Add crashes and fixes found during fuzzy testing

* Let unhandled exceptions propogate to user
 * Report eval_error when break statement is not in loop
 * Fix handling of 0 length scripts closes #193
 * Don't crash on arity mismatch - Specifically affects the case where no overloads exist for a given function
 * Fix error printing for `bind` calls
 * Handle unexpected continue statement
 * Check arity during bind
 * Don't allow arith conversion on variadic function
 * Correct `bind` parameter match count
 * Add in expected Boxed_Value exception cases
 * Check access to AST, don't allow `;` in func def
 * Don't attempt arithmetic unary & call
 * Don't crash on 0 param call to `bind`
 * Catch errors during member function dispatch
 * Properly handle type of const bool &

include/chaiscript/language/chaiscript_common.hpp

@@ -276,10 +276,13 @@ namespace chaiscript
       template<typename T>
         static std::string format_location(const T &t)
         {
-          std::ostringstream oss;
-          oss << "(" << t->filename() << " " << t->start().line << ", " << t->start().column << ")"; 
-
-          return oss.str();
+          if (t) {
+            std::ostringstream oss;
+            oss << "(" << t->filename() << " " << t->start().line << ", " << t->start().column << ")"; 
+            return oss.str();
+          } else {
+            return "(internal)";
+          }
 
         }
 

include/chaiscript/language/chaiscript_eval.hpp

@@ -1117,11 +1117,22 @@ namespace chaiscript
           AST_Node(std::move(t_ast_node_text), AST_Node_Type::File, std::move(t_loc), std::move(t_children)) { }
         virtual ~File_AST_Node() {}
         virtual Boxed_Value eval_internal(chaiscript::detail::Dispatch_Engine &t_ss) const CHAISCRIPT_OVERRIDE {
-          const auto num_children = children.size();
-          for (size_t i = 0; i < num_children-1; ++i) {
-            children[i]->eval(t_ss);
+          try {
+            const auto num_children = children.size();
+
+            if (num_children > 0) {
+              for (size_t i = 0; i < num_children-1; ++i) {
+                children[i]->eval(t_ss);
+              }
+              return children.back()->eval(t_ss);
+            } else {
+              return Boxed_Value();
+            }
+          } catch (const detail::Continue_Loop &) {
+            throw exception::eval_error("Unexpected `continue` statement outside of a loop");
+          } catch (const detail::Break_Loop &) {
+            throw exception::eval_error("Unexpected `break` statement outside of a loop");
           }
-          return children.back()->eval(t_ss);
         }
     };
 
@@ -1158,7 +1169,7 @@ namespace chaiscript
 
           try {
             // short circuit arithmetic operations
-            if (m_oper != Operators::invalid && bv.get_type_info().is_arithmetic())
+            if (m_oper != Operators::invalid && m_oper != Operators::bitwise_and && bv.get_type_info().is_arithmetic())
             {
               return Boxed_Number::do_oper(m_oper, bv);
             } else {

include/chaiscript/language/chaiscript_parser.hpp

@@ -194,6 +194,7 @@ namespace chaiscript
 
       /// Returns the front-most AST node
       AST_NodePtr ast() const {
+        if (m_match_stack.empty()) throw exception::eval_error("Attempted to access AST of failed parse.");
         return m_match_stack.front();
       }
 
@@ -261,7 +262,7 @@ namespace chaiscript
       }
 
       AST_NodePtr optimized_ast(bool t_optimize_blocks = false, bool t_optimize_returns = true) {
-        AST_NodePtr p = m_match_stack.front();
+        AST_NodePtr p = ast();
         //Note, optimize_blocks is currently broken; it breaks stack management
         if (t_optimize_blocks) { optimize_blocks(p); }
         if (t_optimize_returns) { optimize_returns(p); }
@@ -1208,37 +1209,32 @@ namespace chaiscript
       }
 
       /// Reads an end-of-line group from input, without skipping initial whitespace
-      bool Eol_() {
+      bool Eol_(const bool t_eos = false) {
         bool retval = false;
 
         if (has_more_input() && (Symbol_("\r\n") || Char_('\n'))) {
           retval = true;
           ++m_line;
           m_col = 1;
-        } else if (has_more_input() && Char_(';')) {
+        } else if (has_more_input() && !t_eos && Char_(';')) {
           retval = true;
         }
 
         return retval;
       }
 
-      /// Reads (and potentially captures) an end-of-line group from input
-      bool Eol(const bool t_capture = false) {
+      /// Reads until the end of the current statement
+      bool Eos() {
         SkipWS();
 
-        if (!t_capture) {
-          return Eol_();
-        } else {
-          const auto start = m_input_pos;
-          const auto prev_col = m_col;
-          const auto prev_line = m_line;
-          if (Eol_()) {
-            m_match_stack.push_back(make_node<eval::Eol_AST_Node>(std::string(start, m_input_pos), prev_line, prev_col));
-            return true;
-          } else {
-            return false;
-          }
-        }
+        return Eol_(true);
+      }
+
+      /// Reads (and potentially captures) an end-of-line group from input
+      bool Eol() {
+        SkipWS();
+
+        return Eol_();
       }
 
       /// Reads a comma-separated list of values from input. Id's only, no types allowed
@@ -1441,7 +1437,7 @@ namespace chaiscript
             }
           }
 
-          while (Eol()) {}
+          while (Eos()) {}
 
           if (Char(':')) {
             if (!Operator()) {