Struct IsFormulaFn 

pub struct IsFormulaFn;

Trait Implementations

impl Debug for IsFormulaFn

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

Formats the value using the given formatter.

impl Function for IsFormulaFn

Returns whether a value originates from a formula.

Current engine metadata does not track formula provenance at this call site.

Remarks

• This implementation currently returns FALSE for all inputs.
• Errors are not raised solely due to provenance unavailability.
• Arity mismatch returns #VALUE!.

Examples

title: "Literal value"
formula: '=ISFORMULA(10)'
expected: false

title: "Computed value in expression context"
formula: '=ISFORMULA(1+1)'
expected: false

related:
  - TYPE
  - ISNUMBER
  - ISTEXT
faq:
  - q: "Can ISFORMULA currently detect formula provenance?"
    a: "Not yet. This implementation always returns FALSE because provenance metadata is not tracked here."

[formualizer-docgen:schema:start] Name: ISFORMULA Type: IsFormulaFn Min args: 1 Max args: 1 Variadic: false Signature: ISFORMULA(arg1: any@scalar) Arg schema: arg1{kinds=any,required=true,shape=scalar,by_ref=false,coercion=None,max=None,repeating=None,default=false} Caps: PURE [formualizer-docgen:schema:end]

fn caps(&self) -> FnCaps

Capability flags for this function

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

fn min_args(&self) -> usize

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

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

The unified evaluation path.

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

fn variadic(&self) -> bool

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_reference<'a, 'b, 'c>( &self, _args: &'c [ArgumentHandle<'a, 'b>], _ctx: &dyn FunctionContext<'b>, ) -> 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, 'c>( &self, args: &'c [ArgumentHandle<'a, 'b>], ctx: &dyn FunctionContext<'b>, ) -> Result<CalcValue<'b>, ExcelError>

Dispatch to the unified evaluation path with automatic argument validation.