Example #1
0
// RunWithPromptAndPrelude runs a REPL with the given prompt and prelude.
func RunWithPromptAndPrelude(l *loop.Loop, prompt, prelude string) error {
	if prompt == "" {
		prompt = ">"
	}

	prompt = strings.Trim(prompt, " ")
	prompt += " "

	rl, err := readline.New(prompt)
	if err != nil {
		return err
	}

	l.VM().Set("console", map[string]interface{}{
		"log": func(c otto.FunctionCall) otto.Value {
			s := make([]string, len(c.ArgumentList))
			for i := 0; i < len(c.ArgumentList); i++ {
				s[i] = c.Argument(i).String()
			}

			rl.Stdout().Write([]byte(strings.Join(s, " ") + "\n"))
			rl.Refresh()

			return otto.UndefinedValue()
		},
		"warn": func(c otto.FunctionCall) otto.Value {
			s := make([]string, len(c.ArgumentList))
			for i := 0; i < len(c.ArgumentList); i++ {
				s[i] = c.Argument(i).String()
			}

			rl.Stderr().Write([]byte(strings.Join(s, " ") + "\n"))
			rl.Refresh()

			return otto.UndefinedValue()
		},
	})

	if prelude != "" {
		if _, err := io.Copy(rl.Stderr(), strings.NewReader(prelude+"\n")); err != nil {
			return err
		}

		rl.Refresh()
	}

	var d []string

	for {
		ll, err := rl.Readline()
		if err != nil {
			if err == readline.ErrInterrupt {
				if d != nil {
					d = nil

					rl.SetPrompt(prompt)
					rl.Refresh()

					continue
				}

				break
			}

			return err
		}

		if len(d) == 0 && ll == "" {
			continue
		}

		d = append(d, ll)
		s := strings.Join(d, "\n")

		if _, err := parser.ParseFile(nil, "repl", s, 0); err != nil {
			rl.SetPrompt(strings.Repeat(" ", len(prompt)))
		} else {
			rl.SetPrompt(prompt)

			d = nil

			t := looptask.NewEvalTask(s)
			// don't report errors to the loop - this lets us handle them and
			// resume normal operation
			t.SoftError = true
			l.Add(t)
			l.Ready(t)

			v, err := <-t.Value, <-t.Error
			if err != nil {
				if oerr, ok := err.(*otto.Error); ok {
					io.Copy(rl.Stdout(), strings.NewReader(oerr.String()))
				} else {
					io.Copy(rl.Stdout(), strings.NewReader(err.Error()))
				}
			} else {
				f, err := format(v, 80, 2, 5)
				if err != nil {
					panic(err)
				}

				rl.Stdout().Write([]byte(f + "\n"))
			}
		}

		rl.Refresh()
	}

	return rl.Close()
}
Example #2
0
func main() {
	flag.Parse()

	vm := otto.New()

	if *debugger {
		vm.SetDebuggerHandler(repl.DebuggerHandler)
	}

	l := loop.New(vm)

	if err := timers.Define(vm, l); err != nil {
		panic(err)
	}
	if err := promise.Define(vm, l); err != nil {
		panic(err)
	}
	if err := fetch.Define(vm, l); err != nil {
		panic(err)
	}
	if err := process.Define(vm, flag.Args()); err != nil {
		panic(err)
	}

	blockingTask := looptask.NewEvalTask("")

	if len(flag.Args()) == 0 || *openRepl {
		l.Add(blockingTask)
	}

	if len(flag.Args()) > 0 {
		d, err := ioutil.ReadFile(flag.Arg(0))
		if err != nil {
			panic(err)
		}

		// this is a very cheap way of "supporting" shebang lines
		if d[0] == '#' {
			d = []byte("// " + string(d))
		}

		s, err := vm.Compile(flag.Arg(0), string(d))
		if err != nil {
			panic(err)
		}

		if err := l.Eval(s); err != nil {
			panic(err)
		}
	}

	if len(flag.Args()) == 0 || *openRepl {
		go func() {
			if err := erepl.Run(l); err != nil && err != io.EOF {
				panic(err)
			}

			l.Ready(blockingTask)
		}()
	}

	if err := l.Run(); err != nil {
		panic(err)
	}
}