Function newCompleter

internal/driver/interactive.go:345–378

newCompleter creates an autocompletion function for a set of commands.

(fns []string)

// newCompleter creates an autocompletion function for a set of commands.
func newCompleter(fns []string) func(string) string {
	return func(line string) string {
		switch tokens := strings.Fields(line); len(tokens) {
		case 0:
			// Nothing to complete
		case 1:
			// Single token -- complete command name
			if match := matchVariableOrCommand(tokens[0]); match != "" {
				return match
			}
		case 2:
			if tokens[0] == "help" {
				if match := matchVariableOrCommand(tokens[1]); match != "" {
					return tokens[0] + " " + match
				}
				return line
			}
			fallthrough
		default:
			// Multiple tokens -- complete using functions, except for tags
			if cmd := pprofCommands[tokens[0]]; cmd != nil && tokens[0] != "tags" {
				lastTokenIdx := len(tokens) - 1
				lastToken := tokens[lastTokenIdx]
				if strings.HasPrefix(lastToken, "-") {
					lastToken = "-" + functionCompleter(lastToken[1:], fns)
				} else {
					lastToken = functionCompleter(lastToken, fns)
				}
				return strings.Join(append(tokens[:lastTokenIdx], lastToken), " ")
			}
		}
		return line
	}
}

// matchVariableOrCommand attempts to match a string token to the prefix of a Command.
func matchVariableOrCommand(token string) string {