Struct NonEmpty 

pub struct NonEmpty<T> { /* private fields */ }

A homogeneous sequence with at least one element.

The invariant is enforced at construction boundaries while the storage stays vector-backed. That keeps recursive AST shapes such as NonEmpty<Expr<P>> safely indirect, just like Vec<Expr<P>>.

Implementations

impl<T> NonEmpty<T>

pub fn new(first: T, rest: Vec<T>) -> Self

Construct a non-empty sequence from its first item and the remaining items.

pub fn singleton(first: T) -> Self

Construct a singleton non-empty sequence.

pub fn try_from_vec(items: Vec<T>) -> Result<Self, EmptyVecError>

Convert a vector into a non-empty sequence.

Errors

Returns EmptyVecError if items is empty.

pub fn into_vec(self) -> Vec<T>

Convert into a vector, preserving order.

pub fn as_slice(&self) -> &[T]

Borrow as a slice.

pub fn as_mut_slice(&mut self) -> &mut [T]

Mutably borrow as a slice.

pub const fn len(&self) -> usize

Number of elements. Always at least 1.

pub const fn is_empty(&self) -> bool

Returns false; provided for API compatibility with sequence-like code.

pub fn first(&self) -> &T

First element in source order.

pub fn last(&self) -> &T

Last element in source order.

pub fn split_last(&self) -> (&T, &[T])

Split into the last element and the elements before it.

pub fn iter(&self) -> Iter<'_, T>

Iterate over all elements in source order.

pub fn iter_mut(&mut self) -> IterMut<'_, T>

Mutably iterate over all elements in source order.

pub fn push(&mut self, item: T)

Append an item to the end of the sequence.

pub fn map<U>(self, f: impl FnMut(T) -> U) -> NonEmpty<U>

Map each item while preserving non-emptiness.

Trait Implementations

impl<T: Clone> Clone for NonEmpty<T>

fn clone(&self) -> NonEmpty<T>

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl<T: Debug> Debug for NonEmpty<T>

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

Formats the value using the given formatter.

impl<T: Eq> Eq for NonEmpty<T>

impl<T: FormatEquivalent> FormatEquivalent for NonEmpty<T>

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

Returns true if self and other are equivalent up to formatting.

impl<T> From<(T, Vec<T>)> for NonEmpty<T>

fn from((first, rest): (T, Vec<T>)) -> Self

Converts to this type from the input type.

impl<T> From<T> for NonEmpty<T>

fn from(first: T) -> Self

Converts to this type from the input type.

impl<T: Hash> Hash for NonEmpty<T>

fn hash<__H: Hasher>(&self, state: &mut __H)

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H)

where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher.

impl<T> Index<usize> for NonEmpty<T>

type Output = T

The returned type after indexing.

fn index(&self, index: usize) -> &Self::Output

Performs the indexing (container[index]) operation.

impl<T> IndexMut<usize> for NonEmpty<T>

fn index_mut(&mut self, index: usize) -> &mut Self::Output

Performs the mutable indexing (container[index]) operation.

impl<T> IntoIterator for NonEmpty<T>

type Item = T

The type of the elements being iterated over.

type IntoIter = IntoIter<T>

Which kind of iterator are we turning this into?

fn into_iter(self) -> Self::IntoIter

Creates an iterator from a value.

impl<'a, T> IntoIterator for &'a NonEmpty<T>

type Item = &'a T

The type of the elements being iterated over.

type IntoIter = Iter<'a, T>

Which kind of iterator are we turning this into?

fn into_iter(self) -> Self::IntoIter

Creates an iterator from a value.

impl<'a, T> IntoIterator for &'a mut NonEmpty<T>

type Item = &'a mut T

The type of the elements being iterated over.

type IntoIter = IterMut<'a, T>

Which kind of iterator are we turning this into?

fn into_iter(self) -> Self::IntoIter

Creates an iterator from a value.

impl<T: Ord> Ord for NonEmpty<T>

fn cmp(&self, other: &NonEmpty<T>) -> Ordering

This method returns an Ordering between self and other.

fn max(self, other: Self) -> Self

where Self: Sized,

Compares and returns the maximum of two values.

fn min(self, other: Self) -> Self

where Self: Sized,

Compares and returns the minimum of two values.

fn clamp(self, min: Self, max: Self) -> Self

where Self: Sized,

Restrict a value to a certain interval.

impl<T: PartialEq> PartialEq for NonEmpty<T>

fn eq(&self, other: &NonEmpty<T>) -> bool

Tests for self and other values to be equal, and is used by ==.

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

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl<T: PartialOrd> PartialOrd for NonEmpty<T>

fn partial_cmp(&self, other: &NonEmpty<T>) -> Option<Ordering>

This method returns an ordering between self and other values if one exists.

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

Tests less than (for self and other) and is used by the < operator.

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

Tests less than or equal to (for self and other) and is used by the <= operator.

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

Tests greater than (for self and other) and is used by the > operator.

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

Tests greater than or equal to (for self and other) and is used by the >= operator.

impl<T> StructuralPartialEq for NonEmpty<T>

impl<T> TryFrom<Vec<T>> for NonEmpty<T>

type Error = EmptyVecError

The type returned in the event of a conversion error.

fn try_from(value: Vec<T>) -> Result<Self, Self::Error>

Performs the conversion.

impl<T, const N: usize> TryFrom<[T; N]> for NonEmpty<T>

type Error = EmptyVecError

The type returned in the event of a conversion error.

fn try_from(value: [T; N]) -> Result<Self, Self::Error>

Performs the conversion.