lodash.d.ts

// https://raw.githubusercontent.com/donnut/typescript-ramda/master/ramda.d.ts
// https://raw.githubusercontent.com/DefinitelyTyped/DefinitelyTyped/master/lodash/lodash.d.ts

declare namespace fp {

	interface Dictionary<T> {
		[index: string]: T;
	}

	interface CurriedFunction1<T1, R> {
		(): CurriedFunction1<T1, R>;
		(t1: T1): R;
	}

	interface CurriedFunction2<T1, T2, R> {
		(): CurriedFunction2<T1, T2, R>;
		(t1: T1): CurriedFunction1<T2, R>;
		(t1: T1, t2: T2): R;
	}

	interface CurriedFunction3<T1, T2, T3, R> {
		(): CurriedFunction3<T1, T2, T3, R>;
		(t1: T1): CurriedFunction2<T2, T3, R>;
		(t1: T1, t2: T2): CurriedFunction1<T3, R>;
		(t1: T1, t2: T2, t3: T3): R;
	}

	interface CurriedFunction4<T1, T2, T3, T4, R> {
		(): CurriedFunction4<T1, T2, T3, T4, R>;
		(t1: T1): CurriedFunction3<T2, T3, T4, R>;
		(t1: T1, t2: T2): CurriedFunction2<T3, T4, R>;
		(t1: T1, t2: T2, t3: T3): CurriedFunction1<T4, R>;
		(t1: T1, t2: T2, t3: T3, t4: T4): R;
	}

	interface CurriedFunction5<T1, T2, T3, T4, T5, R> {
		(): CurriedFunction5<T1, T2, T3, T4, T5, R>;
		(t1: T1): CurriedFunction4<T2, T3, T4, T5, R>;
		(t1: T1, t2: T2): CurriedFunction3<T3, T4, T5, R>;
		(t1: T1, t2: T2, t3: T3): CurriedFunction2<T4, T5, R>;
		(t1: T1, t2: T2, t3: T3, t4: T4): CurriedFunction1<T5, R>;
		(t1: T1, t2: T2, t3: T3, t4: T4, t5: T5): R;
	}

	interface ListIterator<T, TResult> {
		(value: T, index: number, collection: List<T>): TResult;
	}

	// Common interface between Arrays and jQuery objects
	interface List<T> {
		[index: number]: T;
		length: number;
	}

	interface Static {

		/**
		 * Creates an array of elements corresponding to the given keys, or indexes, of collection. Keys may be
		 * specified as individual arguments or as arrays of keys.
		 *
		 * @param props The property names or indexes of elements to pick, specified individually or in arrays.
		 * @param collection The collection to iterate over.
		 * @return Returns the new array of picked elements.
		 */
		at<T>(props: (number | string | (number | string)[])[]): (collection: List<T>) => T[];

		/**
		 * Returns a curried equivalent of the provided function, with the specified arity. The curried function has
		 * two unusual capabilities. First, its arguments needn't be provided one at a time.
		 */
		curryN(length: number, fn: (...args: any[]) => any): Function;

		/**
		 * Returns a curried equivalent of the provided function. The curried function has two unusual capabilities.
		 * First, its arguments needn't be provided one at a time.
		 */
		curry<T1, T2, TResult>(fn: (a: T1, b: T2) => TResult): CurriedFunction2<T1, T2, TResult>
		curry<T1, T2, T3, TResult>(fn: (a: T1, b: T2, c: T3) => TResult): CurriedFunction3<T1, T2, T3, TResult>
		curry<T1, T2, T3, T4, TResult>(
			fn: (
				a: T1, b: T2, c: T3,
				d: T4
			) => TResult
		): CurriedFunction4<T1, T2, T3, T4, TResult>
		curry<T1, T2, T3, T4, T5, TResult>(
			fn: (
				a: T1, b: T2, c: T3, d: T4,
				e: T5
			) => TResult
		): CurriedFunction5<T1, T2, T3, T4, T5, TResult>
		curry(fn: Function): Function

		/**
		 * Creates a function that returns value.
		 *
		 * @param value The value to return from the new function.
		 * @return Returns the new function.
		 */
		constant<T>(value: T): () => T;

		/**
		 * A no-operation function that returns undefined regardless of the arguments it receives.
		 *
		 * @return undefined
		 */
		noop(...args: any[]): void;

		/**
		 * Creates a function that invokes the method at path on a given object. Any additional arguments are provided
		 * to the invoked method.
		 *
		 * @param path The path of the method to invoke.
		 * @param args The arguments to invoke the method with.
		 * @return Returns the new function.
		 */
		method<TObject, TResult>(path: string, ...args: any[]): (object: TObject) => TResult;

		/**
		 * Creates an object composed of the picked `object` properties.
		 *
		 * @static
		 * @memberOf _
		 * @category Object
		 * @param {...(string|string[])} [props] The property names to pick, specified
		 *  individually or in arrays.
		 * @param {Object} object The source object.
		 * @returns {Object} Returns the new object.
		 */
		pick<TResult extends {}, T extends {}>(predicate: string[], object: T): TResult;
		pick<TResult extends {}, T extends {}>(predicate: string[]): (object: T) => TResult;

		/**
		 * Checks if `value` is `null` or `undefined`.
		 *
		 * @static
		 * @memberOf _
		 * @category Lang
		 * @param {*} value The value to check.
		 * @returns {boolean} Returns `true` if `value` is nullish, else `false`.
		 */
		isNil(value?: any): boolean;

		pluck(val: string): Function;

		/**
		 * Creates a function that memoizes the result of func. If resolver is provided it determines the cache key for
		 * storing the result based on the arguments provided to the memoized function. By default, the first argument
		 * provided to the memoized function is coerced to a string and used as the cache key. The func is invoked with
		 * the this binding of the memoized function.
		 *
		 * @param func The function to have its output memoized.
		 * @return Returns the new memoizing function.
		 */
		memoize(func: Function);

		/**
		 * Creates an object composed of keys generated from the results of running each element of collection through
		 * iteratee. The corresponding value of each key is the last element responsible for generating the key. The
		 * iteratee function is bound to thisArg and invoked with three arguments:
		 * (value, index|key, collection).
		 *
		 * If a property name is provided for iteratee the created _.property style callback returns the property
		 * value of the given element.
		 *
		 * If a value is also provided for thisArg the created _.matchesProperty style callback returns true for
		 * elements that have a matching property value, else false.
		 *
		 * If an object is provided for iteratee the created _.matches style callback returns true for elements that
		 * have the properties of the given object, else false.
		 *
		 * @param term
		 * @param collection The collection to iterate over.
		 * @return Returns the composed aggregate object.
		 */
		keyBy<T>(termn: string): (collection: List<T>) => T;
		keyBy<T>(termn: string, collection: List<T>): T;

		/**
		 * Gets the first element of array.
		 *
		 * @alias _.first
		 *
		 * @param array The array to query.
		 * @return Returns the first element of array.
		 */
		head<T>(array: List<T>): T;

		flatten();

		/**
		 * Iterates over elements of collection, returning the first element predicate returns truthy for.
		 * The predicate is bound to thisArg and invoked with three arguments: (value, index|key, collection).
		 *
		 * If a property name is provided for predicate the created _.property style callback returns the property
		 * value of the given element.
		 *
		 * If a value is also provided for thisArg the created _.matchesProperty style callback returns true for
		 * elements that have a matching property value, else false.
		 *
		 * If an object is provided for predicate the created _.matches style callback returns true for elements that
		 * have the properties of the given object, else false.
		 *
		 * @param predicate The function invoked per iteration.
		 * @param collection The collection to search.
		 * @return Returns the matched element, else undefined.
		 */
		find<T>(predicate: ListIterator<T, boolean>, collection: List<T>): T;
		find<T>(predicate: ListIterator<T, boolean>): (collection: List<T>) => T;

		/**
		 * @see fp.find
		 */
		find<TObject extends {}, T>(predicate: TObject, collection: List<T>): T;
		find<TObject extends {}, T>(predicate: TObject): (collection: List<T>) => T;

		/**
		 * Creates a function that returns the property value at path on a given object.
		 *
		 * @param path The path of the property to get.
		 * @return Returns the new function.
		 */
		property<TObj, TResult>(path: string): (obj: TObj) => TResult;

		/**
		 * Creates an array of the own enumerable property values of object.
		 *
		 * @param object The object to query.
		 * @return Returns an array of property values.
		 */
		values<T>(object?: any): T[];

		/**
		 * @see _.values
		 */

		/**
		 * Creates a debounced function that delays invoking func until after wait milliseconds have elapsed since
		 * the last time the debounced function was invoked. The debounced function comes with a cancel method to
		 * cancel delayed invocations and a flush method to immediately invoke them. Provide an options object to
		 * indicate that func should be invoked on the leading and/or trailing edge of the wait timeout. Subsequent
		 * calls to the debounced function return the result of the last func invocation.
		 *
		 * Note: If leading and trailing options are true, func is invoked on the trailing edge of the timeout only
		 * if the the debounced function is invoked more than once during the wait timeout.
		 *
		 * See David Corbacho’s article for details over the differences between _.debounce and _.throttle.
		 *
		 * @param func The function to debounce.
		 * @param wait The number of milliseconds to delay.
		 * @return Returns the new debounced function.
		 */
		debounce<T extends Function>(wait: number, func: T): T;

		/**
		 * Creates an object composed of keys generated from the results of running each element of collection through
		 * iteratee. The corresponding value of each key is an array of the elements responsible for generating the
		 * key. The iteratee is bound to thisArg and invoked with three arguments:
		 * (value, index|key, collection).
		 *
		 * If a property name is provided for iteratee the created _.property style callback returns the property
		 * value of the given element.
		 *
		 * If a value is also provided for thisArg the created _.matchesProperty style callback returns true for
		 * elements that have a matching property value, else false.
		 *
		 * If an object is provided for iteratee the created _.matches style callback returns true for elements that
		 * have the properties of the given object, else false.
		 *
		 * @param collection The collection to iterate over.
		 * @param iteratee The function invoked per iteration.
		 * @param thisArg The this binding of iteratee.
		 * @return Returns the composed aggregate object.
		 */
		groupBy<T, TKey>(term: string): (collection: List<T>) => T[];

		/**
		 * Checks if `path` is a direct property of `object`.
		 *
		 * @static
		 * @memberOf _
		 * @category Object
		 * @param {Array|string} path The path to check.
		 * @param {Object} object The object to query.
		 * @returns {boolean} Returns `true` if `path` exists, else `false`.
		 */
		has<T extends {}>(path: string, object: T): boolean;
		has<T extends {}>(path: string): (object: T) => boolean;

		/**
		 * Creates an array of the own enumerable property values of object.
		 *
		 * @param object The object to query.
		 * @return Returns an array of property values.
		 */
		values<T>(object?: Object): T[];

		/**
		 * Gets the property value at path of object. If the resolved value is undefined the defaultValue is used
		 * in its place.
		 *
		 * @param path The path of the property to get.
		 * @param object The object to query.
		 * @return Returns the resolved value.
		 */
		get<TObject, TResult>(path: string, object: TObject): TResult;

		/**
		 * @see fp.get
		 */
		get<TResult>(path: string, object: any): TResult;

		/**
		 * @see fp.get
		 */
		get<TResult>(path: string): (object: any) => TResult;

		get<TResult>(path: string[]): (object: any) => TResult;

		getOr<TObject>(fallback: TObject, path: string): (object: any) => TObject;
		getOr<TObject>(fallback: TObject, path: string, object: any): TObject;

		/**
		 * @see fp.method
		 */
		method<TResult>(path: string, ...args: any[]): (object: any) => TResult;

		/**
		 * Returns true if the first parameter is less than the second.
		 */
		lt(a: number, b: number): boolean;
		lt(a: number): (b: number) => boolean;

		/**
		 * Returns a function, fn, which encapsulates if/else-if/else logic. R.cond takes a list of [predicate, transform] pairs.
		 * All of the arguments to fn are applied to each of the predicates in turn until one returns a "truthy" value, at which
		 * point fn returns the result of applying its arguments to the corresponding transformer. If none of the predicates
		 * matches, fn returns undefined.
		 */
		cond(fns: [any, any][]): Function;

		/**
		 * Returns true if its arguments are equivalent, false otherwise. Dispatches to an equals method if present.
		 * Handles cyclical data structures.
		 */
		eq<T>(a: T, b: T): boolean;
		eq<T>(a: T): (b: T) => boolean;

		/**
		 * Returns true if the first parameter is greater than the second.
		 */
		gt(a: number, b: number): boolean;
		gt(a: number): (b: number) => boolean;

		/**
		 * Accepts as its arguments a function and any number of values and returns a function that,
		 * when invoked, calls the original function with all of the values prepended to the
		 * original function's arguments list. In some libraries this function is named `applyLeft`.
		 */
		partial(fn: Function, ...args: any[]): () => {};
		partial(fn: Function): (...args: any[]) => () => {};

		/**
		 * Checks if predicate returns truthy for any element of collection. Iteration is stopped once predicate
		 * returns truthy. The predicate is invoked with three arguments: (value, index|key, collection).
		 *
		 * @param predicate The function invoked per iteration.
		 * @param collection The collection to iterate over.
		 * @return Returns true if any element passes the predicate check, else false.
		 */
		some<T>(predicate: ListIterator<T, boolean>, collection: List<T>): boolean;
		some<T>(predicate: ListIterator<T, boolean>): (collection: List<T>) => boolean;

		/**
		 * Creates a function that returns the result of invoking the provided functions with the this binding of the
		 * created function, where each successive invocation is supplied the return value of the previous.
		 *
		 * @param funcs Functions to invoke.
		 * @return Returns the new function.
		 */
		flow<TResult extends Function>(...funcs: Function[]): TResult;

		/**
		 * Sets the value at path of object. If a portion of path doesn’t exist it’s created. Arrays are created for
		 * missing index properties while objects are created for all other missing properties. Use _.setWith to
		 * customize path creation.
		 *
		 * @param path The path of the property to set.
		 * @param value The value to set.
		 * @param object The object to modify.
		 * @return Returns object.
		 */
		set(path: string, value: any, object: Object);

		/**
		 * This method invokes interceptor and returns value. The interceptor is bound to thisArg and invoked with one
		 * argument; (value). The purpose of this method is to "tap into" a method chain in order to perform operations
		 * on intermediate results within the chain.
		 *
		 * @param interceptor The function to invoke.
		 * @param value The value to provide to interceptor.
		 * @return Returns value.
		 **/
		tap<T>(interceptor: (value: T) => void, value: T): T;
		tap<T>(interceptor: (value: T) => void): (value: T) => T;

		/**
		 * Returns a new list, constructed by applying the supplied function to every element of the supplied list.
		 */
		map<T, U>(fn: Function, list: T[]): U[];
		map<T, U>(fn: Function, obj: U): U;
		map<T, U>(fn: Function): (list: T[]) => U[];

		/**
		 * Returns a new list containing only one copy of each element in the original list, based upon
		 * the value returned by applying the supplied function to each list element. Prefers the first
		 * item if the supplied function produces the same value on two items. R.equals is used for comparison.
		 */
		uniqBy<T, U>(fn: (a: T) => U, list: T[]): T[];
		uniqBy<T, U>(fn: (a: T) => U): (list: T[]) => T[];
		uniqBy<T, U>(identity: string, list: T[]): T[];
		uniqBy<T, U>(identity: string): (list: T[]) => T[];

		/**
		 * Returns `true` if the specified item is somewhere in the list, `false` otherwise.
		 * Equivalent to `indexOf(a)(list) > -1`. Uses strict (`===`) equality checking.
		 */
		includes<T>(value: T, collection: T | T[]): boolean;
		includes<T>(value: T): (collection: T | T[]) => boolean;

		/**
		 * Returns a new list containing only those items that match a given predicate function. The
		 * predicate function is passed one argument: (value).
		 */
		filter(fn: (value) => boolean): (list) => any;
		filter(fn: (value) => boolean, list): any;
		filter(predicate: string): (collection: string) => string[];
		filter<W extends {}, T>(predicate: W): (collection: List<T>) => T[];

		/**
		 * A special placeholder value used to specify "gaps" within curried functions, allowing partial
		 * application of any combination of arguments, regardless of their positions.
		 */
		placeholder: any;

		/**
		 * Turns a named method of an object (or object prototype) into a function that can be
		 * called directly. Passing the optional `len` parameter restricts the returned function to
		 * the initial `len` parameters of the method.
		 *
		 * The returned function is curried and accepts `len + 1` parameters (or `method.length + 1`
		 * when `len` is not specified), and the final parameter is the target object.
		 */
		invokeArgs(name: string, obj: any, len?: number): () => {};
		invokeArgs(name: string): (obj: any, len?: number) => () => {};

		/**
        * Invokes the method at path of object.
        * @param object The object to query.
        * @param path The path of the method to invoke.
        * @param args The arguments to invoke the method with.
        **/
		invoke<TObject extends Object, TResult>(path: string): (object: TObject) => TResult;

		/**
		 * Returns true if its arguments are equivalent, false otherwise. Dispatches to an equals method if present.
		 * Handles cyclical data structures.
		 */
		isEqual<T>(a: T, b: T): boolean;
		isEqual<T>(a: T): (b: T) => boolean;

		/*
		 * A function that always returns true. Any passed in parameters are ignored.
		 */
		stubTrue(): boolean;

		/**
		 * Creates an array of elements, sorted in ascending order by the results of
		 * running each element in a collection through each iteratee. This method
		 * performs a stable sort, that is, it preserves the original sort order of
		 * equal elements. The iteratees are invoked with one argument: (value).
		 *
		 * @static
		 * @memberOf _
		 * @category Collection
		 * @param {Array|Object} collection The collection to iterate over.
		 * @param {...(Function|Function[]|Object|Object[]|string|string[])} [iteratees=[_.identity]]
		 *  The iteratees to sort by, specified individually or in arrays.
		 * @returns {Array} Returns the new sorted array.
		 * @example
		 *
		 * var users = [
		 *   { 'user': 'fred',   'age': 48 },
		 *   { 'user': 'barney', 'age': 36 },
		 *   { 'user': 'fred',   'age': 42 },
		 *   { 'user': 'barney', 'age': 34 }
		 * ];
		 *
		 * _.sortBy(users, function(o) { return o.user; });
		 * // => objects for [['barney', 36], ['barney', 34], ['fred', 48], ['fred', 42]]
		 *
		 * _.sortBy(users, ['user', 'age']);
		 * // => objects for [['barney', 34], ['barney', 36], ['fred', 42], ['fred', 48]]
		 *
		 * _.sortBy(users, 'user', function(o) {
         *   return Math.floor(o.age / 10);
         * });
		 * // => objects for [['barney', 36], ['barney', 34], ['fred', 48], ['fred', 42]]
		 */
		sortBy<T, TSort>(collection: List<T>, iteratee?: ListIterator<T, TSort>): T[];

		/**
		 * An alternative to _.reduce; this method transforms object to a new accumulator object which is the result of
		 * running each of its own enumerable properties through iteratee, with each invocation potentially mutating
		 * the accumulator object. The iteratee is bound to thisArg and invoked with four arguments: (accumulator,
		 * value, key, object). Iteratee functions may exit iteration early by explicitly returning false.
		 *
		 * @param iteratee The function invoked per iteration.
		 * @param object The object to iterate over.
		 * @param accumulator The custom accumulator value.
		 * @param thisArg The this binding of iteratee.
		 * @return Returns the accumulated value.
		 */
		transform<T, TResult>(iteratee: T, accumulator: any): (object: T[]) => TResult[];

		/**
		 * Checks if value is classified as an Array object.
		 * @param value The value to check.
		 *
		 * @return Returns true if value is correctly classified, else false.
		 */
		isArray<T>(value?: any): value is T[];

		/**
		 * Removes all elements from array that predicate returns truthy for and returns an array of the removed
		 * elements. The predicate is bound to thisArg and invoked with three arguments: (value, index, array).
		 *
		 * If a property name is provided for predicate the created _.property style callback returns the property
		 * value of the given element.
		 *
		 * If a value is also provided for thisArg the created _.matchesProperty style callback returns true for
		 * elements that have a matching property value, else false.
		 *
		 * If an object is provided for predicate the created _.matches style callback returns true for elements that
		 * have the properties of the given object, else false.
		 *
		 * Note: Unlike _.filter, this method mutates array.
		 *
		 * @param predicate The function invoked per iteration.
		 * @return Returns the new array of removed elements.
		 */
		remove<T>(predicate: Function|Object): (array: List<T>) => T[];

		/**
		 * Removes all provided values from array using SameValueZero for equality comparisons.
		 *
		 * Note: Unlike _.without, this method mutates array.
		 *
		 * @param array The array to modify.
		 * @param values The values to remove.
		 * @return Returns array.
		 */
		pull<T>(array: T[], ...values: T[]): T[];

		/**
		 * @see _.pull
		 */
		pull<T>(array: List<T>, ...values: T[]): List<T>;

		keys(arg: any);

		range(min: number, max: number): number;

		/**
		 * Recursively flattens a nested array.
		 *
		 * @param array The array to recursively flatten.
		 * @return Returns the new flattened array.
		 */
		flattenDeep<T>(array: T): T[];

		/**
		 * Creates an array of elements split into groups the length of size. If collection can’t be split evenly, the
		 * final chunk will be the remaining elements.
		 *
		 * @param size The length of each chunk.
		 * @param array The array to process.
		 * @return Returns the new array containing chunks.
		 */
		chunk<T>(size: number, array: List<T>): T[][];
		chunk<T>(size: number): (array: List<T>) => T[][];

		/**
		 * The opposite of _.mapValues; this method creates an object with the same values as object and keys generated
		 * by running each own enumerable property of object through iteratee.
		 *
		 * @param iteratee The function invoked per iteration.
		 * @param object The object to iterate over.
		 * @return Returns the new mapped object.
		 */
		mapKeys<T>(iteratee, object): Dictionary<T>;
		mapKeys<T>(iteratee): (object) => Dictionary<T>;

		/**
		 * Checks if value is empty. A value is considered empty unless it’s an arguments object, array, string, or
		 * jQuery-like collection with a length greater than 0 or an object with own enumerable properties.
		 *
		 * @param value The value to inspect.
		 * @return Returns true if value is empty, else false.
		 */
		isEmpty(value?: any): boolean;
	}
}

declare var fp: fp.Static;
declare module "lodash/fp" {
	export = fp;
}