**(datanames: // [[harlowe:Datamap|datamap]]//) -> //[[harlowe:Array|array]]//**

This takes a [[harlowe:datamap|datamap]], and returns a sorted [[harlowe:array|array]] of its data names, sorted
alphabetically.

=== Example usage: ===

''%%(datanames: (dm:'B','Y', 'A','X'))%%'' produces the array ''%%(a: 'A','B')%%''

=== Rationale: ===

Sometimes, you may wish to obtain some information about a datamap. You may want
to list all of its data names, or determine how many entries it has. You can use
the (datanames:) macro to do these things: if you give it a datamap, it produces
a sorted array of all of its names. You can then [[harlowe:print|(print:)]] them, check the length
of the array, obtain a subarray, and other things you can do to arrays.

=== See also: ===

[[harlowe:datavalues|(datavalues:)]], [[harlowe:dataentries|(dataentries:)]]