3		17	18	3
	26	26	0		15	16	3
Skypyblue	412	499	82		32	66	5
	427	491	77		62	38	5
	406	496	65		32	39	9
	417	493	70		33	39	6
	412	496	78		32	38	19

Deployment on PyPI

cd src
make deploy

OR

cd src
python setup.py sdist upload 

Bugs, Problems?

Just open an issue.