Clean up illib (#4428)

* clean option module in illib

* Update NicePrint.fs

* Update NicePrint.fs

* Update NicePrint.fs

* Update NicePrint.fs

* Update NicePrint.fs

src/absil/illib.fs

@@ -37,14 +37,14 @@ let inline isSingleton l =
 
 let inline isNonNull x = not (isNull x)
 let inline nonNull msg x = if isNull x then failwith ("null: " ^ msg) else x
-let (===) x y = LanguagePrimitives.PhysicalEquality x y
+let inline (===) x y = LanguagePrimitives.PhysicalEquality x y
 
 //---------------------------------------------------------------------
 // Library: ReportTime
 //---------------------------------------------------------------------
 let reportTime =
-    let tFirst = ref None     
-    let tPrev = ref None     
+    let tFirst = ref None
+    let tPrev = ref None
     fun showTimes descr ->
         if showTimes then 
             let t = System.Diagnostics.Process.GetCurrentProcess().UserProcessorTime.TotalSeconds
@@ -237,36 +237,12 @@ module Option =
     let mapFold f s opt = 
         match opt with 
         | None -> None,s 
-        | Some x -> let x',s' = f s x in Some x',s'
-
-    let otherwise opt dflt = 
-        match opt with 
-        | None -> dflt 
-        | Some x -> x
-
-    let fold f z x = 
-        match x with 
-        | None -> z 
-        | Some x -> f z x
-
-    let attempt (f: unit -> 'T) = try Some (f()) with _ -> None        
-
-    
-    let orElseWith f opt = 
-        match opt with 
-        | None -> f()
-        | x -> x
-
-    let orElse v opt = 
-        match opt with 
-        | None -> v
-        | x -> x
-
-    let defaultValue v opt = 
-        match opt with 
-        | None -> v
-        | Some x -> x
+        | Some x -> 
+            let x',s' = f s x 
+            Some x',s'
 
+    let attempt (f: unit -> 'T) = try Some (f()) with _ -> None
+        
 module List = 
 
     //let item n xs = List.nth xs n
@@ -442,9 +418,6 @@ module List =
           | x::xs -> if i=n then f x::xs else x::mn (i+1) xs
        
         mn 0 xs
-
-    let rec until p l = match l with [] -> [] | h::t -> if p h then [] else h :: until p t 
-
     let count pred xs = List.fold (fun n x -> if pred x then n+1 else n) 0 xs
 
     // WARNING: not tail-recursive 
@@ -521,23 +494,9 @@ module String =
         if s.Length = 0 then  s
         else lowercase s.[0..0] + s.[ 1.. s.Length - 1 ]
 
+    let dropPrefix (s:string) (t:string) = s.[t.Length..s.Length - 1]
 
-    let tryDropPrefix (s:string) (t:string) = 
-        if s.StartsWith t then 
-            Some s.[t.Length..s.Length - 1]
-        else 
-            None
-
-    let tryDropSuffix (s:string) (t:string) = 
-        if s.EndsWith t then
-            Some s.[0..s.Length - t.Length - 1]
-        else
-            None
-
-    let hasPrefix s t = Option.isSome (tryDropPrefix s t)
-    let dropPrefix s t = match (tryDropPrefix s t) with Some(res) -> res | None -> failwith "dropPrefix"
-
-    let dropSuffix s t = match (tryDropSuffix s t) with Some(res) -> res | None -> failwith "dropSuffix"
+    let dropSuffix (s:string) (t:string) = s.[0..s.Length - t.Length - 1]
 
     open System
     open System.IO

src/fsharp/NicePrint.fs

@@ -71,9 +71,10 @@ module internal PrintUtilities =
                     tcref.DisplayName // has no static params
                 else
                     tcref.DisplayName+"<...>" // shorten
-            if isAttribute then 
-                defaultArg (String.tryDropSuffix name "Attribute") name 
-            else name
+            if isAttribute && name.EndsWith "Attribute" then
+                String.dropSuffix name "Attribute"
+            else 
+                name
         let tyconTextL =
             tagEntityRefName tcref demangled
             |> mkNav tcref.DefinitionRange
@@ -654,9 +655,10 @@ module private PrintTypes =
         | ILAttrib ilMethRef -> 
             let trimmedName = 
                 let name = ilMethRef.DeclaringTypeRef.Name
-                match String.tryDropSuffix name "Attribute" with 
-                | Some shortName -> shortName
-                | None -> name
+                if name.EndsWith "Attribute" then
+                    String.dropSuffix name "Attribute"
+                else
+                    name
             let tref = ilMethRef.DeclaringTypeRef
             let tref = ILTypeRef.Create(scope= tref.Scope, enclosing=tref.Enclosing, name=trimmedName)
             PrintIL.layoutILTypeRef denv tref ++ argsL
@@ -1275,7 +1277,7 @@ module InfoMemberPrinting =
         let paramDatas = minfo.GetParamDatas(amap, m, minst)
         let layout =
             layout ^^
-                if isNil (List.concat paramDatas) then
+                if List.forall isNil paramDatas then
                     WordL.structUnit
                 else
                     sepListL WordL.arrow (List.map ((List.map (layoutParamData denv)) >> sepListL WordL.star) paramDatas)

src/fsharp/TastOps.fs

@@ -1451,7 +1451,7 @@ let tryDestRefTupleTy g ty =
 type UncurriedArgInfos = (TType * ArgReprInfo) list 
 type CurriedArgInfos = (TType * ArgReprInfo) list list
 
-// A 'tau' type is one with its type paramaeters stripped off 
+// A 'tau' type is one with its type parameters stripped off 
 let GetTopTauTypeInFSharpForm g (curriedArgInfos: ArgReprInfo list list) tau m =
     let nArgInfos = curriedArgInfos.Length
     let argtys, rty = stripFunTyN g nArgInfos tau

src/fsharp/TypeChecker.fs

@@ -5112,7 +5112,7 @@ and TcPatBindingName cenv env id ty isMemberThis vis1 topValData (inlineFlag, de
         // isLeftMost indicates we are processing the left-most path through a disjunctive or pattern.
         // For those binding locations, CallNameResolutionSink is called in MakeAndPublishValue, like all other bindings
         // For non-left-most paths, we register the name resolutions here
-        if not isLeftMost && not vspec.IsCompilerGenerated && not (String.hasPrefix vspec.LogicalName "_") then 
+        if not isLeftMost && not vspec.IsCompilerGenerated && not (vspec.LogicalName.StartsWith "_") then 
             let item = Item.Value(mkLocalValRef vspec)
             CallNameResolutionSink cenv.tcSink (id.idRange, env.NameEnv, item, item, emptyTyparInst, ItemOccurence.Binding, env.DisplayEnv, env.eAccessRights)
 

src/fsharp/ast.fs

@@ -100,7 +100,7 @@ type XmlDoc =
             | (lineA::rest) as lines ->
                 let lineAT = lineA.TrimStart([|' '|])
                 if lineAT = "" then processLines rest
-                else if String.hasPrefix lineAT "<" then lines
+                else if lineAT.StartsWith "<" then lines
                 else ["<summary>"] @
                      (lines |> List.map (fun line -> Microsoft.FSharp.Core.XmlAdapters.escape(line))) @
                      ["</summary>"]