Attribute Macro register_rule

#[register_rule]

This procedural macro registers a decorated function with conjure_rules’ global registry, and adds the rule to one or more RuleSet’s.

It may be used in any downstream crate. For more information on linker magic, see the linkme crate.

IMPORTANT: Since the resulting rule may not be explicitly referenced, it may be removed by the compiler’s dead code elimination. To prevent this, you must ensure that either:

1. codegen-units is set to 1, i.e. in Cargo.toml:

[profile.release]
codegen-units = 1

2. The function is included somewhere else in the code

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Functions must have the signature fn(&Expr) -> ApplicationResult. The created rule will have the same name as the function.

Intermediary static variables are created to allow for the decentralized registry, with the prefix CONJURE_GEN_. Please ensure that other variable names in the same scope do not conflict with these.

This macro must decorate a function with the given signature. As arguments, it excepts a tuple of 2-tuples in the format: ((<RuleSet name>, <Priority in RuleSet>), ...)

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For example:

use conjure_core::ast::Expression;
use conjure_core::model::Model;
use conjure_core::rule_engine::{ApplicationError, ApplicationResult, Reduction};
use conjure_core::rule_engine::register_rule;

#[register_rule(("RuleSetName", 10))]
fn identity(expr: &Expression, mdl: &Model) -> ApplicationResult {
  Ok(Reduction::pure(expr.clone()))
}

Register a rule with the given rule sets and priorities.