Struct NonEmptySlice 

pub struct NonEmptySlice<'a, T> { /* private fields */ }

A borrowed slice guaranteed to contain at least one element.

The borrowed counterpart to NonEmptyVec: parse once via NonEmptySlice::from_slice, then NonEmptySlice::first is infallible. Avoids cloning large payloads (e.g. LLM choices arrays) while still removing validate-then-index (is_empty + [0]) sites.

use vtcode_commons::validation::NonEmptySlice;

let values = vec![10, 20];
let parsed = NonEmptySlice::from_slice(&values).expect("non-empty");
assert_eq!(parsed.first(), &10);
assert!(NonEmptySlice::<i32>::from_slice(&[]).is_none());

Implementations

impl<'a, T> NonEmptySlice<'a, T>

pub fn from_slice(slice: &'a [T]) -> Option<Self>

Parse a slice into a non-empty view, returning None when empty.

This is the single boundary where the invariant is established.

pub const fn first(&self) -> &'a T

Infallible access to the first element; no Option to re-check.

pub fn last(&self) -> &'a T

Access the last element.

pub fn len(&self) -> usize

Number of elements; always >= 1.

pub const fn is_empty(&self) -> bool

Always returns false; provided for generic len/is_empty pairing.

pub const fn rest(&self) -> &'a [T]

Borrow the tail after the first element; possibly empty.

Useful for argv-style parsing where first is the program and rest are the arguments.

pub fn iter(&self) -> impl Iterator<Item = &'a T>

Iterate over all elements in order.

Trait Implementations

impl<'a, T: Clone> Clone for NonEmptySlice<'a, T>

fn clone(&self) -> Self

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl<'a, T: Copy> Copy for NonEmptySlice<'a, T>

impl<'a, T: Debug> Debug for NonEmptySlice<'a, T>

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl<'a, T: Eq> Eq for NonEmptySlice<'a, T>

impl<'a, T: PartialEq> PartialEq for NonEmptySlice<'a, T>

fn eq(&self, other: &Self) -> bool

Equality operator ==.

fn ne(&self, other: &Rhs) -> bool

Inequality operator !=.

impl<'a, T: PartialEq> StructuralPartialEq for NonEmptySlice<'a, T>