Add ability to get current script context

closes #277

cheatsheet.md

@@ -455,6 +455,13 @@ the contained function.
 
 If both a 2 parameter and a 3 parameter signature match, the 3 parameter function always wins.
 
+## Context
+
+ * `__LINE__` Current file line number
+ * `__FILE__` Full path of current file
+ * `__CLASS__` Name of current class
+ * `__FUNC__` Mame of current function
+
 
 # Built In Functions
 

include/chaiscript/language/chaiscript_common.hpp

@@ -31,7 +31,8 @@ namespace chaiscript
     {
       static const std::set<std::string> m_reserved_words 
         = {"def", "fun", "while", "for", "if", "else", "&&", "||", ",", "auto", 
-          "return", "break", "true", "false", "class", "attr", "var", "global", "GLOBAL", "_"};
+          "return", "break", "true", "false", "class", "attr", "var", "global", "GLOBAL", "_",
+          "__LINE__", "__FILE__", "__FUNC__", "__CLASS__"};
       return m_reserved_words.count(name) > 0;
     }
 

include/chaiscript/language/chaiscript_eval.hpp

@@ -1368,30 +1368,27 @@ namespace chaiscript
 
           AST_Node_Impl_Ptr<T> guardnode;
 
-          const auto d = t_ss->get_parent_locals();
+          const std::string & class_name = this->children[0]->text;
-          const auto itr = d.find("_current_class_name");
-          const auto class_offset = (itr != d.end())?-1:0;
-          const std::string & class_name = (itr != d.end())?std::string(boxed_cast<std::string>(itr->second)):this->children[0]->text;
 
           //The first param of a method is always the implied this ptr.
           std::vector<std::string> t_param_names{"this"};
           dispatch::Param_Types param_types;
 
-          if ((this->children.size() > static_cast<size_t>(3 + class_offset)) 
+          if ((this->children.size() > 3) 
-               && (this->children[static_cast<size_t>(2 + class_offset)]->identifier == AST_Node_Type::Arg_List)) {
+               && (this->children[2]->identifier == AST_Node_Type::Arg_List)) {
-            auto args = Arg_List_AST_Node<T>::get_arg_names(this->children[static_cast<size_t>(2 + class_offset)]);
+            auto args = Arg_List_AST_Node<T>::get_arg_names(this->children[2]);
             t_param_names.insert(t_param_names.end(), args.begin(), args.end());
-            param_types = Arg_List_AST_Node<T>::get_arg_types(this->children[static_cast<size_t>(2 + class_offset)], t_ss);
+            param_types = Arg_List_AST_Node<T>::get_arg_types(this->children[2], t_ss);
 
-            if (this->children.size() > static_cast<size_t>(4 + class_offset)) {
+            if (this->children.size() > 4) {
-              guardnode = this->children[static_cast<size_t>(3 + class_offset)];
+              guardnode = this->children[3];
             }
           }
           else {
             //no parameters
 
-            if (this->children.size() > static_cast<size_t>(3 + class_offset)) {
+            if (this->children.size() > 3) {
-              guardnode = this->children[static_cast<size_t>(2 + class_offset)];
+              guardnode = this->children[2];
             }
           }
 
@@ -1408,7 +1405,7 @@ namespace chaiscript
           }
 
           try {
-            const std::string & function_name = this->children[static_cast<size_t>(1 + class_offset)]->text;
+            const std::string & function_name = this->children[1]->text;
             auto node = this->children.back();
 
             if (function_name == class_name) {
@@ -1454,13 +1451,10 @@ namespace chaiscript
 
         Boxed_Value eval_internal(const chaiscript::detail::Dispatch_State &t_ss) const override 
         {
-          const auto &d = t_ss->get_parent_locals();
+          std::string class_name = this->children[0]->text;
-          const auto itr = d.find("_current_class_name");
-          const auto class_offset = (itr != d.end())?-1:0;
-          std::string class_name = (itr != d.end())?std::string(boxed_cast<std::string>(itr->second)):this->children[0]->text;
 
           try {
-            std::string attr_name = this->children[static_cast<size_t>(1 + class_offset)]->text;
+            std::string attr_name = this->children[1]->text;
 
             t_ss->add(
                 std::make_shared<dispatch::detail::Dynamic_Object_Function>(
@@ -1470,7 +1464,7 @@ namespace chaiscript
                          }),
                      true
 
-                ), this->children[static_cast<size_t>(1 + class_offset)]->text);
+                ), this->children[1]->text);
           } catch (const exception::name_conflict_error &e) {
             throw exception::eval_error("Attribute redefined '" + e.name() + "'");
           }

include/chaiscript/language/chaiscript_parser.hpp

@@ -839,6 +839,41 @@ namespace chaiscript
           } else if (text == "NaN") {
             m_match_stack.push_back(make_node<eval::Constant_AST_Node<Tracer>>(text, start.line, start.col, 
                   const_var(std::numeric_limits<double>::quiet_NaN())));
+          } else if (text == "__LINE__") {
+            m_match_stack.push_back(make_node<eval::Constant_AST_Node<Tracer>>(text, start.line, start.col, 
+                  const_var(start.line)));
+          } else if (text == "__FILE__") {
+            m_match_stack.push_back(make_node<eval::Constant_AST_Node<Tracer>>(text, start.line, start.col, 
+                  const_var(m_filename)));
+          } else if (text == "__FUNC__") {
+            const std::string fun_name = [&]()->std::string{
+              for (size_t idx = m_match_stack.size() - 1; idx > 0; --idx)
+              {
+                if (m_match_stack[idx-1]->identifier == AST_Node_Type::Id
+                    && m_match_stack[idx-0]->identifier == AST_Node_Type::Arg_List) {
+                  return m_match_stack[idx-1]->text;
+                }
+              }
+              return "NOT_IN_FUNCTION";
+            }();
+
+            m_match_stack.push_back(make_node<eval::Constant_AST_Node<Tracer>>(text, start.line, start.col, 
+                  const_var(std::move(fun_name))));
+          } else if (text == "__CLASS__") {
+            const std::string fun_name = [&]()->std::string{
+              for (size_t idx = m_match_stack.size() - 1; idx > 1; --idx)
+              {
+                if (m_match_stack[idx-2]->identifier == AST_Node_Type::Id
+                    && m_match_stack[idx-1]->identifier == AST_Node_Type::Id
+                    && m_match_stack[idx-0]->identifier == AST_Node_Type::Arg_List) {
+                  return m_match_stack[idx-2]->text;
+                }
+              }
+              return "NOT_IN_CLASS";
+            }();
+
+            m_match_stack.push_back(make_node<eval::Constant_AST_Node<Tracer>>(text, start.line, start.col, 
+                  const_var(std::move(fun_name))));
           } else if (text == "_") {
             m_match_stack.push_back(make_node<eval::Constant_AST_Node<Tracer>>(text, start.line, start.col, 
                   Boxed_Value(std::make_shared<dispatch::Placeholder_Object>())));
@@ -1517,7 +1552,7 @@ namespace chaiscript
       }
 
       /// Reads a function definition from input
-      bool Def(const bool t_class_context = false) {
+      bool Def(const bool t_class_context = false, const std::string &t_class_name = "") {
         bool retval = false;
 
         const auto prev_stack_top = m_match_stack.size();
@@ -1525,6 +1560,10 @@ namespace chaiscript
         if (Keyword("def")) {
           retval = true;
 
+          if (t_class_context) {
+            m_match_stack.push_back(make_node<eval::Id_AST_Node<Tracer>>(t_class_name, m_position.line, m_position.col));
+          }
+
           if (!Id(true)) {
             throw exception::eval_error("Missing function name in definition", File_Position(m_position.line, m_position.col), *m_filename);
           }
@@ -1708,10 +1747,11 @@ namespace chaiscript
             throw exception::eval_error("Missing class name in definition", File_Position(m_position.line, m_position.col), *m_filename);
           }
 
+          const auto class_name = m_match_stack.back()->text;
 
           while (Eol()) {}
 
-          if (!Class_Block()) {
+          if (!Class_Block(class_name)) {
             throw exception::eval_error("Incomplete 'class' block", File_Position(m_position.line, m_position.col), *m_filename);
           }
 
@@ -1908,7 +1948,7 @@ namespace chaiscript
 
 
       /// Reads a curly-brace C-style class block from input
-      bool Class_Block() {
+      bool Class_Block(const std::string &t_class_name) {
         bool retval = false;
 
         const auto prev_stack_top = m_match_stack.size();
@@ -1916,7 +1956,7 @@ namespace chaiscript
         if (Char('{')) {
           retval = true;
 
-          Class_Statements();
+          Class_Statements(t_class_name);
           if (!Char('}')) {
             throw exception::eval_error("Incomplete class block", File_Position(m_position.line, m_position.col), *m_filename);
           }
@@ -2059,7 +2099,7 @@ namespace chaiscript
       }
 
       /// Reads a variable declaration from input
-      bool Var_Decl(const bool t_class_context = false) {
+      bool Var_Decl(const bool t_class_context = false, const std::string &t_class_name = "") {
         bool retval = false;
 
         const auto prev_stack_top = m_match_stack.size();
@@ -2067,6 +2107,8 @@ namespace chaiscript
         if (t_class_context && (Keyword("attr") || Keyword("auto") || Keyword("var"))) {
           retval = true;
 
+          m_match_stack.push_back(make_node<eval::Id_AST_Node<Tracer>>(t_class_name, m_position.line, m_position.col));
+
           if (!Id(true)) {
             throw exception::eval_error("Incomplete attribute declaration", File_Position(m_position.line, m_position.col), *m_filename);
           }
@@ -2176,7 +2218,7 @@ namespace chaiscript
       /// Reads a unary prefixed expression from input
       bool Prefix() {
         const auto prev_stack_top = m_match_stack.size();
-        constexpr const std::array<const char *, 6> prefix_opers{"++", "--", "-", "+", "!", "~"};
+        constexpr const std::array<const char *, 6> prefix_opers{{"++", "--", "-", "+", "!", "~"}};
 
         for (const auto &oper : prefix_opers)
         {
@@ -2351,7 +2393,7 @@ namespace chaiscript
       }
 
       /// Parses statements allowed inside of a class block
-      bool Class_Statements() {
+      bool Class_Statements(const std::string &t_class_name) {
         bool retval = false;
 
         bool has_more = true;
@@ -2359,7 +2401,7 @@ namespace chaiscript
 
         while (has_more) {
           const auto start = m_position;
-          if (Def(true) || Var_Decl(true)) {
+          if (Def(true, t_class_name) || Var_Decl(true, t_class_name)) {
             if (!saw_eol) {
               throw exception::eval_error("Two function definitions missing line separator", File_Position(start.line, start.col), *m_filename);
             }

unittests/execution_context.chai

@@ -0,0 +1,42 @@
+
+
+assert_equal(__LINE__, 3)
+
+def f() {
+  [__LINE__, __CLASS__, __FUNC__]
+}
+
+var res = f()
+
+assert_equal(res[0], 6)
+assert_equal(res[1], "NOT_IN_CLASS")
+assert_equal(res[2], "f")
+
+assert_equal(__CLASS__, "NOT_IN_CLASS")
+assert_equal(__FUNC__, "NOT_IN_FUNCTION")
+
+class C
+{
+  def C() {}
+  def member() { [__LINE__, __CLASS__, __FUNC__]; }
+}
+
+var c = C();
+
+var res2 = c.member();
+
+assert_equal(res2[0], 21)
+assert_equal(res2[1], "C")
+assert_equal(res2[2], "member")
+
+def C::member2() { [__LINE__, __CLASS__, __FUNC__]; }
+
+var res3 = c.member2();
+
+assert_equal(res3[0], 32)
+assert_equal(res3[1], "C")
+assert_equal(res3[2], "member2")
+
+assert_true(__FILE__.find("execution_context.chai") != -1)
+
+