This side by side comparison of F# and Groovy is fully explained at http://hamletdarcy.blogspot.com/2008/07/groovy-vs-f-showdown-side-by-side.html
Versions using open classes/mixins are available here: http://hamletdarcy.blogspot.com/2008/07/awesome-new-groovy-mixin-syntax-and-fs.html



def inits = { list ->
    (0..<list.size()).collect {
        list[0..it]
    }
}

def tails = { list ->
    (0..<list.size()).collect {
        list[it..list.size()-1]
    }
}

//lose def keyword to support recursion. weird.
traverse = {isLeaf, collection ->
    if (isLeaf(collection)) return collection
    return traverse(isLeaf,
        traverse(isLeaf, collection.head()) +
        traverse(isLeaf, collection.tail()))
}

def isPrimitiveList = {
    if (!it) return true
    if (!(it instanceof Collection)) return false
    if (it.head() instanceof Collection) {
        if (it.head().head() instanceof Collection) return false
    }
    true
}

def flatten = traverse.curry(isPrimitiveList)

def segs = { list ->
    flatten(inits(list).collect { tails(it) })
}

def sum = { list ->
    list.collect { it.sum() }
}

def solve = { list -> sum(segs(list)).max() }

def numbers = [31,-41,59,26,-53,58,97,-93,-23,84]
def solution = solve(numbers)
println "Maximum Segment Sum of $numbers is $solution" 		#light       // turns off some OCaml syntax

let rec inits list  =
    let length = List.length list
    List.init length (fun i -> Seq.take (i+1) list )



let tails list =
    inits (List.rev list)




// Groovy lacks a map_concat function, which F# has
// This means Groovy required a custom flatten
// method to flatten a "list of lists of lists" to a
// "list of lists". +1 for F# having better list functions.















let segs list =
    List.map_concat (fun e -> tails e) (inits list)

  
let sum list =
    let sumElement e = List.fold_left (+) 0 e
    List.map sumElement list

let solve list = List.reduce_left (max) (sum (segs list))

let numbers = [31;-41;59;26;-53;58;97;-93;-23;84]
let solution = solve numbers
printfn "Maximum Segment Sum of %A is %d" numbers solution