Add types necessary for refactor of Symbol table

schala-lang/language/src/symbol_table.rs

@@ -13,14 +13,23 @@ type LineNumber = u32;
 type SymbolTrackTable = HashMap<Rc<String>, LineNumber>;
 
 #[derive(PartialEq, Eq, Hash, Debug)]
-struct SymbolPath {
-  name: Rc<String>,
-  enclosing_scopes: Vec<Rc<String>>
+struct PathToSymbol(Vec<Rc<String>>);
+
+#[derive(Debug)]
+struct SymbolPathSegment {
+  segment_name: Rc<String>,
+  segment_type: SymbolPathSegmentKind
+}
+
+#[derive(Debug)]
+enum SymbolPathSegmentKind {
+  NamedScope,
+  TypeVariant
 }
 
 //cf. p. 150 or so of Language Implementation Patterns
 pub struct SymbolTable {
-  values: HashMap<SymbolPath, Symbol>,
+  values: HashMap<PathToSymbol, Symbol>,
 }
 
 //TODO add various types of lookups here, maybe multiple hash tables internally?
@@ -32,10 +41,9 @@ impl SymbolTable {
   }
 
   fn add_new_symbol(&mut self, name: &Rc<String>, path: &Vec<Rc<String>>, symbol: Symbol) {
-    let symbol_path = SymbolPath {
-      name: name.clone(),
-      enclosing_scopes: path.clone(),
-    };
+    let mut vec = path.clone();
+    vec.push(name.clone());
+    let symbol_path = PathToSymbol(vec);
     self.values.insert(symbol_path, symbol);
   }
 
@@ -44,7 +52,9 @@ impl SymbolTable {
   }
 
   pub fn lookup_by_path(&self, name: &Rc<String>, path: &Vec<Rc<String>>) -> Option<&Symbol> {
-    let symbol_path = SymbolPath { name: name.clone(), enclosing_scopes: path.clone() };
+    let mut vec = path.clone();
+    vec.push(name.clone());
+    let symbol_path = PathToSymbol(vec);
     self.values.get(&symbol_path)
   }
 }