refactor: F# 8 lambda syntax and other simplifications

Author: Tarmil

src/Bolero.Html/Builders.fs

@@ -44,7 +44,7 @@ type ChildContentAttr = delegate of receiver: obj * builder: RenderTreeBuilder *
 /// <param name="receiver">The containing component.</param>
 /// <param name="builder">The rendering builder.</param>
 /// <param name="sequence">The rendering sequence number.</param>
-type ChildAndRefContent = delegate of receiver: obj * builder: Rendering.RenderTreeBuilder * sequence: int -> int
+type ChildAndRefContent = delegate of receiver: obj * builder: RenderTreeBuilder * sequence: int -> int
 
 type [<Struct; NoComparison; NoEquality>] AttrBuilder =
     member inline _.Yield([<InlineIfLambda>] attr: Attr) = attr

src/Bolero.Server/Components.fs

@@ -31,7 +31,6 @@ open System.Threading.Tasks
 open Microsoft.AspNetCore.Components
 #if NET8_0
 open Microsoft.AspNetCore.Components.Endpoints
-open Microsoft.AspNetCore.Components.Web
 #endif
 open Microsoft.AspNetCore.Components.RenderTree
 open Microsoft.AspNetCore.Components.Rendering

src/Bolero.Server/Extensions.fs

@@ -80,7 +80,7 @@ type ServerComponentsExtensions =
     /// <param name="page">The page to return.</param>
     [<Extension>]
     static member BoleroPage(_this: Controller, page: Node) =
-        new BoleroPageResult(page)
+        BoleroPageResult(page)
 
     /// <summary>Render the JavaScript tag needed by Bolero in a Razor page.</summary>
     /// <param name="config">The injected Bolero hosting configuration.</param>

src/Bolero.Server/Remoting/Endpoints.fs

@@ -182,8 +182,8 @@ type internal RemotingEndpointDataSource() =
 
     override _.Endpoints =
         endpointBuilders
-        |> Seq.collect (fun b -> b.ApplyFinally())
-        |> Seq.map (fun b -> b.Build())
+        |> Seq.collect _.ApplyFinally()
+        |> Seq.map _.Build()
         |> Array.ofSeq
         :> IReadOnlyList<Endpoint>
 

src/Bolero.Templating.Provider/CodeGen.fs

@@ -31,97 +31,97 @@ open Bolero.TemplatingInternals
 open Bolero.Templating.ConvertExpr
 
 let getThis (args: list<Expr>) : Expr<TemplateNode> =
-    TExpr.Coerce<TemplateNode>(args.[0])
+    TExpr.Coerce<TemplateNode>(args[0])
 
 let MakeCtor (holes: Parsing.Vars) =
     ProvidedConstructor([], fun args ->
         let holes = TExpr.Array<obj> [
             for KeyValue(_, type') in holes ->
                 match type' with
-                | Parsing.HoleType.String -> <@ box "" @>
-                | Parsing.HoleType.Html -> <@ box (Node.Empty()) @>
-                | Parsing.HoleType.Event _ -> <@ box (Events.NoOp<EventArgs>()) @>
-                | Parsing.HoleType.DataBinding _ -> <@ box (null, Events.NoOp<ChangeEventArgs>()) @>
-                | Parsing.HoleType.Attribute -> <@ box (Attr.Empty()) @>
-                | Parsing.HoleType.AttributeValue -> <@ null @>
-                | Parsing.HoleType.Ref -> <@ null @>
+                | HoleType.String -> <@ box "" @>
+                | HoleType.Html -> <@ box (Node.Empty()) @>
+                | HoleType.Event _ -> <@ box (Events.NoOp<EventArgs>()) @>
+                | HoleType.DataBinding _ -> <@ box (null, Events.NoOp<ChangeEventArgs>()) @>
+                | HoleType.Attribute -> <@ box (Attr.Empty()) @>
+                | HoleType.AttributeValue -> <@ null @>
+                | HoleType.Ref -> <@ null @>
         ]
         <@@ (%getThis args).Holes <- %holes @@>)
 
 /// Get the argument lists and bodies for methods that fill a hole of the given type.
-let HoleMethodBodies (holeType: Parsing.HoleType) : (ProvidedParameter list * (Expr list -> Expr)) list =
+let HoleMethodBodies (holeType: HoleType) : (ProvidedParameter list * (Expr list -> Expr)) list =
     let (=>) name ty = ProvidedParameter(name, ty)
     match holeType with
-    | Parsing.HoleType.String ->
+    | HoleType.String ->
         [
             ["value" => typeof<string>], fun args ->
-                <@@ box (%%args.[1]: string) @@>
+                <@@ box (%%args[1]: string) @@>
         ]
-    | Parsing.HoleType.Html ->
+    | HoleType.Html ->
         [
             ["value" => typeof<string>], fun args ->
-                <@@ box (Node.Text (%%args.[1]: string)) @@>
+                <@@ box (Node.Text (%%args[1]: string)) @@>
             ["value" => typeof<Node>], fun args ->
-                <@@ box (%%args.[1]: Node) @@>
+                <@@ box (%%args[1]: Node) @@>
         ]
-    | Parsing.HoleType.Event argTy ->
+    | HoleType.Event argTy ->
         [
             ["value" => EventHandlerOf argTy], fun args ->
-                Expr.Coerce(args.[1], typeof<obj>)
+                Expr.Coerce(args[1], typeof<obj>)
         ]
-    | Parsing.HoleType.DataBinding Parsing.BindingType.BindString ->
+    | HoleType.DataBinding BindingType.BindString ->
         [
             ["value" => typeof<string>; "set" => typeof<Action<string>>], fun args ->
-                <@@ box (box (%%args.[1]: string), Events.OnChange(%%args.[2])) @@>
+                <@@ box (box (%%args[1]: string), Events.OnChange(%%args[2])) @@>
         ]
-    | Parsing.HoleType.DataBinding Parsing.BindingType.BindNumber ->
+    | HoleType.DataBinding BindingType.BindNumber ->
         [
             ["value" => typeof<int>; "set" => typeof<Action<int>>], fun args ->
-                <@@ box (box (%%args.[1]: int), Events.OnChangeInt(%%args.[2])) @@>
+                <@@ box (box (%%args[1]: int), Events.OnChangeInt(%%args[2])) @@>
             ["value" => typeof<float>; "set" => typeof<Action<float>>], fun args ->
-                <@@ box (box (%%args.[1]: float), Events.OnChangeFloat(%%args.[2])) @@>
+                <@@ box (box (%%args[1]: float), Events.OnChangeFloat(%%args[2])) @@>
         ]
-    | Parsing.HoleType.DataBinding Parsing.BindingType.BindBool ->
+    | HoleType.DataBinding BindingType.BindBool ->
         [
             ["value" => typeof<bool>; "set" => typeof<Action<bool>>], fun args ->
-                <@@ box (box (%%args.[1]: bool), Events.OnChangeBool(%%args.[2])) @@>
+                <@@ box (box (%%args[1]: bool), Events.OnChangeBool(%%args[2])) @@>
         ]
-    | Parsing.HoleType.Attribute ->
+    | HoleType.Attribute ->
         [
             ["value" => typeof<Attr>], fun args ->
-                <@@ box (%%args.[1]: Attr) @@>
+                <@@ box (%%args[1]: Attr) @@>
             ["value" => typeof<list<Attr>>], fun args ->
-                <@@ box (Attr.Attrs(%%args.[1]: list<Attr>)) @@>
+                <@@ box (Attr.Attrs(%%args[1]: list<Attr>)) @@>
         ]
-    | Parsing.HoleType.AttributeValue ->
+    | HoleType.AttributeValue ->
         [
             ["value" => typeof<obj>], fun args ->
-                <@@ %%args.[1] @@>
+                <@@ %%args[1] @@>
         ]
-    | Parsing.HoleType.Ref ->
+    | HoleType.Ref ->
         [
             ["value" => typeof<HtmlRef>], fun args ->
-                <@@ box (%%args.[1]: HtmlRef) @@>
+                <@@ box (%%args[1]: HtmlRef) @@>
         ]
 
-let MakeHoleMethods (holeName: string) (holeType: Parsing.HoleType) (index: int) (containerTy: ProvidedTypeDefinition) =
+let MakeHoleMethods (holeName: string) (holeType: HoleType) (index: int) (containerTy: ProvidedTypeDefinition) =
     [
         for args, value in HoleMethodBodies holeType do
             yield ProvidedMethod(holeName, args, containerTy, fun args ->
                 let this = getThis args
-                <@@ (%this).Holes.[index] <- %%(value args)
+                <@@ (%this).Holes[index] <- %%(value args)
                     %this @@>) :> MemberInfo
     ]
 
-let MakeFinalMethod (filename: option<string>) (subTemplateName: option<string>) (content: Parsing.Parsed) =
+let MakeFinalMethod (filename: option<string>) (subTemplateName: option<string>) (content: Parsed) =
     ProvidedMethod("Elt", [], typeof<Node>, fun args ->
         let this = getThis args
         let directExpr =
             let vars = content.Vars |> Map.map (fun k v -> Var(k, TypeOf v))
             let varExprs = vars |> Map.map (fun _ v -> Expr.Var v)
-            ((0, ConvertNode varExprs (Parsing.Concat content.Expr) :> Expr), vars)
+            ((0, ConvertNode varExprs (Concat content.Expr) :> Expr), vars)
             ||> Seq.fold (fun (i, e) (KeyValue(_, var)) ->
-                let value = <@@ (%this).Holes.[i] @@>
+                let value = <@@ (%this).Holes[i] @@>
                 let value = Expr.Coerce(value, var.Type)
                 i + 1, Expr.Let(var, value, e)
             )

src/Bolero.Templating.Provider/ConvertExpr.fs

@@ -67,7 +67,7 @@ let WrapExpr (innerType: Parsing.HoleType) (outerType: Parsing.HoleType) (expr:
 /// Map an expression's vars from its parent, wrapping the expression in let declarations.
 let WrapAndConvert (vars: Map<string, Expr>) (subst: list<Parsing.VarSubstitution>) convert expr =
     let vars, addLets = ((vars, id), subst) ||> List.fold (fun (vars, addLets) wrap ->
-        let unwrapped = vars.[wrap.name]
+        let unwrapped = vars[wrap.name]
         let wrapped = WrapExpr wrap.innerType wrap.outerType unwrapped
         let var = Var(wrap.name, TypeOf wrap.innerType)
         let addLets e = Expr.Let(var, defaultArg wrapped unwrapped, addLets e) |> Expr.Cast
@@ -84,7 +84,7 @@ let rec ConvertAttrTextPart (vars: Map<string, Expr>) (text: Parsing.Expr) : Exp
     | Parsing.PlainHtml text ->
         <@ text @>
     | Parsing.VarContent varName ->
-        let e : Expr<obj> = Expr.Coerce(vars.[varName], typeof<obj>) |> Expr.Cast
+        let e : Expr<obj> = Expr.Coerce(vars[varName], typeof<obj>) |> Expr.Cast
         <@ (%e).ToString() @>
     | Parsing.WrapVars (subst, text) ->
         WrapAndConvert vars subst ConvertAttrTextPart text
@@ -100,11 +100,11 @@ let rec ConvertAttrValue (vars: Map<string, Expr>) (text: Parsing.Expr) : Expr<o
     | Parsing.PlainHtml text ->
         box <@ text @>
     | Parsing.VarContent varName ->
-        box vars.[varName]
+        box vars[varName]
     | Parsing.Fst varName ->
-        box (Expr.TupleGet(vars.[varName], 0))
+        box (Expr.TupleGet(vars[varName], 0))
     | Parsing.Snd varName ->
-        box (Expr.TupleGet(vars.[varName], 1))
+        box (Expr.TupleGet(vars[varName], 1))
     | Parsing.WrapVars (subst, text) ->
         WrapAndConvert vars subst ConvertAttrValue text
     | Parsing.Attr _ | Parsing.Elt _ | Parsing.HtmlRef _ ->
@@ -119,11 +119,11 @@ let rec ConvertAttr (vars: Map<string, Expr>) (attr: Parsing.Expr) : Expr<Attr>
         let value = ConvertAttrValue vars value
         <@ Attr.Make name %value @>
     | Parsing.VarContent varName ->
-        vars.[varName] |> Expr.Cast
+        vars[varName] |> Expr.Cast
     | Parsing.WrapVars (subst, attr) ->
         WrapAndConvert vars subst ConvertAttr attr
     | Parsing.HtmlRef varName ->
-        let ref = vars.[varName] |> Expr.Cast
+        let ref = vars[varName] |> Expr.Cast
         <@ Ref.MakeAttr(%ref) @>
     | Parsing.Fst _ | Parsing.Snd _ | Parsing.PlainHtml _ | Parsing.Elt _ ->
         failwith $"Invalid attribute: {attr}"
@@ -144,7 +144,7 @@ let rec ConvertNode (vars: Map<string, Expr>) (node: Parsing.Expr) : Expr<Node>
         let children = TExpr.Array<Node> (Seq.map (ConvertNode vars) children)
         <@ Node.Elt name %attrs %children @>
     | Parsing.VarContent varName ->
-        vars.[varName] |> Expr.Cast
+        vars[varName] |> Expr.Cast
     | Parsing.WrapVars (subst, node) ->
         WrapAndConvert vars subst ConvertNode node
     | Parsing.Fst _ | Parsing.Snd _ | Parsing.Attr _ | Parsing.HtmlRef _ ->

src/Bolero.Templating.Provider/Parsing.fs

@@ -239,14 +239,14 @@ let ParseText (t: string) (varType: HoleType) : Parsed =
     let mutable vars = Map.empty
     for p in parse do
         if p.Index > lastHoleEnd then
-            parts.Add(PlainHtml t.[lastHoleEnd..p.Index - 1])
-        let varName = p.Groups.[1].Value
+            parts.Add(PlainHtml t[lastHoleEnd..p.Index - 1])
+        let varName = p.Groups[1].Value
         if not (Map.containsKey varName vars) then
             vars <- Map.add varName varType vars
         parts.Add(VarContent varName)
         lastHoleEnd <- p.Index + p.Length
     if lastHoleEnd < t.Length then
-        parts.Add(PlainHtml t.[lastHoleEnd..t.Length - 1])
+        parts.Add(PlainHtml t[lastHoleEnd..t.Length - 1])
     WithVars vars (parts.ToArray() |> List.ofSeq)
 
 /// None if this is not a data binding.

src/Bolero.Templating.Provider/Path.fs

@@ -33,7 +33,7 @@ let Canonicalize (path: string) =
 let GetRelativePath (baseDir: string) (fullPath: string) =
     let rec go (thisDir: string) =
         if thisDir = baseDir then
-            fullPath.[thisDir.Length + 1..]
+            fullPath[thisDir.Length + 1..]
         elif thisDir.Length <= baseDir.Length then
             invalidArg "fullPath" $"'{fullPath}' is not a subdirectory of '{baseDir}'"
         else

src/Bolero/Router.fs

@@ -197,7 +197,7 @@ type PageModel<'T> =
         prop.SetValue(this, value)
 #else
     member internal this.SetModel(value) =
-        (Unsafe.AsRef<'T>(&this.Model)) <- value
+        Unsafe.AsRef<'T>(&this.Model) <- value
 #endif
 
 [<AutoOpen>]
@@ -299,7 +299,7 @@ module private RouterImpl =
                             if getTag x = 0 then
                                 None
                             else
-                                s.write (someDector x).[0]
+                                s.write <| (someDector x)[0]
                     }, ValueSome none
                 | false, _ -> fail (InvalidRouterKind.UnsupportedType ty)
             else

tests/Client/Main.fs

@@ -347,7 +347,7 @@ let view js model dispatch =
         cond model.page <| function
             | Form -> viewForm js model dispatch
             | Collection -> viewCollection model dispatch
-            | Item (k, m) -> ecomp<ViewItemPage,_,_> (k, model.items.[k], m.Model) dispatch { attr.empty() }
+            | Item (k, m) -> ecomp<ViewItemPage,_,_> (k, model.items[k], m.Model) dispatch { attr.empty() }
             | Lazy (x, y) -> viewLazy (x, y) model dispatch
             | Virtual -> viewVirtual model dispatch
             | NotFound -> p { text "Not found" }

tests/Remoting.Client/Main.fs

@@ -138,7 +138,7 @@ let Update (myApi: MyApi) msg model =
 
 let router : Router<Page, Model, Message> =
     {
-        getEndPoint = fun m -> m.page
+        getEndPoint = _.page
         getRoute = function
             | Home -> "/"
             | Custom i -> $"/custom/{i}"
@@ -157,7 +157,7 @@ type Form = Template<"subdir/form.html">
 type Item() =
     inherit ElmishComponent<KeyValuePair<int, string>, Message>()
 
-    override __.View (KeyValue (k, v)) dispatch =
+    override _.View (KeyValue (k, v)) dispatch =
         Tpl.item().key(string k).value(v)
             .remove(fun _ -> dispatch (RemoveItem k))
             .Elt()

tests/Remoting.Server/Startup.fs

@@ -27,8 +27,6 @@ open Microsoft.AspNetCore
 open Microsoft.AspNetCore.Authentication.Cookies
 open Microsoft.AspNetCore.Builder
 open Microsoft.AspNetCore.Hosting
-open Microsoft.AspNetCore.Http
-open Microsoft.AspNetCore.Mvc
 open Microsoft.Extensions.DependencyInjection
 open Microsoft.Extensions.Hosting
 open Microsoft.Extensions.Logging
@@ -47,14 +45,14 @@ module Page =
             ``base`` { attr.href "/" }
         }
         body {
-            div { attr.id "main"; comp<Client.MyApp> }
+            div { attr.id "main"; comp<MyApp> }
             script { attr.src "_content/Microsoft.AspNetCore.Components.WebAssembly.Authentication/AuthenticationService.js" }
             boleroScript
         }
     }
 
 type MyApiHandler(log: ILogger<MyApiHandler>, ctx: IRemoteContext) =
-    inherit RemoteHandler<Client.MyApi>()
+    inherit RemoteHandler<MyApi>()
 
     let mutable items = Map.empty
 
@@ -105,7 +103,7 @@ type Startup() =
         services.AddSwaggerForSystemTextJson(JsonFSharpOptions()) |> ignore
         services.AddEndpointsApiExplorer() |> ignore
 
-    member this.Configure(app: IApplicationBuilder, env: IHostEnvironment, log: ILogger<Startup>) =
+    member this.Configure(app: IApplicationBuilder, env: IHostEnvironment) =
         app.UseAuthentication()
             .UseStaticFiles()
             .UseSwagger()

tests/Unit.Client/Html.fs

@@ -77,7 +77,7 @@ type BoleroComponent() =
                     condUnionState <-
                         match s.Length with
                         | 0 -> Empty
-                        | 1 -> OneChar s.[0]
+                        | 1 -> OneChar s[0]
                         | _ -> ManyChars s)
             }
             cond condUnionState <| function

tests/Unit/Fixture.fs

@@ -31,7 +31,6 @@ open OpenQA.Selenium.Chrome
 // open OpenQA.Selenium.Firefox
 open OpenQA.Selenium.Support.UI
 open Swensen.Unquote
-open Bolero.Tests
 
 /// Defines the setup/teardown for all tests that use the web server and Selenium.
 /// These web tests must be located in the namespace Bolero.Tests.Web

tests/Unit/Tests/Routing.fs

@@ -1,7 +1,6 @@
 namespace Bolero.Tests.Web
 
 open System.Text.RegularExpressions
-open System.Threading
 open FSharp.Reflection
 open NUnit.Framework
 open OpenQA.Selenium
@@ -88,19 +87,19 @@ module Routing =
 
     let failingRouters = [
         failingRouter<``Invalid parameter syntax``> <| fun c ->
-            InvalidRouterKind.ParameterSyntax(c.[0], "{x")
+            InvalidRouterKind.ParameterSyntax(c[0], "{x")
         failingRouter<``Unknown parameter name``> <| fun c ->
-            InvalidRouterKind.UnknownField(c.[0], "y")
+            InvalidRouterKind.UnknownField(c[0], "y")
         failingRouter<``Duplicate field``> <| fun c ->
-            InvalidRouterKind.DuplicateField(c.[0], "x")
+            InvalidRouterKind.DuplicateField(c[0], "x")
         failingRouter<``Incomplete parameter list``> <| fun c ->
-            InvalidRouterKind.MissingField(c.[0], "y")
+            InvalidRouterKind.MissingField(c[0], "y")
         failingRouter<``Identical paths with different parameter names``> <| fun c ->
-            InvalidRouterKind.IdenticalPath(c.[1], c.[0])
+            InvalidRouterKind.IdenticalPath(c[1], c[0])
         failingRouter<``Mismatched type parameters in same position``> <| fun c ->
-            InvalidRouterKind.ParameterTypeMismatch(c.[1], "y", c.[0], "x")
+            InvalidRouterKind.ParameterTypeMismatch(c[1], "y", c[0], "x")
         failingRouter<``Rest parameter in non-final position``> <| fun c ->
-            InvalidRouterKind.RestNotLast(c.[0])
+            InvalidRouterKind.RestNotLast(c[0])
         failingRouter<Dictionary<int, int>> <| fun _ ->
             InvalidRouterKind.UnsupportedType typeof<Dictionary<int, int>>
     ]

tests/Unit/Tests/Templating.fs

@@ -96,7 +96,7 @@ module Templating =
             Double.TryParse(s, NumberStyles.Float, CultureInfo.InvariantCulture, ref 0.)
         let isValidPosition (pos: string) =
             let a = pos.Split(',')
-            isNumber a.[0] && isNumber a.[1]
+            isNumber a[0] && isNumber a[1]
 
         elt.ByClass("btn1").Click()
         elt.Eventually <@ state.Text = "clicked 1" @>