Combining arrays

[springcomp]

The current specification does not have an easy way to create an array that contains all entries from a set of arrays.
Consider the following scenario:

{
 "foo": ["bar", "baz"],
 "boo": ["one", "two"]
}

How do we return the result of concatenating foo and boo ?

One answer is to use the join and split functions like so:

split( join(',', [ join(',', foo), join(',', foo) ]), ',')

This returns:

[ "bar", "baz", "one", "two" ]

The idea would be to overload the merge function which already exists for objects and have it operate on arrays as well.

Specification

merge

object merge([object *argument, [, object $…]])

Accepts zero or more objects and returns a single object with all key/value pairs merged. The function is used to combine multiple objects into one. You can think of as the function using the first object argument as a base object, to which all key/value pairs from subsequent object arguments are merged, one after the other.

array merge([array *argument, [, array $…]])

Accepts zero or more arrays and returns a single array with all entries combined. The function is used to combine multiple arrays into one.

Examples

Given	Expression	Result
n/a	merge()	ex
n/a	merge(`{ }`)	{}
n/a	merge([ ])	[]
{ "foo": ["bar", "baz"], "boo": ["one", "two"] }	merge(foo, boo)	[ "bar", "baz", "one", "two" ]

[springcomp]

The flatten-expression [] is also able to natively concatenate array items.

[foo, boo][] -> [ "bar", "baz", "one", "two" ]