Struct PathTemplate 

pub struct PathTemplate<R: PathRoot = ContextRoot> { /* private fields */ }

A config field naming a write destination, expressed as JSONLogic.

R fixes the rooting: ContextRoot for a path that names its own root, DataRoot for one relative to data.

The static spelling is a JSON string and keeps its precomputed fast path:

{ "path": "data.total" }

A dynamic destination is any expression resolving to a path string:

{ "path": {"cat": ["data.accounts.", {"var": "data.account_id"}, ".balance"]} }

The expression resolves to the name of a location, never to the value at one. It is evaluated against the message context like any other parameter.

Implementations

impl<R: PathRoot> PathTemplate<R>

pub fn compile(&mut self, c: &TemplateCompiler, label: &str) -> Result<()>

Compile the expression and, when it folded to a constant, precompute its (dotted, parts) pair. Called once at engine construction by LogicCompiler.

Errors

As Template::compile, plus a resolution failure if the constant does not coerce to a path string.

pub fn resolve(&self, ctx: &TaskContext<'_>) -> Result<ResolvedPath>

The destination for this message as (dotted path, split parts).

Constant destinations return the precomputed pair — two Arc clones, no splitting, no allocation. Dynamic ones resolve to a plain string and split it.

Errors

crate::DataflowError::LogicEvaluation if the expression fails to evaluate, or if it was never compiled and is not a literal string.

pub fn as_json(&self) -> &Value

The authored JSON, unchanged — for authoring checks and for handlers that re-serialize their own config.

pub fn is_constant(&self) -> bool

Whether the destination folded to a compile-time constant, so Self::resolve returns the precomputed pair.

pub fn constant_path(&self) -> Option<&str>

The constant destination as a dotted string, when it folded to one.

For diagnostics that want to name the destination without a message in hand — error labels, the workflow visualizer, authoring issues. None for a dynamic destination, which has no single answer.

Trait Implementations

impl<R: Clone + PathRoot> Clone for PathTemplate<R>

fn clone(&self) -> PathTemplate<R>

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl<R: Debug + PathRoot> Debug for PathTemplate<R>

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

Formats the value using the given formatter.

impl<R: PathRoot> Default for PathTemplate<R>

fn default() -> Self

Returns the “default value” for a type.

impl<'de, R: PathRoot> Deserialize<'de> for PathTemplate<R>

fn deserialize<D: Deserializer<'de>>(d: D) -> Result<Self, D::Error>

Deserialize this value from the given Serde deserializer.

impl<R: PathRoot> From<&str> for PathTemplate<R>

fn from(path: &str) -> Self

Converts to this type from the input type.

impl<R: PathRoot> From<Value> for PathTemplate<R>

fn from(raw: Value) -> Self

Converts to this type from the input type.