Add F# support to migrate-dotnet* skills #406
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| Original file line number | Diff line number | Diff line change |
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| @@ -0,0 +1,48 @@ | ||
| # F# 11 Compiler Breaking Changes (.NET 11) | ||
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| These breaking changes affect F# projects targeting `net11.0` (which uses F# 11 by default). F# 11 ships with the .NET 11 SDK. | ||
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| > **Note:** .NET 11 is in preview. This covers changes through Preview 1. Additional breaking changes may be introduced in later previews. | ||
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| ## Source-Incompatible Changes | ||
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| ### ML compatibility removal | ||
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| **Impact: Medium.** F# 11 removes all remaining ML/OCaml compatibility constructs that the compiler has carried since F#'s origins as an OCaml dialect. This is a significant cleanup (~7,000 lines of legacy code removed). | ||
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| The following are **removed**: | ||
| - **Source file extensions:** `.ml` and `.mli` files are no longer recognized as F# source files. | ||
| - **Directives:** `#light` and `#indent` directives are removed. (Whitespace-sensitive syntax has been the default for many years.) | ||
| - **Compiler flags:** `--mlcompatibility`, `--light`, `--indentation-syntax`, `--no-indentation-syntax`, and `--ml-keywords` are all removed. | ||
| - **Reserved keywords released:** `asr`, `land`, `lor`, `lsl`, `lsr`, and `lxor` — previously reserved for ML compatibility — are now available as regular identifiers. | ||
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| ```fsharp | ||
| // BREAKS — .ml file extension | ||
| // Rename MyModule.ml → MyModule.fs | ||
| // Rename MyModule.mli → MyModule.fsi | ||
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| // BREAKS — #light directive | ||
| #light "off" // error: directive no longer recognized | ||
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| // FIX — simply remove the directive (whitespace-sensitive syntax is the default) | ||
| ``` | ||
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| **Fix:** | ||
| 1. Rename any `.ml` files to `.fs` and `.mli` files to `.fsi`. | ||
| 2. Remove all `#light` and `#indent` directives from source files. | ||
| 3. Remove `--mlcompatibility` and related flags from project files, build scripts, and CI configurations. | ||
| 4. If you used `asr`, `land`, `lor`, `lsl`, `lsr`, or `lxor` as escaped identifiers (e.g., `` ``asr`` ``), you can now use them as plain identifiers. | ||
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| See also: [dotnet/fsharp#19143](https://github.com/dotnet/fsharp/pull/19143) | ||
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| ## Performance Improvements (non-breaking) | ||
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| ### Parallel compilation enabled by default | ||
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| Parallel compilation (preview in F# 10) is now enabled by default for all projects. This includes parallel reference resolution, graph-based type checking, parallel optimizations, and parallel IL code generation. | ||
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| If you encounter issues, opt out with the `--parallelcompilation-` compiler flag. | ||
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| ### Faster compilation of computation expression-heavy code | ||
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| The compiler's stack-overflow prevention mechanism (`StackGuard`) has been replaced with `RuntimeHelpers.TryEnsureSufficientExecutionStack()`, significantly reducing thread creation for deeply nested computation expressions (e.g., `task { }`, `async { }`). |
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@@ -3,10 +3,10 @@ name: migrate-dotnet8-to-dotnet9 | |
| description: > | ||
| Migrate a .NET 8 project to .NET 9 and resolve all breaking changes. | ||
| USE FOR: upgrading TargetFramework from net8.0 to net9.0, fixing build errors | ||
| after updating the .NET 9 SDK, resolving behavioral changes in .NET 9 / C# 13 / F# 9 / | ||
| ASP.NET Core 9 / EF Core 9, replacing BinaryFormatter (now always throws), | ||
| resolving SYSLIB0054-SYSLIB0057, adapting to params span overload resolution, | ||
| fixing C# 13 / F# 9 compiler changes, updating HttpClientFactory for SocketsHttpHandler, | ||
| and resolving EF Core 9 migration/Cosmos DB changes. | ||
| DO NOT USE FOR: .NET Framework migrations, upgrading from .NET 7 or earlier, | ||
| greenfield .NET 9 projects, or cosmetic modernization unrelated to the upgrade. | ||
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@@ -35,7 +35,7 @@ Migrate a .NET 8 project or solution to .NET 9, systematically resolving all bre | |
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| | Input | Required | Description | | ||
| |-------|----------|-------------| | ||
| | Project or solution path | Yes | The `.csproj`, `.fsproj`, `.sln`, or `.slnx` entry point to migrate | | ||
| | Build command | No | How to build (e.g., `dotnet build`, a repo build script). Auto-detect if not provided | | ||
| | Test command | No | How to run tests (e.g., `dotnet test`). Auto-detect if not provided | | ||
| | Project type hints | No | Whether the project uses ASP.NET Core, EF Core, WinForms, WPF, containers, etc. Auto-detect from PackageReferences and SDK attributes if not provided | | ||
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@@ -48,7 +48,7 @@ Migrate a .NET 8 project or solution to .NET 9, systematically resolving all bre | |
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| ### Step 1: Assess the project | ||
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| 1. Identify how the project is built and tested. Look for build scripts, `.sln`/`.slnx` files, or individual `.csproj`/`.fsproj` files. | ||
| 2. Run `dotnet --version` to confirm the .NET 9 SDK is installed. If it is not, stop and inform the user. | ||
| 3. Determine which technology areas the project uses by examining: | ||
| - **SDK attribute**: `Microsoft.NET.Sdk.Web` → ASP.NET Core; `Microsoft.NET.Sdk.WindowsDesktop` with `<UseWPF>` or `<UseWindowsForms>` → WPF/WinForms | ||
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@@ -63,7 +63,7 @@ Migrate a .NET 8 project or solution to .NET 9, systematically resolving all bre | |
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| ### Step 2: Update the Target Framework | ||
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| 1. In each `.csproj`/`.fsproj` (or `Directory.Build.props` if centralized), change: | ||
| ```xml | ||
| <TargetFramework>net8.0</TargetFramework> | ||
| ``` | ||
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@@ -87,7 +87,8 @@ Work through compilation errors and new warnings systematically. Load the approp | |
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| | If the project uses… | Load reference | | ||
| |-----------------------|----------------| | ||
| | C# project | `references/csharp-compiler-dotnet8to9.md` | | ||
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Contributor
There was a problem hiding this comment. this duplicates the "when to load" at the end. I don't remember doing that-- maybe I forgot? But seems one should be deleted.
Contributor
Author
There was a problem hiding this comment. Removed the duplicate Step 3 table in e95247e. The Reference Documents section at the bottom is now the single source of truth. Step 3 just says to load from that table. Applied to all three skills. |
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| | F# project | `references/fsharp-compiler-dotnet8to9.md` | | ||
| | Any .NET 9 project | `references/core-libraries-dotnet8to9.md` | | ||
| | Any .NET 9 project | `references/sdk-msbuild-dotnet8to9.md` | | ||
| | ASP.NET Core | `references/aspnet-core-dotnet8to9.md` | | ||
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@@ -219,7 +220,8 @@ The `references/` folder contains detailed breaking change information organized | |
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| | Reference file | When to load | | ||
| |----------------|-------------| | ||
| | `references/csharp-compiler-dotnet8to9.md` | Project uses C# (C# 13 compiler breaking changes — InlineArray on records, iterator safe context, collection expression overloads) | | ||
| | `references/fsharp-compiler-dotnet8to9.md` | Project uses F# (F# 9 compiler breaking changes) | | ||
| | `references/core-libraries-dotnet8to9.md` | Always (applies to all .NET 9 projects) | | ||
| | `references/sdk-msbuild-dotnet8to9.md` | Always (SDK and build tooling changes) | | ||
| | `references/aspnet-core-dotnet8to9.md` | Project uses ASP.NET Core | | ||
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| Original file line number | Diff line number | Diff line change |
|---|---|---|
| @@ -0,0 +1,55 @@ | ||
| # F# 9 Compiler Breaking Changes (.NET 9) | ||
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| These breaking changes affect F# projects targeting `net9.0` (which uses F# 9 by default). F# 9 ships with the .NET 9 SDK. | ||
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| ## Source-Incompatible Changes | ||
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| ### Auto-generated `.Is*` properties on discriminated unions | ||
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| **Impact: Medium.** F# 9 auto-generates `.Is*` properties for each case of a discriminated union. If you already defined custom `Is*` properties or members with the same names, a conflict will occur. | ||
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| ```fsharp | ||
| // BREAKS — custom property conflicts with auto-generated one | ||
| type Shape = | ||
| | Circle of radius: float | ||
| | Rectangle of width: float * height: float | ||
| member this.IsCircle = // now conflicts with auto-generated IsCircle | ||
| match this with Circle _ -> true | _ -> false | ||
| ``` | ||
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| **Fix:** Remove the custom `Is*` members — the compiler-generated versions provide the same functionality. | ||
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| ### Struct unions with overlapping fields and reflection | ||
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| **Impact: Low–Medium.** In FSharp.Core 9.0, struct unions with overlapping fields now generate detailed internal mappings to support correct reading via reflection. Code or libraries using `FSharpValue.GetUnionFields` or similar reflection APIs on struct unions may see different behavior or exceptions if they relied on the previous incomplete mapping. | ||
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| **Fix:** Update libraries that reflect over struct unions. The new mapping is more complete and correct. | ||
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| ### `ArgumentOutOfRangeException` for collection index out-of-bounds | ||
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| **Impact: Low.** Accessing an out-of-bounds index in FSharp.Core collections (e.g., `Array`, `List`) now throws `System.ArgumentOutOfRangeException` instead of `System.ArgumentException` in some cases. If your exception-handling code specifically catches `ArgumentException` and not `ArgumentOutOfRangeException`, update it. | ||
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| ```fsharp | ||
| // Before: threw ArgumentException in some cases | ||
| // After: throws ArgumentOutOfRangeException | ||
| try | ||
| let _ = [1; 2; 3].[10] | ||
| () | ||
| with | ||
| | :? System.ArgumentOutOfRangeException -> () // update catch patterns | ||
| ``` | ||
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| ## New Language Features (non-breaking but relevant) | ||
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| ### Nullable reference type support (opt-in) | ||
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| F# 9 adds support for nullable reference types, but this is **off by default**. Enable with `<Nullable>enable</Nullable>` in the `.fsproj` file. Enabling this may surface new warnings about null usage in existing code. | ||
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| ### `_.Property` shorthand for member access in lambdas | ||
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| F# 9 introduces `_.Property` shorthand syntax in pipelines: | ||
| ```fsharp | ||
| customers |> List.map _.Name | ||
| ``` | ||
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| This is purely additive and does not break existing code. |
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| Original file line number | Diff line number | Diff line change |
|---|---|---|
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@@ -4,16 +4,16 @@ description: > | |
| Migrate a .NET 9 project or solution to .NET 10 and resolve all breaking changes. | ||
| USE FOR: upgrading TargetFramework from net9.0 to net10.0, fixing build errors | ||
| after updating the .NET 10 SDK, resolving source and behavioral changes in | ||
| .NET 10 / C# 14 / F# 10 / ASP.NET Core 10 / EF Core 10, updating Dockerfiles, | ||
| resolving obsoletion warnings (SYSLIB0058-SYSLIB0062), SDK/NuGet changes | ||
| (NU1510, PrunePackageReference), System.Linq.Async to built-in | ||
| AsyncEnumerable, OpenApi v2 API changes, cryptography renames, | ||
| C# 14 compiler changes (field keyword, extension keyword, span overloads), | ||
| and F# 10 compiler changes. | ||
| DO NOT USE FOR: .NET Framework migrations, upgrading from .NET 8 or earlier | ||
| (use migrate-dotnet8-to-dotnet9 first), or greenfield .NET 10 projects. | ||
| LOADS REFERENCES: csharp-compiler (C#), fsharp-compiler (F#), | ||
| core-libraries, sdk-msbuild (always); | ||
| aspnet-core, efcore, cryptography, extensions-hosting, | ||
| serialization-networking, winforms-wpf, containers-interop (selective). | ||
| --- | ||
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@@ -41,7 +41,7 @@ Migrate a .NET 9 project or solution to .NET 10, systematically resolving all br | |
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| | Input | Required | Description | | ||
| |-------|----------|-------------| | ||
| | Project or solution path | Yes | The `.csproj`, `.fsproj`, `.sln`, or `.slnx` entry point to migrate | | ||
| | Build command | No | How to build (e.g., `dotnet build`, a repo build script). Auto-detect if not provided | | ||
| | Test command | No | How to run tests (e.g., `dotnet test`). Auto-detect if not provided | | ||
| | Project type hints | No | Whether the project uses ASP.NET Core, EF Core, WinForms, WPF, containers, etc. Auto-detect from PackageReferences and SDK attributes if not provided | | ||
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@@ -54,7 +54,7 @@ Migrate a .NET 9 project or solution to .NET 10, systematically resolving all br | |
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| ### Step 1: Assess the project | ||
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| 1. Identify how the project is built and tested. Look for build scripts, `.sln`/`.slnx` files, or individual `.csproj`/`.fsproj` files. | ||
| 2. Run `dotnet --version` to confirm the .NET 10 SDK is installed. If it is not, stop and inform the user. | ||
| 3. Determine which technology areas the project uses by examining: | ||
| - **SDK attribute**: `Microsoft.NET.Sdk.Web` → ASP.NET Core; `Microsoft.NET.Sdk.WindowsDesktop` with `<UseWPF>` or `<UseWindowsForms>` → WPF/WinForms | ||
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@@ -68,7 +68,7 @@ Migrate a .NET 9 project or solution to .NET 10, systematically resolving all br | |
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| ### Step 2: Update the Target Framework | ||
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| 1. In each `.csproj`/`.fsproj` (or `Directory.Build.props` if centralized), change: | ||
| ```xml | ||
| <TargetFramework>net9.0</TargetFramework> | ||
| ``` | ||
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@@ -89,11 +89,12 @@ Migrate a .NET 9 project or solution to .NET 10, systematically resolving all br | |
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| ### Step 3: Resolve build errors and source-incompatible changes | ||
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| Work through compilation errors and new warnings systematically. Load the appropriate reference documents based on what your solution contains: | ||
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| | If your solution contains… | Load reference | | ||
| |----------------------------|----------------| | ||
| | C# projects | `references/csharp-compiler-dotnet9to10.md` | | ||
|
Contributor
There was a problem hiding this comment. same comment about duplicating when to load table below
Contributor
Author
There was a problem hiding this comment. Fixed in e95247e — same approach as dotnet8-to-dotnet9. |
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| | F# projects | `references/fsharp-compiler-dotnet9to10.md` | | ||
| | Any .NET 10 project | `references/core-libraries-dotnet9to10.md` | | ||
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ViktorHofer marked this conversation as resolved.
Outdated
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| | Any .NET 10 project | `references/sdk-msbuild-dotnet9to10.md` | | ||
| | ASP.NET Core | `references/aspnet-core-dotnet9to10.md` | | ||
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@@ -261,7 +262,8 @@ The `references/` folder contains detailed breaking change information organized | |
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| | Reference file | When to load | | ||
| |----------------|-------------| | ||
| | `references/csharp-compiler-dotnet9to10.md` | Project uses C# (C# 14 compiler breaking changes — field keyword, extension keyword, span overloads) | | ||
| | `references/fsharp-compiler-dotnet9to10.md` | Project uses F# (F# 10 compiler breaking changes) | | ||
| | `references/core-libraries-dotnet9to10.md` | Always (applies to all .NET 10 projects) | | ||
| | `references/sdk-msbuild-dotnet9to10.md` | Always (SDK and build tooling changes) | | ||
| | `references/aspnet-core-dotnet9to10.md` | Project uses ASP.NET Core | | ||
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I pulled out all docs links because they added tokens for no benefit. It can find docs. And the extra text here is surely not necessary
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Applied in e95247e — combined both bullets into a single line and removed the docs link.
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Are you sure on that? I assume that without the link, the LLM will not always initiate a web_fetch call. In other words, doesn't the omission of the links make the process less deterministic?