1 | var iterate = require('./lib/iterate.js')
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2 | , initState = require('./lib/state.js')
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3 | , terminator = require('./lib/terminator.js')
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4 | ;
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5 |
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6 | // Public API
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7 | module.exports = serialOrdered;
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8 | // sorting helpers
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9 | module.exports.ascending = ascending;
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10 | module.exports.descending = descending;
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11 |
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12 | /**
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13 | * Runs iterator over provided sorted array elements in series
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14 | *
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15 | * @param {array|object} list - array or object (named list) to iterate over
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16 | * @param {function} iterator - iterator to run
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17 | * @param {function} sortMethod - custom sort function
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18 | * @param {function} callback - invoked when all elements processed
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19 | * @returns {function} - jobs terminator
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20 | */
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21 | function serialOrdered(list, iterator, sortMethod, callback)
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22 | {
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23 | var state = initState(list, sortMethod);
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24 |
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25 | iterate(list, iterator, state, function iteratorHandler(error, result)
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26 | {
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27 | if (error)
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28 | {
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29 | callback(error, result);
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30 | return;
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31 | }
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32 |
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33 | state.index++;
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34 |
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35 | // are we there yet?
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36 | if (state.index < (state['keyedList'] || list).length)
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37 | {
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38 | iterate(list, iterator, state, iteratorHandler);
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39 | return;
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40 | }
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41 |
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42 | // done here
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43 | callback(null, state.results);
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44 | });
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45 |
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46 | return terminator.bind(state, callback);
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47 | }
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48 |
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49 | /*
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50 | * -- Sort methods
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51 | */
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52 |
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53 | /**
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54 | * sort helper to sort array elements in ascending order
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55 | *
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56 | * @param {mixed} a - an item to compare
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57 | * @param {mixed} b - an item to compare
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58 | * @returns {number} - comparison result
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59 | */
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60 | function ascending(a, b)
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61 | {
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62 | return a < b ? -1 : a > b ? 1 : 0;
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63 | }
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64 |
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65 | /**
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66 | * sort helper to sort array elements in descending order
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67 | *
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68 | * @param {mixed} a - an item to compare
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69 | * @param {mixed} b - an item to compare
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70 | * @returns {number} - comparison result
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71 | */
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72 | function descending(a, b)
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73 | {
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74 | return -1 * ascending(a, b);
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75 | }
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