avl-tree-typed
Version:
Standard AVL tree
354 lines (353 loc) • 17.4 kB
JavaScript
;
var __awaiter = (this && this.__awaiter) || function (thisArg, _arguments, P, generator) {
function adopt(value) { return value instanceof P ? value : new P(function (resolve) { resolve(value); }); }
return new (P || (P = Promise))(function (resolve, reject) {
function fulfilled(value) { try { step(generator.next(value)); } catch (e) { reject(e); } }
function rejected(value) { try { step(generator["throw"](value)); } catch (e) { reject(e); } }
function step(result) { result.done ? resolve(result.value) : adopt(result.value).then(fulfilled, rejected); }
step((generator = generator.apply(thisArg, _arguments || [])).next());
});
};
Object.defineProperty(exports, "__esModule", { value: true });
exports.isTrampolineThunk = exports.makeTrampolineThunk = exports.roundFixed = exports.calcMinUnitsRequired = exports.isWeakKey = exports.throwRangeError = exports.rangeCheck = exports.getMSB = exports.arrayRemove = exports.uuidV4 = void 0;
exports.isComparable = isComparable;
exports.trampoline = trampoline;
exports.makeTrampoline = makeTrampoline;
exports.asyncTrampoline = asyncTrampoline;
exports.makeAsyncTrampoline = makeAsyncTrampoline;
/**
* The function generates a random UUID (Universally Unique Identifier) in TypeScript.
* @returns A randomly generated UUID (Universally Unique Identifier) in the format
* 'xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx' where each 'x' is replaced with a random hexadecimal
* character.
*/
const uuidV4 = function () {
return 'xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx'.replace(/[x]/g, function (c) {
const r = (Math.random() * 16) | 0, v = c == 'x' ? r : (r & 0x3) | 0x8;
return v.toString(16);
});
};
exports.uuidV4 = uuidV4;
/**
* The `arrayRemove` function removes elements from an array based on a specified predicate function
* and returns the removed elements.
* @param {T[]} array - An array of elements that you want to filter based on the provided predicate
* function.
* @param predicate - The `predicate` parameter is a function that takes three arguments:
* @returns The `arrayRemove` function returns an array containing the elements that satisfy the given
* `predicate` function.
*/
const arrayRemove = function (array, predicate) {
let i = -1, len = array ? array.length : 0;
const result = [];
while (++i < len) {
const value = array[i];
if (predicate(value, i, array)) {
result.push(value);
Array.prototype.splice.call(array, i--, 1);
len--;
}
}
return result;
};
exports.arrayRemove = arrayRemove;
/**
* The function `getMSB` returns the most significant bit of a given number.
* @param {number} value - The `value` parameter is a number for which we want to find the position of
* the Most Significant Bit (MSB). The function `getMSB` takes this number as input and calculates the
* position of the MSB in its binary representation.
* @returns The function `getMSB` returns the most significant bit (MSB) of the input `value`. If the
* input value is less than or equal to 0, it returns 0. Otherwise, it calculates the position of the
* MSB using the `Math.clz32` function and bitwise left shifts 1 to that position.
*/
const getMSB = (value) => {
if (value <= 0) {
return 0;
}
return 1 << (31 - Math.clz32(value));
};
exports.getMSB = getMSB;
/**
* The `rangeCheck` function in TypeScript is used to validate if an index is within a specified range
* and throws a `RangeError` with a custom message if it is out of bounds.
* @param {number} index - The `index` parameter represents the value that you want to check if it
* falls within a specified range.
* @param {number} min - The `min` parameter represents the minimum value that the `index` should be
* compared against in the `rangeCheck` function.
* @param {number} max - The `max` parameter in the `rangeCheck` function represents the maximum value
* that the `index` parameter is allowed to have. If the `index` is greater than this `max` value, a
* `RangeError` will be thrown.
* @param [message=Index out of bounds.] - The `message` parameter is a string that represents the
* error message to be thrown if the index is out of bounds. By default, if no message is provided when
* calling the `rangeCheck` function, the message "Index out of bounds." will be used.
*/
const rangeCheck = (index, min, max, message = 'Index out of bounds.') => {
if (index < min || index > max)
throw new RangeError(message);
};
exports.rangeCheck = rangeCheck;
/**
* The function `throwRangeError` throws a RangeError with a custom message if called.
* @param [message=The value is off-limits.] - The `message` parameter is a string that represents the
* error message to be displayed when a `RangeError` is thrown. If no message is provided, the default
* message is 'The value is off-limits.'.
*/
const throwRangeError = (message = 'The value is off-limits.') => {
throw new RangeError(message);
};
exports.throwRangeError = throwRangeError;
/**
* The function `isWeakKey` checks if the input is an object or a function in TypeScript.
* @param {unknown} input - The `input` parameter in the `isWeakKey` function is of type `unknown`,
* which means it can be any type. The function checks if the `input` is an object (excluding `null`)
* or a function, and returns a boolean indicating whether the `input` is a weak
* @returns The function `isWeakKey` returns a boolean value indicating whether the input is an object
* or a function.
*/
const isWeakKey = (input) => {
const inputType = typeof input;
return (inputType === 'object' && input !== null) || inputType === 'function';
};
exports.isWeakKey = isWeakKey;
/**
* The function `calcMinUnitsRequired` calculates the minimum number of units required to accommodate a
* given total quantity based on a specified unit size.
* @param {number} totalQuantity - The `totalQuantity` parameter represents the total quantity of items
* that need to be processed or handled.
* @param {number} unitSize - The `unitSize` parameter represents the size of each unit or package. It
* is used in the `calcMinUnitsRequired` function to calculate the minimum number of units required to
* accommodate a total quantity of items.
*/
const calcMinUnitsRequired = (totalQuantity, unitSize) => Math.floor((totalQuantity + unitSize - 1) / unitSize);
exports.calcMinUnitsRequired = calcMinUnitsRequired;
/**
* The `roundFixed` function in TypeScript rounds a number to a specified number of decimal places.
* @param {number} num - The `num` parameter is a number that you want to round to a certain number of
* decimal places.
* @param {number} [digit=10] - The `digit` parameter in the `roundFixed` function specifies the number
* of decimal places to round the number to. By default, it is set to 10 if not provided explicitly.
* @returns The function `roundFixed` returns a number that is rounded to the specified number of
* decimal places (default is 10 decimal places).
*/
const roundFixed = (num, digit = 10) => {
const multiplier = Math.pow(10, digit);
return Math.round(num * multiplier) / multiplier;
};
exports.roundFixed = roundFixed;
/**
* The function `isPrimitiveComparable` checks if a value is a primitive type that can be compared.
* @param {unknown} value - The `value` parameter in the `isPrimitiveComparable` function is of type
* `unknown`, which means it can be any type. The function checks if the `value` is a primitive type
* that can be compared, such as number, bigint, string, or boolean.
* @returns The function `isPrimitiveComparable` returns a boolean value indicating whether the input
* `value` is a primitive value that can be compared using standard comparison operators (<, >, <=,
* >=).
*/
function isPrimitiveComparable(value) {
const valueType = typeof value;
if (valueType === 'number')
return true;
// if (valueType === 'number') return !Number.isNaN(value);
return valueType === 'bigint' || valueType === 'string' || valueType === 'boolean';
}
/**
* The function `tryObjectToPrimitive` attempts to convert an object to a comparable primitive value by
* first checking the `valueOf` method and then the `toString` method.
* @param {object} obj - The `obj` parameter in the `tryObjectToPrimitive` function is an object that
* you want to convert to a primitive value. The function attempts to convert the object to a primitive
* value by first checking if the object has a `valueOf` method. If the `valueOf` method exists, it
* @returns The function `tryObjectToPrimitive` returns a value of type `ComparablePrimitive` if a
* primitive comparable value is found within the object, or a string value if the object has a custom
* `toString` method that does not return `'[object Object]'`. If neither condition is met, the
* function returns `null`.
*/
function tryObjectToPrimitive(obj) {
if (typeof obj.valueOf === 'function') {
const valueOfResult = obj.valueOf();
if (valueOfResult !== obj) {
if (isPrimitiveComparable(valueOfResult))
return valueOfResult;
if (typeof valueOfResult === 'object' && valueOfResult !== null)
return tryObjectToPrimitive(valueOfResult);
}
}
if (typeof obj.toString === 'function') {
const stringResult = obj.toString();
if (stringResult !== '[object Object]')
return stringResult;
}
return null;
}
/**
* The function `isComparable` in TypeScript checks if a value is comparable, handling primitive values
* and objects with optional force comparison.
* @param {unknown} value - The `value` parameter in the `isComparable` function represents the value
* that you want to check if it is comparable. It can be of any type (`unknown`), and the function will
* determine if it is comparable based on certain conditions.
* @param [isForceObjectComparable=false] - The `isForceObjectComparable` parameter in the
* `isComparable` function is a boolean flag that determines whether to treat non-primitive values as
* comparable objects. When set to `true`, it forces the function to consider non-primitive values as
* comparable objects, regardless of their type.
* @returns The function `isComparable` returns a boolean value indicating whether the `value` is
* considered comparable or not.
*/
function isComparable(value, isForceObjectComparable = false) {
if (value === null || value === undefined)
return false;
if (isPrimitiveComparable(value))
return true;
if (typeof value !== 'object')
return false;
if (value instanceof Date)
return true;
// if (value instanceof Date) return !Number.isNaN(value.getTime());
if (isForceObjectComparable)
return true;
const comparableValue = tryObjectToPrimitive(value);
if (comparableValue === null || comparableValue === undefined)
return false;
return isPrimitiveComparable(comparableValue);
}
/**
* Creates a trampoline thunk object.
*
* A "thunk" is a deferred computation — instead of performing a recursive call immediately,
* it wraps the next step of the computation in a function. This allows recursive processes
* to be executed iteratively, preventing stack overflows.
*
* @template T - The type of the final computation result.
* @param computation - A function that, when executed, returns the next trampoline step.
* @returns A TrampolineThunk object containing the deferred computation.
*/
const makeTrampolineThunk = (computation) => ({
isThunk: true, // Marker indicating this is a thunk
fn: computation // The deferred computation function
});
exports.makeTrampolineThunk = makeTrampolineThunk;
/**
* Type guard to check whether a given value is a TrampolineThunk.
*
* This function is used to distinguish between a final computation result (value)
* and a deferred computation (thunk).
*
* @template T - The type of the value being checked.
* @param value - The value to test.
* @returns True if the value is a valid TrampolineThunk, false otherwise.
*/
const isTrampolineThunk = (value) => typeof value === 'object' && // Must be an object
value !== null && // Must not be null
'isThunk' in value && // Must have the 'isThunk' property
value.isThunk; // The flag must be true
exports.isTrampolineThunk = isTrampolineThunk;
/**
* Executes a trampoline computation until a final (non-thunk) result is obtained.
*
* The trampoline function repeatedly invokes the deferred computations (thunks)
* in an iterative loop. This avoids deep recursive calls and prevents stack overflow,
* which is particularly useful for implementing recursion in a stack-safe manner.
*
* @template T - The type of the final result.
* @param initial - The initial Trampoline value or thunk to start execution from.
* @returns The final result of the computation (a non-thunk value).
*/
function trampoline(initial) {
let current = initial; // Start with the initial trampoline value
while ((0, exports.isTrampolineThunk)(current)) {
// Keep unwrapping while we have thunks
current = current.fn(); // Execute the deferred function to get the next step
}
return current; // Once no thunks remain, return the final result
}
/**
* Wraps a recursive function inside a trampoline executor.
*
* This function transforms a potentially recursive function (that returns a Trampoline<Result>)
* into a *stack-safe* function that executes iteratively using the `trampoline` runner.
*
* In other words, it allows you to write functions that look recursive,
* but actually run in constant stack space.
*
* @template Args - The tuple type representing the argument list of the original function.
* @template Result - The final return type after all trampoline steps are resolved.
*
* @param fn - A function that performs a single step of computation
* and returns a Trampoline (either a final value or a deferred thunk).
*
* @returns A new function with the same arguments, but which automatically
* runs the trampoline process and returns the *final result* instead
* of a Trampoline.
*
* @example
* // Example: Computing factorial in a stack-safe way
* const factorial = makeTrampoline(function fact(n: number, acc: number = 1): Trampoline<number> {
* return n === 0
* ? acc
* : makeTrampolineThunk(() => fact(n - 1, acc * n));
* });
*
* console.log(factorial(100000)); // Works without stack overflow
*/
function makeTrampoline(fn // A function that returns a trampoline step
) {
// Return a wrapped function that automatically runs the trampoline execution loop
return (...args) => trampoline(fn(...args));
}
/**
* Executes an asynchronous trampoline computation until a final (non-thunk) result is obtained.
*
* This function repeatedly invokes asynchronous deferred computations (thunks)
* in an iterative loop. Each thunk may return either a Trampoline<T> or a Promise<Trampoline<T>>.
*
* It ensures that asynchronous recursive functions can run without growing the call stack,
* making it suitable for stack-safe async recursion.
*
* @template T - The type of the final result.
* @param initial - The initial Trampoline or Promise of Trampoline to start execution from.
* @returns A Promise that resolves to the final result (a non-thunk value).
*/
function asyncTrampoline(initial) {
return __awaiter(this, void 0, void 0, function* () {
let current = yield initial; // Wait for the initial step to resolve if it's a Promise
// Keep executing thunks until we reach a non-thunk (final) value
while ((0, exports.isTrampolineThunk)(current)) {
current = yield current.fn(); // Execute the thunk function (may be async)
}
// Once the final value is reached, return it
return current;
});
}
/**
* Wraps an asynchronous recursive function inside an async trampoline executor.
*
* This helper transforms a recursive async function that returns a Trampoline<Result>
* (or Promise<Trampoline<Result>>) into a *stack-safe* async function that executes
* iteratively via the `asyncTrampoline` runner.
*
* @template Args - The tuple type representing the argument list of the original function.
* @template Result - The final return type after all async trampoline steps are resolved.
*
* @param fn - An async or sync function that performs a single step of computation
* and returns a Trampoline (either a final value or a deferred thunk).
*
* @returns An async function with the same arguments, but which automatically
* runs the trampoline process and resolves to the *final result*.
*
* @example
* // Example: Async factorial using trampoline
* const asyncFactorial = makeAsyncTrampoline(async function fact(
* n: number,
* acc: number = 1
* ): Promise<Trampoline<number>> {
* return n === 0
* ? acc
* : makeTrampolineThunk(() => fact(n - 1, acc * n));
* });
*
* asyncFactorial(100000).then(console.log); // Works without stack overflow
*/
function makeAsyncTrampoline(fn) {
// Return a wrapped async function that runs through the async trampoline loop
return (...args) => __awaiter(this, void 0, void 0, function* () {
return asyncTrampoline(fn(...args));
});
}