| 4 | 4 | // |
| 5 | 5 | |
| 6 | 6 | export class List { |
| 7 | | constructor() { |
| 8 | | throw new Error('Remove this line and implement the function'); |
| 7 | /** |
| 8 | * Creates a new List |
| 9 | * @param {Array} [values=[]] - Initial values for the list |
| 10 | */ |
| 11 | constructor(values = []) { |
| 12 | this.values = values; |
| 9 | 13 | } |
| 10 | 14 | |
| 11 | 15 | /** |
| 12 | | * @param {List} other |
| 13 | | * @return {List} |
| 16 | * Appends another list to this list |
| 17 | * @param {List} other - The list to append |
| 18 | * @return {List} A new list containing all elements from both lists |
| 19 | * |
| 20 | * Handled Edge Cases: Empty lists, null/undefined other list |
| 14 | 21 | */ |
| 15 | 22 | append(other) { |
| 16 | | throw new Error('Remove this line and implement the function'); |
| 23 | // Edge Case: Handle null or undefined other list |
| 24 | if (!other) { |
| 25 | return new List(this.values); |
| 26 | } |
| 27 | |
| 28 | // Edge Case: Handle empty lists |
| 29 | if (this.values.length === 0 && other.values.length === 0) { |
| 30 | return new List([]); |
| 31 | } |
| 32 | |
| 33 | const result = []; |
| 34 | for (let i = 0; i < this.values.length; i++) { |
| 35 | result.push(this.values[i]); |
| 36 | } |
| 37 | for (let i = 0; i < other.values.length; i++) { |
| 38 | result.push(other.values[i]); |
| 39 | } |
| 40 | return new List(result); |
| 17 | 41 | } |
| 18 | 42 | |
| 19 | 43 | /** |
| 20 | | * @param {List} others |
| 21 | | * @return {List} |
| 44 | * Concatenates multiple lists into one |
| 45 | * @param {List} others - A list of lists to concatenate |
| 46 | * @return {List} A new list with all elements from all lists flattened |
| 47 | * |
| 48 | * Handled Edge Cases: Empty lists, nested empty lists |
| 22 | 49 | */ |
| 23 | 50 | concat(others) { |
| 24 | | throw new Error('Remove this line and implement the function'); |
| 51 | // Edge Case: Handle empty others list |
| 52 | if (!others || others.values.length === 0) { |
| 53 | return new List(this.values); |
| 54 | } |
| 55 | |
| 56 | let result = []; |
| 57 | |
| 58 | // Add elements from current list |
| 59 | for (let i = 0; i < this.values.length; i++) { |
| 60 | result.push(this.values[i]); |
| 61 | } |
| 62 | |
| 63 | // Add elements from each list in others |
| 64 | for (let i = 0; i < others.values.length; i++) { |
| 65 | const list = others.values[i]; |
| 66 | // Edge Case: Handle if an element in others is not a List |
| 67 | if (list && Array.isArray(list.values)) { |
| 68 | for (let j = 0; j < list.values.length; j++) { |
| 69 | result.push(list.values[j]); |
| 70 | } |
| 71 | } |
| 72 | } |
| 73 | |
| 74 | return new List(result); |
| 25 | 75 | } |
| 26 | 76 | |
| 27 | 77 | /** |
| 28 | | * @param {(any) => boolean} predicate |
| 29 | | * @return {List} |
| 78 | * Filters the list based on a predicate function |
| 79 | * @param {(any) => boolean} predicate - Function to test each element |
| 80 | * @return {List} A new list containing only elements that pass the predicate |
| 81 | * |
| 82 | * Handled Edge Cases: Empty list, all elements filtered out, all elements pass |
| 30 | 83 | */ |
| 31 | 84 | filter(predicate) { |
| 32 | | throw new Error('Remove this line and implement the function'); |
| 85 | // Edge Case: Handle empty list |
| 86 | if (this.values.length === 0) { |
| 87 | return new List([]); |
| 88 | } |
| 89 | |
| 90 | const result = []; |
| 91 | for (let i = 0; i < this.values.length; i++) { |
| 92 | if (predicate(this.values[i])) { |
| 93 | result.push(this.values[i]); |
| 94 | } |
| 95 | } |
| 96 | |
| 97 | return new List(result); |
| 33 | 98 | } |
| 34 | 99 | |
| 35 | 100 | /** |
| 36 | | * @param {(any) => any} expression |
| 37 | | * @return {List} |
| 101 | * Transforms each element using the provided function |
| 102 | * @param {(any) => any} expression - Function to transform each element |
| 103 | * @return {List} A new list with transformed elements |
| 104 | * |
| 105 | * Handled Edge Cases: Empty list |
| 38 | 106 | */ |
| 39 | 107 | map(expression) { |
| 40 | | throw new Error('Remove this line and implement the function'); |
| 108 | // Edge Case: Handle empty list |
| 109 | if (this.values.length === 0) { |
| 110 | return new List([]); |
| 111 | } |
| 112 | |
| 113 | const result = []; |
| 114 | for (let i = 0; i < this.values.length; i++) { |
| 115 | result.push(expression(this.values[i])); |
| 116 | } |
| 117 | |
| 118 | return new List(result); |
| 41 | 119 | } |
| 42 | 120 | |
| 43 | 121 | /** |
| 44 | | * @return {number} |
| 122 | * Returns the number of elements in the list |
| 123 | * @return {number} The length of the list |
| 124 | * |
| 125 | * Handled Edge Cases: Empty list |
| 45 | 126 | */ |
| 46 | 127 | length() { |
| 47 | | throw new Error('Remove this line and implement the function'); |
| 128 | // Edge Case: Handle empty list |
| 129 | let count = 0; |
| 130 | for (let i = 0; i < this.values.length; i++) { |
| 131 | count++; |
| 132 | } |
| 133 | return count; |
| 48 | 134 | } |
| 49 | 135 | |
| 50 | 136 | /** |
| 51 | | * @param {(acc: any, el: any) => any} callback |
| 52 | | * @param {any} initial |
| 53 | | * @return {any} |
| 137 | * Folds the list from the left using a callback function |
| 138 | * @param {(acc: any, el: any) => any} callback - Function to apply to each element |
| 139 | * @param {any} initial - Initial accumulator value |
| 140 | * @return {any} The final accumulator value |
| 141 | * |
| 142 | * Handled Edge Cases: Empty list |
| 54 | 143 | */ |
| 55 | 144 | foldl(callback, initial) { |
| 56 | | throw new Error('Remove this line and implement the function'); |
| 145 | // Edge Case: Handle empty list |
| 146 | if (this.values.length === 0) { |
| 147 | return initial; |
| 148 | } |
| 149 | |
| 150 | let accumulator = initial; |
| 151 | for (let i = 0; i < this.values.length; i++) { |
| 152 | accumulator = callback(accumulator, this.values[i]); |
| 153 | } |
| 154 | |
| 155 | return accumulator; |
| 57 | 156 | } |
| 58 | 157 | |
| 59 | 158 | /** |
| 60 | | * @param {(acc: any, el: any) => any} callback |
| 61 | | * @param {any} initial |
| 62 | | * @return {any} |
| 159 | * Folds the list from the right using a callback function |
| 160 | * @param {(acc: any, el: any) => any} callback - Function to apply to each element |
| 161 | * @param {any} initial - Initial accumulator value |
| 162 | * @return {any} The final accumulator value |
| 163 | * |
| 164 | * Handled Edge Cases: Empty list |
| 63 | 165 | */ |
| 64 | 166 | foldr(callback, initial) { |
| 65 | | throw new Error('Remove this line and implement the function'); |
| 167 | // Edge Case: Handle empty list |
| 168 | if (this.values.length === 0) { |
| 169 | return initial; |
| 170 | } |
| 171 | |
| 172 | let accumulator = initial; |
| 173 | for (let i = this.values.length - 1; i >= 0; i--) { |
| 174 | accumulator = callback(accumulator, this.values[i]); |
| 175 | } |
| 176 | |
| 177 | return accumulator; |
| 66 | 178 | } |
| 67 | 179 | |
| 68 | 180 | /** |
| 69 | | * @return {List} |
| 181 | * Reverses the order of elements in the list |
| 182 | * @return {List} A new list with elements in reverse order |
| 183 | * |
| 184 | * Handled Edge Cases: Empty list |
| 70 | 185 | */ |
| 71 | 186 | reverse() { |
| 72 | | throw new Error('Remove this line and implement the function'); |
| 187 | // Edge Case: Handle empty list |
| 188 | if (this.values.length === 0) { |
| 189 | return new List([]); |
| 190 | } |
| 191 | |
| 192 | const result = []; |
| 193 | for (let i = this.values.length - 1; i >= 0; i--) { |
| 194 | result.push(this.values[i]); |
| 195 | } |
| 196 | |
| 197 | return new List(result); |
| 73 | 198 | } |
| 74 | 199 | } |