Struct FnDescriptor 

pub struct FnDescriptor {
    pub namespace: &'static str,
    pub name: &'static str,
    pub params: Vec<Param>,
    pub return_type: PylonType,
    pub impl_strategy: ImplStrategy,
    pub cast_target: bool,
    pub volatility: FnVolatility,
}

One overload of a stdlib function.

Fields

namespace: &'static str

PyQL namespace: "std", "math", or "cal".

name: &'static str

Unqualified function name, e.g. "count", "str_lower".

params: Vec<Param>

Ordered parameter list for this overload.

return_type: PylonType

Return type for this overload.

impl_strategy: ImplStrategy

How the transpiler should emit this call.

cast_target: bool

True when this overload backs a Function-strategy type cast entry.

volatility: FnVolatility

Call-result stability, independent of impl_strategy — a SqlBuiltin like uuidv7() is volatile even though it installs no PylonFnDef of its own. Consumers gate on this: a pointer default wants volatile, a filter predicate almost never does.

Implementations

impl FnDescriptor

pub fn is_aggregate(&self) -> bool

True when any parameter is set-typed — i.e. this overload is an aggregate and only makes sense over a multilink path or a subquery, never over a single scalar pointer.

pub fn returns_set(&self) -> bool

True when the call yields a set rather than a single value (std::array_unpack) — meaningless inside a filter predicate.

pub fn is_intrinsic(&self) -> bool

True for TranspilerIntrinsic overloads, which need compile-time type context and so can’t be validated by arity alone.

pub fn is_variadic(&self) -> bool

True when the overload accepts a trailing variadic parameter, so any argument count at or above params.len() - 1 is legal.

Trailing among the positional parameters: json_set(target, path..., value := …) declares named-only ones after the variadic, and they are passed by name rather than counted against it.

pub fn variadic_index(&self) -> Option<usize>

Index of the variadic parameter, when one is declared.

pub fn named_count(&self) -> usize

Count of parameters a call passes by name rather than by position.

Trait Implementations

impl Clone for FnDescriptor

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 FnDescriptor

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

Formats the value using the given formatter.