1 files changed, 51 insertions, 0 deletions
diff --git a/tiger-compiler/lib/misc/scoped-map.hh b/tiger-compiler/lib/misc/scoped-map.hh
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+++ b/tiger-compiler/lib/misc/scoped-map.hh
@@ -0,0 +1,51 @@
+/**
+ ** \file misc/scoped-map.hh
+ ** \brief Declaration of misc::scoped_map.
+ **
+ ** This implements a stack of dictionnaries.  Each time a scope is
+ ** opened, a new dictionnary is added on the top of the stack; the
+ ** dictionary is removed when the scope is closed.  Lookup of keys
+ ** is done in the last added dictionnary first (LIFO).
+ **
+ ** In particular this class is used to implement symbol tables.
+ **/
+
+#pragma once
+
+#include <map>
+#include <ostream>
+#include <stack>
+#include <vector>
+
+namespace misc
+{
+  template <typename Key, typename Data> class scoped_map
+  {
+    // FIXME DONE: Some code was deleted here.
+  public:
+    // initializes a new stack with an empty map on top as the first scope
+    scoped_map()
+    {
+      scopes_.push_back(std::map<Key,Data>());
+    }
+    void put(const Key& key, const Data& value);
+    Data get(const Key& key) const requires(!std::is_pointer_v<Data>);
+    Data get(const Key& key) const requires(std::is_pointer_v<Data>);
+    std::ostream& dump(std::ostream& ostr) const;
+    void scope_begin();
+    void scope_end();
+
+  private:
+    std::vector<std::map<Key, Data>> scopes_;
+  };
+
+  template <typename Key, typename Data>
+  std::ostream& operator<<(std::ostream& ostr,
+                           const scoped_map<Key, Data>& tbl);
+
+  // FIXME DONE: Some code was deleted here.
+  // heehee
+
+} // namespace misc
+
+#include <misc/scoped-map.hxx>