def delete_code(self, target):
if type(target) is ast.Attribute:
return [
T('delattr({}, {!r})').format(self.visit(target.value),
target.attr)
]
elif type(target) is ast.Subscript:
if type(target.slice) is ast.Slice and target.slice.step is None:
return [
T("(lambda o, **t: type('translator', (), {{t[m]: "
"staticmethod(object.__getattribute__(d[m], '__get__'"
")(o, type(o))) for d in [object.__getattribute__("
"type(o), '__dict__')] for m in t if m in d}})())({},"
" __delitem__='__getitem__', __delslice__="
"'__getslice__', __len__='__len__')[{}]").format(
self.visit(target.value), self.visit(target.slice))
]
else:
return [
T("(lambda o: object.__getattribute__("
"object.__getattribute__(type(o), '__dict__')"
"['__delitem__'], '__get__')(o, type(o)))"
"({})({})").format(self.visit(target.value),
self.slice_repr(target.slice))
]
elif type(target) is ast.Name:
return [self.delete_var(target.id)]
elif type(target) in (ast.List, ast.Tuple):
return [c for elt in target.elts for c in self.delete_code(elt)]
else:
raise NotImplementedError('Case not caught: %s' %
str(type(target)))
def visit_FunctionDef(self, tree):
# self.visit() returns something of the form
# ('lambda x, y, z=5, *args: ', ['x', 'y', 'z', 'args'])
args, arg_names = self.visit(tree.args)
decoration = T('{}')
for decorator in tree.decorator_list:
decoration = decoration.format(T('{}({})').format(self.visit(decorator), T('{}')))
ns = self.next_child()
body = ns.many_to_one(tree.body)
if arg_names:
body = assignment_component(body,
T(', ').join(ns.var(name) for name in arg_names),
T(', ').join(arg_names))
body = self.close(ns, body)
function_code = args + body
doc = ast.get_docstring(tree, clean=False)
if tree.decorator_list:
return assignment_component(
T('{after}'),
self.store_var(tree.name),
decoration.format(assignment_component(
'__func',
'__func, __func.__name__' + ('' if doc is None else ', __func.__doc__'),
T('{}, {!r}' + ('' if doc is None else ', {!r}')).format(
function_code, tree.name, doc))))
else:
return assignment_component(
T('{after}'),
T('{}, {}.__name__' + ('' if doc is None else ', {}.__doc__')).format(
self.store_var(tree.name), self.var(tree.name), self.var(tree.name)),
T('{}, {!r}' + ('' if doc is None else ', {!r}')).format(
function_code, tree.name, doc))
def get_init_code(tree, table):
# Calculate the helper variables that we will need, wrap the output
# code in a definition of those variables.
# TODO: Short-circuit to something far simpler if the program has but one
# print statement.
output = Namespace(table).many_to_one(tree.body)
doc = ast.get_docstring(tree, clean=False)
if doc is not None:
output = assignment_component(output, T("{__g}['__doc__']"), repr(doc))
output = provide(
output.format(__l=T('{__g}')),
__print=T("__import__('__builtin__').__dict__['print']"),
__exec="__import__('trace').Trace(count=False,"
" trace=False).runctx",
__y="(lambda f: (lambda x: x(x))(lambda y:"
" f(lambda: y(y)())))",
__g=T("globals()"),
__sys="__import__('sys')",
__types="__import__('types')")
return output.close()
def visit_Compare(self, tree):
assert len(tree.ops) == len(tree.comparators)
return T('({})').format(
self.visit(tree.left) + T('').join([
cmpop_code[type(tree.ops[i])] + self.visit(tree.comparators[i])
for i in range(len(tree.ops))
]))
def visit_Assign(self, tree):
targets = [self.visit(target) for target in tree.targets]
value = self.visit(tree.value)
targets = T(', ').join(targets)
return assignment_component(T('{after}'), targets,
value if len(tree.targets) == 1
else T('[{}]*{}').format(value, len(tree.targets)))
def get_init_code(tree, table):
"""Get one-lined code from `tree` and `table.
Calculate the helper variables that we will need, and wrap the output
code (computed from `tree`) with definitions of those variables.
TODO: Short-circuit to something far simpler if the program has only one
print statement.
Arguments:
tree: Python AST node
table: symtable.symtable
Returns:
string - valid one-line code
"""
output = Namespace(table).many_to_one(tree.body)
doc = ast.get_docstring(tree, clean=False)
if doc is not None:
output = assignment_component(output, T("{__g}['__doc__']"), repr(doc))
output = provide(output.format(__l=T('{__g}')),
__print=T("__import__('__builtin__').__dict__['print']"),
__y="(lambda f: (lambda x: x(x))(lambda y:"
" f(lambda: y(y)())))",
__g=T("globals()"),
__contextlib="__import__('contextlib')",
__sys="__import__('sys')",
__types="__import__('types')")
return output.close()
def close(self, ns, body, **subs):
return provide(
body,
__l='{}',
__f=T('{{{}}}').format(T(', ').join(
T('{!r}: lambda: {}').format(v, self.var(v)) for v in ns.table.get_frees())),
**subs)
def visit_While(self, tree):
test = self.visit(tree.test)
body = self.many_to_one(tree.body, after='__this()')
orelse = self.many_to_one(tree.orelse, after='__after()')
return lambda_function({'__after': T('lambda: {after}')}).format(
T('{__y}(lambda __this: lambda: {} if {} else {})()').format(
provide(body, __break='__after', __continue='__this'),
test, orelse))
def visit_Raise(self, tree):
if tree.type is None:
return T('([] for [] in []).throw(*{__sys}.exc_info())')
else:
return T('([] for [] in []).throw({}{}{})').format(
self.visit(tree.type),
'' if tree.inst is None else ', ' + self.visit(tree.inst),
'' if tree.tback is None else ', ' + self.visit(tree.tback))
def visit_Lambda(self, tree):
args, arg_names = self.visit(tree.args)
ns = self.next_child()
body = ns.visit(tree.body)
if arg_names:
body = assignment_component(body, T(', ').join(ns.store_var(name)
for name in arg_names), T(', ').join(arg_names))
body = self.close(ns, body)
return '(' + args + body + ')'
def lambda_function(arguments_to_values, prettyprinted=False):
# arguments_to_values :: {argument_i: value_i}
# :: string
if prettyprinted:
raise NotImplementedError
else:
return T('(lambda {}: {})({})').format(
T(', ').join(arguments_to_values.keys()), T('{}'),
T(', ').join(arguments_to_values.values()))
def comprehension_code(self, generators, wrap):
iter0 = self.visit(generators[0].iter)
ns = self.next_child()
return self.close(
ns,
wrap(ns, T(' ').join(
[T('for {} in {__iter}').format(ns.visit(generators[0].target))] +
['if ' + ns.visit(i) for i in generators[0].ifs] +
map(ns.visit, generators[1:]))),
__iter=iter0)
def visit_TryFinally(self, tree):
body = self.many_to_one(
tree.body, after=T('(lambda after: after())')).format(
pre_return=T('(lambda ret: lambda after: ret)({pre_return}'),
post_return=T('{post_return})'))
finalbody = self.many_to_one(tree.finalbody, after=T('{after}'))
if 'pre_return' in finalbody.free():
finalbody = T('({})(lambda ret: {})').format(
finalbody.format(
after='lambda change_ret: False',
pre_return=
T('(lambda ret: lambda change_ret: change_ret(ret))({pre_return}'
),
post_return=T('{post_return})')),
assignment_component('True', '__out[0]', 'lambda after: ret'))
else:
finalbody = finalbody.format(after='False')
return \
lambda_function({'__out': '[None]'}).format(
lambda_function({
'__ctx': T(
"{__contextlib}.nested(type('except', (), {{"
"'__enter__': lambda self: None, "
"'__exit__': lambda __self, __exctype, __value, __traceback: "
"{finalbody}}})(), "
"type('try', (), {{"
"'__enter__': lambda self: None, "
"'__exit__': lambda __self, __exctype, __value, __traceback: "
"{body}}})())").format(
body=assignment_component('False', '__out[0]', body),
finalbody=finalbody)
}).format(
T('[__ctx.__enter__(), __ctx.__exit__(None, None, None), __out[0](lambda: {after})][2]')))
def var(self, name):
name = self.mangle(name)
sym = self.table.lookup(name)
if sym.is_global() or (self.table.get_type() == 'module' and sym.is_local()):
return T('{}').format(name)
elif sym.is_local():
return T('{__l}[{!r}]').format(name)
elif sym.is_free():
return T('{__f}[{!r}]()').format(name)
else:
raise SyntaxError('confusing symbol {!r}'.format(name))
def visit_Print(self, tree):
to_print = T('{}')
if tree.dest is not None:
# Abuse varargs to get the right evaluation order
to_print = T('file={}, *[{}]').format(self.visit(tree.dest), to_print)
to_print = to_print.format(T(', ').join(self.visit(x) for x in tree.values))
if not tree.nl:
# TODO: This is apparently good enough for 2to3, but gets
# many cases wrong (tests/unimplemented/softspace.py).
to_print += ", end=' '"
return T('({__print}({}), {after})[1]').format(to_print)
def visit_ImportFrom(self, tree):
return T('(lambda __mod: {})(__import__({!r}, {__g}, {__l},'
' {!r}, {!r}))').format(
assignment_component(
T('{after}'),
T(', ').join(self.store_var(alias.name if alias.asname is None
else alias.asname) for alias in tree.names),
T(', ').join('__mod.' + alias.name for alias in tree.names)),
'' if tree.module is None else tree.module,
tuple(alias.name for alias in tree.names),
tree.level)
def lambda_function(arguments_to_values):
"""
Arguments:
arguments_to_values: {string: string | T} - e.g. {'a': '47'}
Returns:
T - e.g. (lambda a: {})(47)
"""
return T('(lambda {}: {})({})').format(
T(', ').join(arguments_to_values.keys()), T('{}'),
T(', ').join(arguments_to_values.values()))
def delete_var(self, name):
name = self.mangle(name)
sym = self.table.lookup(name)
if sym.is_global():
return T('{__g}.pop({!r})').format(name)
elif sym.is_local():
return T('{__l}.pop({!r})').format(name)
elif sym.is_free():
raise SyntaxError('deleting free variable {!r}'.format(name))
else:
raise SyntaxError('confusing symbol {!r}'.format(name))
def visit_Import(self, tree):
after = T('{after}')
for alias in tree.names:
ids = alias.name.split('.')
if alias.asname is None:
after = assignment_component(after, self.store_var(ids[0]),
T('__import__({!r}, {__g}, {__l})').format(alias.name))
else:
after = assignment_component(after, self.store_var(alias.asname),
T('.').join([T('__import__({!r}, {__g}, {__l})').format(
alias.name)] + ids[1:]))
return after
def visit_ClassDef(self, tree):
bases = (T(', ').join(map(self.visit, tree.bases)) + ',' *
(len(tree.bases) == 1))
decoration = T('{}')
for decorator in tree.decorator_list:
decoration = decoration.format(
T('{}({})').format(self.visit(decorator), T('{}')))
ns = self.next_child()
body = ns.many_to_one(tree.body, after=T('{__l}'))
doc = ast.get_docstring(tree, clean=False)
body = self.close(
ns, "{{'__module__': __name__{}}}".format(
'' if doc is None else ", '__doc__': {!r}".format(doc)), body)
if tree.bases:
class_code = T(
"(lambda b, d: d.get('__metaclass__', getattr(b[0], "
"'__class__', type(b[0])))({!r}, b, d))(({}), "
"{})").format(tree.name, bases, body)
else:
class_code = T("(lambda d: d.get('__metaclass__', {__g}.get("
"'__metaclass__', {__types}.ClassType))({!r}, (), "
"d))({})").format(tree.name, body)
class_code = decoration.format(class_code)
return assignment_component(T('{after}'), self.store_var(tree.name),
class_code)
def visit_For(self, tree):
item = self.visit(tree.target)
items = self.visit(tree.iter)
body = self.many_to_one(tree.body, after='__this()')
orelse = self.many_to_one(tree.orelse, after='__after()')
return lambda_function({'__items': T('iter({})').format(items), '__sentinel':
'[]', '__after': T('lambda: {after}')}).format(
T('{__y}(lambda __this: lambda: {})()').format(
lambda_function({'__i': 'next(__items, __sentinel)'}).format(
T('{} if __i is not __sentinel else {}').format(
provide(
assignment_component(body, item, '__i'),
__break='__after', __continue='__this'),
orelse))))
def slice_repr(self, slice):
if type(slice) is ast.Ellipsis:
return T('Ellipsis')
elif type(slice) is ast.Slice:
return T('slice({}, {}, {})').format(
'None' if slice.lower is None else self.visit(slice.lower),
'None' if slice.upper is None else self.visit(slice.upper),
'None' if slice.step is None else self.visit(slice.step))
elif type(slice) is ast.ExtSlice:
return T('({})').format(T(', ').join(map(self.slice_repr, slice.dims)) +
','*(len(slice.dims) == 1))
elif type(slice) is ast.Index:
return self.visit(slice.value)
else:
raise NotImplementedError('Case not caught: %s' % str(type(slice)))
def visit_Call(self, tree):
func = self.visit(tree.func)
args = [self.visit(arg) for arg in tree.args]
keywords = [self.visit(kw) for kw in tree.keywords]
if tree.starargs is None:
starargs = []
else:
starargs = ["*" + self.visit(tree.starargs)]
if tree.kwargs is None:
kwargs = []
else:
kwargs = ["**" + self.visit(tree.kwargs)]
elems = args + keywords + starargs + kwargs
comma_sep_elems = T(', ').join(elems)
return T('{}({})').format(func, comma_sep_elems)
def visit_Exec(self, tree):
body = self.visit(tree.body)
if tree.globals is None:
exec_code = T('{__exec}({}, {__g}, {__l})').format(body)
elif tree.locals is None:
exec_code = T(
'(lambda b, g: {__exec}(b, {__g} if g is None else g, '
'{__l} if g is None else g))({}, {})').format(
body, self.visit(tree.globals))
else:
exec_code = T(
'(lambda b, g, l: {__exec}(b, {__g} if g is None else g, '
'({__l} if g is None else g) if l is None else l))({}, {}, {})'
).format(body, self.visit(tree.globals), self.visit(tree.locals))
return T('({}, {after})[1]').format(exec_code)
def many_to_one(self, trees, after='None'):
# trees :: [Tree]
# return :: string
return reduce(
lambda ctx, tree: ctx.format(after=self.visit(tree)),
trees,
T('{after}')).format(after=after)
def var(self, name):
name = self.mangle(name)
sym = self.table.lookup(name)
if self.table.get_type() == 'module' or (
sym.is_global()
and self.table.is_optimized()) or name == 'None':
return T('{}').format(name)
elif sym.is_global():
return T('({__l}[{!r}] if {!r} in __l else {})').format(
name, name, name)
elif sym.is_local():
return T('{__l}[{!r}]').format(name)
elif sym.is_free():
return T('{___f_' + name + '}()').format(name)
else:
raise SyntaxError('confusing symbol {!r}'.format(name))
def visit_arguments(self, tree):
# this should return something of the form
# ('lambda x, y, z=5, *args: ', ['x', 'y', 'z', 'args'])
padded_defaults = [None] * (len(tree.args) -
len(tree.defaults)) + tree.defaults
arg_names = [arg.id for arg in tree.args]
args = zip(padded_defaults, tree.args)
args = [a.id if d is None else a.id + "=" + self.visit(d) for (d, a) in args]
if tree.vararg is not None:
args += ["*" + tree.vararg]
arg_names += [tree.vararg]
if tree.kwarg is not None:
args += ["**" + tree.kwarg]
arg_names += [tree.kwarg]
args = T(', ').join(args)
return (T('lambda {}: ').format(args), arg_names)
def close(self, ns, local, body, **subs):
if self.table.get_type() == 'function':
subs = dict(
subs, **{
'___f_' + v: T('lambda: {}').format(self.var(v))
for v in self.table.get_locals()
})
return provide(body, __l=local, **subs)
def provide(body, **subs):
body = T('{}').format(body)
needed = set(body.free()).intersection(subs)
if needed:
return lambda_function({k: subs[k] for k in needed}).format(
body.format(**{k: k for k in needed}))
else:
return body
def visit_Exec(self, tree):
body = self.visit(tree.body)
if tree.globals is None and self.table.get_type() == 'module':
exec_code = T("eval(compile({}, '<string>', 'exec'), "
"None, {__l})").format(body)
elif tree.globals is None:
exec_code = T(
"(lambda b, c: (eval(compile(b, '<string>', 'exec'), "
"None, c), {__l}.update(c)))({}, {__l}.copy())").format(body)
elif tree.locals is None and self.table.get_type() == 'module':
exec_code = T(
"(lambda b, g: eval(compile(b, '<string>', 'exec'), g, "
"{__l} if g is None else g))({}, {})").format(
body, self.visit(tree.globals))
elif tree.locals is None:
exec_code = T(
"(lambda b, g, c: (eval(compile(b, '<string>', 'exec'), g, "
"c if g is None else g), "
"{__l}.update(c)))({}, {}, {__l}.copy())").format(
body, self.visit(tree.globals))
elif self.table.get_type() == 'module':
exec_code = T(
"(lambda b, g, l: eval(compile(b, '<string>', 'exec'), g, "
"({__l} if g is None else g) if l is None "
"else l))({}, {}, {})").format(body, self.visit(tree.globals),
self.visit(tree.locals))
else:
exec_code = T(
"(lambda b, g, l, c: (eval(compile(b, '<string>', 'exec'), g, "
"(c if g is None else g) if l is None else l), "
"{__l}.update(c)))({}, {}, {}, {__l}.copy())").format(
body, self.visit(tree.globals), self.visit(tree.locals))
return T('({}, {after})[1]').format(exec_code)