From 68f96f9213e849d0d7c4cedf3edeaec99743ee27 Mon Sep 17 00:00:00 2001
From: Boris Kolpackov <boris@codesynthesis.com>
Date: Mon, 24 Aug 2015 09:51:15 +0200
Subject: New variable architecture

---
 build/variable.ixx | 403 +++++++++++++++++++++++++++++++++++++++++++++--------
 1 file changed, 345 insertions(+), 58 deletions(-)

(limited to 'build/variable.ixx')

diff --git a/build/variable.ixx b/build/variable.ixx
index b97815e..16ea7c0 100644
--- a/build/variable.ixx
+++ b/build/variable.ixx
@@ -4,108 +4,395 @@
 
 namespace build
 {
-  // value_proxy
+  // value
   //
-  inline bool value_proxy::
-  empty () const {return as<const list_value&> ().empty ();}
+  template <typename T>
+  inline void
+  assign (value& v, const variable& var)
+  {
+    auto t (&value_traits<T>::value_type);
+
+    if (v.type != t)
+      assign (v, t, var);
+  }
+
+  template <typename T>
+  inline typename value_traits<T>::type
+  as (value& v)
+  {
+    return value_traits<T>::as (v);
+  }
+
+  template <typename T>
+  inline typename value_traits<T>::const_type
+  as (const value& v)
+  {
+    return value_traits<T>::as (v);
+  }
+
+  template <typename T>
+  inline bool
+  assign (name& n)
+  {
+    return value_traits<T>::assign (n);
+  }
+
+  template <typename T>
+  inline typename value_traits<T>::type
+  as (name& n)
+  {
+    return value_traits<T>::as (n);
+  }
 
-  inline const value_proxy& value_proxy::
-  operator= (value_ptr v) const
+  template <typename T>
+  inline typename value_traits<T>::const_type
+  as (const name& n)
   {
-    *p = std::move (v);
+    return value_traits<T>::as (n);
+  }
+
+  template <typename T>
+  inline value& value::
+  operator= (T v)
+  {
+    value_traits<T>::assign (*this, std::move (v));
+    return *this;
+  }
+
+  template <typename T>
+  inline value& value::
+  operator+= (T v)
+  {
+    value_traits<T>::append (*this, std::move (v));
     return *this;
   }
 
-  inline const value_proxy& value_proxy::
-  operator= (const value_proxy& v) const
+  inline void value::
+  assign (names v, const variable& var)
+  {
+    data_ = std::move (v);
+    state_ = (type != nullptr && type->assign != nullptr
+              ? type->assign (data_, var)
+              : !data_.empty ())
+      ? state_type::filled
+      : state_type::empty;
+  }
+
+  // bool value
+  //
+  inline bool_value<name> value_traits<bool>::
+  as (value& v)
+  {
+    assert (v.type == bool_type);
+    return bool_value<name> (v.data_.front ());
+  }
+
+  inline bool_value<const name> value_traits<bool>::
+  as (const value& v)
   {
-    if (this != &v)
+    assert (v.type == bool_type);
+    return bool_value<const name> (v.data_.front ());
+  }
+
+  inline void value_traits<bool>::
+  assign (value& v, bool x)
+  {
+    if (v.null ())
     {
-      if (v)
-        *p = v.as<const value&> ().clone ();
-      else
-        p->reset ();
+      if (v.type == nullptr)
+        v.type = bool_type;
+      v.data_.emplace_back (name ());
+      v.state_ = value::state_type::empty;
     }
 
-    return *this;
+    as (v) = x;
+    v.state_ = value::state_type::filled;
   }
 
-  inline const value_proxy& value_proxy::
-  operator= (list_value v) const
+  inline void value_traits<bool>::
+  append (value& v, bool x)
   {
-    if (*p == nullptr)
-      p->reset (new list_value (std::move (v)));
+    if (v.null ())
+      assign (v, x);
     else
-      //@@ Assuming it is a list_value.
-      //
-      as<list_value&> () = std::move (v);
+      as (v) += x; // Cannot be empty.
+  }
 
-    return *this;
+  // string value
+  //
+  inline std::string& value_traits<std::string>::
+  as (value& v)
+  {
+    assert (v.type == string_type);
+    return v.data_.front ().value;
   }
 
-  inline const value_proxy& value_proxy::
-  operator= (std::string v) const
+  inline const std::string& value_traits<std::string>::
+  as (const value& v)
   {
-    // In most cases this is used to initialize a new variable, so
-    // don't bother trying to optimize for the case where p is not
-    // NULL.
-    //
-    p->reset (new list_value (std::move (v)));
+    assert (v.type == string_type);
+    return v.data_.front ().value;
+  }
+
+  inline void value_traits<std::string>::
+  assign (value& v, std::string x)
+  {
+    if (v.null ())
+    {
+      if (v.type == nullptr)
+        v.type = string_type;
+      v.data_.emplace_back (name ());
+      v.state_ = value::state_type::empty;
+    }
+
+    v.state_ = (as (v) = std::move (x)).empty ()
+      ? value::state_type::empty
+      : value::state_type::filled;
+  }
+
+  inline void value_traits<std::string>::
+  append (value& v, std::string x)
+  {
+    if (v.null ())
+      assign (v, std::move (x));
+    else
+      v.state_ = (as (v) += std::move (x)).empty ()
+        ? value::state_type::empty
+        : value::state_type::filled;
+  }
+
+  // dir_path value
+  //
+  inline dir_path& value_traits<dir_path>::
+  as (value& v)
+  {
+    assert (v.type == dir_path_type);
+    return v.data_.front ().dir;
+  }
+
+  inline const dir_path& value_traits<dir_path>::
+  as (const value& v)
+  {
+    assert (v.type == dir_path_type);
+    return v.data_.front ().dir;
+  }
+
+  inline void value_traits<dir_path>::
+  assign (value& v, dir_path x)
+  {
+    if (v.null ())
+    {
+      if (v.type == nullptr)
+        v.type = dir_path_type;
+      v.data_.emplace_back (name ());
+      v.state_ = value::state_type::empty;
+    }
+
+    v.state_ = (as (v) = std::move (x)).empty ()
+      ? value::state_type::empty
+      : value::state_type::filled;
+  }
+
+  inline void value_traits<dir_path>::
+  append (value& v, dir_path x)
+  {
+    if (v.null ())
+      assign (v, std::move (x));
+    else
+      v.state_ = (as (v) /= std::move (x)).empty ()
+        ? value::state_type::empty
+        : value::state_type::filled;
+  }
+
+  // name value
+  //
+  inline name& value_traits<name>::
+  as (value& v)
+  {
+    assert (v.type == name_type);
+    return v.data_.front ();
+  }
+
+  inline const name& value_traits<name>::
+  as (const value& v)
+  {
+    assert (v.type == name_type);
+    return v.data_.front ();
+  }
+
+  inline void value_traits<name>::
+  assign (value& v, name x)
+  {
+    if (v.null ())
+    {
+      if (v.type == nullptr)
+        v.type = name_type;
+      v.data_.emplace_back (name ());
+      v.state_ = value::state_type::empty;
+    }
+
+    v.state_ = (as (v) = std::move (x)).empty ()
+      ? value::state_type::empty
+      : value::state_type::filled;
+  }
+
+  // vector<T> value
+  //
+  template <typename T, typename D>
+  inline vector_value<T, D>& vector_value<T, D>::
+  assign (std::vector<T> v)
+  {
+    d->clear ();
+    d->insert (d->end (),
+               std::make_move_iterator (v.begin ()),
+               std::make_move_iterator (v.end ()));
     return *this;
   }
 
-  inline const value_proxy& value_proxy::
-  operator= (dir_path v) const
+  template <typename T, typename D>
+  template <typename D1>
+  inline vector_value<T, D>& vector_value<T, D>::
+  assign (const vector_value<T, D1>& v)
   {
-    p->reset (new list_value (std::move (v)));
+    d->clear ();
+    d->insert (d->end (), v.begin (), v.end ());
     return *this;
   }
 
-  inline const value_proxy& value_proxy::
-  operator= (std::nullptr_t) const
+  template <typename T, typename D>
+  template <typename D1>
+  inline vector_value<T, D>& vector_value<T, D>::
+  append (const vector_value<T, D1>& v)
   {
-    p->reset ();
+    d->insert (d->end (), v.begin (), v.end ());
     return *this;
   }
 
-  inline const value_proxy& value_proxy::
-  operator+= (const value_proxy& v) const
+  template <typename T>
+  inline vector_value<T, names> value_traits<std::vector<T>>::
+  as (value& v)
+  {
+    assert (v.type == &value_traits<std::vector<T>>::value_type);
+    return vector_value<T, names> (v.data_);
+  }
+
+  template <typename T>
+  inline vector_value<T, const names> value_traits<std::vector<T>>::
+  as (const value& v)
   {
-    if (v && this != &v)
+    assert (v.type == &value_traits<std::vector<T>>::value_type);
+    return vector_value<T, const names> (v.data_);
+  }
+
+  template <typename T>
+  template <typename V>
+  inline void value_traits<std::vector<T>>::
+  assign (value& v, V x)
+  {
+    if (v.null ())
     {
-      if (*p == nullptr)
-        *this = v;
-      else
-        //@@ Assuming it is a list_value.
-        //
-        *this += v.as<const list_value&> ();
+      if (v.type == nullptr)
+        v.type = &value_traits<std::vector<T>>::value_type;
+      v.state_ = value::state_type::empty;
     }
 
-    return *this;
+    v.state_ = (as (v).assign (std::move (x))).empty ()
+      ? value::state_type::empty
+      : value::state_type::filled;
   }
 
-  inline const value_proxy& value_proxy::
-  operator+= (const list_value& v) const
+  template <typename T>
+  template <typename V>
+  inline void value_traits<std::vector<T>>::
+  append (value& v, V x)
   {
-    if (*p == nullptr)
-      *this = v;
+    if (v.null ())
+      assign (v, std::move (x));
     else
+      v.state_ = (as (v).append (std::move (x))).empty ()
+        ? value::state_type::empty
+        : value::state_type::filled;
+  }
+
+  // map<K, V> value
+  //
+  template <typename K, typename V>
+  inline map_value<K, V, names> value_traits<std::map<K, V>>::
+  as (value& v)
+  {
+    assert ((v.type == &value_traits<std::map<K, V>>::value_type));
+    return map_value<K, V, names> (v.data_);
+  }
+
+  template <typename K, typename V>
+  inline map_value<K, V, const names> value_traits<std::map<K, V>>::
+  as (const value& v)
+  {
+    assert ((v.type == &value_traits<std::map<K, V>>::value_type));
+    return map_value<K, V, const names> (v.data_);
+  }
+
+  template <typename K, typename V>
+  template <typename M>
+  inline void value_traits<std::map<K, V>>::
+  assign (value& v, M x)
+  {
+    if (v.null ())
     {
-      list_value& lv (as<list_value&> ());
-      lv.insert (lv.end (), v.begin (), v.end ());
+      if (v.type == nullptr)
+        v.type = &value_traits<std::map<K, V>>::value_type;
+      v.state_ = value::state_type::empty;
     }
 
-    return *this;
+    v.state_ = (as (v).assign (std::move (x))).empty ()
+      ? value::state_type::empty
+      : value::state_type::filled;
   }
 
-  inline const value_proxy& value_proxy::
-  operator+= (std::string v) const
+  template <typename K, typename V>
+  template <typename M>
+  inline void value_traits<std::map<K, V>>::
+  append (value& v, M x)
   {
-    if (*p == nullptr)
-      *this = v;
+    if (v.null ())
+      assign (v, std::move (x));
     else
-      as<list_value&> ().emplace_back (std::move (v));
+      v.state_ = (as (v).append (std::move (x))).empty ()
+        ? value::state_type::empty
+        : value::state_type::filled;
+  }
 
-    return *this;
+  // variable_map::iterator_adapter
+  //
+  template <typename I>
+  inline typename I::reference variable_map::iterator_adapter<I>::
+  operator* () const
+  {
+    auto& r (I::operator* ());
+    const variable& var (r.first);
+    auto& val (r.second);
+
+    // First access after being assigned a type?
+    //
+    if (var.type != nullptr && val.type != var.type)
+      build::assign (const_cast<value&> (val), var.type, var);
+
+    return r;
+  }
+
+  template <typename I>
+  inline typename I::pointer variable_map::iterator_adapter<I>::
+  operator-> () const
+  {
+    auto p (I::operator-> ());
+    const variable& var (p->first);
+    auto& val (p->second);
+
+    // First access after being assigned a type?
+    //
+    if (var.type != nullptr && val.type != var.type)
+      build::assign (const_cast<value&> (val), var.type, var);
+
+    return p;
   }
 }
-- 
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