def clos(state, node):
"""closure nodes"""
# we extend given env type, so that subsequent unifications will
# be reflected to us (when unifying different branches, then
# sealing)
with state.current(node.env):
env_type = expr(state, node.env)
assert type(env_type) in row.types
gen_type = closure.env_gen(env_type, state.depth)
tool.debug("gen_type:", gen_type.show())
state.pure(gen_type)
def constraint(args_type):
state.unify(gen_type, args_type[0])
# we need to preconstrain env type, because it may contain
# functions and we need to know whether they are regular functions
# or closures before calling them
with state.current(node.code):
assert type(node.code) is ast.Abs
code_type = abs(state, node.code, constraint)
state.pure(code_type)
return closure.clos(code_type, gen_type)
def find_instance(self, mono):
'''find typeclass instance matching mono'''
tool.debug('finding instance of:', self.name, mono.show())
# print('finding instance of:', self.name, 'for:', mono.show())
t = type(mono)
matches = []
for scheme, instance in self.instances.items():
# TODO what about depth ?
fresh = hm.instantiate( scheme )
try:
# note: we unify in a fresh union_find
hm.unify(tool.UnionFind(), fresh, mono)
matches.append( (scheme, instance) )
except error.Type:
pass
if not matches:
raise error.Type('typeclass {0} has no instance for type {1}'
.format( self.name, mono.show() ))
if len(matches) > 1:
raise error.Type('ambiguous {0} instances for {1}'.format(self.name, mono.show()))
return matches[0]
def row_gen(state, node):
# this will row-generalize type for node
node_type = expr(state, node.expr)
assert type(node_type) in row.types, "closure env should be a record: {0}".format(node_type.show())
# copy tuple, then add a fresh row type variable
var = row.Var(state.depth)
if type(node_type) is row.Empty:
gen_type = var
else:
gen_type = row.record(*tuple(iter(node_type)))
gen_type.set_terminator(var)
tool.debug("gen_type:", gen_type.show())
return gen_type
def find_overload(self, identifier, mono):
tool.debug('finding overload for:', identifier, ':', mono.show())
proto = self.definition[identifier]
uf = tool.UnionFind()
fresh = hm.instantiate(hm.generalize(proto))
vars = fresh.variables()
assert len(vars) == 1
hm.unify(uf, fresh, mono)
a = next(iter(vars))
t = uf.find( a )
scheme, instance = self.find_instance(t)
return instance[identifier]
def coercion(state, node):
"""function/closure coercion"""
node_type = expr(state, node.expr).nice(state.uf)
assert type(node_type) is App, "cannot coerce to function type: {0}".format(node_type.show())
if node_type.func is func:
return node_type
if node_type.func is closure.clos:
# seal env types
env_type = node_type.args[1]
# print('env_type:', env_type.show())
# print('variables:', env_type.variables())
if env_type.variables():
state.unify(env_type.var(), row.empty)
code_type = node_type.args[0]
tool.debug("after sealing:")
tool.debug("env:", env_type.nice(state.uf).show())
tool.debug("code:", code_type.nice(state.uf).show())
# return partial application of the closure code to env
res = code_type.args[1]
# nullary closures:
if not res.is_func_type():
return unit >> res
return res
assert False, "cannot coerce to function type: {0}".format(node_type.show())
def unify(uf, a, b):
"""unify types ta and tb"""
a = uf.find(a)
b = uf.find(b)
# TODO introduce kinds ?
ta = type(a)
tb = type(b)
with tool.indentation():
if tool.DEBUG:
na, nb = a.nice(uf), b.nice(uf)
sa, sb = show(na, nb)
if na.variables() or nb.variables():
tool.debug("unify:", sa)
tool.debug("with:", sb)
if ta is App and tb is App and a.func == b.func:
for ai, bi in zip(a.args, b.args):
unify(uf, ai, bi)
elif ta in row.types and tb in row.types:
row.unify(uf, a, b)
elif ta is typeclass.Var or tb is typeclass.Var:
typeclass.unify(uf, a, b)
elif ta is Var or tb is Var:
var = a if ta is Var else b
other = b if ta is Var else a
# print('unifying:', ta, tb)
# TODO what if we auto-unify ? is this legal ?
# assert var is not other
if type(other) is App:
# TODO delay occurs_check?
occurs_check(var, other)
if type(other) is Var and var.depth < other.depth:
var, other = other, var
# TODO should we nice before linking ?
uf.link(var, other)
if tool.DEBUG and type(other) is Var:
with tool.indentation():
tool.debug("repr:", sa if a is other else sb)
elif a != b:
sa, sb = show(a, b, 0, True)
raise error.Type("""can not unify types {0} and {1}""".format(sa, sb))
out += ' : ' + str(poly)
ts.cleanup()
if not args.codegen:
print(out)
continue
with tool.debug_scope('closure conversion'):
# closure conversion
node = closure.toplevel( closure.State(), node)
# typecheck closure conversion
with tool.debug_scope('typecheck closure conversion'):
poly = hm.toplevel(cc, node )
tool.debug('closure conversion type:', poly)
with tool.debug_scope("codegen"):
code = codegen.toplevel(cs, node)
if code and type(node) in ast.expression_types:
code = codegen.print_expr(cs, poly.body, code, out)
cc.cleanup()
if code:
with open('debug', 'w') as file:
print('file', 'lli', file = file)
print('run',
def unify(uf, a, b):
"""unify row types ra and rb"""
a = uf.find(a)
b = uf.find(b)
ta = type(a)
tb = type(b)
assert ta in types and tb in types
# print( ra, rb)
if ta is Extension and tb is Extension:
if a.label == b.label:
# unify heads
hm.unify(uf, a.mono, b.mono)
# unify tails
unify(uf, a.tail, b.tail)
else:
try:
# try pulling b's head in a
tool.debug("pulling", b.label)
pa = a.pull(b.label)
unify(uf, pa, b)
# it worked: remember pa is originially a
uf.link(pa, a)
except PullError:
try:
# try pulling a's head in b
tool.debug("pulling", a.label)
pb = b.pull(a.label)
unify(uf, a, pb)
# it worked: remember pa is originially b
uf.link(pb, b)
except PullError:
tool.debug("union")
# none of it worked: neither heads is present in
# other type. try to unify both to record union
# unify a's tail var with a fresh copy of b
try:
unify(uf, a.var(), b.fresh())
unify(uf, b.var(), a.fresh())
except FreshError:
sa, sb = hm.show(a, b)
raise error.Type("can not unify row type {0} with {1}".format(sa, sb))
elif ta is Var or tb is Var:
var = a if ta is Var else b
other = a if tb is Var else b
uf.link(var, other)
# tool.debug('repr:', other.show())
elif a != b:
raise error.Type("can not unify row type {0} with {1}".format(a.show(), b.show()))
else:
assert ta is Empty and tb is Empty
