From 7b3f06b269809f9be10fa41c1ce5cf761dd1b8fb Mon Sep 17 00:00:00 2001
From: Jason Turner <jason@emptycrate.com>
Date: Tue, 3 May 2016 14:41:16 -0600
Subject: [PATCH] Even more scope / block simplification

---
 .../chaiscript/language/chaiscript_common.hpp |  4 +--
 .../chaiscript/language/chaiscript_eval.hpp   | 14 ++++++++++
 .../language/chaiscript_optimizer.hpp         | 27 ++++++++++++++-----
 3 files changed, 37 insertions(+), 8 deletions(-)

diff --git a/include/chaiscript/language/chaiscript_common.hpp b/include/chaiscript/language/chaiscript_common.hpp
index 2f06f21..17a7492 100644
--- a/include/chaiscript/language/chaiscript_common.hpp
+++ b/include/chaiscript/language/chaiscript_common.hpp
@@ -34,7 +34,7 @@ namespace chaiscript
   /// Types of AST nodes available to the parser and eval
   enum class AST_Node_Type { Id, Fun_Call, Arg_List, Equation, Var_Decl,
     Array_Call, Dot_Access,
-    Lambda, Block, Def, While, If, For, Inline_Array, Inline_Map, Return, File, Prefix, Break, Continue, Map_Pair, Value_Range,
+    Lambda, Block, Scopeless_Block, Def, While, If, For, Inline_Array, Inline_Map, Return, File, Prefix, Break, Continue, Map_Pair, Value_Range,
     Inline_Range, Try, Catch, Finally, Method, Attr_Decl,  
     Logical_And, Logical_Or, Reference, Switch, Case, Default, Ternary_Cond, Noop, Class, Binary, Arg, Global_Decl, Constant, Compiled
   };
@@ -47,7 +47,7 @@ namespace chaiscript
     const char *ast_node_type_to_string(AST_Node_Type ast_node_type) {
       static const char * const ast_node_types[] = { "Id", "Fun_Call", "Arg_List", "Equation", "Var_Decl",
                                     "Array_Call", "Dot_Access", 
-                                    "Lambda", "Block", "Def", "While", "If", "For", "Inline_Array", "Inline_Map", "Return", "File", "Prefix", "Break", "Continue", "Map_Pair", "Value_Range",
+                                    "Lambda", "Block", "Scopeless_Block", "Def", "While", "If", "For", "Inline_Array", "Inline_Map", "Return", "File", "Prefix", "Break", "Continue", "Map_Pair", "Value_Range",
                                     "Inline_Range", "Try", "Catch", "Finally", "Method", "Attr_Decl",
                                     "Logical_And", "Logical_Or", "Reference", "Switch", "Case", "Default", "Ternary Condition", "Noop", "Class", "Binary", "Arg", "Global_Decl", "Constant", "Compiled"};
 
diff --git a/include/chaiscript/language/chaiscript_eval.hpp b/include/chaiscript/language/chaiscript_eval.hpp
index e4d6031..c3c473b 100644
--- a/include/chaiscript/language/chaiscript_eval.hpp
+++ b/include/chaiscript/language/chaiscript_eval.hpp
@@ -635,6 +635,20 @@ namespace chaiscript
 
     };
 
+    template<typename T>
+    struct Scopeless_Block_AST_Node final : AST_Node_Impl<T> {
+        Scopeless_Block_AST_Node(std::string t_ast_node_text, Parse_Location t_loc, std::vector<AST_Node_Impl_Ptr<T>> t_children) :
+          AST_Node_Impl<T>(std::move(t_ast_node_text), AST_Node_Type::Scopeless_Block, std::move(t_loc), std::move(t_children)) { }
+
+        Boxed_Value eval_internal(const chaiscript::detail::Dispatch_State &t_ss) const override {
+          const auto num_children = this->children.size();
+          for (size_t i = 0; i < num_children-1; ++i) {
+            this->children[i]->eval(t_ss);
+          }
+          return this->children.back()->eval(t_ss);
+        }
+    };
+
     template<typename T>
     struct Block_AST_Node final : AST_Node_Impl<T> {
         Block_AST_Node(std::string t_ast_node_text, Parse_Location t_loc, std::vector<AST_Node_Impl_Ptr<T>> t_children) :
diff --git a/include/chaiscript/language/chaiscript_optimizer.hpp b/include/chaiscript/language/chaiscript_optimizer.hpp
index 2ff4ad0..92f4ad1 100644
--- a/include/chaiscript/language/chaiscript_optimizer.hpp
+++ b/include/chaiscript/language/chaiscript_optimizer.hpp
@@ -31,11 +31,20 @@ namespace chaiscript {
 
     template<typename T>
       auto child_at(const eval::AST_Node_Impl_Ptr<T> &node, const size_t offset) {
+        if (node->children[offset]->identifier == AST_Node_Type::Compiled) {
+          return dynamic_cast<const eval::Compiled_AST_Node<T>&>(*node->children[offset]).m_original_node;
+        } else {
+          return node->children[offset];
+        }
+
+
+        /*
         if (node->identifier == AST_Node_Type::Compiled) {
           return dynamic_cast<const eval::Compiled_AST_Node<T>&>(*node).m_original_node->children[offset];
         } else {
           return node->children[offset];
         }
+        */
       }
 
     template<typename T>
@@ -88,6 +97,7 @@ namespace chaiscript {
       for (size_t i = 0; i < num; ++i) {
         const auto &child = child_at(node, i);
         if (child->identifier != AST_Node_Type::Block
+            && child->identifier != AST_Node_Type::For
             && contains_var_decl_in_scope(child)) {
           return true;
         }
@@ -99,14 +109,19 @@ namespace chaiscript {
     struct Block {
       template<typename T>
       auto optimize(const eval::AST_Node_Impl_Ptr<T> &node) {
-        if (node->identifier == AST_Node_Type::Block
-            && node->children.size() == 1
-            && !contains_var_decl_in_scope(node))
+        if (node->identifier == AST_Node_Type::Block)
         {
-          return node->children[0];
-        } else {
-          return node;
+          if (!contains_var_decl_in_scope(node))
+          {
+            if (node->children.size() == 1) {
+              return node->children[0];
+            } else {
+              return chaiscript::make_shared<eval::AST_Node_Impl<T>, eval::Scopeless_Block_AST_Node<T>>(node->text, node->location, node->children);
+            }
+          }
         }
+
+        return node;
       }
     };