Struct arithmetic_eval::fns::Assert

pub struct Assert;

Assertion function.

Type

fn(bool)

Examples

let program = r#"
    assert(1 + 2 == 3); # this assertion is fine
    assert(3^2 == 10); # this one will fail
"#;
let block = F32Grammar::parse_statements(Span::new(program)).unwrap();

let mut interpreter = Interpreter::new();
interpreter.insert_native_fn("assert", fns::Assert);
let err = interpreter.evaluate(&block).unwrap_err();
assert_eq!(err.main_span().fragment, "assert(3^2 == 10)");
assert_matches!(
    err.source(),
    EvalError::NativeCall(ref msg) if msg == "Assertion failed"
);

Trait Implementations

impl Clone for Assert

fn clone(&self) -> Assert

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Copy for Assert

impl Debug for Assert

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

Formats the value using the given formatter.

impl<T: Grammar> NativeFn<T> for Assert

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

Executes the function on the specified arguments.