Implement return, implement instant break, add exit function, implement dumping and loading of AST via encoding/json

cmd/scpt/main.go

@@ -5,32 +5,65 @@ import (
 	"flag"
 	"fmt"
 	"gitea.arsenm.dev/Arsen6331/scpt"
+	"io/ioutil"
 	"log"
 	"os"
 )
 
 func main() {
-	filePath := flag.String("file", "", "File to parse")
+	useStdin := flag.Bool("stdin", false, "Parse STDIN")
+	dumpAST := flag.Bool("dump-ast", false, "Dump the AST as JSON to STDOUT and quit")
+	loadAST := flag.String("load-ast", "", "Load JSON AST from specified file and execute it")
 	flag.Parse()
 
-	if *filePath == "" {
-		log.Fatalln("Use --file to specify a file to parse")
+	var ast *scpt.AST
+
+	if *loadAST != "" {
+		data, err := ioutil.ReadFile(*loadAST)
+		if err != nil {
+			log.Fatalln("Error opening specified file:", err)
+		}
+		ast, err = scpt.LoadAST(data)
+		if err != nil {
+			log.Fatalln("Error loading AST:", err)
+		}
+	} else if *useStdin {
+		var err error
+		ast, err = scpt.Parse(os.Stdin)
+		if err != nil {
+			log.Fatalln("Error parsing STDIN:", err)
+		}
+	} else {
+		if flag.NArg() < 1 {
+			log.Fatalln("Filepath or --stdin required")
+		}
+		filePath := flag.Args()[0]
+		file, err := os.Open(filePath)
+		if err != nil {
+			log.Fatalln("Error opening specified file:", err)
+		}
+		ast, err = scpt.Parse(file)
+		if err != nil {
+			log.Fatalln("Error parsing file:", err)
+		}
 	}
 
-	file, err := os.Open(*filePath)
-	if err != nil {
-		log.Fatalln("Error opening specified file:", err)
-	}
-	ast, err := scpt.Parse(file)
-	if err != nil {
-		log.Fatalln("Error parsing file:", err)
+	if *dumpAST {
+		data, err := ast.DumpPretty()
+		if err != nil {
+			log.Fatalln("Error dumping AST:", err)
+		}
+		fmt.Println(string(data))
+		os.Exit(0)
 	}
+
 	scpt.AddFuncs(scpt.FuncMap{
 		"print":           scptPrint,
 		"display-dialog":  displayDialog,
 		"do-shell-script": doShellScript,
 	})
-	err = ast.Execute()
+
+	err := ast.Execute()
 	if err != nil {
 		log.Fatalln("Error executing script:", err)
 	}