45 lines
1.5 KiB
JavaScript
45 lines
1.5 KiB
JavaScript
"use strict";
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//---------------------------------------------------------------------------
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// @syndicate-lang/core, an implementation of Syndicate dataspaces for JS.
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// Copyright (C) 2016-2018 Tony Garnock-Jones <tonyg@leastfixedpoint.com>
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//
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// This program is free software: you can redistribute it and/or modify
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// it under the terms of the GNU General Public License as published by
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// the Free Software Foundation, either version 3 of the License, or
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// (at your option) any later version.
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//
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// This program is distributed in the hope that it will be useful,
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// but WITHOUT ANY WARRANTY; without even the implied warranty of
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// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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// GNU General Public License for more details.
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//
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// You should have received a copy of the GNU General Public License
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// along with this program. If not, see <https://www.gnu.org/licenses/>.
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//---------------------------------------------------------------------------
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// Utilities for Maps of Sets
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var Immutable = require('immutable');
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function add(ms, key, val) {
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return ms.set(key, (ms.get(key) || Immutable.Set()).add(val));
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}
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function remove(ms, key, val) {
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var oldSet = ms.get(key);
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if (oldSet) {
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var newSet = oldSet.remove(val);
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if (newSet.isEmpty()) {
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ms = ms.remove(key);
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} else {
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ms = ms.set(key, newSet);
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}
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}
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return ms;
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}
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///////////////////////////////////////////////////////////////////////////
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module.exports.add = add;
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module.exports.remove = remove;
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