Basic arg parser (#216)

WoofWare.Myriad.Plugins/SynExpr/SynArgPats.fs

@@ -1,16 +1,30 @@
 namespace WoofWare.Myriad.Plugins
 
 open Fantomas.FCS.Syntax
+open Fantomas.FCS.Text.Range
 
 [<RequireQualifiedAccess>]
 module internal SynArgPats =
-    let create (caseNames : Ident list) : SynArgPats =
+    let createNamed (caseNames : string list) : SynArgPats =
         match caseNames.Length with
         | 0 -> SynArgPats.Pats []
-        | 1 -> [ SynPat.named caseNames.[0].idText ] |> SynArgPats.Pats
-        | _ ->
-            caseNames
-            |> List.map (fun i -> SynPat.named i.idText)
-            |> SynPat.tuple
+        | 1 ->
+            SynPat.Named (SynIdent.SynIdent (Ident.create caseNames.[0], None), false, None, range0)
+            |> List.singleton
+            |> SynArgPats.Pats
+        | len ->
+            caseNames
+            |> List.map (fun name -> SynPat.Named (SynIdent.SynIdent (Ident.create name, None), false, None, range0))
+            |> fun t -> SynPat.Tuple (false, t, List.replicate (len - 1) range0, range0)
+            |> fun t -> SynPat.Paren (t, range0)
+            |> List.singleton
+            |> SynArgPats.Pats
+
+    let create (pats : SynPat list) : SynArgPats =
+        match pats.Length with
+        | 0 -> SynArgPats.Pats []
+        | 1 -> [ pats.[0] ] |> SynArgPats.Pats
+        | len ->
+            SynPat.Paren (SynPat.Tuple (false, pats, List.replicate (len - 1) range0, range0), range0)
             |> List.singleton
             |> SynArgPats.Pats