Crate specification_core 

Composable, strongly typed business rules.

A Specification evaluates a borrowed candidate. Specifications compose through Specification::and, Specification::or, and Specification::not without dynamic dispatch or heap allocation.

use specification_core::Specification;

let is_adult = |age: &u8| *age >= 18;
let is_senior = |age: &u8| *age >= 65;
let eligible = is_adult.and(is_senior.not());

assert!(eligible.is_satisfied_by(&42));
assert!(!eligible.is_satisfied_by(&70));

Structs

AllOf

A borrowed collection evaluated with logical AND.

Always

A specification that always returns true.

And

A specification that requires both of two specifications to be satisfied.

AnyOf

A borrowed collection evaluated with logical OR.

AsyncAnd

An asynchronous specification that requires both operands to succeed.

AsyncNot

An asynchronous specification that negates another specification.

AsyncOr

An asynchronous specification that accepts either operand.

BoxedAsyncSpecification

An explicitly type-erased asynchronous specification.

BoxedSpecification

An explicitly type-erased, owned specification.

Cooldown

A specification satisfied after a named timestamp is at least one duration old.

EvaluationContext

Immutable input data for specifications that need counters, flags, time, and application-specific user data.

FirstMatch

Ordered, typed decisions selected by the first matching specification.

FixedClock

A clock fixed at one instant, useful for deterministic evaluation and tests.

Flag

A specification satisfied when a named context flag is true.

MaxCount

A specification satisfied while a named counter remains strictly below a maximum.

Never

A specification that always returns false.

Not

A specification that negates another specification’s result.

Or

A specification that requires either of two specifications to be satisfied.

SharedSpecification

An explicitly type-erased specification that can be shared across threads.

Traits

AsyncSpecification

A runtime-neutral asynchronous rule over a borrowed, Sync candidate.

Clock

A deterministic source of evaluation time supplied by the caller.

DecisionSpecification

A rule that selects a typed decision for a candidate.

Specification

A deterministic boolean rule over a borrowed candidate.

Type Aliases

BoxFuture

A boxed Send future used by the object-safe asynchronous adapter.