Enum Statement 

pub enum Statement {
    InputDecl(InputDecl),
    Binding(Binding),
    ModuleDef(ModuleDef),
    ExternPort(ExternPort),
    Cursor(CursorDecl),
    Pragma {
        name: String,
        span: Span,
    },
}

A top-level statement.

Variants

InputDecl(InputDecl)

input name[: type] — declares one per-cycle kernel input slot. The name becomes both an input slot (settable via set_input) and a passthrough output (readable via get_constant/pull).

Surface forms (parser desugars the tuple into N InputDecls, mirroring the module-signature param-list shape from a host-provided cycle module):

input cycle: u64
input (cycle: u64, q: f64)

Binding(Binding)

A name-to-expression binding. The modifier on the binding determines its lifecycle:

• no modifier — per-cycle: re-evaluated every cycle.
• const — effectively-const for the scope’s lifetime: materialized at the earliest opportunity (compile-time fold if the RHS is fold-eligible, otherwise scope-init pull after materialize-wiring has populated extern slots). Authors don’t need to know which path the runtime takes — the contract is “fixed once, then immutable.”
• shared — cell-backed, mutable across kernel instances in the same lineage. See SRD-16 §“Mutability Rules: Shared Mutable”.
• volatile — per-cycle, excluded from hash_const. See SRD-44.

Surface forms:

x := mul(cycle, 2)                  // per-cycle
const pi := 3.14                    // const, folds at compile
const ann_opts := str_concat(...)   // const, materializes at scope-init
shared budget := 100                // shared cell
(a, b) := split_pair(...)           // tuple destructuring

ModuleDef(ModuleDef)

name(param: type, ...) -> (output: type, ...) := { body }

ExternPort(ExternPort)

extern name: type = default

Cursor(CursorDecl)

cursor name = Cursor() or cursor name = constructor_expr

Pragma

pragma <name> — a module-level directive opting into a compile-time graph transform (SRD 15 §“Module-Level Pragmas”). First-class grammar, distinct from line comments. Recognised pragmas trigger CompileEvent::PragmaAcknowledged; unknown names trigger CompileEvent::UnknownPragma and are otherwise ignored (forward-compatible).

Fields

name: String

span: Span

Trait Implementations

impl Clone for Statement

fn clone(&self) -> Statement

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for Statement

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

Formats the value using the given formatter.