graceTesting.ffg

let data = [{"Name": "John Doe", "Grade": 95 }, {"Name": "Mary Jane", "Grade": 98 }, {"Name": "Alice Templeton", "Grade": 90 }]
let sum = List/fold { cons: \x y -> x + y : Natural, nil: 0 }
let len = \d -> List/length d
let introduce = \person -> "Hello, "+person."Name" + " how are you doing, you got a "

let replicate
      : forall (a : Type) . Natural -> a -> List a
      = \n -> \x -> Natural/fold n (\xs -> [ x ] + xs) []


let generate
      : forall (a : Type) . Natural -> (Natural -> a) -> List a
      = \n -> \f -> List/map (\x -> f x.index) (List/indexed (replicate n { }))
      

let divide: 
    Natural -> Natural -> Natural -> Real -> Real 
    = \x -> \y -> \s -> \i ->
    let xb = x*s
    # Get a list of numbers 0, y, 2*y, y*3, ... y*xb
    let l = generate xb (\xs -> (xs)*y) : List Natural
    # Filter list so any numbers bigger than x are 0
    let l = List/map (\v ->
        let d = v : Natural
        let ret = if Real/lessThan v xb
        then d
        else if Real/equal v xb
        then d
        else 0
        in ret 
        ) l : List Natural
    # Count numbers greater than 0
    let d = List/fold { cons: \next -> \acc -> 
        let next = next : Natural
        in if Real/equal next 0
        then acc
        else (acc + i) 
        , nil: 0 } (l)
    
    in (d)

let forceValue = merge { Some: \n -> n, None: \_ -> "" }    
    
let textFold = \t s -> 
      let last = forceValue (List/last t)
      let nmo = List/reverse (List/drop 1 (List/reverse t))
      in (List/fold {cons: \x -> \y -> x + s + y:Text, nil: last } nmo)
    
let res = List/map (\student -> introduce student) data
let res = res 
in {
  "Student Names": textFold (List/map (\student -> student."Name") data) ", ",
  "Student Total": sum (List/map (\student -> student."Grade") data),
  "Student Count": len data,
  "Student Avg": divide (sum (List/map (\student -> student."Grade" : Natural) data)) (len data) 100 0.01,
}