From a38b254a981776d14b46cfacf4d84188d7b4a378 Mon Sep 17 00:00:00 2001
From: Jason Turner <jason@emptycrate.com>
Date: Fri, 28 Oct 2016 10:56:12 -0600
Subject: [PATCH] Only allow `class` in top level scope

 * Throw error if class is in unexpected place
 * Allow catching of `eval_error` from inside of script

closes #297
---
 include/chaiscript/language/chaiscript_eval.hpp   |  7 ++-----
 include/chaiscript/language/chaiscript_parser.hpp | 12 ++++++++----
 unittests/class_inside_scope.chai                 | 10 +++++-----
 3 files changed, 15 insertions(+), 14 deletions(-)

diff --git a/include/chaiscript/language/chaiscript_eval.hpp b/include/chaiscript/language/chaiscript_eval.hpp
index ae26fec..4488022 100644
--- a/include/chaiscript/language/chaiscript_eval.hpp
+++ b/include/chaiscript/language/chaiscript_eval.hpp
@@ -1313,11 +1313,8 @@ namespace chaiscript
           try {
             retval = this->children[0]->eval(t_ss);
           }
-          catch (exception::eval_error &) {
-            if (this->children.back()->identifier == AST_Node_Type::Finally) {
-              this->children.back()->children[0]->eval(t_ss);
-            }
-            throw;
+          catch (const exception::eval_error &e) {
+            retval = handle_exception(t_ss, Boxed_Value(std::ref(e)));
           }
           catch (const std::runtime_error &e) {
             retval = handle_exception(t_ss, Boxed_Value(std::ref(e)));
diff --git a/include/chaiscript/language/chaiscript_parser.hpp b/include/chaiscript/language/chaiscript_parser.hpp
index 769c631..3588c07 100644
--- a/include/chaiscript/language/chaiscript_parser.hpp
+++ b/include/chaiscript/language/chaiscript_parser.hpp
@@ -1700,12 +1700,16 @@ namespace chaiscript
       }
 
       /// Reads a class block from input
-      bool Class() {
+      bool Class(const bool t_class_allowed) {
         bool retval = false;
 
         size_t prev_stack_top = m_match_stack.size();
 
         if (Keyword("class")) {
+          if (!t_class_allowed) {
+            throw exception::eval_error("Class definitions only allowed at top scope", File_Position(m_position.line, m_position.col), *m_filename);
+          }
+
           retval = true;
 
           if (!Id()) {
@@ -2375,7 +2379,7 @@ namespace chaiscript
       }
 
       /// Top level parser, starts parsing of all known parses
-      bool Statements() {
+      bool Statements(const bool t_class_allowed = false) {
         bool retval = false;
 
         bool has_more = true;
@@ -2383,7 +2387,7 @@ namespace chaiscript
 
         while (has_more) {
           const auto start = m_position;
-          if (Def() || Try() || If() || While() || Class() || For() || Switch()) {
+          if (Def() || Try() || If() || While() || Class(t_class_allowed) || For() || Switch()) {
             if (!saw_eol) {
               throw exception::eval_error("Two function definitions missing line separator", File_Position(start.line, start.col), *m_filename);
             }
@@ -2424,7 +2428,7 @@ namespace chaiscript
           /// \todo respect // -*- coding: utf-8 -*- on line 1 or 2 see: http://evanjones.ca/python-utf8.html)
         }
 
-        if (Statements()) {
+        if (Statements(true)) {
           if (m_position.has_more()) {
             throw exception::eval_error("Unparsed input", File_Position(m_position.line, m_position.col), t_fname);
           } else {
diff --git a/unittests/class_inside_scope.chai b/unittests/class_inside_scope.chai
index 30d21c1..27fe806 100644
--- a/unittests/class_inside_scope.chai
+++ b/unittests/class_inside_scope.chai
@@ -1,8 +1,8 @@
 
 
-{
-  class C {
-    var data;
-    def C() {}
-  }
+try {
+  parse("{  class C {    var data;    def C() {}  } }")
+  assert_false(true)
+} catch  (e) {
+  assert_true(true)
 }