More work in symbol_table, reduced_ast

schala-lang/language/src/reduced_ast.rs

@@ -189,6 +189,7 @@ impl<'a> Reducer<'a> {
 
     let Symbol { local_name, spec, .. } = match self.symbol_table.lookup_by_fqsn(&sym_name) {
       Some(s) => s,
+      //TODO investigate why this fails
       //None => return Expr::ReductionError(format!("Symbol {:?} not found", sym_name)),
       None => return Expr::Sym(name)
     };
@@ -197,7 +198,7 @@ impl<'a> Reducer<'a> {
       SymbolSpec::RecordConstructor { .. } => Expr::ReductionError(format!("AST reducer doesn't expect a RecordConstructor here")),
       SymbolSpec::DataConstructor { index, type_args, type_name } => Expr::Constructor {
         type_name: type_name.clone(),
-        name,
+        name: local_name.clone(),
         tag: index.clone(),
         arity: type_args.len(),
       },

schala-lang/language/src/symbol_table/mod.rs

@@ -107,37 +107,6 @@ impl<K> NameTable<K> {
   }
 }
 
-
-/// Keeps track of what names were used in a given namespace. Call try_register to add a name to
-/// the table, or report an error if a name already exists.
-struct DuplicateNameTrackTable {
-  table: HashMap<Rc<String>, LineNumber>,
-}
-
-impl DuplicateNameTrackTable {
-  fn new() -> DuplicateNameTrackTable {
-    DuplicateNameTrackTable { table: HashMap::new() }
-  }
-
-  fn try_register(&mut self, name: &Rc<String>, id: &ItemId, decl_locations: &DeclLocations) -> Result<(), LineNumber> {
-    match self.table.entry(name.clone()) {
-      Entry::Occupied(o) => {
-        let line_number = o.get();
-        Err(*line_number)
-      },
-      Entry::Vacant(v) => {
-        let line_number = if let Some(loc) = decl_locations.lookup(id) {
-          loc.line_num
-        } else {
-          0
-        };
-        v.insert(line_number);
-        Ok(())
-      }
-    }
-  }
-}
-
 #[derive(PartialEq, Eq, Hash, Debug, Clone, PartialOrd, Ord)]
 pub struct FullyQualifiedSymbolName(pub Vec<ScopeSegment>);
 
@@ -395,9 +364,6 @@ impl SymbolTable {
   fn add_symbols_from_scope<'a>(&'a mut self, statements: &Vec<Statement>, scope_name_stack: &mut Vec<ScopeSegment>) -> Result<(), String> {
     use self::ast::Declaration::*;
 
-    let mut seen_identifiers = DuplicateNameTrackTable::new();
-    let mut seen_modules = DuplicateNameTrackTable::new();
-
     for statement in statements.iter() {
       match statement {
         Statement { kind: StatementKind::Declaration(decl), id, location, } => {
@@ -405,13 +371,9 @@ impl SymbolTable {
 
           match decl {
             FuncSig(ref signature) => {
-              seen_identifiers.try_register(&signature.name, id, &self.decl_locations)
-                .map_err(|line| format!("Duplicate function definition: {}. It's already defined at {}", signature.name, line))?;
               self.add_function_signature(signature, scope_name_stack)?
             }
             FuncDecl(ref signature, ref body) => {
-              seen_identifiers.try_register(&signature.name, id, &self.decl_locations)
-                .map_err(|line| format!("Duplicate function definition: {}. It's already defined at {}", signature.name, line))?;
               self.add_function_signature(signature, scope_name_stack)?;
               scope_name_stack.push(ScopeSegment{
                 name: signature.name.clone(),
@@ -421,13 +383,9 @@ impl SymbolTable {
               output?
             },
             TypeDecl { name, body, mutable } => {
-              seen_identifiers.try_register(&name.name, &id, &self.decl_locations)
-                .map_err(|line| format!("Duplicate type definition: {}. It's already defined at {}", name.name, line))?;
               self.add_type_decl(name, body, mutable, scope_name_stack)?
             },
             Binding { name, .. } => {
-              seen_identifiers.try_register(&name, &id, &self.decl_locations)
-                .map_err(|line| format!("Duplicate variable definition: {}. It's already defined at {}", name, line))?;
               self.add_new_symbol(name, scope_name_stack, SymbolSpec::Binding);
             }
             _ => ()
@@ -435,8 +393,6 @@ impl SymbolTable {
         },
         Statement { kind: StatementKind::Module(ModuleSpecifier { name, contents}), id, location } => {
           self.decl_locations.add_location(id, *location);
-          seen_modules.try_register(name, id, &self.decl_locations)
-            .map_err(|line| format!("Duplicate module definition: {}. It's already defined at {}", name, line))?;
           scope_name_stack.push(ScopeSegment { name: name.clone() });
           let output = self.add_symbols_from_scope(contents, scope_name_stack);
           scope_name_stack.pop();