make minor changes to variable names in library.

Change the exeption code for file validation in library.

DeathSocket/Domain.fs

@@ -1,11 +1,12 @@
 namespace DeathSocket
 
+    [<AutoOpen>]
     module Domain =
 
         open System.Drawing
-        
+
         type ImageSpec =
-            { filePath: string;
+            { originalPath: string;
               savePath: string;
               colour: Brush; 
               penWidth: float32 

DeathSocket/GridPainter.fs

@@ -1,11 +1,16 @@
 namespace DeathSocket
 
+    open System.IO
+
     module GridPainter =
 
         open Validation
         open ImageServices
 
-        let applyGridToImage spec =
-            validateFilePath |> ignore
-            drawGrid spec
-            0
+        let applyGrid spec =
+            try
+                validateFilePath |> ignore
+                drawGrid spec |> ignore
+            with
+            | :? FileNotFoundException as ex -> printfn"%s" ex.Message
+            

DeathSocket/ImageServices.fs

@@ -1,34 +1,32 @@
 module internal ImageServices
 
-open System.Drawing
-open DeathSocket.Domain
-open System.Drawing.Imaging
+    open System.Drawing
+    open System.Drawing.Imaging
+    open DeathSocket
 
-    let createHorizontalLines width height columns =
-        let interval = width / columns
-        [| for point in 1 .. columns ->
+    let createHorizontalLines width height rows =
+        let interval = width / rows
+        [| for point in 1 .. (rows - 1) ->
             [|Point (0, (interval * point))
               Point (height, (interval * point) )|]|]
 
-    let createVerticalLines width height columns =
+    let createVerticalLines height columns =
         let interval = height / columns
-        [| for point in 1 .. columns ->
+        [| for point in 1 .. (columns - 1) ->
             [| Point ((interval * point), 0)
                Point ((interval * point), height)|]|]
 
     let drawGrid spec =
-        let img = Bitmap.FromFile spec.filePath
+        let img = Bitmap.FromFile spec.originalPath
         let graphics = Graphics.FromImage img
         let pen = new Pen (spec.colour, width = spec.penWidth)
         let horizontalLines =
             createHorizontalLines (img.Size.Width) (img.Size.Height) (spec.columns)
-        let verticalLines =
-            createVerticalLines (img.Size.Width) (img.Size.Height) (spec.columns)
+        let verticalLines = createVerticalLines (img.Size.Height) (spec.columns)
         for line in horizontalLines do graphics.DrawLines (pen, line)
         for line in verticalLines do graphics.DrawLines (pen, line)
         img.Save (spec.savePath, ImageFormat.Png)
         img.Dispose ()
         graphics.Dispose ()
         pen.Dispose ()
-        0
-
+        ()

DeathSocket/ScratchPad.fsx

@@ -6,7 +6,6 @@
 open System.Drawing
 open System
 open DeathSocket
-open Domain
 open Validation
 open ImageServices
 
@@ -52,9 +51,9 @@ let validationTest = validateFilePath testSavePath
 let horizontalLines =
     createHorizontalLines (testImg.Size.Width) (testImg.Size.Height) 10
 let verticalLines =
-    createVerticalLines (testImg.Size.Width) (testImg.Size.Height) 10
+    createVerticalLines (testImg.Size.Height) 10
 let spec =
-    { filePath = testImagePath
+    { originalPath = testImagePath
       savePath = testSavePath
       colour = Brushes.Red
       penWidth = float32 (10)

DeathSocket/Validation.fs

@@ -5,6 +5,5 @@ open System.IO
     let validateFilePath path =
         match File.Exists path with
         | true -> ()
-        | false ->
-            invalidArg "File Path" "The image can not be loaded because the file path specified does not exist."
+        | false -> raise (new FileNotFoundException (path + "could not be found."))