restructure project

cmd/monkey/main.go

@@ -0,0 +1,137 @@
+package main
+
+import (
+	"flag"
+	"fmt"
+	"io"
+	"log"
+	"os"
+	"os/user"
+	"path"
+	"strings"
+
+	"github.com/pkg/profile"
+
+	"monkey/internal"
+	"monkey/internal/compiler"
+	"monkey/internal/lexer"
+	"monkey/internal/object"
+	"monkey/internal/parser"
+	"monkey/internal/repl"
+)
+
+var (
+	engine      string
+	interactive bool
+	compile     bool
+	version     bool
+	debug       bool
+
+	profileCPU bool
+	profileMem bool
+)
+
+func init() {
+	flag.Usage = func() {
+		fmt.Fprintf(flag.CommandLine.Output(), "Usage: %s [options] [<filename>]\n", path.Base(os.Args[0]))
+		flag.PrintDefaults()
+		os.Exit(0)
+	}
+
+	flag.BoolVar(&version, "v", false, "display version information")
+	flag.BoolVar(&debug, "d", false, "enable debug mode")
+	flag.BoolVar(&compile, "c", false, "compile input to bytecode")
+
+	flag.BoolVar(&interactive, "i", false, "enable interactive mode")
+	flag.StringVar(&engine, "e", "vm", "engine to use (eval or vm)")
+
+	flag.BoolVar(&profileCPU, "profile-cpu", false, "Enable CPU profiling.")
+	flag.BoolVar(&profileMem, "profile-mem", false, "Enable Memory profiling.")
+}
+
+// Indent indents a block of text with an indent string
+func Indent(text, indent string) string {
+	if text[len(text)-1:] == "\n" {
+		result := ""
+		for _, j := range strings.Split(text[:len(text)-1], "\n") {
+			result += indent + j + "\n"
+		}
+		return result
+	}
+	result := ""
+	for _, j := range strings.Split(strings.TrimRight(text, "\n"), "\n") {
+		result += indent + j + "\n"
+	}
+	return result[:len(result)-1]
+}
+
+func main() {
+	flag.Parse()
+
+	if version {
+		fmt.Printf("%s %s", path.Base(os.Args[0]), internal.FullVersion())
+		os.Exit(0)
+	}
+
+	user, err := user.Current()
+	if err != nil {
+		log.Fatalf("could not determine current user: %s", err)
+	}
+
+	args := flag.Args()
+
+	if profileCPU {
+		defer profile.Start(profile.CPUProfile).Stop()
+	} else if profileMem {
+		defer profile.Start(profile.MemProfile).Stop()
+	}
+
+	if compile {
+		if len(args) < 1 {
+			log.Fatal("no source file given to compile")
+		}
+		f, err := os.Open(args[0])
+		if err != nil {
+			log.Fatal(err)
+		}
+		defer f.Close()
+
+		b, err := io.ReadAll(f)
+		if err != nil {
+			log.Fatal(err)
+		}
+
+		l := lexer.New(string(b))
+		p := parser.New(l)
+
+		program := p.ParseProgram()
+		if len(p.Errors()) != 0 {
+			log.Fatal(p.Errors())
+		}
+
+		c := compiler.New()
+		err = c.Compile(program)
+		if err != nil {
+			log.Fatal(err)
+		}
+
+		code := c.Bytecode()
+		fmt.Printf("Main:\n%s\n", code.Instructions)
+
+		fmt.Print("Constants:\n")
+		for i, constant := range code.Constants {
+			fmt.Printf("%04d %s\n", i, constant.Inspect())
+			if fn, ok := constant.(*object.CompiledFunction); ok {
+				fmt.Printf("%s\n", Indent(fn.Instructions.String(), "     "))
+			}
+		}
+	} else {
+		opts := &repl.Options{
+			Debug:       debug,
+			Engine:      engine,
+			Interactive: interactive,
+		}
+		repl := repl.New(user.Username, args, opts)
+		repl.Run()
+	}
+}