Struct RoundDownFn 

pub struct RoundDownFn;

Trait Implementations

impl Debug for RoundDownFn

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

Formats the value using the given formatter.

impl Function for RoundDownFn

Rounds a number toward zero to a specified number of digits.

Remarks

• Positive num_digits affects decimals; negative values affect digits left of the decimal.
• Always reduces magnitude toward zero (unlike INT for negatives).
• Input errors are propagated.

Examples

title: "Trim decimals without rounding up"
formula: "=ROUNDDOWN(3.14159,3)"
expected: 3.141

title: "Round down a negative value at the hundreds place"
formula: "=ROUNDDOWN(-987.65,-2)"
expected: -900

related:
  - ROUND
  - ROUNDUP
  - TRUNC
faq:
  - q: "Does ROUNDDOWN always move toward negative infinity?"
    a: "No. It moves toward zero, which is different from FLOOR-style behavior on negatives."

[formualizer-docgen:schema:start] Name: ROUNDDOWN Type: RoundDownFn Min args: 2 Max args: 2 Variadic: false Signature: ROUNDDOWN(arg1: number@scalar, arg2: number@scalar) Arg schema: arg1{kinds=number,required=true,shape=scalar,by_ref=false,coercion=NumberLenientText,max=None,repeating=None,default=false}; arg2{kinds=number,required=true,shape=scalar,by_ref=false,coercion=NumberLenientText,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>], _: &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.