def unify(u, v, s): # no check at the moment
""" Find substitution so that u == v while satisfying s
>>> from logpy.unify import unify, var
>>> x = var('x')
>>> unify((1, x), (1, 2), {})
{~x: 2}
"""
u = walk(u, s)
v = walk(v, s)
if u == v:
return s
if isvar(u):
return assoc(s, u, v)
if isvar(v):
return assoc(s, v, u)
types = (type(u), type(v))
if types in unify_dispatch:
return unify_dispatch[types](u, v, s)
for (typu, typv), unify_fn in unify_isinstance_list:
if isinstance(u, typu) and isinstance(v, typv):
return unify_fn(u, v, s)
for typ, fn in seq_registry:
action = False
if isinstance(u, typ):
u = fn(u); action=True
if isinstance(v, typ):
v = fn(v); action=True
if action:
return unify(u, v, s)
else:
return False
def unify(u, v, s): # no check at the moment
""" Find substitution so that u == v while satisfying s
>>> from logpy.unify import unify, var
>>> x = var('x')
>>> unify((1, x), (1, 2), {})
{~x: 2}
"""
u = walk(u, s)
v = walk(v, s)
if u == v:
return s
if isvar(u):
return assoc(s, u, v)
if isvar(v):
return assoc(s, v, u)
types = (type(u), type(v))
if types in unify_dispatch:
return unify_dispatch[types](u, v, s)
else:
return False
def unify(u, v, s): # no check at the moment
""" Find substitution so that u == v while satisfying s
>>> from logpy.unify import unify, var
>>> x = var('x')
>>> unify((1, x), (1, 2), {})
{~x: 2}
"""
u = walk(u, s)
v = walk(v, s)
if u == v:
return s
if isvar(u):
return assoc(s, u, v)
if isvar(v):
return assoc(s, v, u)
types = (type(u), type(v))
if types in unify_dispatch:
return unify_dispatch[types](u, v, s)
else:
return False
def reify(e, s):
""" Replace variables of expression with substitution
>>> from logpy.unify import reify, var
>>> x, y = var(), var()
>>> e = (1, x, (3, y))
>>> s = {x: 2, y: 4}
>>> reify(e, s)
(1, 2, (3, 4))
>>> e = {1: x, 3: (y, 5)}
>>> reify(e, s)
{1: 2, 3: (4, 5)}
"""
if isvar(e):
return reify(s[e], s) if e in s else e
if type(e) in reify_dispatch:
return reify_dispatch[type(e)](e, s)
for typ, reify_fn in reify_isinstance_list:
if isinstance(e, typ):
return reify_fn(e, s)
else:
return e
def reify_var(v, s):
assert isvar(v)
return reify(s[v], s) if v in s else v
def test_isvar():
assert not isvar(3)
assert isvar(var(3))
def test_context_manager():
with variables(1):
assert isvar(1)
assert not isvar(1)
