Struct FunctionSignature 

pub struct FunctionSignature {
    pub name: SmolStr,
    pub params: Vec<ParamDecl>,
    pub variadic: Option<ParamDecl>,
    pub return_ty: ReturnTy,
    pub categories: FnCategories,
}

A function catalog entry.

The return type is modelled as a closure so consumers can express signature-dependent return inference (e.g., coalesce(T, T) -> T). Signature-independent functions return a constant.

Spec deviation note (§8.2): the spec’s shorthand is variadic: Option<Type>; we use ParamDecl so the trailing variadic parameter can carry a name and default consistently with params. Only variadic.ty is semantically significant; name is diagnostic-only and default is unused.

Fields

name: SmolStr

Function name as it appears in a count(…) call.

params: Vec<ParamDecl>

Fixed-arity parameter list in declaration order.

variadic: Option<ParamDecl>

Optional trailing variadic parameter (spec §8.2 shorthand).

return_ty: ReturnTy

How the return type is computed (constant vs argument-derived).

categories: FnCategories

Purity / determinism flags used by the sema purity checker.

Trait Implementations

impl Clone for FunctionSignature

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 FunctionSignature

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

Formats the value using the given formatter.