Pseudo code is easily converted to Zorro Code. For Haikin Ashi:

Close = (Open+High+Low+Close)/4
Open = [Open (previous bar) + Close (previous bar)]/2
High = Max (High,Open,Close)
Low = Min (Low,Open, Close)

==>

vars Close = series((priceOpen()+priceHigh()+priceLow()+priceClose())/4);
vars Open = series((priceOpen(1)+priceClose(1))/2);
vars High = series(max(priceHigh(),max(priceOpen(),priceClose())));
vars Low = series(min(priceLow(),min(priceOpen(),priceClose())));

Only take care to count correctly the number of brackets.