Test of pseudo-monads in haxe

maybe.hx

import haxe.ds.Option;

using Test.OptionTools;

class OptionTools {
    static public function fmap<T>(m :Option<T>, f :T->T) :Option<T> {
        switch m {
          case Some(x): return Some(f(x));
          case None: return None;
        }
    }
    
    static public function afmap<T>(m :Array<Option<T>>, f :T->T) :Array<Option<T>> {
        return m.map(function(o) { return fmap(o, f); });
    }
}

class Test {
    static function main() {      
        function add3(x) {            
            return x + 3;
        }

        var val = Some(4);
        trace(val.fmap(add3));
        
        trace('---------');
        
        var vals = [Some(2), None, Some(3)];
        var res = vals.afmap(add3);
        for (v in res) trace(v);
    }
}