Function promptly::prompt_opt [−][src]
pub fn prompt_opt<T, S>(msg: S) -> Result<Option<T>, ReadlineError> where
T: Promptable,
S: AsRef<str>,
Prompt until input can be parsed as T
, returning None
for empty input.
Empty string input results in None
Examples
use promptly::prompt_opt; // Prompt for an optional string let name: Option<String> = prompt_opt("Enter your name (optional)")?; // Prompt for optional paths with path completion. Returns `None` if empty input. let photo: Option<PathBuf> = prompt_opt("Enter a path to a profile picture")?;
Errors
Returns a ReadlineError
if readline fails.
Input that can’t be coerced into the specified type results in re-prompting.