{{alias}}
    Returns a regular expression to capture a POSIX filename extension.

    When executed against dotfile filenames (e.g., `.gitignore`), the regular
    expression does not capture the basename as a filename extension.

    Returns
    -------
    re: RegExp
        Regular expression.

    Examples
    --------
    > var RE = {{alias}}();
    > var ext = RE.exec( '/foo/bar/index.js' )[ 1 ]
    '.js'
    > ext = RE.exec( './foo/bar/.gitignore' )[ 1 ]
    ''
    > ext = RE.exec( 'foo/file.pdf' )[ 1 ]
    '.pdf'
    > ext = RE.exec( '/foo/bar/file' )[ 1 ]
    ''
    > ext = RE.exec( 'index.js' )[ 1 ]
    '.js'
    > ext = RE.exec( '.' )[ 1 ]
    ''
    > ext = RE.exec( './' )[ 1 ]
    ''
    > ext = RE.exec( '' )[ 1 ]
    ''


{{alias}}.REGEXP
    Regular expression to capture a POSIX filename extension.

    Examples
    --------
    > var ext = {{alias}}.REGEXP.exec( '/foo/bar/index.js' )[ 1 ]
    '.js'

    See Also
    --------