Please update the code to reflect the latest version of lambda.r:
```
map(x, fn, y) %::% . : Function : . : .
map(EMPTY, fn, y) %as% y

map(x, fn, y=c()) %when% { 
    is.null(dim(x)) 
} %as% {
  map(x[-1], fn, c(y, fn(x[[1]])))
}

map(x, fn, y=c()) %as% {
  map(x[,-1,drop=FALSE], fn, c(y, fn(x[,1])))
}
```