3 releases (1 stable)
1.0.1 | Mar 8, 2020 |
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0.2.1 | Jan 4, 2020 |
0.2.0 | Jan 4, 2020 |
#887 in Math
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Evaluator
Provides interfaces and implementations for logic constructs that return values without accepting arguments, either via closure captures, global state, calculation or otherwise.
Usage
Evaluator types
The three main evaluator types are ImmEval
, Eval
and RcEval
(there's also DummyEval
, which is rarely useful except for dynamically dispatched evaluator calls).
ImmEval
Evaluates Sized
values using a closure without any caching.
Eval
Evaluates Copy
-able values using an internal cache.
RcEval
Evaluates all kinds of values by returning a reference counter to the result. The most flexible yet the slowest type.
DummyEval
Takes a single Clone
-able (remember, Copy
implies Clone
) object and returns it when evaluated. Useful if you have a Box<dyn Evaluator>
and want to save a few cycles on the closure indirection if the evaluator which you placed there always returns the same value.
You can implement your own evaluators by implementing the Evaluator
and RcEvaluator
traits, which are responsible for the eval()
methods.
Creating evaluators
Evaluators are created using the From
trait, taking a closure as the only argument. They accept closures (or any type that implements Fn
, really) that returns the kind of value that the evaluator accepts as the output (Sized
for ImmEval
, Copy
for Eval
and any value for RcEval
).