Segregated symbols into 5 separate namespaces

The different namespaces are:

  Function      Value expression functions, which receive a "context"
  Option        Command-line options
  Precommand    Commands which are invoked before reading the journal
  Command       Commands which are invoked after reading the journal
  Directive     Directives that occur at column 0 in a data file

This greatly eases the ability for Python uses to add intercept hooks to
change how the basic Ledger module functions.  An example of what should
be possible soon:

  import ledger

  def my_foo_handler(value):
      print "--foo received:", value

  ledger.add_handler(ledger.Option, "foo=", my_foo_handler)

1 files changed, 78 insertions, 15 deletions

diff --git a/src/scope.h b/src/scope.h
index 36eb54f1..7cf89c3e 100644
--- a/src/scope.h
+++ b/src/scope.h
@@ -55,6 +55,61 @@ namespace ledger {
  *
  * Long.
  */
+struct symbol_t
+{
+  enum kind_t {
+    UNKNOWN,
+    FUNCTION,
+    OPTION,
+    PRECOMMAND,
+    COMMAND,
+    DIRECTIVE
+  };
+
+  kind_t	   kind;
+  string	   name;
+  expr_t::ptr_op_t definition;
+
+  symbol_t() : kind(UNKNOWN), name(""), definition(NULL) {
+    TRACE_CTOR(symbol_t, "");
+  }
+  symbol_t(kind_t _kind, string _name, expr_t::ptr_op_t _definition = NULL)
+    : kind(_kind), name(_name), definition(_definition) {
+    TRACE_CTOR(symbol_t, "symbol_t::kind_t, string");
+  }
+  symbol_t(const symbol_t& sym)
+    : kind(sym.kind), name(sym.name),
+      definition(sym.definition) {
+    TRACE_CTOR(symbol_t, "copy");
+  }
+  ~symbol_t() throw() {
+    TRACE_DTOR(symbol_t);
+  }
+
+  bool operator<(const symbol_t& sym) const {
+    return kind < sym.kind || name < sym.name;
+  }
+
+#if defined(HAVE_BOOST_SERIALIZATION)
+private:
+  /** Serialization. */
+
+  friend class boost::serialization::access;
+
+  template<class Archive>
+  void serialize(Archive& ar, const unsigned int /* version */) {
+    ar & kind;
+    ar & name;
+    ar & definition;
+  }
+#endif // HAVE_BOOST_SERIALIZATION
+};
+
+/**
+ * @brief Brief
+ *
+ * Long.
+ */
 class scope_t
 {
 public:
@@ -65,8 +120,10 @@ public:
     TRACE_DTOR(scope_t);
   }
 
-  virtual void define(const string&, expr_t::ptr_op_t) {}
-  virtual expr_t::ptr_op_t lookup(const string& name) = 0;
+  virtual void define(const symbol_t::kind_t, const string&,
+		      expr_t::ptr_op_t) {}
+  virtual expr_t::ptr_op_t lookup(const symbol_t::kind_t kind,
+				  const string& name) = 0;
 
 #if defined(HAVE_BOOST_SERIALIZATION)
 private:
@@ -100,14 +157,16 @@ public:
     TRACE_DTOR(child_scope_t);
   }
 
-  virtual void define(const string& name, expr_t::ptr_op_t def) {
+  virtual void define(const symbol_t::kind_t kind,
+		      const string& name, expr_t::ptr_op_t def) {
     if (parent)
-      parent->define(name, def);
+      parent->define(kind, name, def);
   }
 
-  virtual expr_t::ptr_op_t lookup(const string& name) {
+  virtual expr_t::ptr_op_t lookup(const symbol_t::kind_t kind,
+				  const string& name) {
     if (parent)
-      return parent->lookup(name);
+      return parent->lookup(kind, name);
     return NULL;
   }
 
@@ -132,7 +191,7 @@ private:
  */
 class symbol_scope_t : public child_scope_t
 {
-  typedef std::map<const string, expr_t::ptr_op_t> symbol_map;
+  typedef std::map<symbol_t, expr_t::ptr_op_t> symbol_map;
 
   symbol_map symbols;
 
@@ -147,9 +206,11 @@ public:
     TRACE_DTOR(symbol_scope_t);
   }
 
-  virtual void define(const string& name, expr_t::ptr_op_t def);
+  virtual void define(const symbol_t::kind_t kind, const string& name,
+		      expr_t::ptr_op_t def);
 
-  virtual expr_t::ptr_op_t lookup(const string& name);
+  virtual expr_t::ptr_op_t lookup(const symbol_t::kind_t kind,
+				  const string& name);
 
 #if defined(HAVE_BOOST_SERIALIZATION)
 private:
@@ -259,15 +320,17 @@ public:
     TRACE_DTOR(bind_scope_t);
   }
 
-  virtual void define(const string& name, expr_t::ptr_op_t def) {
-    parent->define(name, def);
-    grandchild.define(name, def);
+  virtual void define(const symbol_t::kind_t kind, const string& name,
+		      expr_t::ptr_op_t def) {
+    parent->define(kind, name, def);
+    grandchild.define(kind, name, def);
   }
 
-  virtual expr_t::ptr_op_t lookup(const string& name) {
-    if (expr_t::ptr_op_t def = grandchild.lookup(name))
+  virtual expr_t::ptr_op_t lookup(const symbol_t::kind_t kind,
+				  const string& name) {
+    if (expr_t::ptr_op_t def = grandchild.lookup(kind, name))
       return def;
-    return child_scope_t::lookup(name);
+    return child_scope_t::lookup(kind, name);
   }
 
 #if defined(HAVE_BOOST_SERIALIZATION)