* remove rec module to narrow it to only types

* factorize a bit the existing functions

Author: smoothdeveloper

src/ZMidi/Read.fs

@@ -1,4 +1,4 @@
-module rec DataTypes
+module DataTypes
 type midiportnumber = byte
 type word8 = byte
 type word16 = uint16
@@ -55,7 +55,7 @@ type MidiEvent =
     | SysRealtimeEvent of MidiSysRealtimeEvent
     | MetaEvent of MidiMetaEvent
 
-type MidiVoiceEvent =
+and MidiVoiceEvent =
     /// Note off.
     /// 
     /// > 80 to 8F (0 to F is channel number) * note * velocity
@@ -112,7 +112,7 @@ type MidiVoiceEvent =
     | PitchBend of status: bits7 * bend: word14
 
 
-type MidiTextType =
+and MidiTextType =
     | GenericText
     | CopyrightNotice
     | SequenceName
@@ -123,48 +123,48 @@ type MidiTextType =
 
 
 /// Sequential messages with delta time 0 are played simultaneously.  
-type MidiMessage = {
+and MidiMessage = {
     timestamp: DeltaTime
     event: MidiEvent
 }
 
-type MidiTrack = MidiMessage array
+and MidiTrack = MidiMessage array
 
-type MidiFile = {
+and MidiFile = {
      header : MidiHeader
      tracks : MidiTrack array
  }
 
-type MidiSysExEvent =
-    /// Single SysEx event.
-    ///
-    /// > F0 * length * data
-    /// 
-    /// An uninterpreted sys-ex event.
-    | SysExSingle of byte array
-
-    /// SysEx sent as (non-standard) multiple continuation 
-    /// packets.
-    ///
-    /// > F0 * length * packet1 ... [SysExContPacket]
-    ///
-    | SysExCont of byte array * MidiSysExContPacket array
-
-    /// Escape sequence of one-or-more SysEx events.
-    ///
-    /// > F7 * length * data
-    ///
-    | SysExEscape of byte array
+and MidiSysExEvent =
+  /// Single SysEx event.
+  ///
+  /// > F0 * length * data
+  /// 
+  /// An uninterpreted sys-ex event.
+  | SysExSingle of byte array
+
+  /// SysEx sent as (non-standard) multiple continuation 
+  /// packets.
+  ///
+  /// > F0 * length * packet1 ... [SysExContPacket]
+  ///
+  | SysExCont of byte array * MidiSysExContPacket array
+
+  /// Escape sequence of one-or-more SysEx events.
+  ///
+  /// > F7 * length * data
+  ///
+  | SysExEscape of byte array
 
 /// Continuation packet for a (non-standard) multi-part SysEx 
 /// event.
 /// 
 /// Apprently this format is use by Casio.
-type MidiSysExContPacket = MidiSysExContPacket of DeltaTime * byte array
+and MidiSysExContPacket = MidiSysExContPacket of DeltaTime * byte array
 
 
 
-type MidiMetaEvent =
+and MidiMetaEvent =
 
     ///  Text / copywright etc.
     /// 
@@ -267,7 +267,7 @@ type MidiMetaEvent =
 /// computer (as opposed to MIDI generated by a synthesizer or 
 /// sequencer).
 ///
-type MidiSysCommonEvent =
+and MidiSysCommonEvent =
     /// Time code quarter frame.
     /// 
     /// > F1 * payload
@@ -322,7 +322,7 @@ type MidiSysCommonEvent =
 /// These events may not be pertinent to MIDI files generated on a 
 /// computer (as opposed to MIDI generated by a synthesizer or 
 /// sequencer).
-type MidiSysRealtimeEvent =
+and MidiSysRealtimeEvent =
     /// Timing signal.
     /// 
     /// > F8 
@@ -380,8 +380,9 @@ type MidiSysRealtimeEvent =
     ///
     | SystemReset
 
-[<RequireQualifiedAccess>]
-type MidiScaleType = Major | Minor | OtherScale of word8
+
+
+and [<RequireQualifiedAccess>] MidiScaleType = Major | Minor | OtherScale of word8
 
 module Internal =
   module ParserMonad =
@@ -412,6 +413,7 @@ module Internal =
       member state.posPastEnd = state.pos >= state.input.Length
       member state.moved direction = { state with pos = state.pos + direction }
       member state.get () = state.input.[state.pos]
+
     type ErrorMessage = string
     type ParseError = ParseError of Pos * ErrorMessage
 
@@ -423,28 +425,38 @@ module Internal =
 
     let getPos = parserM (fun state -> (Ok (state.pos), state))
 
-    let peek = parserM (fun ({ pos = pos; input = input } as state) ->
+    let inline failPastEndOrResult (state: ParserState) funcName getResultAndState =
       if state.posPastEnd then
-        err pos  "peek - no more data", state
-      else
-        Ok input.[pos], state
-    )
-
-    let cond pred = parserM (fun ({ pos = pos; input = input } as state) ->
-      if state.posPastEnd then 
-        err pos  "cond - no more data", state
+        (err state.pos  (funcName + " - no more data")), state
       else
-        let a = state.get()
-        (if pred a then Ok (Some a) else (Ok None)), state.moved(1)
-    )
-
-    let dropW8 = parserM (fun (state) ->
-      if state.posPastEnd then 
-        err state.pos  "dropW8 - no more data", state
-      else
-        Ok (), state.moved(1)
-    )
+        let res, state = getResultAndState state
+        Ok res, state
 
+    let inline checkedPastEndOrResult fName getResultAndNextState = parserM <| fun state -> failPastEndOrResult state fName getResultAndNextState
+    
+    let peek = checkedPastEndOrResult "peek" (fun state -> state.get(), state)
+
+    let cond pred =
+      checkedPastEndOrResult "cond" (
+        fun state -> 
+          let a = state.get()
+          (if pred a then Some a else None), state.moved(1)
+      )
+    
+    let dropW8 = 
+      checkedPastEndOrResult "dropW8" (
+        fun state -> (), state.moved(1)
+      )
+
+    let word8 = 
+      checkedPastEndOrResult "word8" (
+        fun state -> state.get(), state.moved(1)
+      )
+
+    let word16be : ParserM<word16> =
+      checkedPastEndOrResult "word16be" (
+        fun state -> failwith "uncons2!!!"
+      )