Van: Rob Stapper [mailto:r.stapper@lijbrandt.nl]
Verzonden: donderdag 16 juli 2015 8:48
Aan: 'Graydon Saunders'
Onderwerp: RE: [basex-talk] Union of maps?

Hoi Graydon,

Here’s one of my map-extensions. This one I use for merging maps.

It’s also an example of how to create your own high-order-functions.

Hopes is it helps.

Cheers,

Rob Stapper

declare function ext.map:merge

( $sourceMap as map(*)

, $targetMap as map(*)

, $updateFunction as function(*)

) as map(*)

{

fold-left( map:keys( $sourceMap)

, $targetMap

, function( $targetMap

, $key

)

{

map:put( $targetMap

, $key

, $updateFunction( map:get( $sourceMap, $key)

, map:get( $targetMap, $key)

)

}

)

} ;

Van: basex-talk-bounces@mailman.uni-konstanz.de [mailto:basex-talk-bounces@mailman.uni-konstanz.de] Namens Graydon Saunders
Verzonden: woensdag 15 juli 2015 20:01
Aan: BaseX
Onderwerp: [basex-talk] Union of maps?

Hi --

In BaseX 8.2.1, I have a bunch of maps; the maps may have some overlap of key values. I would like to merge/find the union of all of these maps while retaining all the values associated with each key in the resulting map-of-all-maps. (Combined map? Any word can be wrong, here! :)

map:merge() doesn't do this; http://docs.basex.org/wiki/Map_Module#map:merge says

"The associated value for each such key is taken from the last map in the input sequence $input that contains an entry with this key." and testing confirms this.

Is there a straightforward way to do this that I'm missing?

Thanks!

Graydon