Add type for talking about symbol paths

to symbol table

schala-lang/language/src/symbol_table.rs

@@ -7,9 +7,15 @@ use crate::ast;
 use crate::ast::{TypeBody, TypeSingletonName, Signature};
 use crate::typechecking::TypeName;
 
+#[derive(PartialEq, Eq, Hash, Debug)]
+struct SymbolPath {
+  name: Rc<String>,
+  enclosing_scopes: Vec<Rc<String>>
+}
+
 //cf. p. 150 or so of Language Implementation Patterns
 pub struct SymbolTable {
-  pub values: HashMap<Rc<String>, Symbol> //TODO this will eventually have real type information
+  values: HashMap<SymbolPath, Symbol> //TODO this will eventually have real type information
 }
 
 //TODO add various types of lookups here, maybe multiple hash tables internally? also make values
@@ -19,8 +25,20 @@ impl SymbolTable {
     SymbolTable { values: HashMap::new() }
   }
 
+  pub fn add_new_symbol(&mut self, path: &Rc<String>, symbol: Symbol) {
+    let symbol_path = SymbolPath {
+      name: path.clone(),
+      enclosing_scopes: vec![]
+    };
+    self.values.insert(symbol_path, symbol);
+  }
+
   pub fn lookup_by_name(&self, name: &Rc<String>) -> Option<&Symbol> {
-    self.values.get(name)
+    let symbol_path = SymbolPath {
+      name: name.clone(),
+      enclosing_scopes: vec![]
+    };
+    self.values.get(&symbol_path)
   }
 }
 
@@ -81,7 +99,7 @@ impl SymbolTable {
   pub fn debug_symbol_table(&self) -> String {
     let mut output = format!("Symbol table\n");
     for (name, sym) in &self.values {
-      write!(output, "{} -> {}\n", name, sym).unwrap();
+      write!(output, "{:?} -> {}\n", name, sym).unwrap();
     }
     output
   }
@@ -93,8 +111,8 @@ impl SymbolTable {
       (_, None) => local_type_context.new_universal_type()
     }).collect();
     let spec = SymbolSpec::Func(types);
-    self.values.insert(
-      signature.name.clone(),
+    self.add_new_symbol(
+      &signature.name,
       Symbol { name: signature.name.clone(), spec }
     );
     Ok(())
@@ -113,7 +131,7 @@ impl SymbolTable {
             type_name: name.clone(),
             type_args: vec![],
           };
-          self.values.insert(variant_name.clone(), Symbol { name: variant_name.clone(), spec });
+          self.add_new_symbol(variant_name, Symbol { name: variant_name.clone(), spec });
         },
         Variant::TupleStruct(variant_name, tuple_members) => {
           let type_args = tuple_members.iter().map(|type_name| match type_name {
@@ -126,7 +144,7 @@ impl SymbolTable {
             type_args
           };
           let symbol = Symbol { name: variant_name.clone(), spec };
-          self.values.insert(variant_name.clone(), symbol);
+          self.add_new_symbol(variant_name, symbol);
         },
         //TODO if there is only one variant, and it is a record, it doesn't need to have an
         //explicit name
@@ -134,7 +152,7 @@ impl SymbolTable {
           let fields = HashMap::new();
           let spec = SymbolSpec::RecordConstructor { fields };
           let symbol = Symbol { name: name.clone(), spec };
-          self.values.insert(name.clone(), symbol);
+          self.add_new_symbol(name, symbol);
         },
       }
     }