How to execute a MAL function in a monetdb database ?

I'm reading the MonetDB Internal Description because I'm interested to implement a special procedure direct in the MonetDB Algebra Language (MAL) instead of SQL-frontend (I hope to gain more performance by doing so). Here is a sample MAL code provide in the MonetDB documentation

function sample(nme:str, val:any_1):bit; c := 2 * 3; b := bbp.bind(nme); #find a BAT h := algebra.select(b,val,val); t := aggr.count(h); x := io.print(t); y := io.print(val); end sample; My question is how to execute such a MAL code upon one of my existing database ?

Thans for any replay