feat: 增加 GenerateCommand 和 GenerateTask 实现生成项目骨架

src/main/java/org/jcnc/snow/cli/SnowCLI.java

@@ -29,6 +29,7 @@ public class SnowCLI {
      * 值为返回相应 {@link CLICommand} 实例的 Supplier。
      */
     private static final Map<String, Supplier<CLICommand>> COMMANDS = Map.of(
+            "generate", GenerateCommand::new,
             "compile", CompileCommand::new,
             "run", RunCommand::new,
             "version", VersionCommand::new,
@@ -37,6 +38,7 @@ public class SnowCLI {
             "install", InstallCommand::new,
             "publish", PublishCommand::new,
             "clean", CleanCommand::new
+
     );
 
     /**

src/main/java/org/jcnc/snow/cli/commands/GenerateCommand.java

@@ -0,0 +1,59 @@
+package org.jcnc.snow.cli.commands;
+
+import org.jcnc.snow.cli.api.CLICommand;
+import org.jcnc.snow.pkg.dsl.CloudDSLParser;
+import org.jcnc.snow.pkg.lifecycle.LifecycleManager;
+import org.jcnc.snow.pkg.lifecycle.LifecyclePhase;
+import org.jcnc.snow.pkg.model.Project;
+import org.jcnc.snow.pkg.tasks.GenerateTask;
+
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.nio.file.Paths;
+
+/**
+ * CLI 命令：根据 project.cloud 生成项目目录结构。
+ *
+ * <pre>
+ * $ snow generate
+ * </pre>
+ *
+ * - 若当前目录不存在 project.cloud，则提示先执行 snow init。
+ * - 成功后会在控制台输出已创建的目录/文件列表。
+ */
+public final class GenerateCommand implements CLICommand {
+
+    @Override
+    public String name() {
+        return "generate";
+    }
+
+    @Override
+    public String description() {
+        return "Generate project directory structure based on project.cloud.";
+    }
+
+    @Override
+    public void printUsage() {
+        System.out.println("Usage: snow generate");
+    }
+
+    @Override
+    public int execute(String[] args) throws Exception {
+        Path dsl = Paths.get("project.cloud");
+        if (Files.notExists(dsl)) {
+            System.err.println("project.cloud not found. Please run `snow init` first.");
+            return 1;
+        }
+
+        /* 1. 解析 DSL */
+        Project project = CloudDSLParser.parse(dsl);
+
+        /* 2. 执行生成任务 —— 复用 Lifecycle INIT 阶段 */
+        LifecycleManager lm = new LifecycleManager();
+        lm.register(LifecyclePhase.INIT, new GenerateTask(project));
+        lm.executeAll();
+
+        return 0;
+    }
+}

src/main/java/org/jcnc/snow/pkg/tasks/GenerateTask.java

@@ -0,0 +1,91 @@
+package org.jcnc.snow.pkg.tasks;
+
+import org.jcnc.snow.pkg.model.Project;
+
+import java.io.IOException;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.nio.file.Paths;
+import java.util.List;
+
+/**
+ * 任务：依据 {@link Project} 元数据创建标准项目目录。
+ * <p>
+ * 生成内容：
+ * <ul>
+ *   <li>src/          —— 源码目录</li>
+ *   <li>test/         —— 测试源码目录</li>
+ *   <li>build/        —— 编译输出目录</li>
+ *   <li>dist/         —— 打包输出目录</li>
+ *   <li>src/main.snow —— “Hello, Snow!” 示例入口</li>
+ * </ul>
+ */
+public final class GenerateTask implements Task {
+
+    private final Project project;
+
+    public GenerateTask(Project project) {
+        this.project = project;
+    }
+
+    @Override
+    public void run() throws IOException {
+        Path root = Paths.get(".").toAbsolutePath();
+
+        /* -------- 创建目录 -------- */
+        List<Path> dirs = List.of(
+                root.resolve("src"),
+                root.resolve("test"),
+                root.resolve("build"),
+                root.resolve("dist")
+        );
+
+        for (Path dir : dirs) {
+            if (Files.notExists(dir)) {
+                Files.createDirectories(dir);
+                System.out.println("[generate] created directory " + root.relativize(dir));
+            }
+        }
+
+        /* -------- 创建示例入口文件 -------- */
+        Path mainSnow = root.resolve("src").resolve("main.snow");
+        if (Files.notExists(mainSnow)) {
+            Files.writeString(mainSnow, """
+                    module: Math
+                        function: main
+                            parameter:
+                            return_type: int
+                            body:
+                                Math.factorial(6)
+                                return 0
+                            end body
+                        end function
+                    
+                        function: factorial
+                            parameter:
+                                declare n:int
+                            return_type: int
+                            body:
+                                declare num1:int = 1
+                                loop:
+                                    initializer:
+                                        declare counter:int = 1
+                                    condition:
+                                        counter <= n
+                                    update:
+                                        counter = counter + 1
+                                    body:
+                                        num1 = num1 * counter
+                                    end body
+                                end loop
+                                return num1
+                            end body
+                        end function
+                    end module
+                    """);
+            System.out.println("[generate] created src/main.snow");
+        }
+
+        System.out.println("[generate] project scaffold is ready.");
+    }
+}