Struct arithmetic_eval::fns::Len

pub struct Len;

Function returning array / object length.

Type

(using arithmetic-typing notation)

([T]) -> Num

Examples

let program = "len(()) == 0 && len((1, 2, 3)) == 3";
let program = Untyped::<F32Grammar>::parse_statements(program)?;
let module = ExecutableModule::new("tes_len", &program)?;

let mut env = Environment::new();
env.insert_native_fn("len", fns::Len);
assert_eq!(module.with_env(&env)?.run()?, Value::Bool(true));

Trait Implementations

impl Clone for Len

fn clone(&self) -> Len

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for Len

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

Formats the value using the given formatter.

impl Default for Len

fn default() -> Len

Returns the “default value” for a type.

impl<T: FromPrimitive> NativeFn<T> for Len

fn evaluate( &self, args: Vec<SpannedValue<T>>, ctx: &mut CallContext<'_, T>, ) -> EvalResult<T>

Executes the function on the specified arguments.

impl Copy for Len