1 | ;
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2 |
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3 | const Promise = require('bluebird');
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4 | const { parseArgs, shuffle } = require('./util');
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5 |
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6 | class Query {
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7 |
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8 | /**
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9 | * Query constructor.
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10 | *
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11 | * @param {Array} data
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12 | */
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13 | constructor(data) {
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14 | this.data = data;
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15 | this.length = data.length;
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16 | }
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17 |
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18 | /**
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19 | * Returns the number of elements.
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20 | *
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21 | * @return Number
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22 | */
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23 | count() {
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24 | return this.length;
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25 | }
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26 |
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27 | /**
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28 | * Iterates over all documents.
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29 | *
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30 | * @param {Function} iterator
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31 | */
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32 | forEach(iterator) {
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33 | const { data, length } = this;
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34 |
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35 | for (let i = 0; i < length; i++) {
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36 | iterator(data[i], i);
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37 | }
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38 | }
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39 |
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40 | /**
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41 | * Returns an array containing all documents.
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42 | *
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43 | * @return {Array}
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44 | */
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45 | toArray() {
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46 | return this.data;
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47 | }
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48 |
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49 | /**
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50 | * Returns the document at the specified index. `num` can be a positive or
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51 | * negative number.
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52 | *
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53 | * @param {Number} i
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54 | * @return {Document|Object}
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55 | */
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56 | eq(i) {
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57 | const index = i < 0 ? this.length + i : i;
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58 | return this.data[index];
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59 | }
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60 |
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61 | /**
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62 | * Returns the first document.
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63 | *
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64 | * @return {Document|Object}
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65 | */
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66 | first() {
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67 | return this.eq(0);
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68 | }
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69 |
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70 | /**
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71 | * Returns the last document.
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72 | *
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73 | * @return {Document|Object}
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74 | */
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75 | last() {
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76 | return this.eq(-1);
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77 | }
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78 |
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79 | /**
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80 | * Returns the specified range of documents.
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81 | *
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82 | * @param {Number} start
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83 | * @param {Number} [end]
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84 | * @return {Query}
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85 | */
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86 | slice(start, end) {
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87 | return new this.constructor(this.data.slice(start, end));
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88 | }
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89 |
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90 | /**
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91 | * Limits the number of documents returned.
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92 | *
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93 | * @param {Number} i
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94 | * @return {Query}
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95 | */
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96 | limit(i) {
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97 | return this.slice(0, i);
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98 | }
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99 |
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100 | /**
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101 | * Specifies the number of items to skip.
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102 | *
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103 | * @param {Number} i
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104 | * @return {Query}
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105 | */
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106 | skip(i) {
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107 | return this.slice(i);
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108 | }
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109 |
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110 | /**
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111 | * Returns documents in a reversed order.
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112 | *
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113 | * @return {Query}
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114 | */
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115 | reverse() {
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116 | return new this.constructor(this.data.slice().reverse());
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117 | }
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118 |
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119 | /**
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120 | * Returns documents in random order.
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121 | *
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122 | * @return {Query}
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123 | */
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124 | shuffle() {
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125 | return new this.constructor(shuffle(this.data));
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126 | }
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127 |
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128 | /**
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129 | * Finds matching documents.
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130 | *
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131 | * @param {Object} query
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132 | * @param {Object} [options]
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133 | * @param {Number} [options.limit=0] Limits the number of documents returned.
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134 | * @param {Number} [options.skip=0] Skips the first elements.
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135 | * @param {Boolean} [options.lean=false] Returns a plain JavaScript object.
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136 | * @return {Query|Array}
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137 | */
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138 | find(query, options = {}) {
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139 | const filter = this._schema._execQuery(query);
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140 | const { data, length } = this;
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141 | const { lean = false } = options;
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142 | let { limit = length, skip } = options;
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143 | const arr = [];
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144 |
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145 | for (let i = 0; limit && i < length; i++) {
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146 | const item = data[i];
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147 |
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148 | if (filter(item)) {
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149 | if (skip) {
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150 | skip--;
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151 | } else {
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152 | arr.push(lean ? item.toObject() : item);
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153 | limit--;
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154 | }
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155 | }
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156 | }
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157 |
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158 | return lean ? arr : new this.constructor(arr);
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159 | }
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160 |
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161 | /**
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162 | * Finds the first matching documents.
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163 | *
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164 | * @param {Object} query
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165 | * @param {Object} [options]
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166 | * @param {Number} [options.skip=0] Skips the first elements.
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167 | * @param {Boolean} [options.lean=false] Returns a plain JavaScript object.
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168 | * @return {Document|Object}
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169 | */
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170 | findOne(query, options = {}) {
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171 | options.limit = 1;
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172 |
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173 | const result = this.find(query, options);
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174 | return options.lean ? result[0] : result.data[0];
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175 | }
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176 |
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177 | /**
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178 | * Sorts documents.
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179 | *
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180 | * Example:
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181 | *
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182 | * ``` js
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183 | * query.sort('date', -1);
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184 | * query.sort({date: -1, title: 1});
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185 | * query.sort('-date title');
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186 | * ```
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187 | *
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188 | * If the `order` equals to `-1`, `desc` or `descending`, the data will be
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189 | * returned in reversed order.
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190 | *
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191 | * @param {String|Object} orderby
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192 | * @param {String|Number} [order]
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193 | * @return {Query}
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194 | */
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195 | sort(orderby, order) {
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196 | const sort = parseArgs(orderby, order);
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197 | const fn = this._schema._execSort(sort);
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198 |
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199 | return new this.constructor(this.data.slice().sort(fn));
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200 | }
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201 |
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202 | /**
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203 | * Creates an array of values by iterating each element in the collection.
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204 | *
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205 | * @param {Function} iterator
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206 | * @return {Array}
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207 | */
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208 | map(iterator) {
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209 | const { data, length } = this;
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210 | const result = new Array(length);
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211 |
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212 | for (let i = 0; i < length; i++) {
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213 | result[i] = iterator(data[i], i);
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214 | }
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215 |
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216 | return result;
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217 | }
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218 |
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219 | /**
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220 | * Reduces a collection to a value which is the accumulated result of iterating
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221 | * each element in the collection.
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222 | *
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223 | * @param {Function} iterator
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224 | * @param {*} [initial] By default, the initial value is the first document.
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225 | * @return {*}
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226 | */
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227 | reduce(iterator, initial) {
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228 | const { data, length } = this;
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229 | let result, i;
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230 |
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231 | if (initial === undefined) {
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232 | i = 1;
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233 | result = data[0];
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234 | } else {
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235 | i = 0;
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236 | result = initial;
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237 | }
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238 |
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239 | for (; i < length; i++) {
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240 | result = iterator(result, data[i], i);
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241 | }
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242 |
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243 | return result;
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244 | }
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245 |
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246 | /**
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247 | * Reduces a collection to a value which is the accumulated result of iterating
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248 | * each element in the collection from right to left.
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249 | *
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250 | * @param {Function} iterator
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251 | * @param {*} [initial] By default, the initial value is the last document.
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252 | * @return {*}
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253 | */
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254 | reduceRight(iterator, initial) {
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255 | const { data, length } = this;
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256 | let result, i;
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257 |
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258 | if (initial === undefined) {
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259 | i = length - 2;
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260 | result = data[length - 1];
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261 | } else {
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262 | i = length - 1;
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263 | result = initial;
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264 | }
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265 |
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266 | for (; i >= 0; i--) {
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267 | result = iterator(result, data[i], i);
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268 | }
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269 |
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270 | return result;
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271 | }
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272 |
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273 | /**
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274 | * Creates a new array with all documents that pass the test implemented by the
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275 | * provided function.
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276 | *
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277 | * @param {Function} iterator
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278 | * @return {Query}
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279 | */
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280 | filter(iterator) {
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281 | const { data, length } = this;
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282 | const arr = [];
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283 |
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284 | for (let i = 0; i < length; i++) {
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285 | const item = data[i];
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286 | if (iterator(item, i)) arr.push(item);
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287 | }
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288 |
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289 | return new this.constructor(arr);
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290 | }
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291 |
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292 | /**
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293 | * Tests whether all documents pass the test implemented by the provided
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294 | * function.
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295 | *
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296 | * @param {Function} iterator
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297 | * @return {Boolean}
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298 | */
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299 | every(iterator) {
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300 | const { data, length } = this;
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301 |
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302 | for (let i = 0; i < length; i++) {
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303 | if (!iterator(data[i], i)) return false;
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304 | }
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305 |
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306 | return true;
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307 | }
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308 |
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309 | /**
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310 | * Tests whether some documents pass the test implemented by the provided
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311 | * function.
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312 | *
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313 | * @param {Function} iterator
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314 | * @return {Boolean}
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315 | */
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316 | some(iterator) {
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317 | const { data, length } = this;
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318 |
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319 | for (let i = 0; i < length; i++) {
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320 | if (iterator(data[i], i)) return true;
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321 | }
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322 |
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323 | return false;
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324 | }
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325 |
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326 | /**
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327 | * Update all documents.
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328 | *
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329 | * @param {Object} data
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330 | * @param {Function} [callback]
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331 | * @return {Promise}
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332 | */
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333 | update(data, callback) {
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334 | const model = this._model;
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335 | const stack = this._schema._parseUpdate(data);
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336 |
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337 | return Promise.mapSeries(this.data, item => model._updateWithStack(item._id, stack)).asCallback(callback);
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338 | }
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339 |
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340 | /**
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341 | * Replace all documents.
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342 | *
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343 | * @param {Object} data
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344 | * @param {Function} [callback]
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345 | * @return {Promise}
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346 | */
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347 | replace(data, callback) {
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348 | const model = this._model;
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349 |
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350 | return Promise.map(this.data, item => model.replaceById(item._id, data)).asCallback(callback);
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351 | }
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352 |
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353 | /**
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354 | * Remove all documents.
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355 | *
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356 | * @param {Function} [callback]
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357 | * @return {Promise}
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358 | */
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359 | remove(callback) {
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360 | const model = this._model;
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361 |
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362 | return Promise.mapSeries(this.data, item => model.removeById(item._id)).asCallback(callback);
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363 | }
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364 |
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365 | /**
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366 | * Populates document references.
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367 | *
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368 | * @param {String|Object} expr
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369 | * @return {Query}
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370 | */
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371 | populate(expr) {
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372 | const stack = this._schema._parsePopulate(expr);
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373 | const { data, length } = this;
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374 | const model = this._model;
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375 |
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376 | for (let i = 0; i < length; i++) {
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377 | data[i] = model._populate(data[i], stack);
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378 | }
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379 |
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380 | return this;
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381 | }
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382 | }
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383 |
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384 | Query.prototype.size = Query.prototype.count;
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385 |
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386 | Query.prototype.each = Query.prototype.forEach;
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387 |
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388 | Query.prototype.random = Query.prototype.shuffle;
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389 |
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390 | module.exports = Query;
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