Struct CountFn 

pub struct CountFn;

Trait Implementations

impl Debug for CountFn

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

Formats the value using the given formatter.

impl Function for CountFn

fn caps(&self) -> FnCaps

Capability flags for this function

fn name(&self) -> &'static str

fn min_args(&self) -> usize

fn variadic(&self) -> bool

fn arg_schema(&self) -> &'static [ArgSchema]

fn eval_scalar<'a, 'b>( &self, args: &'a [ArgumentHandle<'a, 'b>], _ctx: &dyn FunctionContext, ) -> Result<LiteralValue, ExcelError>

The default, scalar evaluation path.

fn eval_fold( &self, f: &mut dyn FnFoldCtx, ) -> Option<Result<LiteralValue, ExcelError>>

An optional, optimized path for reduction functions (e.g., SUM, COUNT).

fn namespace(&self) -> &'static str

fn volatile(&self) -> bool

fn aliases(&self) -> &'static [&'static str]

Optional list of additional alias names (case-insensitive) that should resolve to this function. Default: empty slice. Implementors can override to expose legacy names. Returned slice must have ’static lifetime (typically a static array reference).

fn function_salt(&self) -> u64

fn eval_map( &self, _m: &mut dyn FnMapCtx, ) -> Option<Result<LiteralValue, ExcelError>>

An optional, optimized path for element-wise functions (e.g., SIN, ABS).

fn eval_window<'a, 'b>( &self, _w: &mut SimpleWindowCtx<'a, 'b>, ) -> Option<Result<LiteralValue, ExcelError>>

An optional, optimized path for windowed functions (e.g., MOVING_AVERAGE).

fn eval_reference<'a, 'b>( &self, _args: &'a [ArgumentHandle<'a, 'b>], _ctx: &dyn FunctionContext, ) -> Option<Result<ReferenceType, ExcelError>>

Optional reference result path. Only called by the interpreter/engine when the callsite expects a reference (e.g., range combinators, by-ref argument positions, or spill sources).

fn dispatch<'a, 'b>( &self, args: &'a [ArgumentHandle<'a, 'b>], ctx: &dyn FunctionContext, ) -> Result<LiteralValue, ExcelError>

Dispatch to the most optimal evaluation path based on capabilities. This default implementation checks caps and calls the appropriate eval method.