Struct arithmetic_eval::fns::While

pub struct While;

Loop function that evaluates the provided closure while a certain condition is true. Returns the loop state afterwards.

Type

(using arithmetic-typing notation)

('T, ('T) -> Bool, ('T) -> 'T) -> 'T

Examples

let program = "
    factorial = |x| {
        (_, acc) = while(
            (x, 1),
            |(i, _)| i >= 1,
            |(i, acc)| (i - 1, acc * i),
        );
        acc
    };
    factorial(5) == 120 && factorial(10) == 3628800
";
let program = Untyped::<F32Grammar>::parse_statements(program)?;
let module = ExecutableModule::new("test_while", &program)?;

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

Trait Implementations

impl Clone for While

fn clone(&self) -> While

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Debug for While

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

Formats the value using the given formatter.

impl Default for While

fn default() -> While

Returns the “default value” for a type.

impl<T: 'static + Clone> NativeFn<T> for While

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

Executes the function on the specified arguments.

impl Copy for While