Struct PathRef 

pub struct PathRef<'a> { /* private fields */ }

A path that borrows its joined form instead of owning one.

What an engine has in hand when it reads a key out of its own page: the bytes are there, in the joined spelling a path keeps, and building a StorePath per key would allocate once for every entry on the hot path of loading a map.

It carries the same checked-ness as an owned path and can be had no other way: either PathRef::parse walked the key, or it borrows a path that was walked already. So a caller holding one needs no opinion about how a path is spelled, which is the whole point - the alternative is passing &str and hoping every reader remembers what it is.

Implementations

impl<'a> PathRef<'a>

pub fn parse(joined: &'a str) -> Result<Self, StorePathError>

Reads a key an engine holds, refusing one this library did not write.

The same walk StorePath::parse_joined makes, without the allocation that follows it.

pub fn as_str(&self) -> &'a str

The whole path as one string, which is what it was built from.

pub fn is_root(&self) -> bool

pub fn level_under(&self, prefix: &StorePath) -> Under<'a>

Where this sits under prefix, and the level it sits at. See StorePath::level_under, which answers the same question of an owned path.

pub fn name_under(&self, prefix: &StorePath) -> Option<Level<'a>>

The level directly under prefix, or None when prefix does not hold this path. See StorePath::name_under.

pub fn to_path(&self) -> StorePath

An owned copy, for a caller that has to keep it past the borrow.

This is where the allocation the type exists to avoid is finally paid, so it is paid by whoever actually keeps the path.

Trait Implementations

impl<'a> Clone for PathRef<'a>

fn clone(&self) -> Self

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl<'a> Copy for PathRef<'a>

impl Debug for PathRef<'_>

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

Formats the value using the given formatter.

impl Display for PathRef<'_>

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

Formats the value using the given formatter.

impl<'a> Eq for PathRef<'a>

impl<'a> From<&'a StorePath> for PathRef<'a>

Borrowing a path costs nothing and checks nothing: it has been through the check already.

fn from(path: &'a StorePath) -> Self

Converts to this type from the input type.

impl<'a> Hash for PathRef<'a>

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<'a> Ord for PathRef<'a>

fn cmp(&self, other: &Self) -> 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.

fn clamp_to<R>(self, range: R) -> Self

where Self: Sized, R: ClampBounds<Self>,

🔬This is a nightly-only experimental API. (clamp_to)

Restrict a value to a certain range.

impl<'a> PartialEq for PathRef<'a>

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

Equality operator ==.

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

Inequality operator !=.

impl PartialEq<StorePath> for PathRef<'_>

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

Equality operator ==.

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

Inequality operator !=.

impl<'a> PartialOrd for PathRef<'a>

fn partial_cmp(&self, other: &Self) -> 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<'a> StructuralPartialEq for PathRef<'a>