import unittest from test import support from _testcapi import getargs_keywords, getargs_keyword_only """ > How about the following counterproposal. This also changes some of > the other format codes to be a little more regular. > > Code C type Range check > > b unsigned char 0..UCHAR_MAX > h signed short SHRT_MIN..SHRT_MAX > B unsigned char none ** > H unsigned short none ** > k * unsigned long none > I * unsigned int 0..UINT_MAX > i int INT_MIN..INT_MAX > l long LONG_MIN..LONG_MAX > K * unsigned long long none > L long long LLONG_MIN..LLONG_MAX > Notes: > > * New format codes. > > ** Changed from previous "range-and-a-half" to "none"; the > range-and-a-half checking wasn't particularly useful. Plus a C API or two, e.g. PyInt_AsLongMask() -> unsigned long and PyInt_AsLongLongMask() -> unsigned long long (if that exists). """ LARGE = 0x7FFFFFFF VERY_LARGE = 0xFF0000121212121212121242 from _testcapi import UCHAR_MAX, USHRT_MAX, UINT_MAX, ULONG_MAX, INT_MAX, \ INT_MIN, LONG_MIN, LONG_MAX, PY_SSIZE_T_MIN, PY_SSIZE_T_MAX, \ SHRT_MIN, SHRT_MAX # fake, they are not defined in Python's header files LLONG_MAX = 2**63-1 LLONG_MIN = -2**63 ULLONG_MAX = 2**64-1 class Int: def __int__(self): return 99 class IntSubclass(int): def __int__(self): return 99 class BadInt: def __int__(self): return 1.0 class BadInt2: def __int__(self): return True class BadInt3(int): def __int__(self): return True class Unsigned_TestCase(unittest.TestCase): def test_b(self): from _testcapi import getargs_b # b returns 'unsigned char', and does range checking (0 ... UCHAR_MAX) self.assertRaises(TypeError, getargs_b, 3.14) self.assertEqual(99, getargs_b(Int())) self.assertEqual(0, getargs_b(IntSubclass())) self.assertRaises(TypeError, getargs_b, BadInt()) self.assertEqual(1, getargs_b(BadInt2())) self.assertEqual(0, getargs_b(BadInt3())) self.assertRaises(OverflowError, getargs_b, -1) self.assertEqual(0, getargs_b(0)) self.assertEqual(UCHAR_MAX, getargs_b(UCHAR_MAX)) self.assertRaises(OverflowError, getargs_b, UCHAR_MAX + 1) self.assertEqual(42, getargs_b(42)) self.assertRaises(OverflowError, getargs_b, VERY_LARGE) def test_B(self): from _testcapi import getargs_B # B returns 'unsigned char', no range checking self.assertRaises(TypeError, getargs_B, 3.14) self.assertEqual(99, getargs_B(Int())) self.assertEqual(0, getargs_B(IntSubclass())) self.assertRaises(TypeError, getargs_B, BadInt()) self.assertEqual(1, getargs_B(BadInt2())) self.assertEqual(0, getargs_B(BadInt3())) self.assertEqual(UCHAR_MAX, getargs_B(-1)) self.assertEqual(0, getargs_B(0)) self.assertEqual(UCHAR_MAX, getargs_B(UCHAR_MAX)) self.assertEqual(0, getargs_B(UCHAR_MAX+1)) self.assertEqual(42, getargs_B(42)) self.assertEqual(UCHAR_MAX & VERY_LARGE, getargs_B(VERY_LARGE)) def test_H(self): from _testcapi import getargs_H # H returns 'unsigned short', no range checking self.assertRaises(TypeError, getargs_H, 3.14) self.assertEqual(99, getargs_H(Int())) self.assertEqual(0, getargs_H(IntSubclass())) self.assertRaises(TypeError, getargs_H, BadInt()) self.assertEqual(1, getargs_H(BadInt2())) self.assertEqual(0, getargs_H(BadInt3())) self.assertEqual(USHRT_MAX, getargs_H(-1)) self.assertEqual(0, getargs_H(0)) self.assertEqual(USHRT_MAX, getargs_H(USHRT_MAX)) self.assertEqual(0, getargs_H(USHRT_MAX+1)) self.assertEqual(42, getargs_H(42)) self.assertEqual(VERY_LARGE & USHRT_MAX, getargs_H(VERY_LARGE)) def test_I(self): from _testcapi import getargs_I # I returns 'unsigned int', no range checking self.assertRaises(TypeError, getargs_I, 3.14) self.assertEqual(99, getargs_I(Int())) self.assertEqual(0, getargs_I(IntSubclass())) self.assertRaises(TypeError, getargs_I, BadInt()) self.assertEqual(1, getargs_I(BadInt2())) self.assertEqual(0, getargs_I(BadInt3())) self.assertEqual(UINT_MAX, getargs_I(-1)) self.assertEqual(0, getargs_I(0)) self.assertEqual(UINT_MAX, getargs_I(UINT_MAX)) self.assertEqual(0, getargs_I(UINT_MAX+1)) self.assertEqual(42, getargs_I(42)) self.assertEqual(VERY_LARGE & UINT_MAX, getargs_I(VERY_LARGE)) def test_k(self): from _testcapi import getargs_k # k returns 'unsigned long', no range checking # it does not accept float, or instances with __int__ self.assertRaises(TypeError, getargs_k, 3.14) self.assertRaises(TypeError, getargs_k, Int()) self.assertEqual(0, getargs_k(IntSubclass())) self.assertRaises(TypeError, getargs_k, BadInt()) self.assertRaises(TypeError, getargs_k, BadInt2()) self.assertEqual(0, getargs_k(BadInt3())) self.assertEqual(ULONG_MAX, getargs_k(-1)) self.assertEqual(0, getargs_k(0)) self.assertEqual(ULONG_MAX, getargs_k(ULONG_MAX)) self.assertEqual(0, getargs_k(ULONG_MAX+1)) self.assertEqual(42, getargs_k(42)) self.assertEqual(VERY_LARGE & ULONG_MAX, getargs_k(VERY_LARGE)) class Signed_TestCase(unittest.TestCase): def test_h(self): from _testcapi import getargs_h # h returns 'short', and does range checking (SHRT_MIN ... SHRT_MAX) self.assertRaises(TypeError, getargs_h, 3.14) self.assertEqual(99, getargs_h(Int())) self.assertEqual(0, getargs_h(IntSubclass())) self.assertRaises(TypeError, getargs_h, BadInt()) self.assertEqual(1, getargs_h(BadInt2())) self.assertEqual(0, getargs_h(BadInt3())) self.assertRaises(OverflowError, getargs_h, SHRT_MIN-1) self.assertEqual(SHRT_MIN, getargs_h(SHRT_MIN)) self.assertEqual(SHRT_MAX, getargs_h(SHRT_MAX)) self.assertRaises(OverflowError, getargs_h, SHRT_MAX+1) self.assertEqual(42, getargs_h(42)) self.assertRaises(OverflowError, getargs_h, VERY_LARGE) def test_i(self): from _testcapi import getargs_i # i returns 'int', and does range checking (INT_MIN ... INT_MAX) self.assertRaises(TypeError, getargs_i, 3.14) self.assertEqual(99, getargs_i(Int())) self.assertEqual(0, getargs_i(IntSubclass())) self.assertRaises(TypeError, getargs_i, BadInt()) self.assertEqual(1, getargs_i(BadInt2())) self.assertEqual(0, getargs_i(BadInt3())) self.assertRaises(OverflowError, getargs_i, INT_MIN-1) self.assertEqual(INT_MIN, getargs_i(INT_MIN)) self.assertEqual(INT_MAX, getargs_i(INT_MAX)) self.assertRaises(OverflowError, getargs_i, INT_MAX+1) self.assertEqual(42, getargs_i(42)) self.assertRaises(OverflowError, getargs_i, VERY_LARGE) def test_l(self): from _testcapi import getargs_l # l returns 'long', and does range checking (LONG_MIN ... LONG_MAX) self.assertRaises(TypeError, getargs_l, 3.14) self.assertEqual(99, getargs_l(Int())) self.assertEqual(0, getargs_l(IntSubclass())) self.assertRaises(TypeError, getargs_l, BadInt()) self.assertEqual(1, getargs_l(BadInt2())) self.assertEqual(0, getargs_l(BadInt3())) self.assertRaises(OverflowError, getargs_l, LONG_MIN-1) self.assertEqual(LONG_MIN, getargs_l(LONG_MIN)) self.assertEqual(LONG_MAX, getargs_l(LONG_MAX)) self.assertRaises(OverflowError, getargs_l, LONG_MAX+1) self.assertEqual(42, getargs_l(42)) self.assertRaises(OverflowError, getargs_l, VERY_LARGE) def test_n(self): from _testcapi import getargs_n # n returns 'Py_ssize_t', and does range checking # (PY_SSIZE_T_MIN ... PY_SSIZE_T_MAX) self.assertRaises(TypeError, getargs_n, 3.14) self.assertRaises(TypeError, getargs_n, Int()) self.assertEqual(0, getargs_n(IntSubclass())) self.assertRaises(TypeError, getargs_n, BadInt()) self.assertRaises(TypeError, getargs_n, BadInt2()) self.assertEqual(0, getargs_n(BadInt3())) self.assertRaises(OverflowError, getargs_n, PY_SSIZE_T_MIN-1) self.assertEqual(PY_SSIZE_T_MIN, getargs_n(PY_SSIZE_T_MIN)) self.assertEqual(PY_SSIZE_T_MAX, getargs_n(PY_SSIZE_T_MAX)) self.assertRaises(OverflowError, getargs_n, PY_SSIZE_T_MAX+1) self.assertEqual(42, getargs_n(42)) self.assertRaises(OverflowError, getargs_n, VERY_LARGE) class LongLong_TestCase(unittest.TestCase): def test_L(self): from _testcapi import getargs_L # L returns 'long long', and does range checking (LLONG_MIN # ... LLONG_MAX) self.assertRaises(TypeError, getargs_L, 3.14) self.assertRaises(TypeError, getargs_L, "Hello") self.assertEqual(99, getargs_L(Int())) self.assertEqual(0, getargs_L(IntSubclass())) self.assertRaises(TypeError, getargs_L, BadInt()) self.assertEqual(1, getargs_L(BadInt2())) self.assertEqual(0, getargs_L(BadInt3())) self.assertRaises(OverflowError, getargs_L, LLONG_MIN-1) self.assertEqual(LLONG_MIN, getargs_L(LLONG_MIN)) self.assertEqual(LLONG_MAX, getargs_L(LLONG_MAX)) self.assertRaises(OverflowError, getargs_L, LLONG_MAX+1) self.assertEqual(42, getargs_L(42)) self.assertRaises(OverflowError, getargs_L, VERY_LARGE) def test_K(self): from _testcapi import getargs_K # K return 'unsigned long long', no range checking self.assertRaises(TypeError, getargs_K, 3.14) self.assertRaises(TypeError, getargs_K, Int()) self.assertEqual(0, getargs_K(IntSubclass())) self.assertRaises(TypeError, getargs_K, BadInt()) self.assertRaises(TypeError, getargs_K, BadInt2()) self.assertEqual(0, getargs_K(BadInt3())) self.assertEqual(ULLONG_MAX, getargs_K(ULLONG_MAX)) self.assertEqual(0, getargs_K(0)) self.assertEqual(0, getargs_K(ULLONG_MAX+1)) self.assertEqual(42, getargs_K(42)) self.assertEqual(VERY_LARGE & ULLONG_MAX, getargs_K(VERY_LARGE)) class Paradox: "This statement is false." def __bool__(self): raise NotImplementedError class Boolean_TestCase(unittest.TestCase): def test_p(self): from _testcapi import getargs_p self.assertEqual(0, getargs_p(False)) self.assertEqual(0, getargs_p(None)) self.assertEqual(0, getargs_p(0)) self.assertEqual(0, getargs_p(0.0)) self.assertEqual(0, getargs_p(0j)) self.assertEqual(0, getargs_p('')) self.assertEqual(0, getargs_p(())) self.assertEqual(0, getargs_p([])) self.assertEqual(0, getargs_p({})) self.assertEqual(1, getargs_p(True)) self.assertEqual(1, getargs_p(1)) self.assertEqual(1, getargs_p(1.0)) self.assertEqual(1, getargs_p(1j)) self.assertEqual(1, getargs_p('x')) self.assertEqual(1, getargs_p((1,))) self.assertEqual(1, getargs_p([1])) self.assertEqual(1, getargs_p({1:2})) self.assertEqual(1, getargs_p(unittest.TestCase)) self.assertRaises(NotImplementedError, getargs_p, Paradox()) class Tuple_TestCase(unittest.TestCase): def test_tuple(self): from _testcapi import getargs_tuple ret = getargs_tuple(1, (2, 3)) self.assertEqual(ret, (1,2,3)) # make sure invalid tuple arguments are handled correctly class seq: def __len__(self): return 2 def __getitem__(self, n): raise ValueError self.assertRaises(TypeError, getargs_tuple, 1, seq()) class Keywords_TestCase(unittest.TestCase): def test_positional_args(self): # using all positional args self.assertEqual( getargs_keywords((1,2), 3, (4,(5,6)), (7,8,9), 10), (1, 2, 3, 4, 5, 6, 7, 8, 9, 10) ) def test_mixed_args(self): # positional and keyword args self.assertEqual( getargs_keywords((1,2), 3, (4,(5,6)), arg4=(7,8,9), arg5=10), (1, 2, 3, 4, 5, 6, 7, 8, 9, 10) ) def test_keyword_args(self): # all keywords self.assertEqual( getargs_keywords(arg1=(1,2), arg2=3, arg3=(4,(5,6)), arg4=(7,8,9), arg5=10), (1, 2, 3, 4, 5, 6, 7, 8, 9, 10) ) def test_optional_args(self): # missing optional keyword args, skipping tuples self.assertEqual( getargs_keywords(arg1=(1,2), arg2=3, arg5=10), (1, 2, 3, -1, -1, -1, -1, -1, -1, 10) ) def test_required_args(self): # required arg missing try: getargs_keywords(arg1=(1,2)) except TypeError as err: self.assertEqual(str(err), "Required argument 'arg2' (pos 2) not found") else: self.fail('TypeError should have been raised') def test_too_many_args(self): try: getargs_keywords((1,2),3,(4,(5,6)),(7,8,9),10,111) except TypeError as err: self.assertEqual(str(err), "function takes at most 5 arguments (6 given)") else: self.fail('TypeError should have been raised') def test_invalid_keyword(self): # extraneous keyword arg try: getargs_keywords((1,2),3,arg5=10,arg666=666) except TypeError as err: self.assertEqual(str(err), "'arg666' is an invalid keyword argument for this function") else: self.fail('TypeError should have been raised') def test_surrogate_keyword(self): try: getargs_keywords((1,2), 3, (4,(5,6)), (7,8,9), **{'\uDC80': 10}) except TypeError as err: self.assertEqual(str(err), "'\udc80' is an invalid keyword argument for this function") else: self.fail('TypeError should have been raised') class KeywordOnly_TestCase(unittest.TestCase): def test_positional_args(self): # using all possible positional args self.assertEqual( getargs_keyword_only(1, 2), (1, 2, -1) ) def test_mixed_args(self): # positional and keyword args self.assertEqual( getargs_keyword_only(1, 2, keyword_only=3), (1, 2, 3) ) def test_keyword_args(self): # all keywords self.assertEqual( getargs_keyword_only(required=1, optional=2, keyword_only=3), (1, 2, 3) ) def test_optional_args(self): # missing optional keyword args, skipping tuples self.assertEqual( getargs_keyword_only(required=1, optional=2), (1, 2, -1) ) self.assertEqual( getargs_keyword_only(required=1, keyword_only=3), (1, -1, 3) ) def test_required_args(self): self.assertEqual( getargs_keyword_only(1), (1, -1, -1) ) self.assertEqual( getargs_keyword_only(required=1), (1, -1, -1) ) # required arg missing with self.assertRaisesRegex(TypeError, "Required argument 'required' \(pos 1\) not found"): getargs_keyword_only(optional=2) with self.assertRaisesRegex(TypeError, "Required argument 'required' \(pos 1\) not found"): getargs_keyword_only(keyword_only=3) def test_too_many_args(self): with self.assertRaisesRegex(TypeError, "Function takes at most 2 positional arguments \(3 given\)"): getargs_keyword_only(1, 2, 3) with self.assertRaisesRegex(TypeError, "function takes at most 3 arguments \(4 given\)"): getargs_keyword_only(1, 2, 3, keyword_only=5) def test_invalid_keyword(self): # extraneous keyword arg with self.assertRaisesRegex(TypeError, "'monster' is an invalid keyword argument for this function"): getargs_keyword_only(1, 2, monster=666) def test_surrogate_keyword(self): with self.assertRaisesRegex(TypeError, "'\udc80' is an invalid keyword argument for this function"): getargs_keyword_only(1, 2, **{'\uDC80': 10}) class Bytes_TestCase(unittest.TestCase): def test_c(self): from _testcapi import getargs_c self.assertRaises(TypeError, getargs_c, b'abc') # len > 1 self.assertEqual(getargs_c(b'a'), b'a') self.assertEqual(getargs_c(bytearray(b'a')), b'a') self.assertRaises(TypeError, getargs_c, memoryview(b'a')) self.assertRaises(TypeError, getargs_c, 's') self.assertRaises(TypeError, getargs_c, None) def test_s(self): from _testcapi import getargs_s self.assertEqual(getargs_s('abc\xe9'), b'abc\xc3\xa9') self.assertRaises(TypeError, getargs_s, 'nul:\0') self.assertRaises(TypeError, getargs_s, b'bytes') self.assertRaises(TypeError, getargs_s, bytearray(b'bytearray')) self.assertRaises(TypeError, getargs_s, memoryview(b'memoryview')) self.assertRaises(TypeError, getargs_s, None) def test_s_star(self): from _testcapi import getargs_s_star self.assertEqual(getargs_s_star('abc\xe9'), b'abc\xc3\xa9') self.assertEqual(getargs_s_star('nul:\0'), b'nul:\0') self.assertEqual(getargs_s_star(b'bytes'), b'bytes') self.assertEqual(getargs_s_star(bytearray(b'bytearray')), b'bytearray') self.assertEqual(getargs_s_star(memoryview(b'memoryview')), b'memoryview') self.assertRaises(TypeError, getargs_s_star, None) def test_s_hash(self): from _testcapi import getargs_s_hash self.assertEqual(getargs_s_hash('abc\xe9'), b'abc\xc3\xa9') self.assertEqual(getargs_s_hash('nul:\0'), b'nul:\0') self.assertEqual(getargs_s_hash(b'bytes'), b'bytes') self.assertRaises(TypeError, getargs_s_hash, bytearray(b'bytearray')) self.assertRaises(TypeError, getargs_s_hash, memoryview(b'memoryview')) self.assertRaises(TypeError, getargs_s_hash, None) def test_z(self): from _testcapi import getargs_z self.assertEqual(getargs_z('abc\xe9'), b'abc\xc3\xa9') self.assertRaises(TypeError, getargs_z, 'nul:\0') self.assertRaises(TypeError, getargs_z, b'bytes') self.assertRaises(TypeError, getargs_z, bytearray(b'bytearray')) self.assertRaises(TypeError, getargs_z, memoryview(b'memoryview')) self.assertIsNone(getargs_z(None)) def test_z_star(self): from _testcapi import getargs_z_star self.assertEqual(getargs_z_star('abc\xe9'), b'abc\xc3\xa9') self.assertEqual(getargs_z_star('nul:\0'), b'nul:\0') self.assertEqual(getargs_z_star(b'bytes'), b'bytes') self.assertEqual(getargs_z_star(bytearray(b'bytearray')), b'bytearray') self.assertEqual(getargs_z_star(memoryview(b'memoryview')), b'memoryview') self.assertIsNone(getargs_z_star(None)) def test_z_hash(self): from _testcapi import getargs_z_hash self.assertEqual(getargs_z_hash('abc\xe9'), b'abc\xc3\xa9') self.assertEqual(getargs_z_hash('nul:\0'), b'nul:\0') self.assertEqual(getargs_z_hash(b'bytes'), b'bytes') self.assertRaises(TypeError, getargs_z_hash, bytearray(b'bytearray')) self.assertRaises(TypeError, getargs_z_hash, memoryview(b'memoryview')) self.assertIsNone(getargs_z_hash(None)) def test_y(self): from _testcapi import getargs_y self.assertRaises(TypeError, getargs_y, 'abc\xe9') self.assertEqual(getargs_y(b'bytes'), b'bytes') self.assertRaises(TypeError, getargs_y, b'nul:\0') self.assertRaises(TypeError, getargs_y, bytearray(b'bytearray')) self.assertRaises(TypeError, getargs_y, memoryview(b'memoryview')) self.assertRaises(TypeError, getargs_y, None) def test_y_star(self): from _testcapi import getargs_y_star self.assertRaises(TypeError, getargs_y_star, 'abc\xe9') self.assertEqual(getargs_y_star(b'bytes'), b'bytes') self.assertEqual(getargs_y_star(b'nul:\0'), b'nul:\0') self.assertEqual(getargs_y_star(bytearray(b'bytearray')), b'bytearray') self.assertEqual(getargs_y_star(memoryview(b'memoryview')), b'memoryview') self.assertRaises(TypeError, getargs_y_star, None) def test_y_hash(self): from _testcapi import getargs_y_hash self.assertRaises(TypeError, getargs_y_hash, 'abc\xe9') self.assertEqual(getargs_y_hash(b'bytes'), b'bytes') self.assertEqual(getargs_y_hash(b'nul:\0'), b'nul:\0') self.assertRaises(TypeError, getargs_y_hash, bytearray(b'bytearray')) self.assertRaises(TypeError, getargs_y_hash, memoryview(b'memoryview')) self.assertRaises(TypeError, getargs_y_hash, None) def test_w_star(self): # getargs_w_star() modifies first and last byte from _testcapi import getargs_w_star self.assertRaises(TypeError, getargs_w_star, 'abc\xe9') self.assertRaises(TypeError, getargs_w_star, b'bytes') self.assertRaises(TypeError, getargs_w_star, b'nul:\0') self.assertRaises(TypeError, getargs_w_star, memoryview(b'bytes')) self.assertEqual(getargs_w_star(bytearray(b'bytearray')), b'[ytearra]') self.assertEqual(getargs_w_star(memoryview(bytearray(b'memoryview'))), b'[emoryvie]') self.assertRaises(TypeError, getargs_w_star, None) class Unicode_TestCase(unittest.TestCase): def test_u(self): from _testcapi import getargs_u self.assertEqual(getargs_u('abc\xe9'), 'abc\xe9') self.assertRaises(TypeError, getargs_u, 'nul:\0') self.assertRaises(TypeError, getargs_u, b'bytes') self.assertRaises(TypeError, getargs_u, bytearray(b'bytearray')) self.assertRaises(TypeError, getargs_u, memoryview(b'memoryview')) self.assertRaises(TypeError, getargs_u, None) def test_u_hash(self): from _testcapi import getargs_u_hash self.assertEqual(getargs_u_hash('abc\xe9'), 'abc\xe9') self.assertEqual(getargs_u_hash('nul:\0'), 'nul:\0') self.assertRaises(TypeError, getargs_u_hash, b'bytes') self.assertRaises(TypeError, getargs_u_hash, bytearray(b'bytearray')) self.assertRaises(TypeError, getargs_u_hash, memoryview(b'memoryview')) self.assertRaises(TypeError, getargs_u_hash, None) def test_Z(self): from _testcapi import getargs_Z self.assertEqual(getargs_Z('abc\xe9'), 'abc\xe9') self.assertRaises(TypeError, getargs_Z, 'nul:\0') self.assertRaises(TypeError, getargs_Z, b'bytes') self.assertRaises(TypeError, getargs_Z, bytearray(b'bytearray')) self.assertRaises(TypeError, getargs_Z, memoryview(b'memoryview')) self.assertIsNone(getargs_Z(None)) def test_Z_hash(self): from _testcapi import getargs_Z_hash self.assertEqual(getargs_Z_hash('abc\xe9'), 'abc\xe9') self.assertEqual(getargs_Z_hash('nul:\0'), 'nul:\0') self.assertRaises(TypeError, getargs_Z_hash, b'bytes') self.assertRaises(TypeError, getargs_Z_hash, bytearray(b'bytearray')) self.assertRaises(TypeError, getargs_Z_hash, memoryview(b'memoryview')) self.assertIsNone(getargs_Z_hash(None)) def test_main(): tests = [ Signed_TestCase, Unsigned_TestCase, Boolean_TestCase, Tuple_TestCase, Keywords_TestCase, KeywordOnly_TestCase, Bytes_TestCase, Unicode_TestCase, ] try: from _testcapi import getargs_L, getargs_K except ImportError: pass # PY_LONG_LONG not available else: tests.append(LongLong_TestCase) support.run_unittest(*tests) if __name__ == "__main__": test_main()