feat: convet a named debruijn to a name

crates/uplc/src/debruijn/bimap.rs

@@ -0,0 +1,32 @@
+use std::collections::HashMap;
+
+use crate::ast::Unique;
+
+use super::Level;
+
+pub struct BiMap {
+    left: HashMap<Unique, Level>,
+    right: HashMap<Level, Unique>,
+}
+
+impl BiMap {
+    pub(super) fn new() -> Self {
+        BiMap {
+            right: HashMap::new(),
+            left: HashMap::new(),
+        }
+    }
+
+    pub(super) fn insert(&mut self, unique: Unique, level: Level) {
+        self.left.insert(unique, level);
+        self.right.insert(level, unique);
+    }
+
+    pub(super) fn get(&self, unique: &Unique) -> Option<&Level> {
+        self.left.get(unique)
+    }
+
+    pub(super) fn get_right(&self, level: &Level) -> Option<&Unique> {
+        self.right.get(level)
+    }
+}