Struct fasteval::evalns::CachedCallbackNamespace

pub struct CachedCallbackNamespace<'a> { /* fields omitted */ }

CachedCallbackNamespace is useful when your variable/function lookups are expensive.

Each variable+args combo will only be looked up once, and then it will be cached and re-used for subsequent lookups.

See module-level documentation for example.

Methods

impl<'a> CachedCallbackNamespace<'a>

pub fn new<F>(cb: F) -> Self where
    F: FnMut(&str, Vec<f64>) -> Option<f64> + 'a, 

Trait Implementations

impl<'_> Cached for CachedCallbackNamespace<'_>

fn cache_create(&mut self, name: String, val: f64) -> Result<(), Error>

Creates a new cached entry. If an entry with the same name already exists, an AlreadyExists Error is returned.

fn cache_set(&mut self, name: String, val: f64)

Sets a cached entry. It doesn't matter whether or not a previous value existed with this name.

fn cache_clear(&mut self)

Clear all cached entries. Values will be recalculated and cached again the next time they are looked up.

impl<'_> EvalNamespace for CachedCallbackNamespace<'_>

fn lookup(
    &mut self,
    name: &str,
    args: Vec<f64>,
    keybuf: &mut String
) -> Option<f64>

Returns a cached value if possible, otherwise delegates to the callback function.