Add 'continue' command for loops. Also enhance for() unit tests which are now breaking and need to be fixed

include/chaiscript/language/chaiscript_common.hpp

@@ -494,6 +494,14 @@ namespace chaiscript
         Break_Loop() { }
       };
 
+      /**
+       * Special type indicating a call to 'continue'
+       */
+      struct Continue_Loop {
+        Continue_Loop() { }
+      };
+
+
       /// Creates a new scope then pops it on destruction
       struct Scope_Push_Pop
       {

include/chaiscript/language/chaiscript_eval.hpp

@@ -802,8 +802,14 @@ namespace chaiscript
             throw exception::eval_error("While condition not boolean");
           }
           while (cond) {
+            try {
               try {
                 this->children[1]->eval(t_ss);
+              } catch (detail::Continue_Loop &) {
+                // we got a continue exception, which means all of the remaining 
+                // loop implementation is skipped and we just need to continue to
+                // the next condition test
+              }
 
               try {
                 cond = boxed_cast<bool>(this->children[0]->eval(t_ss));
@@ -914,13 +920,27 @@ namespace chaiscript
           while (cond) {
             try {
               if (this->children.size() == 4) {
+ 
+                try {
                   this->children[3]->eval(t_ss);
+                } catch (detail::Continue_Loop &) {
+                  // we got a continue exception, which means all of the remaining 
+                  // loop implementation is skipped and we just need to continue to
+                  // the next iteration step
+                }
+
 		this->children[2]->eval(t_ss);
 
                 cond = boxed_cast<bool>(this->children[1]->eval(t_ss));
               }
               else {
+                try {
                   this->children[2]->eval(t_ss);
+                } catch (detail::Continue_Loop &) {
+                  // we got a continue exception, which means all of the remaining 
+                  // loop implementation is skipped and we just need to continue to
+                  // the next iteration step
+                }
 
                 this->children[1]->eval(t_ss);
 
@@ -1129,6 +1149,16 @@ namespace chaiscript
         }
     };
 
+    struct Continue_AST_Node : public AST_Node {
+      public:
+        Continue_AST_Node(const std::string &t_ast_node_text = "", int t_id = AST_Node_Type::Break, const boost::shared_ptr<std::string> &t_fname=boost::shared_ptr<std::string>(), int t_start_line = 0, int t_start_col = 0, int t_end_line = 0, int t_end_col = 0) :
+          AST_Node(t_ast_node_text, t_id, t_fname, t_start_line, t_start_col, t_end_line, t_end_col) { }
+        virtual ~Continue_AST_Node() {}
+        virtual Boxed_Value eval_internal(chaiscript::detail::Dispatch_Engine &){
+          throw detail::Continue_Loop();
+        }
+    };
+
     struct Map_Pair_AST_Node : public AST_Node {
       public:
         Map_Pair_AST_Node(const std::string &t_ast_node_text = "", int t_id = AST_Node_Type::Map_Pair, const boost::shared_ptr<std::string> &t_fname=boost::shared_ptr<std::string>(), int t_start_line = 0, int t_start_col = 0, int t_end_line = 0, int t_end_col = 0) :

include/chaiscript/language/chaiscript_parser.hpp

@@ -1760,6 +1760,23 @@ namespace chaiscript
           return retval;
         }
 
+        /**
+         * Reads a continue statement from input
+         */
+        bool Continue() {
+          bool retval = false;
+
+          size_t prev_stack_top = m_match_stack.size();
+
+          if (Keyword("continue")) {
+            retval = true;
+
+            build_match(AST_NodePtr(new eval::Continue_AST_Node()), prev_stack_top);
+          }
+
+          return retval;
+        }
+
         /**
          * Reads a dot expression(member access), then proceeds to check if it's a function or array call
          */
@@ -2257,6 +2274,14 @@ namespace chaiscript
               retval = true;
               saw_eol = false;
             }
+            else if (Continue()) {
+              if (!saw_eol) {
+                throw exception::eval_error("Two expressions missing line separator", File_Position(prev_line, prev_col), *m_filename);
+              }
+              has_more = true;
+              retval = true;
+              saw_eol = false;
+            }
             else if (Equation()) {
               if (!saw_eol) {
                 throw exception::eval_error("Two expressions missing line separator", File_Position(prev_line, prev_col), *m_filename);

unittests/break_for.chai

@@ -0,0 +1,11 @@
+var j = 0;
+
+for (var i = 0; i < 10; ++i) {
+  if (i == 5) {
+    break
+  }
+
+  j = i
+}
+
+assert_equal(4, j);

unittests/continue_for.chai

@@ -0,0 +1,16 @@
+var j = 0;
+var k = 0;
+
+for (var i = 0; i < 10; ++i)
+{
+  j = i
+  if (i > 5)
+  {
+    continue
+  } 
+
+  k = i
+}
+
+assert_equal(5, k);
+assert_equal(9, j);

unittests/continue_while.chai

@@ -0,0 +1,14 @@
+var i = 0
+var j = 0
+
+while (i < 10) {
+  if (++i > 5)
+  {
+    continue
+  }
+
+  j = i;
+}
+
+assert_equal(10, i);
+assert_equal(5, j);

unittests/for.chai

@@ -5,3 +5,55 @@ for (var i = 0; i < 5; ++i) {
 }
 
 assert_equal([0,1,2,3,4], ret);
+
+
+var j = 0;
+
+for (;j<10; ++j)
+{
+}
+
+assert_equal(10, j);
+
+
+var k = 0;
+
+for (;k<10; )
+{
+  ++k;
+}
+
+assert_equal(10, k);
+
+
+for (;;)
+{
+  break;
+}
+
+var l = 0;
+
+for (;;l = 1)
+{
+  break;
+}
+
+assert_equal(0, l)
+
+def isTrue(x)
+{
+  if (x == 5) 
+  {
+    return true
+  } else {
+    return false
+  }
+}
+
+for (var m = 0; isTrue(m); m = m + 1)
+{
+  
+}
+
+assert_equal(5, m);
+