Struct Path 

pub struct Path { /* private fields */ }

A parsed, validated context path — the canonical IR for the flow.ir $.a.b / ctx.a.b / RFC 9535-style bracket path syntax. The full syntax and rejection rules are documented on the module-level docs and on Path::read / Path::write and the FromStr implementation below.

Illegal path syntax cannot be represented by this type: the only way to construct a Path is FromStr::from_str (equivalently str::parse) or Deserialize, both of which reject malformed input up front. Once you hold a Path, Path::read / Path::write never re-derive or re-validate the segment list.

Implementations

impl Path

pub fn read<'a>(&self, ctx: &'a Value) -> Result<&'a Value, EvalError>

Read the value this path resolves to inside ctx.

The root path ($ / ctx with no segments) resolves to ctx itself. A missing key along the way raises EvalError::PathNotFound — malformed syntax is rejected earlier, at parse time, so read can never raise EvalError::InvalidPath.

pub fn write(&self, ctx: &mut Value, value: Value) -> Result<(), EvalError>

Write value at the location this path resolves to inside ctx, mutating ctx in place.

The root path ($ / ctx with no segments) replaces ctx wholesale. Missing intermediate objects along the way are created automatically (a null — or altogether absent — intermediate promotes to an empty object, same as before this type existed). If an intermediate segment already holds a concrete non-object value (a string, number, bool, or array), the write is rejected with EvalError::TypeError instead of silently clobbering it; ctx is left byte-for-byte unmodified in that case (a rejected write never partially applies, because every intermediate object promotion this method performs only ever touches a freshly-created — previously null/absent — subtree, which by construction cannot itself contain a pre-existing conflicting value further down).

Trait Implementations

impl Clone for Path

fn clone(&self) -> Path

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for Path

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

Formats the value using the given formatter.

impl<'de> Deserialize<'de> for Path

fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>

where D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl Display for Path

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

Canonical string form: the original root token ($ or ctx) + .key for each identifier-safe segment, ["key"] bracket form otherwise. Path::from_str(path.to_string()) always re-parses to an equal Path (round-trip law, including root-token preservation) — the canonical form may normalize each segment’s representation (e.g. a segment reachable only via dot form on the way in is still rendered via dot form; a segment that required bracket form on the way in is rendered via bracket form) without changing the parsed segment list.

impl Eq for Path

impl FromStr for Path

type Err = PathParseError

The associated error which can be returned from parsing.

fn from_str(path: &str) -> Result<Self, Self::Err>

Parses a string s to return a value of this type.

impl Hash for Path

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 PartialEq for Path

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

Equality operator ==.

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

Inequality operator !=.

impl Serialize for Path

fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>

where S: Serializer,

Serialize this value into the given Serde serializer.

impl StructuralPartialEq for Path