[Rust] Added basic class inheritance support (#3920)

src/Fable.Cli/CHANGELOG.md

@@ -7,6 +7,11 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## Unreleased
 
+### Added
+
+* [Rust] Added basic class inheritance support (by @ncave)
+* [Rust] Added String.Replace(char, char) and test (by @ncave)
+
 ## 4.22.0 - 2024-10-02
 
 ### Added

src/Fable.Transforms/FSharp2Fable.Util.fs

@@ -2329,7 +2329,7 @@ module Util =
                 getMangledAbstractMemberName ent memb.CompiledName overloadHash
             else if
                 // use DisplayName for getters/setters (except for Rust)
-                (isGetter || isSetter) && com.Options.Language <> Rust
+                (isGetter || isSetter) && not (com.Options.Language = Rust)
             then
                 getMemberDisplayName memb
             else
@@ -2399,7 +2399,12 @@ module Util =
             let isPythonStaticMember =
                 com.Options.Language = Python && not memb.IsInstanceMember
 
-            if not info.isMangled && info.isGetter && not isPythonStaticMember then
+            if
+                not info.isMangled
+                && info.isGetter
+                && not isPythonStaticMember
+                && not (com.Options.Language = Rust)
+            then
                 // Set the field as maybe calculated so it's not displaced by beta reduction
                 let kind =
                     Fable.FieldInfo.Create(
@@ -2410,7 +2415,7 @@ module Util =
                     )
 
                 Fable.Get(callee, kind, typ, r)
-            elif not info.isMangled && info.isSetter then
+            elif not info.isMangled && info.isSetter && not (com.Options.Language = Rust) then
                 let membType = memb.CurriedParameterGroups[0].[0].Type |> makeType Map.empty
                 let arg = callInfo.Args |> List.tryHead |> Option.defaultWith makeNull
                 Fable.Set(callee, Fable.FieldSet(info.name), membType, arg, r)
@@ -2578,7 +2583,7 @@ module Util =
                 match tryGlobalOrImportedFSharpEntity com e with
                 | Some expr -> Some expr
                 // AttachMembers classes behave the same as global/imported classes
-                | None when com.Options.Language <> Rust && isAttachMembersEntity com e ->
+                | None when not (com.Options.Language = Rust) && isAttachMembersEntity com e ->
                     FsEnt.Ref e |> entityIdent com |> Some
                 | None -> None
 
@@ -2696,7 +2701,7 @@ module Util =
 
     /// Removes optional arguments set to None in tail position
     let transformOptionalArguments
-        (_com: IFableCompiler)
+        (com: IFableCompiler)
         (_ctx: Context)
         (_r: SourceLocation option)
         (memb: FSharpMemberOrFunctionOrValue)
@@ -2705,6 +2710,7 @@ module Util =
         if
             memb.CurriedParameterGroups.Count <> 1
             || memb.CurriedParameterGroups[0].Count <> (List.length args)
+            || com.Options.Language = Rust // keep all optional args for Rust
         then
             args
         else

src/Fable.Transforms/FSharp2Fable.fs

@@ -46,7 +46,7 @@ let private transformBaseConsCall
             "Only inheriting from primary constructors is supported" |> addWarning com [] r
 
         match makeCallFrom com ctx r Fable.Unit genArgs None baseArgs baseCons with
-        | Fable.Call(_baseExpr, info, t, r) ->
+        | Fable.Call(_baseExpr, info, t, r) when not (com.Options.Language = Rust) ->
             // The baseExpr will be the exposed constructor function,
             // replace with a direct reference to the entity
             let baseExpr =
@@ -381,7 +381,7 @@ let private getImplementedSignatureInfo
             && countNonCurriedParamsForSignature sign = 1
 
         let name =
-            if (isGetter || isSetter) && com.Options.Language <> Rust then
+            if (isGetter || isSetter) && not (com.Options.Language = Rust) then
                 Naming.removeGetSetPrefix sign.Name
             else
                 sign.Name
@@ -778,7 +778,7 @@ let private transformExpr (com: IFableCompiler) (ctx: Context) appliedGenArgs fs
                     &&
                     // The replacement only needs to happen when var.FullType = byref<fsExpr.Type>
                     fsExpr.Type = var.FullType.GenericArguments.[0]
-                    && com.Options.Language <> Rust
+                    && not (com.Options.Language = Rust)
                 then
                     // Getting byref value is compiled as FSharpRef op_Dereference
                     return Replacements.Api.getRefCell com r (List.head v.Type.Generics) v
@@ -1909,7 +1909,7 @@ let private transformMemberDecl
     // for Rust, retain inlined functions that have [<CompiledName("...")>] attribute
     elif
         isInline memb
-        && (Compiler.Language <> Rust || not (hasAttrib Atts.compiledName memb.Attributes))
+        && not (Compiler.Language = Rust && (hasAttrib Atts.compiledName memb.Attributes))
     then
         []
     elif memb.IsImplicitConstructor then
@@ -1949,7 +1949,7 @@ let private transformMemberDecl
         | _ -> transformMemberFunctionOrValue com ctx memb args body
 
 let private addUsedRootName (com: Compiler) name (usedRootNames: Set<string>) =
-    if com.Options.Language <> Rust && Set.contains name usedRootNames then
+    if not (com.Options.Language = Rust) && Set.contains name usedRootNames then
         "Cannot have two module members with same name: " + name |> addError com [] None
 
     Set.add name usedRootNames

src/Fable.Transforms/Replacements.Api.fs

@@ -40,6 +40,7 @@ let tryBaseConstructor (com: ICompiler) ctx (ent: EntityRef) (argTypes: Lazy<Typ
     match com.Options.Language with
     | Python -> Py.Replacements.tryBaseConstructor com ctx ent argTypes genArgs args
     | Dart -> Dart.Replacements.tryBaseConstructor com ctx ent argTypes genArgs args
+    | Rust -> Rust.Replacements.tryBaseConstructor com ctx ent argTypes genArgs args
     | _ -> JS.Replacements.tryBaseConstructor com ctx ent argTypes genArgs args
 
 let makeMethodInfo (com: ICompiler) r (name: string) (parameters: (string * Type) list) (returnType: Type) =

src/Fable.Transforms/Rust/AST/Rust.AST.Helpers.fs

@@ -1065,23 +1065,23 @@ module Types =
 
     let mkParenTy ty : Ty = TyKind.Paren(ty) |> mkTy
 
-    let mkRefTy nameOpt ty : Ty =
-        let lifetimeOpt = nameOpt |> Option.map mkLifetime
+    let mkRefTy (lifetimeOpt: Symbol option) ty : Ty =
+        let opt_lifetime = lifetimeOpt |> Option.map mkLifetime
 
         TyKind.Rptr(
-            lifetimeOpt,
+            opt_lifetime,
             {
                 ty = ty
                 mutbl = Mutability.Not
             }
         )
         |> mkTy
 
-    let mkMutRefTy nameOpt ty : Ty =
-        let lifetimeOpt = nameOpt |> Option.map mkLifetime
+    let mkMutRefTy (lifetimeOpt: Symbol option) ty : Ty =
+        let opt_lifetime = lifetimeOpt |> Option.map mkLifetime
 
         TyKind.Rptr(
-            lifetimeOpt,
+            opt_lifetime,
             {
                 ty = ty
                 mutbl = Mutability.Mut
@@ -1331,14 +1331,20 @@ module Items =
         else
             item |> mkPublicAssocItem
 
-    let mkFnItem attrs name kind : Item =
+    let mkTyAliasAssocItem attrs name ty generics bounds : AssocItem =
         let ident = mkIdent name
-        ItemKind.Fn kind |> mkItem attrs ident
+
+        AssocItemKind.TyAlias(Defaultness.Final, generics, mkVec bounds, Some(ty))
+        |> mkAssocItem attrs ident
 
     let mkFnAssocItem attrs name kind : AssocItem =
         let ident = mkIdent name
         AssocItemKind.Fn kind |> mkAssocItem attrs ident
 
+    let mkFnItem attrs name kind : Item =
+        let ident = mkIdent name
+        ItemKind.Fn kind |> mkItem attrs ident
+
     let mkUseItem attrs names kind : Item =
         let mkUseTree prefix kind : UseTree =
             {