feat: add example and init subcommand

.github/workflows/main.yaml

@@ -7,6 +7,7 @@ env:
   # libcxx version to match whats already installed
   # https://github.com/actions/runner-images/blob/main/images/ubuntu/Ubuntu2404-Readme.md
   LLVM_VERSION: '18.1.3'
+  CPP2B_LIBCXX_BUILD_ROOT: '/tmp/llvm-project/build'
 
 jobs:
   typos-check:
@@ -61,7 +62,7 @@ jobs:
           CC=clang-18 CXX=clang++-18 cmake -G Ninja -S runtimes -B build -DLLVM_ENABLE_RUNTIMES="libcxx;libcxxabi;libunwind"
           ninja -C build
       - uses: actions/checkout@v4
-      - run: CPP2B_LIBCXX_BUILD_ROOT=/tmp/llvm-project/build CC=clang-18 ./build.sh
+      - run: CC=clang-18 ./build.sh
       - uses: actions/upload-artifact@v4
         with:
           name: cpp2b
@@ -83,5 +84,30 @@ jobs:
         with:
           name: cpp2b
       - run: chmod +x cpp2b
-      - run: CPP2B_LIBCXX_BUILD_ROOT=/tmp/llvm-project/build ./cpp2b build
-      - run: CPP2B_LIBCXX_BUILD_ROOT=/tmp/llvm-project/build ./.cache/cpp2/bin/cpp2b build
+      - run: ./cpp2b build
+      - run: ./.cache/cpp2/bin/cpp2b build
+
+  build-examples:
+    name: build examples
+    needs: [build-script-windows, build-script-linux]
+    runs-on: ${{ matrix.os }}
+    strategy:
+      matrix:
+        example:
+          - init
+        os:
+          - windows-latest
+          - ubuntu-24.04
+    steps:
+      - uses: actions/checkout@v4
+      - uses: actions/download-artifact@v4
+        id: cpp2b-binary
+        with:
+          name: 'cpp2b-${{ matrix.os }}'
+      - uses: actions/cache/restore@v4
+        if: "'${{ matrix.os }}' == 'ubuntu-24.04'"
+        with:
+          path: /tmp/llvm-project/build
+          key: 'libcxx-${{ env.LLVM_VERSION }}'
+      - run: '${{ steps.cpp2b-binary.outputs.download-path }} build'
+        working-directory: "examples/${{ matrix.example }}"

examples/init/.gitignore

@@ -0,0 +1,2 @@
+# cpp2b cache directory
+.cache/cpp2

examples/init/README.md

@@ -0,0 +1,5 @@
+This project is the result of running
+
+```bash
+cpp2b init
+```

examples/init/build.cpp2

@@ -0,0 +1,6 @@
+import cpp2b.build;
+
+build: (inout b: cpp2b::build) -> void = {
+	// rename binary so instead of it being 'src/main' it will be 'init'
+	b.binary_name("src/main", "init");
+}

examples/init/src/main.cpp2

@@ -0,0 +1 @@
+main: () = std::println("Hello, init!");

src/main.cpp2

@@ -16,6 +16,10 @@ log_info: <Args...: type>(fmt: std::format_string<Args...>, forward args...: Arg
 	std::println("\033[0;36mINFO\033[0m: {}", std::format(fmt, args...));
 }
 
+log_success: <Args...: type>(fmt: std::format_string<Args...>, forward args...: Args) = {
+	std::println("\033[0;32mSUCCESS\033[0m: {}", std::format(fmt, args...));
+}
+
 ensure_dir: (dir: fs::path) = {
 	status := fs::status(dir);
 
@@ -358,6 +362,7 @@ main: (args) -> int = {
 			return inspect arg -> int {
 				is "build" = subcommands::build(remaining_args);
 				is "clean" = subcommands::clean(remaining_args);
+				is "init"  = subcommands::init(remaining_args);
 				is "run"   = subcommands::run(remaining_args);
 				is _       = subcommands::unknown(arg);
 			};
@@ -496,16 +501,21 @@ warn_if_error: (context, p: fs::path, ec: std::error_code) -> void = {
 	}
 }
 
+
 find_root_dir: (dir: fs::path) -> std::optional<fs::path> = {
+	return find_root_dir(dir, "build.cpp2");
+}
+
+find_root_dir: (dir: fs::path, filename) -> std::optional<fs::path> = {
 	if dir.empty() { return std::nullopt; }
 
-	if fs::exists(dir / "build.cpp2") {
+	if fs::exists(dir / filename) {
 		return dir;
 	}
 
 	if !dir.has_parent_path() { return std::nullopt; }
 
-	return find_root_dir(dir.parent_path());
+	return find_root_dir(dir.parent_path(), filename);
 }
 
 build_binary_result: @struct type = {
@@ -905,7 +915,7 @@ subcommands: type = {
 				return build_result.exit_code;
 			}
 
-			log_info("binary built {} ({}ms)", fs::relative(build_result.outpath).generic_string(), build_result.duration.count());
+			log_success("binary built {} ({}ms)", fs::relative(build_result.outpath).generic_string(), build_result.duration.count());
 		}
 
 		return 0;
@@ -926,6 +936,55 @@ subcommands: type = {
 		return 0;
 	}
 
+	init: (args) -> int = {
+		if fs::exists("build.cpp2") {
+			log_error("already initialized cpp2b project!");
+			return 1;
+		}
+
+		dirname := fs::current_path().filename().string();
+
+		ensure_dir("src");
+
+		main_cpp2: std::ofstream = ("src/main.cpp2", std::ios::binary);
+		main_cpp2 << "main: () = std::println(\"Hello, (dirname)$!\");\n";
+
+		build_cpp2: std::ofstream = ("build.cpp2", std::ios::binary);
+		build_cpp2 << "import cpp2b.build;\n\n";
+		build_cpp2 << "build: (inout b: cpp2b::build) -> void = {\n";
+		build_cpp2 << "\t// rename binary so instead of it being 'src/main' it will be '(dirname)$'\n";
+		build_cpp2 << "\tb.binary_name(\"src/main\", \"(dirname)$\");\n";
+		build_cpp2 << "}\n";
+
+		main_cpp2.flush();
+		main_cpp2.close();
+		build_cpp2.flush();
+		build_cpp2.close();
+
+		log_info("added build.cpp2");
+		log_info("added src/main.cpp2");
+
+		if !fs::exists(".gitignore") {
+			if !find_root_dir(fs::current_path(), ".git") {
+				log_warning("assuming git repository");
+			}
+
+			gitignore: std::ofstream = (".gitignore", std::ios::binary);
+			gitignore << "# cpp2b cache directory\n";
+			gitignore << ".cache/cpp2\n";
+
+			gitignore.flush();
+			gitignore.close();
+
+			log_info("added .gitignore");
+		}
+
+		log_success("initialized cpp2b project '{}'", dirname);
+		log_info("run `cpp2b build` to build your project");
+
+		return 0;
+	}
+
 	unknown: (subcommand) -> int = {
 		log_error("unknown subcommand {}", subcommand);
 		return 1;