Array functions

An array is an ordered group of values. These values are stored in an Array, or in a Page which is an object that contains an array as one of its elements. When page’s are passed to an array function, only the array element of the page is examined or transformed. Other elements of the page are passed directly through to the output.

`Append`	Adds items to end of array.
`Drop`	Removes items from start of array.
`Filter`	Fetches specific items from array.
`Foreach`	Iterates over array items.
`IsEmpty`	Tests whether array is empty.
`IsNonEmpty`	Tests whether an array contains items.
`Map`	Applies a function to all array items.
`Prepend`	Adds items to start of array.
`Take`	Fetches items from start of array.