Very naive REPL

repl/command.go

@@ -0,0 +1,42 @@
+package repl
+
+import (
+	"fmt"
+	"os"
+)
+
+var (
+	helpCmd = Command{
+		Name:  ".help",
+		Usage: " type `.help` for help",
+		Action: func(r *REPL, args []string) error {
+			for _, cmd := range r.Commands {
+				fmt.Printf("%-20s\t%s\n", cmd.Name, cmd.Usage)
+			}
+
+			return nil
+		},
+	}
+	clearCmd = Command{
+		Name:  ".clear",
+		Usage: " type `.clear` to clear the screen",
+		Action: func(r *REPL, args []string) error {
+			_, _ = os.Stdout.Write([]byte("\033[2J\033[H"))
+			return nil
+		},
+	}
+	exitCmd = Command{
+		Name:  ".exit",
+		Usage: " type `.exit` to exit this REPL",
+		Action: func(r *REPL, args []string) error {
+			os.Exit(0)
+			return nil
+		},
+	}
+)
+
+type Command struct {
+	Name   string
+	Usage  string
+	Action func(r *REPL, args []string) error
+}