Merge pull request #161 from iuribrindeiro/dotnet-platform-example

Dotnet platform example

.gitignore

@@ -20,4 +20,4 @@ examples/Tuples/main
 roc_nightly/
 
 # macOS directory attributes
-.DS_Store
+.DS_Store

ci_scripts/all_tests.sh

@@ -71,3 +71,6 @@ cd ./examples/GoPlatform
 go build ./platform/main.go
 cd ../..
 expect ci_scripts/expect_scripts/GoPlatform.exp
+
+$ROC build ./examples/DotNetPlatform/main.roc --lib --output ./examples/DotNetPlatform/platform/interop
+expect ci_scripts/expect_scripts/DotNetPlatform.exp

ci_scripts/expect_scripts/DotNetPlatform.exp

@@ -0,0 +1,20 @@
+#!/usr/bin/expect
+
+# uncomment line below for debugging
+# exp_internal 1
+
+set timeout 25
+
+cd "./examples/DotNetPlatform/platform/"
+
+spawn dotnet run
+
+expect "Hello from .NET!\r\n" {
+  expect "Hi from roc! (in a .NET platform) 🔥🦅🔥\r\n" {
+    expect eof
+    exit 0
+  }
+}
+
+puts stderr "\nError: output was different from expected value."
+exit 1

examples/DotNetPlatform/.gitignore

@@ -0,0 +1,6 @@
+# publish and debug artifacts
+bin
+obj
+platform/publish
+
+interop.*

examples/DotNetPlatform/README.md

@@ -0,0 +1,60 @@
+# DotNet Platform 
+
+A minimal .NET platform
+
+## Full Code
+
+main.roc:
+```roc
+file:main.roc
+```
+
+platform/main.roc:
+```
+file:platform/main.roc
+```
+
+platform/DotNetRocPlatform.csproj:
+```
+file:platform/DotNetRocPlatform.csproj
+```
+
+platform/Program.cs:
+```
+file:platform/Program.cs
+```
+
+## Build & Run 
+
+1. Build the roc app that is using the dotnet platform:
+
+```cli
+cd examples/DotNetPlatform/
+roc build main.roc --lib --output ./platform/interop
+```
+> _use `arch -arm64` if you are running in a Apple Silicon mac._
+
+This will produce a shared library file that we'll be able to import from a .NET context.
+
+To run:
+```cli
+cd platform
+dotnet run
+```
+This should print "Hello from .NET".
+
+
+## Build & Run Binary
+
+If you want to build a binary for the app using native AOT:
+
+1. Publish the dotnet app
+```cli
+dotnet publish -c Release
+```
+> _use `arch -arm64` if you are running in a Apple Silicon mac._
+
+2. `cd` into the into the `publish` folder and run the binary:
+```cli
+./DotNetRocPlatform
+```

examples/DotNetPlatform/main.roc

@@ -0,0 +1,6 @@
+app "dotnetapp"
+    packages { platform: "./platform/main.roc" }
+    imports []
+    provides [main] to platform
+
+main = "Hi from roc! (in a .NET platform) 🔥🦅🔥"

examples/DotNetPlatform/platform/DotNetRocPlatform.csproj

@@ -0,0 +1,16 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project Sdk="Microsoft.NET.Sdk">
+  <PropertyGroup>
+    <OutputType>Exe</OutputType>
+    <TargetFramework>net8.0</TargetFramework>
+    <Nullable>enable</Nullable>
+    <AllowUnsafeBlocks>true</AllowUnsafeBlocks>
+    <PublishAot>true</PublishAot>
+    <ImplicitUsings>true</ImplicitUsings>
+  </PropertyGroup>
+  <ItemGroup>
+    <None Update="interop.*">
+      <CopyToOutputDirectory>Always</CopyToOutputDirectory>
+    </None>
+  </ItemGroup>
+</Project>

examples/DotNetPlatform/platform/Program.cs

@@ -0,0 +1,46 @@
+using System.Reflection;
+using System.Runtime.InteropServices;
+using System.Text;
+using static System.Console;
+using static Platform;
+
+NativeLibrary.SetDllImportResolver(Assembly.GetExecutingAssembly(), CustomResolver);
+
+WriteLine("Hello from .NET!");
+
+MainFromRoc(out var rocStr);
+
+WriteLine(rocStr);
+
+//Load native library even when the name doesn't exactly match the name of the library defined in `LibraryImport`
+//eg: `interop.so.1.0` instead of `interop.so`
+static IntPtr CustomResolver(string libraryName, Assembly assembly, DllImportSearchPath? searchPath)
+{
+    var libFile = Directory
+        .EnumerateFiles(Directory.GetCurrentDirectory())
+        .FirstOrDefault(e => e.Contains(libraryName));
+
+    if (libFile != null)
+    {
+        return NativeLibrary.Load(libFile, assembly, searchPath);
+    }
+
+    return IntPtr.Zero;
+}
+
+public static partial class Platform
+{
+    [LibraryImport("interop", EntryPoint = "roc__mainForHost_1_exposed_generic")]
+    internal static partial void MainFromRoc(out RocStr rocStr);
+}
+
+public unsafe struct RocStr
+{
+    public byte* Bytes;
+    public UIntPtr Len;
+    public UIntPtr Capacity;
+
+    public override string ToString() => Encoding.UTF8.GetString(Bytes, (int)Len.ToUInt32());
+
+    public static implicit operator string(RocStr rocStr) => rocStr.ToString();
+}

examples/DotNetPlatform/platform/main.roc

@@ -0,0 +1,9 @@
+platform "dotnetplatform"
+    requires {} { main : Str }
+    exposes []
+    packages {}
+    imports []
+    provides [mainForHost]
+
+mainForHost : Str
+mainForHost = main

examples/GoPlatform/README.md

@@ -9,6 +9,11 @@ main.roc:
 file:main.roc
 ```
 
+platform/main.roc:
+```
+file:platform/main.roc
+```
+
 platform/go.mod:
 ```
 file:platform/go.mod

examples/index.md

@@ -24,6 +24,7 @@ You can find the source code for all of these at [github.com/roc-lang/examples](
 - [Record Builder](/RecordBuilder/README.html)
 - [Multi-line Comments](/MultiLineComments/README.html)
 - [Go Platform](/GoPlatform/README.html)
+- [.NET Platform](/DotNetPlatform/README.html)
 
 ## External examples
 

flake.nix

@@ -48,6 +48,7 @@
                       customRust # for static-site-gen platform
                       perl # for ci/update_basic_cli_url.sh
                       go # for GoPlatform example
+                      dotnet-sdk_8 # for DotnetPlatform example
 		                ] ++ linuxInputs;
 
                     # nix does not store libs in /usr/lib or /lib