| paul@6 | 1 | #!/usr/bin/env python |
| paul@6 | 2 | |
| paul@6 | 3 | """ |
| paul@6 | 4 | Operator-related functions. |
| paul@6 | 5 | |
| paul@60 | 6 | Copyright (C) 2015, 2016 Paul Boddie <paul@boddie.org.uk> |
| paul@6 | 7 | |
| paul@6 | 8 | This program is free software; you can redistribute it and/or modify it under |
| paul@6 | 9 | the terms of the GNU General Public License as published by the Free Software |
| paul@6 | 10 | Foundation; either version 3 of the License, or (at your option) any later |
| paul@6 | 11 | version. |
| paul@6 | 12 | |
| paul@6 | 13 | This program is distributed in the hope that it will be useful, but WITHOUT |
| paul@6 | 14 | ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS |
| paul@6 | 15 | FOR A PARTICULAR PURPOSE. See the GNU General Public License for more |
| paul@6 | 16 | details. |
| paul@6 | 17 | |
| paul@6 | 18 | You should have received a copy of the GNU General Public License along with |
| paul@6 | 19 | this program. If not, see <http://www.gnu.org/licenses/>. |
| paul@6 | 20 | """ |
| paul@6 | 21 | |
| paul@60 | 22 | def _binary_op(this, other, op): |
| paul@6 | 23 | |
| paul@60 | 24 | "Test the types of 'this' and 'other', performing 'op' if identical." |
| paul@6 | 25 | |
| paul@60 | 26 | if this.__class__ is other.__class__: |
| paul@60 | 27 | return op(this, other) |
| paul@6 | 28 | else: |
| paul@6 | 29 | return NotImplemented |
| paul@6 | 30 | |
| paul@6 | 31 | def _negate(result): |
| paul@6 | 32 | |
| paul@6 | 33 | "Negate any valid logical value." |
| paul@6 | 34 | |
| paul@6 | 35 | if result is NotImplemented: |
| paul@6 | 36 | return result |
| paul@6 | 37 | else: |
| paul@6 | 38 | return not result |
| paul@6 | 39 | |
| paul@6 | 40 | # vim: tabstop=4 expandtab shiftwidth=4 |
