def unify(constraints, broadcasting=None):
"""
Unify a set of constraints and return a concrete solution
>>> import blaze
>>> d1 = blaze.dshape('10, int32')
>>> d2 = blaze.dshape('T, float32')
>>> [result], constraints = unify([(d1, d2)], [True])
>>> result
dshape("10, float32")
>>> constraints
[]
"""
S = IdentityDict()
constraints = [(simplify(ds1, S), simplify(ds2, S))
for ds1, ds2 in constraints]
# Compute a solution to a set of constraints
constraints, b_env = normalize(constraints, broadcasting)
logger.debug("Normalized constraints: %s", constraints)
solution, remaining = unify_constraints(constraints, S)
logger.debug("Initial solution: %s", solution)
seed_typesets(remaining, solution)
merge_typevar_sets(remaining, solution)
# Compute a type substitution with concrete types from the solution
# TODO: incorporate broadcasting environment during reification
substitution = reify(solution)
logger.debug("Substitution: %s", substitution)
# Reify and promote the datashapes
result = [substitute(substitution, ds2) for ds1, ds2 in constraints]
return result, remaining
def test_simplify_implements(self):
ds = dshape('10, A : numeric')
self.assertEqual(str(ds), '10, A : numeric')
solution = IdentityDict()
ds = simplify(ds, solution)
self.assertEqual(str(ds), '10, A')
A = ds.parameters[-1]
[x] = solution[A]
self.assertEqual(set(x), set(numeric))
