add more things???

Stackulator.fs

@@ -0,0 +1,100 @@
+open System
+open System.Numerics
+
+type Stack = StackContents of Complex list
+
+let splitPart (what:char) index (stringIn:string) = stringIn.Split(what).[index]
+let spliti = splitPart 'i'
+let firstInSpliti = spliti 0
+let secondInSpliti = spliti 1
+let isDoubleAsString text = System.Double.TryParse text |> fst
+let doubleFromString text = System.Double.TryParse text |> snd
+let isImaginaryAsString (text:string) =
+  match text.Contains("i") with
+  | false -> false
+  | true ->
+    let normalPart = firstInSpliti text
+    isDoubleAsString normalPart
+let imaginaryFromString text =
+  let imaginaryPart = doubleFromString (firstInSpliti text)
+  Complex(0.0, imaginaryPart)
+
+let showStack (StackContents contents) =
+  printfn "%A" contents // Print unpacked StackContents with formatting string
+  StackContents (contents) // Repack the StackContents
+
+let push value (StackContents contents) =
+  StackContents (value::contents)
+
+let pop (StackContents contents) =
+  match contents with
+  | top::rest -> // Separate top from rest
+    (top, StackContents rest) // Stack contents must be the StackContents type.
+  | [] -> // Check for stack underflow
+    failwith "Stack underflow"
+
+let binary func stack =
+  let x, newStack = pop stack
+  let y, newestStack = pop newStack
+  let z = func y x // This is deliberately swapped, because we are working on a stack
+  push z newestStack
+
+let unary func stack =
+  let x, newStack = pop stack
+  push (func x) stack
+
+let dup stack =
+  let x, _ = pop stack // Drop the new stack, we want to duplicate "x"
+  push x stack
+
+let swap stack =
+  let x, newStack = pop stack
+  let y, newerStack = pop newStack
+  push y (push x newerStack)
+
+let drop stack =
+  let _, newStack = pop stack // Pop one off the top and ignore it
+  newStack
+
+let numberInput value stack = push value stack
+
+let add = binary (+)
+let multiply = binary (*)
+let subtract = binary (-)
+let divide = binary (/)
+let negate = unary (fun x -> -(x))
+let square = unary (fun x -> x * x)
+let cube = dup >> dup >> multiply >> multiply
+let exponent =  binary ( ** )
+
+let show stack =
+  let value, _ = pop(stack)
+  printfn "%A" value
+  stack // We're going to keep the same stack as before.
+
+let empty = StackContents []
+
+let splitString (text:string) = text.Split ' '
+
+let processTokenString stack token =
+  match token with
+  | "*" -> stack |> multiply
+  | "+" -> stack |> add
+  | "/" -> stack |> divide
+  | "+-" -> stack |> negate
+  | "sqr" -> stack |> square
+  | "cub" -> stack |> cube
+  | "**" | "^" -> stack |> exponent
+  | _ when isDoubleAsString token ->
+    let doubleInString = doubleFromString token
+    numberInput (Complex(doubleInString, 0.0)) stack
+  | _ when isImaginaryAsString token ->
+    let imaginaryInString = imaginaryFromString token
+    numberInput imaginaryInString stack
+  | _ -> showStack stack // For easier debugging.
+
+Console.Write("Please enter your expression here: ")
+let userExpression = Console.ReadLine()
+let splitExpression = splitString userExpression
+
+let resultantStack = List.fold processTokenString (empty) (Array.toList splitExpression) |> showStack