refactor StreamDetails type and fix functions accordingly

Author: Jamil Maqdis Anton

src/Append.fs

@@ -15,7 +15,7 @@ and Id =
     | Auto
 
 module append =
-    let appendNewMessage: IStreamStore -> StreamDetails -> MessageDetails -> Async<AppendResult> =
+    let appendNewMessage: IStreamStore -> AppendStreamDetails -> MessageDetails -> Async<AppendResult> =
         fun store streamDetails messageDetails ->
             let toId: Id -> System.Guid =
                 function
@@ -30,13 +30,12 @@ module append =
 
             let toVersion: Version -> int =
                 function
-                | Version.None
                 | Version.Any -> ExpectedVersion.Any
                 | Version.EmptyStream -> ExpectedVersion.EmptyStream
                 | Version.NoStream -> ExpectedVersion.NoStream
                 | Version.SpecificVersion version -> version
 
-            let append: IStreamStore -> StreamDetails -> MessageDetails -> Async<AppendResult> =
+            let append: IStreamStore -> AppendStreamDetails -> MessageDetails -> Async<AppendResult> =
                 fun store stream msg ->
                     store.AppendToStream(stream.streamName, toVersion stream.version, createMessage msg)
                     |> Async.AwaitTask

src/Read.fs

@@ -10,35 +10,26 @@ type ReadingDirection =
     | Backward
 
 module Read =
-    let toStartPosition: int option -> int =
-        function
-        | Some position -> position
-        | None -> 0
-
-    let readFromStreamAsync: IStreamStore -> ReadingDirection -> StreamDetails -> int -> Async<ReadStreamPage> =
+    let readFromStreamAsync: IStreamStore -> ReadingDirection -> ReadStreamDetails -> int -> Async<ReadStreamPage> =
         fun store readingDirection streamDetails msgCount ->
             match readingDirection with
-            | Forward ->
-                store.ReadStreamForwards
-                    (streamDetails.streamName, toStartPosition streamDetails.startPosition, msgCount)
-            | Backward ->
-                store.ReadStreamBackwards
-                    (streamDetails.streamName, toStartPosition streamDetails.startPosition, msgCount)
+            | Forward -> store.ReadStreamForwards(streamDetails.streamName, streamDetails.startPosition, msgCount)
+            | Backward -> store.ReadStreamBackwards(streamDetails.streamName, streamDetails.startPosition, msgCount)
             |> Async.AwaitTask
 
-    let readFromStreamAsync': IStreamStore -> ReadingDirection -> StreamDetails -> int -> CancellationToken -> Async<ReadStreamPage> =
+    let readFromStreamAsync': IStreamStore -> ReadingDirection -> ReadStreamDetails -> int -> CancellationToken -> Async<ReadStreamPage> =
         fun store readingDirection streamDetails msgCount cancellationToken ->
             match readingDirection with
             | Forward ->
                 store.ReadStreamForwards
-                    (streamDetails.streamName, toStartPosition streamDetails.startPosition, msgCount, cancellationToken)
+                    (streamDetails.streamName, streamDetails.startPosition, msgCount, cancellationToken)
             | Backward ->
                 store.ReadStreamBackwards
-                    (streamDetails.streamName, toStartPosition streamDetails.startPosition, msgCount, cancellationToken)
+                    (streamDetails.streamName, streamDetails.startPosition, msgCount, cancellationToken)
             |> Async.AwaitTask
 
 module ReadExtras =
-    let readStreamMessages: IStreamStore -> ReadingDirection -> StreamDetails -> int -> AsyncResult<List<StreamMessage>, string> =
+    let readStreamMessages: IStreamStore -> ReadingDirection -> ReadStreamDetails -> int -> AsyncResult<List<StreamMessage>, string> =
         fun store readingDirection streamDetails msgCount ->
             Read.readFromStreamAsync store readingDirection streamDetails msgCount
             |> Async.bind (fun readStreamPage ->

src/Types.fs

@@ -1,15 +1,16 @@
 namespace SqlStreamStore.FSharp
 
-
 [<RequireQualifiedAccessAttribute>]
 type Version =
-    | None
     | Any
     | EmptyStream
     | NoStream
     | SpecificVersion of int
 
-type StreamDetails =
+type AppendStreamDetails =
     { streamName: string
-      startPosition: int option
       version: Version }
+
+type ReadStreamDetails =
+    { streamName: string
+      startPosition: int }