--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/dil/semantic/Scope.d	Sun Mar 09 00:12:19 2008 +0100
@@ -0,0 +1,72 @@
+/++
+  Author: Aziz Köksal
+  License: GPL3
++/
+module dil.semantic.Scope;
+
+import dil.semantic.Symbol;
+import dil.semantic.Symbols;
+import dil.lexer.Identifier;
+import common;
+
+/// Builds a hierarchy of environments.
+class Scope
+{
+  Scope parent; /// The surrounding scope, or null if this is the root scope.
+
+  ScopeSymbol symbol; /// The current symbol with the symbol table.
+
+  this(Scope parent, ScopeSymbol symbol)
+  {
+    this.parent = parent;
+    this.symbol = symbol;
+  }
+
+  /// Find a symbol in this scope.
+  /// Params:
+  ///   name = the name of the symbol.
+  Symbol lookup(Identifier* name)
+  {
+    return symbol.lookup(name);
+  }
+
+  /// Create a new inner scope and return that.
+  Scope enter(ScopeSymbol symbol)
+  {
+    return new Scope(this, symbol);
+  }
+
+  /// Destroy this scope and return the outer scope.
+  Scope exit()
+  {
+    auto sc = parent;
+    // delete this;
+    return sc;
+  }
+
+  /// Search for the enclosing Class scope.
+  Scope classScope()
+  {
+    auto scop = this;
+    do
+    {
+      if (scop.symbol.isClass)
+        return scop;
+      scop = scop.parent;
+    } while (scop)
+    return null;
+  }
+
+  /// Search for the enclosing Module scope.
+  Scope moduleScope()
+  {
+    auto scop = this;
+    do
+    {
+      if (scop.symbol.isModule)
+        return scop;
+      scop = scop.parent;
+    } while (scop)
+    return null;
+  }
+}