1 #!/usr/bin/env python 2 3 """ 4 Tuple objects. 5 6 Copyright (C) 2015, 2016, 2017 Paul Boddie <paul@boddie.org.uk> 7 8 This program is free software; you can redistribute it and/or modify it under 9 the terms of the GNU General Public License as published by the Free Software 10 Foundation; either version 3 of the License, or (at your option) any later 11 version. 12 13 This program is distributed in the hope that it will be useful, but WITHOUT 14 ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS 15 FOR A PARTICULAR PURPOSE. See the GNU General Public License for more 16 details. 17 18 You should have received a copy of the GNU General Public License along with 19 this program. If not, see <http://www.gnu.org/licenses/>. 20 """ 21 22 from __builtins__.iteration.iterator import itemiterator 23 from __builtins__.sequence import hashable, sequence 24 from native import tuple_init, \ 25 list_element, list_len, list_setsize, list_setelement 26 27 class tuple(sequence, hashable): 28 29 "Implementation of tuple." 30 31 def __init__(self, args=None): 32 33 "Initialise the tuple." 34 35 # Reserve an attribute for a fragment reference along with some space 36 # for elements. 37 38 self.__data__ = tuple_init(size) 39 40 if args is None: 41 size = 0 42 else: 43 size = args.__len__() 44 list_setsize(self.__data__, size) 45 46 # Populate the tuple. 47 48 i = 0 49 while i < size: 50 list_setelement(self.__data__, i, args[i]) 51 i += 1 52 53 def __hash__(self): 54 55 "Return a hashable value for the tuple." 56 57 return self._hashvalue(hash) 58 59 def __getslice__(self, start, end=None, step=1): 60 61 """ 62 Return a slice starting from 'start', with the optional 'end' and 63 'step'. 64 """ 65 66 return tuple(get_using(sequence.__getslice__, self)(start, end, step)) 67 68 def __len__(self): 69 70 "Return the length of the tuple." 71 72 return list_len(self.__data__) 73 74 def __add__(self, other): pass 75 76 def __str__(self): 77 78 "Return a string representation." 79 80 return self._str("(", ")") 81 82 __repr__ = __str__ 83 84 def __bool__(self): 85 86 "Tuples are true if non-empty." 87 88 return self.__len__() != 0 89 90 def __iter__(self): 91 92 "Return an iterator." 93 94 return itemiterator(self) 95 96 # Special implementation methods. 97 98 def __get_single_item__(self, index): 99 100 "Return the item at the normalised (positive) 'index'." 101 102 self._check_index(index) 103 return list_element(self.__data__, index) 104 105 def __set_single_item__(self, index, value): 106 107 "Set at the normalised (positive) 'index' the given 'value'." 108 109 raise TypeError 110 111 # vim: tabstop=4 expandtab shiftwidth=4