Struct Beam 

pub struct Beam {

    pub id: BeamId,
    pub description: Option<String>,
    pub needs: Vec<Spanned<BeamId>>,
    pub params: Vec<String>,
    pub inputs: Vec<String>,
    pub outputs: Vec<String>,
    pub run: Vec<StringTemplate>,
    pub env: Vec<(String, StringTemplate)>,
    pub cwd: Option<String>,
    pub executor: ExecutorKind,
    pub allow_failure: bool,
    pub dir: PathBuf,
    pub span: Span,
    pub source: SourceId,
    pub scope: Scope,
}

A single beam: the unit of work produced by evaluating a beam { ... } declaration.

Load-time vs. schedule-time rendering: description, inputs, outputs, cwd, and the executor’s options are rendered once, at load time, into plain values — referencing a beam parameter there is a load error. run and env are kept as StringTemplates and rendered at schedule time (via crate::render_template), once the beam’s parameters are bound into a Scope built from Beam::scope via Scope::with_params.

Fields

id: BeamId

description: Option<String>

needs: Vec<Spanned<BeamId>>

Each entry keeps the span of the reference that produced it, so a needs entry that does not resolve is underlined exactly, rather than the whole beam declaration containing it.

params: Vec<String>

inputs: Vec<String>

Evaluated but inert in this crate: the cache (out of scope here) is the only intended consumer.

outputs: Vec<String>

run: Vec<StringTemplate>

env: Vec<(String, StringTemplate)>

cwd: Option<String>

executor: ExecutorKind

allow_failure: bool

dir: PathBuf

The directory of the defining Beamfile, used as the cwd base. Always absolute for a project built by crate::loader::load_project (it derives this via std::path::absolute, not the file’s possibly-relative path, so it stays correct even if the process’s current directory changes between loading and running) — except for load_str’s single-file front door, which has no real file on disk to resolve against and uses "." (see its doc comment).

span: Span

source: SourceId

Which source file this beam was defined in, for diagnostics.

scope: Scope

The defining file’s evaluated file-level let bindings. The engine composes this with the beam’s own parameter values at schedule time — beam.scope.with_params(&beam.params, &args) — before rendering run/env.

Trait Implementations

impl Clone for Beam

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 Beam

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

Formats the value using the given formatter.