function curry( fcn, arity, thisArg ) {
	var context;
	var len;
	if ( !isFunction( fcn ) ) {
		throw new TypeError( format( 'invalid argument. First argument must be a function. Value: `%s`.', fcn ) );
	}
	if ( arguments.length < 2 ) {
		len = fcn.length;
		if ( !isPositiveInteger( len ) ) {
			throw new TypeError( format( 'invalid argument. First argument must be a function having at least one parameter. Value: `%s`.', len ) );
		}
	} else if ( arguments.length > 2 ) {
		len = arity;
		context = thisArg;
		if ( !isPositiveInteger( len ) ) {
			throw new TypeError( format( 'invalid argument. Arity argument must be a positive integer. Value: `%s`.', len ) );
		}
	} else if ( isPositiveInteger( arity ) ) {
		len = arity;
	} else {
		len = fcn.length;
		if ( !isPositiveInteger( len ) ) {
			throw new TypeError( format( 'invalid argument. First argument must be a function having at least one parameter. Value: `%s`.', len ) );
		}
		context = arity;
	}
	return createCurried( [] );

	/**
	* Returns a curry function.
	*
	* @private
	* @param {Array} args - arguments
	* @returns {Function} curry function
	*/
	function createCurried( args ) {
		return curried;

		/**
		* Curry function.
		*
		* @private
		* @param {*} v - curried function parameter
		* @returns {(Function|*)} partially applied curry function or curried function result
		*/
		function curried( v ) {
			var cargs = args.slice();
			cargs.push( v );
			if ( cargs.length < len ) {
				return createCurried( cargs );
			}
			return fcn.apply( context, cargs );
		}
	}
}
Transforms a function into a sequence of functions each accepting a single argument.

@param {Function} fcn - function to curry
@param {PositiveInteger} [arity=fcn.length] - number of parameters
@param {*} [thisArg] - evaluation context
@throws {TypeError} first argument must be a function
@throws {TypeError} first argument must be a function having at least one parameter
@throws {TypeError} `arity` argument must be a positive integer
@returns {Function} curry function

@example
function add( x, y ) {
    return x + y;
}

var f = curry( add );

var sum = f( 2 )( 3 );
// returns 5