Merge pull request #18 from GraHms/develop

feature: include REPL

commands/commands.go

@@ -0,0 +1,31 @@
+package commands
+
+import (
+	"os"
+	"fmt"
+	"github.com/grahms/samoralang/evaluator"
+	"github.com/grahms/samoralang/lexer"
+	"github.com/grahms/samoralang/object"
+	"github.com/grahms/samoralang/parser"
+)
+
+var Commands = map[string]func([]byte)  {
+	"run": func(input []byte) {
+		Execute(string(input))
+	},
+}
+
+func Execute(input string) int {
+	env := object.NewEnvironment()
+	l := lexer.New(input)
+
+	p := parser.New(l)
+
+	program := p.ParseProgram()
+	if len(p.Errors()) != 0 {
+		fmt.Printf("Error parsing: %s\n", p.Errors())
+		os.Exit(1)
+	}
+	_ = evaluator.Eval(program, env)
+	return 0
+}

commands/start_repl.go

@@ -0,0 +1,13 @@
+package commands
+
+import (
+	"os"
+	"bufio"
+	"github.com/grahms/samoralang/repl"
+)
+
+func StartREPL() {
+		in := bufio.NewReader(os.Stdin)
+  	out := os.Stdout
+		repl.Start(in, out)
+}

main.go

@@ -3,46 +3,33 @@ package main
 import (
 	"flag"
 	"fmt"
-	"github.com/grahms/samoralang/evaluator"
-	"github.com/grahms/samoralang/lexer"
-	"github.com/grahms/samoralang/object"
-	"github.com/grahms/samoralang/parser"
-	"io"
+	"github.com/grahms/samoralang/commands"
 	"os"
 )
 
 func main() {
 
 	flag.Parse()
 
-	var input []byte
-	var err error
-
-	if len(flag.Args()) > 0 {
-		input, err = os.ReadFile(os.Args[1])
-	} else {
-		input, err = io.ReadAll(os.Stdin)
+	switch len(flag.Args()) {
+	case 0:
+		commands.StartREPL()	
+	case 1:
+		handleCommand("run", 1)
+	default:
+		handleCommand(os.Args[1], 2)
 	}
-
-	if err != nil {
-		fmt.Printf("Error reading: %s\n", err.Error())
-	}
-
-	Execute(string(input))
 }
 
-func Execute(input string) int {
+func handleCommand(command string, arg_n int) {
+	input_file := os.Args[arg_n]
+	input, err := os.ReadFile(input_file)
 
-	env := object.NewEnvironment()
-	l := lexer.New(input)
-
-	p := parser.New(l)
-
-	program := p.ParseProgram()
-	if len(p.Errors()) != 0 {
-		fmt.Printf("Error parsing: %s\n", p.Errors())
-		os.Exit(1)
+	if err != nil {
+		pwd, _ := os.Getwd()
+		fmt.Printf("Error: can't open %s/%s\n", pwd, input_file)
+		return
 	}
-	_ = evaluator.Eval(program, env)
-	return 0
+
+	commands.Commands[command](input);
 }

repl/repl.go

@@ -10,7 +10,7 @@ import (
 	"io"
 )
 
-const PROMPT = ">> "
+const PROMPT = ">>> "
 
 func Start(in io.Reader, out io.Writer) {
 	scanner := bufio.NewScanner(in)
@@ -32,7 +32,6 @@ func Start(in io.Reader, out io.Writer) {
 		}
 		evaluated := evaluator.Eval(program, env)
 		if evaluated != nil {
-			_, _ = io.WriteString(out, evaluated.Inspect())
 			_, _ = io.WriteString(out, "\n")
 		}