Struct BuildContext 

pub struct BuildContext { /* private fields */ }

What the compiler tells a node factory about the node it is building: the bindings under construction when the node was asked for, and the program tree’s resource scope.

Every factory receives one (crate::dsl::registry::NodeBuildFn). A factory that records attribution reads Self::binding: rate_adj := control_set("rate", target) builds control_set with binding() equal to Some("rate_adj"). A node built inside another binding’s construction sees the whole chain in Self::bindings, outermost first: an argument that is itself a call compiles as an intermediate binding the compiler names after its enclosing one (x := f(control_set("r", t)) builds control_set under ["x", "x__anon_0"]), and a module body’s bindings compile under the binding that called the module. The context is a value the compiler hands down, so attribution is exact under nesting and on any thread.

A node that looks up a host resource when it evaluates keeps a clone of Self::resources (resource.rs).

A #[polydat_node] node reads the context through a setup that names ctx first, #[poly_const(setup, from = (ctx, key))], whose function takes &BuildContext and returns what the node keeps; the macro’s new() then takes the context as its first argument. A caller building such a node directly passes BuildContext::with_binding or BuildContext::new.

Implementations

impl BuildContext

pub fn new(bindings: Vec<String>, resources: ResourceScope) -> Self

A context for a node built under bindings (outermost first) in the program tree whose resource scope is resources.

pub fn with_binding(name: impl Into<String>) -> Self

A context for a node built by the binding name alone, in a tree of its own with no accessor installed: what a host’s test passes to build a node that records its binding.

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

The binding whose construction built the node: the innermost of Self::bindings. None for a node built outside any binding, such as one a caller builds directly with build_node.

pub fn bindings(&self) -> &[String]

Every binding under construction when the node was built, outermost first.

pub fn resources(&self) -> &ResourceScope

The resource scope of the program tree the node belongs to.

Trait Implementations

impl Clone for BuildContext

fn clone(&self) -> Self

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for BuildContext

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

Formats the value using the given formatter.

impl Default for BuildContext

fn default() -> Self

Returns the “default value” for a type.