Fix default cmake build to use readline and gdb. Add simple try/catch/throw exceptions

include/chaiscript/language/chaiscript_eval.hpp

@@ -579,6 +579,40 @@ namespace chaiscript
         return retval;
     }
 
+    /**
+     * Evaluates an if/elseif/else block
+     */
+    template <typename Eval_System>
+    Boxed_Value eval_try(Eval_System &ss, const TokenPtr &node) {
+        Boxed_Value retval;        
+        retval = Boxed_Value();
+
+        ss.new_scope();
+        try {
+            retval = eval_token(ss, node->children[0]);
+        }
+        catch (std::exception &) {
+            // nothing
+            std::cout << "DEBUG: std::exception caught" << std::endl;
+        }
+        catch (Boxed_Value &bv) {
+            if (node->children.size() > 2) {
+                if (node->children[1]->text == "catch") {
+                    if (node->children.size() > 3) {
+                        ss.add_object(node->children[2]->text, bv);
+                        retval = eval_token(ss, node->children[3]);
+                    }
+                    else {
+                        retval = eval_token(ss, node->children[2]);
+                    }
+                }
+            }
+        }
+        ss.pop_scope();
+
+        return retval;
+    }
+
     /**
      * Evaluates an if/elseif/else block
      */
@@ -924,6 +958,10 @@ namespace chaiscript
                 return eval_dot_access(ss, node);
             break;
 
+            case(Token_Type::Try) :
+                return eval_try(ss, node);
+            break;
+
             case(Token_Type::If) :
                 return eval_if(ss, node);
             break;

include/chaiscript/language/chaiscript_parser.hpp

@@ -916,6 +916,60 @@ namespace chaiscript
             return retval;
         }
 
+        /**
+         * Reads a function definition from input
+         */
+        bool Try() {
+            bool retval = false;
+            bool is_annotated = false;
+
+            TokenPtr annotation;
+
+            if (Annotation()) {
+                while (Eol_());
+                annotation = match_stack.back();
+                match_stack.pop_back();
+                is_annotated = true;
+            }
+
+            int prev_stack_top = match_stack.size();
+
+            if (Keyword("try")) {
+                retval = true;
+
+                while (Eol());
+
+                if (!Block()) {
+                    throw Eval_Error("Incomplete 'try' block", File_Position(line, col), filename);
+                }
+
+                bool has_matches = true;
+                while (has_matches) {
+                    while (Eol());
+                    has_matches = false;
+                    if (Keyword("catch", true)) {
+                        if (Char('(')) {
+                            if (!(Id(true) && Char(')'))) {
+                                throw Eval_Error("Incomplete 'catch' expression", File_Position(line, col), filename);
+                            }
+                        }
+
+                        while (Eol());
+
+                        if (!Block()) {
+                            throw Eval_Error("Incomplete 'catch' block", File_Position(line, col), filename);
+                        }
+                        
+                        has_matches = true;
+                    }
+                }
+
+                build_match(Token_Type::Try, prev_stack_top);
+            }
+
+            return retval;
+        }
+
         /**
          * Reads an if/elseif/else block from input
          */
@@ -1550,6 +1604,14 @@ namespace chaiscript
                     retval = true;
                     saw_eol = true;
                 }
+                else if (Try()) {
+                    if (!saw_eol) {
+                        throw Eval_Error("Two function definitions missing line separator", match_stack.back());
+                    }
+                    has_more = true;
+                    retval = true;
+                    saw_eol = true;
+                }
                 else if (If()) {
                     if (!saw_eol) {
                         throw Eval_Error("Two function definitions missing line separator", match_stack.back());