Preparation for sharing

- rustfmt
- clippy
- comments
- README

src/pipeline/import_resolution/alias_map.rs

@@ -1,18 +1,20 @@
-use hashbrown::{HashMap, HashSet};
-
 use std::hash::Hash;
 
-use crate::interner::Token;
+use hashbrown::{HashMap, HashSet};
+
+use crate::interner::Sym;
 
 #[derive(Clone, Debug, Default)]
-pub struct AliasMap{
-  pub targets: HashMap<Token<Vec<Token<String>>>, Token<Vec<Token<String>>>>,
-  pub aliases: HashMap<Token<Vec<Token<String>>>, HashSet<Token<Vec<Token<String>>>>>,
+pub struct AliasMap {
+  pub targets: HashMap<Sym, Sym>,
+  pub aliases: HashMap<Sym, HashSet<Sym>>,
 }
 impl AliasMap {
-  pub fn new() -> Self {Self::default()}
+  pub fn new() -> Self {
+    Self::default()
+  }
 
-  pub fn link(&mut self, alias: Token<Vec<Token<String>>>, target: Token<Vec<Token<String>>>) {
+  pub fn link(&mut self, alias: Sym, target: Sym) {
     let prev = self.targets.insert(alias, target);
     debug_assert!(prev.is_none(), "Alias already has a target");
     multimap_entry(&mut self.aliases, &target).insert(alias);
@@ -21,9 +23,7 @@ impl AliasMap {
       for alt in alts {
         // Assert that this step has always been done in the past
         debug_assert!(
-          self.aliases.get(&alt)
-            .map(HashSet::is_empty)
-            .unwrap_or(true),
+          self.aliases.get(&alt).map(HashSet::is_empty).unwrap_or(true),
           "Alias set of alias not empty"
         );
         debug_assert!(
@@ -35,7 +35,7 @@ impl AliasMap {
     }
   }
 
-  pub fn resolve(&self, alias: Token<Vec<Token<String>>>) -> Option<Token<Vec<Token<String>>>> {
+  pub fn resolve(&self, alias: Sym) -> Option<Sym> {
     self.targets.get(&alias).copied()
   }
 }
@@ -44,10 +44,11 @@ impl AliasMap {
 /// map-to-set (aka. multimap)
 fn multimap_entry<'a, K: Eq + Hash + Clone, V>(
   map: &'a mut HashMap<K, HashSet<V>>,
-  key: &'_ K
+  key: &'_ K,
 ) -> &'a mut HashSet<V> {
-  map.raw_entry_mut()
+  map
+    .raw_entry_mut()
     .from_key(key)
     .or_insert_with(|| (key.clone(), HashSet::new()))
     .1
-}
+}