Trait Ctx 

pub trait Ctx {
    // Required methods
    fn date_system(&self) -> DateSystem;
    fn now_serial(&self) -> f64;
    fn random(&mut self) -> f64;

    // Provided methods
    fn computed_criterion(
        &mut self,
        _row: usize,
        _col: usize,
        _db: &Array,
        _record: usize,
    ) -> Option<bool> { ... }
    fn has_lambda(&self) -> bool { ... }
    fn call_lambda(&mut self, _arg: Value) -> Option<Value> { ... }
}

Services a function may need from the host.

Required Methods

fn date_system(&self) -> DateSystem

fn now_serial(&self) -> f64

Current local date-time serial.

fn random(&mut self) -> f64

Uniform in [0, 1).

Provided Methods

fn computed_criterion( &mut self, _row: usize, _col: usize, _db: &Array, _record: usize, ) -> Option<bool>

For the database functions: whether the formula in the criteria cell at (row, col) holds for record (a row of db below its labels). None when that cell holds no formula or the criteria didn’t come from a reference.

fn has_lambda(&self) -> bool

For GROUPBY/PIVOTBY: whether their function argument is a LAMBDA (its value is then not used).

fn call_lambda(&mut self, _arg: Value) -> Option<Value>

Calls that LAMBDA with arg (one group’s values) and returns its single result; None when there is no lambda.

Dyn Compatibility

This trait is dyn compatible.

In older versions of Rust, dyn compatibility was called "object safety".

Implementors