Random notes re: symbol table

I'm proably gonna want to redo the symbol table stuff after reading Language
Implementation Patterns, esp. to accomodate scopes

schala-lang/src/typechecking.rs

@@ -11,6 +11,12 @@ use parsing;
 pub struct TypeContext {
   type_var_count: u64,
   bindings: HashMap<Rc<String>, Type>,
+  //symbol_table: SymbolTable
+}
+
+//cf. p. 150 or so of Language Implementation Patterns
+struct SymbolTable {
+
 }
 
 #[derive(Debug, PartialEq, Clone)]