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// devela::text::str::namespace::take
//
//! Implements take methods for [`Str`].
//
use crate::{Str, unwrap};
/// # `take*` API methods for subslicing.
#[rustfmt::skip]
impl Str {
// take_first
/// Returns the first `n` elements of the slice.
///
/// Equivalent to `&string[..n]`.
///
/// # Panics
/// Panics if `n` > `string.len()`
/// or if the split point falls outside a UTF-8 code point boundary.
///
/// # Example
/// ```
/// # use devela::Str;
/// let s = "Hello world!";
/// assert_eq!(Str::take_first(s, 0), "");
/// assert_eq!(Str::take_first(s, 3), "Hel");
/// assert_eq!(Str::take_first(s, 12), "Hello world!");
/// // assert_eq!(Str::take_first(s, 13), "Hello world!"); // panics
/// ```
#[must_use] #[inline(always)]
pub const fn take_first(string: &str, n: usize) -> &str {
string.split_at(n).0
}
/// Returns the first `n` elements of the string.
///
/// Equivalent to `&string[..n]`.
///
/// Returns `None` if `n` > `string.len()`
/// or if the split point falls outside a UTF-8 code point boundary.
#[must_use]
#[inline(always)]
pub const fn take_first_checked(string: &str, n: usize) -> Option<&str> {
match string.split_at_checked(n) {
Some((substring, _)) => Some(substring),
None => None,
}
}
/// Returns the first `n` elements of the exclusive string.
///
/// Equivalent to `&mut string[..n]`.
///
/// # Panics
/// Panics if `n` > `string.len()`
/// or if the split point falls outside a UTF-8 code point boundary.
#[must_use]
#[inline(always)]
pub const fn take_first_mut(string: &mut str, n: usize) -> &mut str {
string.split_at_mut(n).0
}
/// Returns the first `n` elements of the exclusive string.
///
/// Equivalent to `&mut string[..n]`.
///
/// Returns `None` if `n` > `string.len()`
/// or if the split point falls outside a UTF-8 code point boundary.
#[must_use]
#[inline(always)]
pub const fn take_first_mut_checked(string: &mut str, n: usize) -> Option<&mut str> {
match string.split_at_mut_checked(n) {
Some((substring, _)) => Some(substring),
None => None,
}
}
// take_last
/// Returns the last `n` elements of the string.
///
/// Equivalent to `&string[string.len() - n..]`.
///
/// # Panics
/// Panics if `n` > `string.len()`
/// or if the split point falls outside a UTF-8 code point boundary.
#[must_use]
#[inline(always)]
pub const fn take_last(string: &str, n: usize) -> &str {
string.split_at(string.len() - n).1
}
/// Returns the last `n` elements of the string.
///
/// Equivalent to `&string[string.len() - n..]`.
///
/// Returns `None` if `n` > `string.len()`
/// or if the split point falls outside a UTF-8 code point boundary.
#[must_use]
#[inline(always)]
pub const fn take_last_checked(string: &str, n: usize) -> Option<&str> {
Some(unwrap![some? string.split_at_checked(string.len() - n)].1)
}
/// Returns the last `n` elements of the exclusive string.
///
/// Equivalent to `&mut string[string.len() - n..]`.
///
/// # Panics
/// Panics if `n` > `string.len()`
/// or if the split point falls outside a UTF-8 code point boundary.
#[must_use]
#[inline(always)]
pub const fn take_last_mut(string: &mut str, n: usize) -> &mut str {
string.split_at_mut(string.len() - n).1
}
/// Returns the last `n` elements of the exclusive string.
///
/// Equivalent to `&mut string[string.len() - n..]`.
///
/// Returns `None` if `n` > `string.len()`
/// or if the split point falls outside a UTF-8 code point boundary.
#[must_use]
#[inline(always)]
pub const fn take_last_mut_checked(string: &mut str, n: usize) -> Option<&mut str> {
Some(unwrap![some? string.split_at_mut_checked(string.len() - n)].1)
}
// take_omit_last
/// Returns the string omitting the last `n` elements.
///
/// Equivalent to `&string[..string.len() - n]`.
///
/// # Panics
/// Panics if `n` > `string.len()`
/// or if the split point falls outside a UTF-8 code point boundary.
#[must_use]
#[inline(always)]
pub const fn take_omit_last(string: &str, n: usize) -> &str {
string.split_at(string.len() - n).0
}
/// Returns the string omitting the last `n` elements.
///
/// Equivalent to `&string[..string.len() - n]`.
///
/// Returns `None` if `n` > `string.len()`
/// or if the split point falls outside a UTF-8 code point boundary.
#[must_use]
#[inline(always)]
pub const fn take_omit_last_checked(string: &str, n: usize) -> Option<&str> {
Some(unwrap![some? string.split_at_checked(string.len() - n)].0)
}
/// Returns the exclusive string omitting the last `n` elements.
///
/// Equivalent to `&mut string[..string.len() - n]`.
///
/// # Panics
/// Panics if `n` > `string.len()`
/// or if the split point falls outside a UTF-8 code point boundary.
#[must_use]
#[inline(always)]
pub const fn take_omit_last_mut(string: &mut str, n: usize) -> &mut str {
string.split_at_mut(string.len() - n).0
}
/// Returns the exclusive string omitting the last `n` elements.
///
/// Equivalent to `&mut string[..string.len() - n]`.
///
/// Returns `None` if `n` > `string.len()`
/// or if the split point falls outside a UTF-8 code point boundary.
#[must_use]
#[inline(always)]
pub const fn take_omit_last_mut_checked(string: &mut str, n: usize) -> Option<&mut str> {
Some(unwrap![some? string.split_at_mut_checked(string.len() - n)].0)
}
}