Readonly[unscopables]Is an object whose properties have the value 'true' when they will be absent when used in a 'with' statement.
Optional Readonly[unscopables]?: booleanIs an object whose properties have the value 'true' when they will be absent when used in a 'with' statement.
Optionallength?: booleanGets or sets the length of the array. This is a number one higher than the highest index in the array.
Gets or sets the length of the array. This is a number one higher than the highest index in the array.
Static[species]ensure that built-in class methods create a primitive Array, instead of an instance of this List class.
it is extremely important that we set the [Symbol.species] static property to Array,
otherwise any Array method that creates another Array (such as map and splice) will create an instance of List instead of an Array.
this will eventually become a huge hindrance in future computationally heavy subclasses of this class that utilize the splice often.
related reading material:
Symbol.species static property: mdn link.Symbol.species instead of symbol_species from "alias.ts": see the comment inside the body of [Symbol.iterator].Returns the value of the first element in the array where predicate is true, and undefined otherwise.
find calls predicate once for each element of the array, in ascending order, until it finds one where predicate returns true. If such an element is found, find immediately returns that element value. Otherwise, find returns undefined.
OptionalthisArg: anyIf provided, it will be used as the this value for each invocation of predicate. If it is not provided, undefined is used instead.
Returns the index of the first element in the array where predicate is true, and -1 otherwise.
find calls predicate once for each element of the array, in ascending order, until it finds one where predicate returns true. If such an element is found, findIndex immediately returns that element index. Otherwise, findIndex returns -1.
OptionalthisArg: anyIf provided, it will be used as the this value for each invocation of predicate. If it is not provided, undefined is used instead.
Changes all array elements from start to end index to a static value and returns the modified array
value to fill array section with
Optionalstart: numberindex to start filling the array at. If start is negative, it is treated as length+start where length is the length of the array.
Optionalend: numberindex to stop filling the array at. If end is negative, it is treated as length+end.
Returns the this object after copying a section of the array identified by start and end to the same array starting at position target
If target is negative, it is treated as length+target where length is the length of the array.
If start is negative, it is treated as length+start. If end is negative, it is treated as length+end.
Optionalend: numberIf not specified, length of the this object is used as its default value.
Determines whether an array includes a certain element, returning true or false as appropriate.
The element to search for.
OptionalfromIndex: numberThe position in this array at which to begin searching for searchElement.
Calls a defined callback function on each element of an array. Then, flattens the result into a new array. This is identical to a map followed by flat with depth 1.
A function that accepts up to three arguments. The flatMap method calls the callback function one time for each element in the array.
OptionalthisArg: ThisAn object to which the this keyword can refer in the callback function. If thisArg is omitted, undefined is used as the this value.
Returns the value of the last element in the array where predicate is true, and undefined otherwise.
findLast calls predicate once for each element of the array, in descending order, until it finds one where predicate returns true. If such an element is found, findLast immediately returns that element value. Otherwise, findLast returns undefined.
OptionalthisArg: anyIf provided, it will be used as the this value for each invocation of predicate. If it is not provided, undefined is used instead.
Returns the index of the last element in the array where predicate is true, and -1 otherwise.
findLastIndex calls predicate once for each element of the array, in descending order, until it finds one where predicate returns true. If such an element is found, findLastIndex immediately returns that element index. Otherwise, findLastIndex returns -1.
OptionalthisArg: anyIf provided, it will be used as the this value for each invocation of predicate. If it is not provided, undefined is used instead.
Returns a copy of an array with its elements sorted.
OptionalcompareFn: (a: T, b: T) => numberFunction used to determine the order of the elements. It is expected to return a negative value if the first argument is less than the second argument, zero if they're equal, and a positive value otherwise. If omitted, the elements are sorted in ascending, ASCII character order.
[11, 2, 22, 1].toSorted((a, b) => a - b) // [1, 2, 11, 22]
Copies an array and removes elements and, if necessary, inserts new elements in their place. Returns the copied array.
The zero-based location in the array from which to start removing elements.
The number of elements to remove.
Elements to insert into the copied array in place of the deleted elements.
The copied array.
Copies an array and removes elements while returning the remaining elements.
The zero-based location in the array from which to start removing elements.
OptionaldeleteCount: numberThe number of elements to remove.
A copy of the original array with the remaining elements.
Copies an array, then overwrites the value at the provided index with the given value. If the index is negative, then it replaces from the end of the array.
The index of the value to overwrite. If the index is negative, then it replaces from the end of the array.
The value to write into the copied array.
The copied array with the updated value.
Returns a string representation of an array. The elements are converted to string using their toLocaleString methods.
Optionaloptions: NumberFormatOptions & DateTimeFormatOptionsCombines two or more arrays. This method returns a new array without modifying any existing arrays.
Additional arrays and/or items to add to the end of the array.
Combines two or more arrays. This method returns a new array without modifying any existing arrays.
Adds all the elements of an array into a string, separated by the specified separator string.
Optionalseparator: stringA string used to separate one element of the array from the next in the resulting string. If omitted, the array elements are separated with a comma.
Returns a copy of a section of an array. For both start and end, a negative index can be used to indicate an offset from the end of the array. For example, -2 refers to the second to last element of the array.
Optionalstart: numberThe beginning index of the specified portion of the array. If start is undefined, then the slice begins at index 0.
Optionalend: numberThe end index of the specified portion of the array. This is exclusive of the element at the index 'end'. If end is undefined, then the slice extends to the end of the array.
Sorts an array in place. This method mutates the array and returns a reference to the same array.
OptionalcompareFn: (a: T, b: T) => numberFunction used to determine the order of the elements. It is expected to return a negative value if the first argument is less than the second argument, zero if they're equal, and a positive value otherwise. If omitted, the elements are sorted in ascending, ASCII character order.
[11,2,22,1].sort((a, b) => a - b)
Removes elements from an array and, if necessary, inserts new elements in their place, returning the deleted elements.
The zero-based location in the array from which to start removing elements.
OptionaldeleteCount: numberThe number of elements to remove.
An array containing the elements that were deleted.
Removes elements from an array and, if necessary, inserts new elements in their place, returning the deleted elements.
The zero-based location in the array from which to start removing elements.
The number of elements to remove.
Elements to insert into the array in place of the deleted elements.
An array containing the elements that were deleted.
Returns the index of the first occurrence of a value in an array, or -1 if it is not present.
The value to locate in the array.
OptionalfromIndex: numberThe array index at which to begin the search. If fromIndex is omitted, the search starts at index 0.
Returns the index of the last occurrence of a specified value in an array, or -1 if it is not present.
The value to locate in the array.
OptionalfromIndex: numberThe array index at which to begin searching backward. If fromIndex is omitted, the search starts at the last index in the array.
Determines whether all the members of an array satisfy the specified test.
A function that accepts up to three arguments. The every method calls the predicate function for each element in the array until the predicate returns a value which is coercible to the Boolean value false, or until the end of the array.
OptionalthisArg: anyAn object to which the this keyword can refer in the predicate function. If thisArg is omitted, undefined is used as the this value.
Determines whether all the members of an array satisfy the specified test.
A function that accepts up to three arguments. The every method calls the predicate function for each element in the array until the predicate returns a value which is coercible to the Boolean value false, or until the end of the array.
OptionalthisArg: anyAn object to which the this keyword can refer in the predicate function. If thisArg is omitted, undefined is used as the this value.
Determines whether the specified callback function returns true for any element of an array.
A function that accepts up to three arguments. The some method calls the predicate function for each element in the array until the predicate returns a value which is coercible to the Boolean value true, or until the end of the array.
OptionalthisArg: anyAn object to which the this keyword can refer in the predicate function. If thisArg is omitted, undefined is used as the this value.
Performs the specified action for each element in an array.
A function that accepts up to three arguments. forEach calls the callbackfn function one time for each element in the array.
OptionalthisArg: anyAn object to which the this keyword can refer in the callbackfn function. If thisArg is omitted, undefined is used as the this value.
Calls a defined callback function on each element of an array, and returns an array that contains the results.
A function that accepts up to three arguments. The map method calls the callbackfn function one time for each element in the array.
OptionalthisArg: anyAn object to which the this keyword can refer in the callbackfn function. If thisArg is omitted, undefined is used as the this value.
Returns the elements of an array that meet the condition specified in a callback function.
A function that accepts up to three arguments. The filter method calls the predicate function one time for each element in the array.
OptionalthisArg: anyAn object to which the this keyword can refer in the predicate function. If thisArg is omitted, undefined is used as the this value.
Returns the elements of an array that meet the condition specified in a callback function.
A function that accepts up to three arguments. The filter method calls the predicate function one time for each element in the array.
OptionalthisArg: anyAn object to which the this keyword can refer in the predicate function. If thisArg is omitted, undefined is used as the this value.
Calls the specified callback function for all the elements in an array. The return value of the callback function is the accumulated result, and is provided as an argument in the next call to the callback function.
Calls the specified callback function for all the elements in an array. The return value of the callback function is the accumulated result, and is provided as an argument in the next call to the callback function.
A function that accepts up to four arguments. The reduce method calls the callbackfn function one time for each element in the array.
If initialValue is specified, it is used as the initial value to start the accumulation. The first call to the callbackfn function provides this value as an argument instead of an array value.
Calls the specified callback function for all the elements in an array, in descending order. The return value of the callback function is the accumulated result, and is provided as an argument in the next call to the callback function.
Calls the specified callback function for all the elements in an array, in descending order. The return value of the callback function is the accumulated result, and is provided as an argument in the next call to the callback function.
A function that accepts up to four arguments. The reduceRight method calls the callbackfn function one time for each element in the array.
If initialValue is specified, it is used as the initial value to start the accumulation. The first call to the callbackfn function provides this value as an argument instead of an array value.
StaticisStaticfromCreates an array from an async iterator or iterable object.
Creates an array from an async iterator or iterable object.
inserts an item at the specified index, shifting all items ahead of it one position to the front.
negative indices are also supported for indicating the position of the newly added item after the array's length has incremented.
import { assertEquals } from "jsr:@std/assert"
const arr = new List([0, 1, 2, 3, 4])
arr.insert(-1, 5) // similar to pushing
assertEquals([...arr], [0, 1, 2, 3, 4, 5])
arr.insert(-2, 4.5)
assertEquals([...arr], [0, 1, 2, 3, 4, 4.5, 5])
arr.insert(1, 0.5)
assertEquals([...arr], [0, 0.5, 1, 2, 3, 4, 4.5, 5])
deletes an item at the specified index, shifting all items ahead of it one position to the back.
negative indices are also supported for indicating the deletion index from the end of the array.
import { assertEquals } from "jsr:@std/assert"
const arr = new List([0, 0.5, 1, 2, 3, 4, 4.5, 5])
arr.delete(-1) // similar to popping
assertEquals([...arr], [0, 0.5, 1, 2, 3, 4, 4.5])
arr.delete(-2)
assertEquals([...arr], [0, 0.5, 1, 2, 3, 4.5])
arr.delete(1)
assertEquals([...arr], [0, 1, 2, 3, 4.5])
swap the position of two items by their index.
if any of the two indices is out of bound, then appropriate number of empty elements will be created to fill the gap;
similar to how index-based assignment works (i.e. my_list[off_bound_index] = "something" will increase my_list's length).
import { assertEquals } from "jsr:@std/assert"
const arr = new List<string>(["0", "4", "2", "3", "1", "5", "6"])
arr.swap(1, 4)
assertEquals(arr.slice(), ["0", "1", "2", "3", "4", "5", "6"])
// swapping elements with an out of bound index will create additional intermediate `empty` elements.
// moreover, the existing element that is swapped will have `undefined` put in its place instead of `empty`.
assertEquals(arr.length, 7)
arr.swap(5, 9)
assertEquals(arr.length, 10)
assertEquals(arr.slice(), ["0", "1", "2", "3", "4", undefined, "6", , , "5"]) // notice the empty entries.
sets the value at the specified index.
prefer using this method instead of index-based assignment, because subclasses may additionally cary out more operations with this method.
for attaining compatibility between List and its subclasses, it would be in your best interest to use the set method.
my_list[index] = "hello"my_list.set(index, "hello")StaticfromStaticof
a very simple python-like
Lists class, that allows for in-between insertions, deletions, and replacements, to keep the list compact.TODO: add examples