repl.txt

{{alias}}( collection, [options,] predicate, done )
    Tests whether at least one element in a collection passes a test implemented
    by a predicate function, iterating from right to left.

    When invoked, the predicate function is provided a maximum of four
    arguments:

    - value: collection value.
    - index: collection index.
    - collection: the input collection.
    - next: a callback to be invoked after processing a collection `value`.

    The actual number of provided arguments depends on function length. If the
    predicate function accepts two arguments, the predicate function is
    provided:

    - value
    - next

    If the predicate function accepts three arguments, the predicate function is
    provided:

    - value
    - index
    - next

    For every other predicate function signature, the predicate function is
    provided all four arguments.

    The `next` callback takes two arguments:

    - error: error argument.
    - result: test result.

    If a provided function calls the `next` callback with a truthy `error`
    argument, the function suspends execution and immediately calls the `done`
    callback for subsequent `error` handling.

    The function immediately returns upon encountering a non-falsy `result`
    value and calls the `done` callback with `null` as the first argument and
    `true` as the second argument.

    If all elements fail, the function calls the `done` callback with `null`
    as the first argument and `false` as the second argument.

    Execution is *not* guaranteed to be asynchronous. To guarantee asynchrony,
    wrap the `done` callback in a function which either executes at the end of
    the current stack (e.g., `nextTick`) or during a subsequent turn of the
    event loop (e.g., `setImmediate`, `setTimeout`).

    The function does not support dynamic collection resizing.

    The function does not skip `undefined` elements.

    Parameters
    ----------
    collection: Array|TypedArray|Object
        Input collection over which to iterate. If provided an object, the
        object must be array-like (excluding strings and functions).

    options: Object (optional)
        Function options.

    options.limit: integer (optional)
        Maximum number of pending invocations. Default: Infinity.

    options.series: boolean (optional)
        Boolean indicating whether to process each collection element
        sequentially. Default: false.

    options.thisArg: any (optional)
        Execution context.

    predicate: Function
        The test function to invoke for each element in a collection.

    done: Function
        A callback invoked either upon processing all collection elements or
        upon encountering an error.

    Examples
    --------
    // Basic usage:
    > function predicate( value, next ) {
    ...     setTimeout( onTimeout, value );
    ...     function onTimeout() {
    ...         console.log( value );
    ...         next( null, false );
    ...     }
    ... };
    > function done( error, bool ) {
    ...     if ( error ) {
    ...         throw error;
    ...     }
    ...     console.log( bool );
    ... };
    > var arr = [ 1000, 2500, 3000 ];
    > {{alias}}( arr, predicate, done )
    1000
    2500
    3000
    false

    // Limit number of concurrent invocations:
    > function predicate( value, next ) {
    ...     setTimeout( onTimeout, value );
    ...     function onTimeout() {
    ...         console.log( value );
    ...         next( null, false );
    ...     }
    ... };
    > function done( error, bool ) {
    ...     if ( error ) {
    ...         throw error;
    ...     }
    ...     console.log( bool );
    ... };
    > var opts = { 'limit': 2 };
    > var arr = [ 1000, 2500, 3000 ];
    > {{alias}}( arr, opts, predicate, done )
    2500
    3000
    1000
    false

    // Process sequentially:
    > function predicate( value, next ) {
    ...     setTimeout( onTimeout, value );
    ...     function onTimeout() {
    ...         console.log( value );
    ...         next( null, false );
    ...     }
    ... };
    > function done( error, bool ) {
    ...     if ( error ) {
    ...         throw error;
    ...     }
    ...     console.log( bool );
    ... };
    > var opts = { 'series': true };
    > var arr = [ 1000, 2500, 3000 ];
    > {{alias}}( arr, opts, predicate, done )
    3000
    2500
    1000
    false


{{alias}}.factory( [options,] predicate )
    Returns a function which tests whether at least one element in a collection
    passes a test implemented by a predicate function, iterating from right to
    left.

    Parameters
    ----------
    options: Object (optional)
        Function options.

    options.limit: integer (optional)
        Maximum number of pending invocations. Default: Infinity.

    options.series: boolean (optional)
        Boolean indicating whether to process each collection element
        sequentially. Default: false.

    options.thisArg: any (optional)
        Execution context.

    predicate: Function
        The test function to invoke for each element in a collection.

    Returns
    -------
    out: Function
        A function which tests each element in a collection.

    Examples
    --------
    > function predicate( value, next ) {
    ...     setTimeout( onTimeout, value );
    ...     function onTimeout() {
    ...         console.log( value );
    ...         next( null, false );
    ...     }
    ... };
    > var opts = { 'series': true };
    > var f = {{alias}}.factory( opts, predicate );
    > function done( error, bool ) {
    ...     if ( error ) {
    ...         throw error;
    ...     }
    ...     console.log( bool );
    ... };
    > var arr = [ 1000, 2500, 3000 ];
    > f( arr, done )
    3000
    2500
    1000
    false
    > arr = [ 1000, 1500, 2000 ];
    > f( arr, done )
    2000
    1500
    1000
    false

    See Also
    --------