diff --git a/gnovm/cmd/gno/repl.go b/gnovm/cmd/gno/repl.go index 1acb96c3cb9..0a9d4934ce3 100644 --- a/gnovm/cmd/gno/repl.go +++ b/gnovm/cmd/gno/repl.go @@ -2,10 +2,11 @@ package main import ( "bufio" - "bytes" "context" + "errors" "flag" "fmt" + "go/scanner" "os" "strings" @@ -88,10 +89,10 @@ func execRepl(cfg *replCfg, args []string) error { // gno> import "gno.land/p/demo/avl" // import the p/demo/avl package // gno> func a() string { return "a" } // declare a new function named a // gno> /src // print current generated source -// gno> /editor // enter in editor mode to add several lines +// gno> /editor // enter in multi-line mode, end with ';' // gno> /reset // remove all previously inserted code // gno> println(a()) // print the result of calling a() -// gno> /exit +// gno> /exit // alternative to `) } @@ -99,30 +100,59 @@ func execRepl(cfg *replCfg, args []string) error { } func runRepl(cfg *replCfg) error { - // init repl state r := repl.NewRepl() if cfg.initialCommand != "" { handleInput(r, cfg.initialCommand) } - var multiline bool - for { - fmt.Fprint(os.Stdout, "gno> ") + fmt.Fprint(os.Stdout, "gno> ") - input, err := getInput(multiline) - if err != nil { - return err + inEdit := false + prev := "" + liner := bufio.NewScanner(os.Stdin) + + for liner.Scan() { + line := liner.Text() + + if l := strings.TrimSpace(line); l == ";" { + line, inEdit = "", false + } else if l == "/editor" { + line, inEdit = "", true + fmt.Fprintln(os.Stdout, "// enter a single ';' to quit and commit") + } + if prev != "" { + line = prev + "\n" + line + prev = "" + } + if inEdit { + fmt.Fprint(os.Stdout, "... ") + prev = line + continue } - multiline = handleInput(r, input) + if err := handleInput(r, line); err != nil { + var goScanError scanner.ErrorList + if errors.As(err, &goScanError) { + // We assune that a Go scanner error indicates an incomplete Go statement. + // Append next line and retry. + prev = line + } else { + fmt.Fprintln(os.Stderr, err) + } + } + + if prev == "" { + fmt.Fprint(os.Stdout, "gno> ") + } else { + fmt.Fprint(os.Stdout, "... ") + } } + return nil } -// handleInput reads the input string and parses it depending if it -// is a specific command, or source code. It returns true if the following -// input is expected to be on more than one line. -func handleInput(r *repl.Repl, input string) bool { +// handleInput executes specific "/" commands, or evaluates input as Gno source code. +func handleInput(r *repl.Repl, input string) error { switch strings.TrimSpace(input) { case "/reset": r.Reset() @@ -130,49 +160,14 @@ func handleInput(r *repl.Repl, input string) bool { fmt.Fprintln(os.Stdout, r.Src()) case "/exit": os.Exit(0) - case "/editor": - fmt.Fprintln(os.Stdout, "// Entering editor mode (^D to finish)") - return true case "": - // avoid to increase the repl execution counter if sending empty content - fmt.Fprintln(os.Stdout, "") - return false + // Avoid to increase the repl execution counter if no input. default: out, err := r.Process(input) if err != nil { - fmt.Fprintln(os.Stderr, err) + return err } fmt.Fprintln(os.Stdout, out) } - - return false -} - -const ( - inputBreaker = "^D" - nl = "\n" -) - -func getInput(ml bool) (string, error) { - s := bufio.NewScanner(os.Stdin) - var mlOut bytes.Buffer - for s.Scan() { - line := s.Text() - if !ml { - return line, nil - } - - if line == inputBreaker { - break - } - - mlOut.WriteString(line) - mlOut.WriteString(nl) - } - - if err := s.Err(); err != nil { - return "", err - } - - return mlOut.String(), nil + return nil } diff --git a/gnovm/pkg/repl/repl.go b/gnovm/pkg/repl/repl.go index 0f60b948f39..c7786cf08b0 100644 --- a/gnovm/pkg/repl/repl.go +++ b/gnovm/pkg/repl/repl.go @@ -161,7 +161,7 @@ func (r *Repl) Process(input string) (out string, err error) { return r.handleExpression(exp) } - return "", fmt.Errorf("error parsing code:\n\t- as expression (error: %q)\n\t- as declarations (error: %q)", expErr.Error(), declErr.Error()) + return "", fmt.Errorf("error parsing code:\n\t- as expression: %w\n\t- as declarations: %w", expErr, declErr) } func (r *Repl) handleExpression(e *ast.File) (string, error) {