Rule execution now runs, no tests tho

src/rule/repository.rs

@@ -0,0 +1,45 @@
+use std::fmt::Debug;
+
+use mappable_rc::Mrc;
+
+use crate::expression::Expr;
+
+use super::{super::expression::Rule, executor::execute, RuleError};
+
+pub struct Repository(Vec<Rule>);
+impl Repository { 
+    pub fn new(mut rules: Vec<Rule>) -> Self {
+        rules.sort_by_key(|r| r.prio);
+        Self(rules)
+    }
+
+    pub fn step(&self, mut code: Mrc<[Expr]>) -> Result<Option<Mrc<[Expr]>>, RuleError> {
+        let mut ran_once = false;
+        for rule in self.0.iter() {
+            if let Some(tmp) = execute(
+                Mrc::clone(&rule.source), Mrc::clone(&rule.target),
+                Mrc::clone(&code)
+            )? {
+                ran_once = true;
+                code = tmp;
+            }
+        }
+        Ok(if ran_once {Some(code)} else {None})
+    }
+
+    pub fn long_step(&self, mut code: Mrc<[Expr]>) -> Result<Mrc<[Expr]>, RuleError> {
+        while let Some(tmp) = self.step(Mrc::clone(&code))? {
+            code = tmp
+        }
+        Ok(code)
+    }
+}
+
+impl Debug for Repository {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        for rule in self.0.iter() {
+            writeln!(f, "{rule:?}")?
+        }
+        Ok(())
+    } 
+}