functions in data.tree yaml.R

library(data.tree)
library(yaml)


yaml <- "
node1:
  value: 2
  fnct: >
    function(x) {
      2 * x
    }
node2:
  value: 6
  # can be named if you prefer, though that will have no impact
  fnct: >
    DoCalculate <- function(node) {
      node$value * 2
    }

"


lol <- yaml.load(yaml)
tree <- as.Node(lol)


evaluator <- function(node) node$fnct <- eval(parse(text = node$fnct))

tree$Do(fun = evaluator, 
        filterFun = function(node) !is.null(node$fnct))



tree$node1$fnct(5)
tree$node2$fnct(tree$node2)


# if you want to reference an enclosing node from within your function, you can define the functions
# having a node argument, and do a slightly more complex evaluator function. e.g.

yaml <- "
node1:
  value: 2
  fnct: >
    function(node) {
      2 * node$value
    }
node2:
  value: 5
  fnct: >
    function(node) {
      node$value ^ 2 
    }

"


lol <- yaml.load(yaml)
tree <- as.Node(lol)

evaluator <- function(node) {
  f <- eval(parse(text = node$fnct))
  # warp the function and call using node
  f2 <- function() {
    f(node)
  }
  node$fnct <- f2
}


tree$Do(fun = evaluator, 
        filterFun = function(node) !is.null(node$fnct))



tree$node1$fnct()
tree$node2$fnct()


Aggregate(tree, "fnct", sum)