def children_of_for_loop_are_checked():
_assert_child_expression_is_checked(lambda generate:
nodes.for_(
nodes.attr(generate.unbound_ref(), "blah"),
nodes.list_literal([]),
[],
[]
)
)
_assert_child_expression_is_checked(lambda generate:
nodes.for_(
generate.target(),
generate.unbound_ref(),
[],
[]
),
)
_assert_child_statement_is_checked(lambda generate:
nodes.for_(
generate.target(),
nodes.list_literal([]),
[generate.unbound_ref_statement()],
[]
),
)
_assert_child_statement_is_checked(lambda generate:
nodes.for_(
generate.target(),
nodes.list_literal([]),
[],
[generate.unbound_ref_statement()],
),
)
def for_loop_has_child_names_resolved():
_assert_children_resolved(
lambda ref: nodes.for_(ref, nodes.list_literal([]), [], []),
)
_assert_children_resolved(
lambda ref: nodes.for_(nodes.ref("target"), ref, [], []),
other_names=["target"]
)
_assert_children_resolved(
lambda ref: nodes.for_(nodes.ref("target"), nodes.list_literal([]), [nodes.expression_statement(ref)], []),
other_names=["target"]
)
_assert_children_resolved(
lambda ref: nodes.for_(nodes.ref("target"), nodes.list_literal([]), [], [nodes.expression_statement(ref)]),
other_names=["target"]
)
def for_statement_target_can_be_supertype_of_iterable_element_type():
ref_node = nodes.ref("xs")
node = nodes.for_(nodes.subscript(nodes.ref("ys"), nodes.int_literal(0)), ref_node, [])
update_context(node, type_bindings={
"xs": types.list_type(types.int_type),
"ys": types.list_type(types.object_type),
})
def test_parse_for_loop_with_else_body():
expected = nodes.for_(
nodes.ref("x"), nodes.ref("xs"),
[],
[nodes.ret(nodes.ref("x"))],
)
_assert_statement_parse(expected, "for x in xs:\n pass\nelse:\n return x")
def declarations_in_both_body_and_else_body_of_for_loop_are_not_definitely_bound():
_assert_name_is_not_definitely_bound(lambda generate:
nodes.for_(
generate.target(),
nodes.list_literal([]),
[generate.assignment()],
[generate.assignment()]
),
)
def for_statement_has_iterable_type_checked():
ref_node = nodes.ref("xs")
node = nodes.for_(nodes.ref("x"), ref_node, [])
try:
update_context(node)
assert False, "Expected error"
except errors.TypeCheckError as error:
assert_equal(ref_node, error.node)
def else_body_of_for_loop_is_type_checked():
assert_statement_is_type_checked(
lambda bad_statement: nodes.for_(nodes.ref("x"), nodes.ref("xs"), [], [
bad_statement
]),
type_bindings={
"xs": types.list_type(types.str_type),
}
)
def iter_method_must_take_no_arguments():
cls = types.class_type("Blah")
cls.attrs.add("__iter__", types.func([types.str_type], types.iterable(types.str_type)))
ref_node = nodes.ref("xs")
node = nodes.for_(nodes.ref("x"), ref_node, [])
try:
update_context(node, type_bindings={"x": None, "xs": cls})
assert False, "Expected error"
except errors.TypeCheckError as error:
assert_equal(ref_node, ephemeral.root_node(error.node))
def for_statement_requires_iterable_to_have_iter_method():
ref_node = nodes.ref("xs")
node = nodes.for_(nodes.ref("x"), ref_node, [])
try:
update_context(node, type_bindings={"xs": types.int_type})
assert False, "Expected error"
except errors.UnexpectedValueTypeError as error:
assert_equal(ref_node, error.node)
assert_equal("iterable type", error.expected)
assert_equal(types.int_type, error.actual)
def iter_method_must_return_iterator():
cls = types.class_type("Blah")
cls.attrs.add("__iter__", types.func([], types.iterable(types.str_type)))
ref_node = nodes.ref("xs")
node = nodes.for_(nodes.ref("x"), ref_node, [])
try:
update_context(node, type_bindings={"x": None, "xs": cls})
assert False, "Expected error"
except errors.BadSignatureError as error:
assert_equal(ref_node, error.node)
def for_statement_target_can_be_variable():
node = nodes.for_(nodes.ref("x"), nodes.ref("xs"), [])
# Unassigned case
update_context(node, type_bindings={
"xs": types.list_type(types.str_type),
})
# Assigned case
update_context(node, type_bindings={
"x": types.str_type,
"xs": types.list_type(types.str_type),
})
def for_statement_accepts_iterable_with_iter_method():
cls = types.class_type("Blah")
cls.attrs.add("__iter__", types.func([], types.iterator(types.str_type)))
node = nodes.for_(nodes.ref("x"), nodes.ref("xs"), [])
type_bindings = {
"xs": cls,
}
context = update_context(node, type_bindings=type_bindings)
assert_equal(types.str_type, context.lookup_name("x"))
def test_transform_for_loop(self):
_assert_transform(
nodes.for_(
nodes.ref("x"),
nodes.ref("xs"),
[nodes.ret(nodes.ref("x"))],
),
"""
var __nope_u_iterator0 = $builtins.iter(xs)
var __nope_u_element1
while True:
__nope_u_element1 = $builtins.next(__nope_u_iterator0, $internals.loop_sentinel)
if __nope_u_element1 is $internals.loop_sentinel:
break
x = __nope_u_element1
return x
"""
)
def for_statement_target_cannot_be_strict_subtype_of_iterable_element_type():
target_sequence_node = nodes.ref("ys")
target_node = nodes.subscript(target_sequence_node, nodes.int_literal(0))
iterable_node = nodes.ref("xs")
node = nodes.for_(target_node, iterable_node, [])
try:
update_context(node, type_bindings={
"xs": types.list_type(types.object_type),
"ys": types.list_type(types.int_type),
})
assert False, "Expected error"
except errors.UnexpectedTargetTypeError as error:
assert_equal(target_sequence_node, ephemeral.root_node(error.node))
assert_equal(
ephemeral.FormalArg(ephemeral.attr(target_sequence_node, "__setitem__"), 1),
ephemeral.underlying_node(error.node)
)
assert_equal(types.object_type, error.value_type)
assert_equal(types.int_type, error.target_type)
def for_statement_requires_iterable_getitem_method_to_accept_integers():
cls = types.class_type("Blah")
cls.attrs.add("__getitem__", types.func([types.str_type], types.str_type))
ref_node = nodes.ref("xs")
node = nodes.for_(nodes.ref("x"), ref_node, [])
type_bindings = {
"xs": cls,
}
try:
update_context(node, type_bindings=type_bindings)
assert False, "Expected error"
except errors.UnexpectedTargetTypeError as error:
assert_equal(ref_node, ephemeral.root_node(error.node))
assert_equal(
ephemeral.FormalArg(ephemeral.attr(ref_node, "__getitem__"), 0),
ephemeral.underlying_node(error.node)
)
assert_equal(types.int_type, error.value_type)
assert_equal(types.str_type, error.target_type)
def test_transform_for_loop_with_else_branch(self):
_assert_transform(
nodes.for_(
nodes.ref("x"),
nodes.ref("xs"),
[nodes.ret(nodes.ref("x"))],
[nodes.ret(nodes.ref("y"))],
),
"""
var __nope_u_iterator0 = $builtins.iter(xs)
var __nope_u_element1
var __nope_u_normal_exit2 = False
while True:
__nope_u_element1 = $builtins.next(__nope_u_iterator0, $internals.loop_sentinel)
if __nope_u_element1 is $internals.loop_sentinel:
__nope_u_normal_exit2 = True
break
x = __nope_u_element1
return x
if __nope_u_normal_exit2:
return y
"""
)
def break_is_valid_in_for_loop_body():
node = nodes.for_(nodes.ref("x"), nodes.ref("xs"), [nodes.break_()])
check_loop_control(node, False)
def test_parse_for_loop():
expected = nodes.for_(nodes.ref("x"), nodes.ref("xs"), [nodes.ret(nodes.ref("x"))])
_assert_statement_parse(expected, "for x in xs:\n return x")
def for_loop_target_is_defined_but_not_definitely_bound():
_assert_name_is_not_definitely_bound(lambda generate:
nodes.for_(generate.target(), nodes.list_literal([]), [], [])
)
def for_loop_target_is_declared():
node = nodes.for_(nodes.ref("target"), nodes.list_literal([]), [], [])
declarations = find_declarations(node)
assert_equal("target", declarations.declaration("target").name)
assert isinstance(declarations.declaration("target"), name_declaration.VariableDeclarationNode)