noWin.fs

(*
6.9
A company consists of departments with sub-departments,
which again can have sub-departments and so on.
(The company can also be considered as a department.)

1.  Assume that each department has a name and a (possibly)
    empty list of sub-departments Declare and F# type Department.
2   Extend this type so that each department has its own gross income.
3.  Declare a function to extract a list of pairs
    (Department name, gross income), for all departments.
4.  Declare a function to extract the total income for a given department
    by adding up its gross income, including the income of its sub-departments.
5.  Declare a function to extract a list of pairs
    (Department name, total income) for all departments.
6.  Declare a function format of type Department -> string, which can be used
    to get a textual form of a department such that names of sub-departments
    will occur suitably indented (e.g., with four spaces) on separate lines.
    (use printf to print out the results.
    Do not use printf in the declaration of format.)

*)
//1.1
type DepartmentName = String
type GrossIncome = Integer
type Department = Dep of DepartmentName * Department List * GrossIncome
//1.2 extension type Department with GrossIncome

//1.3 -> map(DepartmentName*GrossIncome)

let rec extractPairsAndGross :Department -> (DepartmentName*GrossIncome) List = function
    |(dName,dList,dGI):Department -> (dName,dGI)::List.foldBack(fun x list -> extractPairsAndGross(x)@list) dList []

//1.4
let rec totalIncome = function
    |(_,[],dGI)         -> dGI //muligvis ligegyldig?
    |(dName,dList,dGI)  -> List.foldBack(fun x list -> totalIncome(x) + list) dList []

//1.5
let rec extractPairsAndTotal = function
    |(dName,dList,dGI):Department    -> (dName,totalIncome((dName,dList,dGI)))::List.foldBack(fun x list -> extractPairsAndTotal(x)@list) dList []

//1.6
let sysout :Department -> string = function
    |(dName,dList,_)    -> printf(dName) //fuck ..