// This file is part of ICU4X. For terms of use, please see the file
// called LICENSE at the top level of the ICU4X source tree
// (online at: https://github.com/unicode-org/icu4x/blob/main/LICENSE ).
use Cow;
/// A token returned by the [`Parser`].
///
/// # Examples
///
/// ```
/// use icu_pattern::{Parser, ParserOptions, PatternToken};
///
/// let input = "{0}, {1}";
///
/// let mut parser = Parser::new(
/// input,
/// ParserOptions {
/// allow_raw_letters: false,
/// },
/// );
///
/// let mut result = vec![];
///
/// while let Some(element) =
/// parser.try_next().expect("Failed to advance iterator")
/// {
/// result.push(element);
/// }
///
/// assert_eq!(
/// result,
/// &[
/// PatternToken::Placeholder(0),
/// PatternToken::Literal {
/// content: ", ".into(),
/// quoted: false
/// },
/// PatternToken::Placeholder(1),
/// ]
/// );
/// ```
///
/// # Type parameters
///
/// - `P`: A placeholder type which implements [`FromStr`].
///
/// # Lifetimes
///
/// - `s`: The life time of an input string slice being parsed.
///
/// [`Parser`]: crate::Parser
/// [`FromStr`]: std::str::FromStr