add: dynamic template function

internal/cli/new.go

@@ -2,11 +2,12 @@ package cli
 
 import (
 	"fmt"
+	"github.com/nevalang/neva/internal"
 	"os"
 	"path/filepath"
 
 	"github.com/nevalang/neva/pkg"
-	cli "github.com/urfave/cli/v2"
+	"github.com/urfave/cli/v2"
 )
 
 func newNewCmd(workdir string) *cli.Command {
@@ -19,21 +20,36 @@ func newNewCmd(workdir string) *cli.Command {
 				if err := os.Mkdir(pathArg, 0755); err != nil {
 					return err
 				}
-				return createNevaMod(pathArg)
+				return createNevaMod(pathArg, "hello-world")
 			}
-			return createNevaMod(workdir)
+			return createNevaMod(workdir, "hello-world")
+		},
+		Flags: []cli.Flag{
+			&cli.StringFlag{
+				Name:     "template",
+				Usage:    "Specify the template for creating new projects.",
+				Required: false,
+
+				Action: func(context *cli.Context, templateName string) error {
+					if templateName == "" {
+						templateName = "hello-world"
+					}
+					pathArg := context.Args().First()
+					if err := os.Mkdir(pathArg, 0755); err != nil {
+						return err
+					}
+					return createNevaMod(pathArg, templateName)
+
+				},
+			},
 		},
 	}
 }
 
-func createNevaMod(path string) error {
+func createNevaMod(path string, templateName string) error {
 	// Create neva.yml file
 	nevaYmlContent := fmt.Sprintf("neva: %s", pkg.Version)
-	if err := os.WriteFile(
-		filepath.Join(path, "neva.yml"),
-		[]byte(nevaYmlContent),
-		0644,
-	); err != nil {
+	if err := os.WriteFile(filepath.Join(path, "neva.yml"), []byte(nevaYmlContent), 0644); err != nil {
 		return err
 	}
 
@@ -43,22 +59,26 @@ func createNevaMod(path string) error {
 		return err
 	}
 
-	// Create main.neva file
-	mainNevaContent := `import { fmt }
-
-def Main(start any) (stop any) {
-	fmt.Println
-	---
-	:start -> 'Hello, World!' -> println -> :stop
-}`
-
+	mainNevaContent, err := readTemplate(templateName + ".neva")
+	if err != nil {
+		return err
+	}
 	if err := os.WriteFile(
 		filepath.Join(srcPath, "main.neva"),
 		[]byte(mainNevaContent),
 		0644,
 	); err != nil {
 		return err
 	}
-
 	return nil
 }
+func readTemplate(templateName string) (string, error) {
+	fileData, err := internal.Efs.ReadFile(fmt.Sprintf("templates/%s", templateName))
+	if err != nil {
+		if os.IsNotExist(err) {
+			return "", fmt.Errorf("no such template: %s, available templates see: https://github.com/nevalang/neva/tree/main/internal/templates", templateName)
+		}
+		return "", fmt.Errorf("failed to read template file %s: %w", templateName, err)
+	}
+	return string(fileData), nil
+}

internal/embed.go

@@ -3,5 +3,5 @@ package internal
 import "embed"
 
 //nolint:golint
-//go:embed runtime
+//go:embed runtime templates
 var Efs embed.FS

internal/templates/empty.neva

@@ -0,0 +1,11 @@
+// import as here
+// eg. import { fmt }
+
+def Main(start any) (stop any) {
+    // code as here
+
+    ---
+    // flow as here
+
+    :start -> :stop
+}

internal/templates/hello-world.neva

@@ -0,0 +1,7 @@
+import { fmt }
+
+def Main(start Any)(stop Any) {
+    println fmt.println<string>
+    ---
+    :start -> "hello world!" -> println -> stop
+}

internal/templates/package.neva

@@ -0,0 +1,7 @@
+// don't forget modify i/o type and name
+
+pub def YourNode(in Any)(out Any) {
+    // code as here
+    ---
+    // flow as here
+}