Added nop operator to prevent incorrect aliasing

langkit/langkit_parser.cpp

@@ -121,7 +121,7 @@ std::pair<Token_Iterator, bool> And_Rule(Token_Iterator iter, Token_Iterator end
 }
 
 std::pair<Token_Iterator, bool> Kleene_Rule
-    (Token_Iterator iter, Token_Iterator end, TokenPtr parent, bool keep, int new_id, struct Rule rule) {
+    (Token_Iterator iter, Token_Iterator end, TokenPtr parent, bool keep, int new_id, Rule rule) {
 
     TokenPtr prev_parent = parent;
     std::pair<Token_Iterator, bool> result;
@@ -149,7 +149,7 @@ std::pair<Token_Iterator, bool> Kleene_Rule
 }
 
 std::pair<Token_Iterator, bool> Plus_Rule
-    (Token_Iterator iter, Token_Iterator end, TokenPtr parent, bool keep, int new_id, struct Rule rule) {
+    (Token_Iterator iter, Token_Iterator end, TokenPtr parent, bool keep, int new_id, Rule rule) {
 
     unsigned int prev_size;
     TokenPtr prev_parent = parent;
@@ -196,7 +196,7 @@ std::pair<Token_Iterator, bool> Plus_Rule
 }
 
 std::pair<Token_Iterator, bool> Optional_Rule
-    (Token_Iterator iter, Token_Iterator end, TokenPtr parent, bool keep, int new_id, struct Rule rule) {
+    (Token_Iterator iter, Token_Iterator end, TokenPtr parent, bool keep, int new_id, Rule rule) {
 
     TokenPtr prev_parent = parent;
     Token_Iterator new_iter = iter;
@@ -224,6 +224,33 @@ std::pair<Token_Iterator, bool> Optional_Rule
     return std::pair<Token_Iterator, bool>(result.first, true);
 }
 
+std::pair<Token_Iterator, bool> Nop_Rule
+    (Token_Iterator iter, Token_Iterator end, TokenPtr parent, bool keep, int new_id, Rule rule) {
+
+    TokenPtr prev_parent = parent;
+    Token_Iterator new_iter = iter;
+
+    if (new_id != -1) {
+        parent = TokenPtr(new Token("", new_id, parent->filename));
+    }
+
+    std::pair<Token_Iterator, bool> result;
+    result.second = true;
+    if ((new_iter != end) && (result.second == true)) {
+        result = rule(new_iter, end, parent);
+        new_iter = result.first;
+    }
+
+    if (new_id != -1) {
+        parent->filename = (*iter)->filename;
+        parent->start = (*iter)->start;
+        parent->end = (*(result.first - 1))->end;
+
+        prev_parent->children.push_back(parent);
+    }
+
+    return std::pair<Token_Iterator, bool>(iter, true);
+}
 
 Rule Str(const std::string &text, bool keep) {
     return Rule(boost::bind(String_Rule, _1, _2, _3, _4, _5, text), keep);
@@ -246,3 +273,7 @@ Rule Ign(Rule rule) {
 
     return rule;
 }
+
+Rule Nop(Rule rule) {
+    return Rule(boost::bind(Nop_Rule, _1, _2, _3, _4, _5, rule));
+}

langkit/langkit_parser.hpp

@@ -8,9 +8,11 @@
 
 #include "langkit_lexer.hpp"
 
+struct RuleImpl;
+
 typedef std::vector<TokenPtr>::iterator Token_Iterator;
 typedef boost::function<std::pair<Token_Iterator, bool>(Token_Iterator, Token_Iterator, TokenPtr, bool, int)> RuleFun;
-typedef std::tr1::shared_ptr<struct RuleImpl> RuleImplPtr;
+typedef std::tr1::shared_ptr<RuleImpl> RuleImplPtr;
 
 struct RuleImpl {
     RuleFun rule;
@@ -45,6 +47,9 @@ std::pair<Token_Iterator, bool> Plus_Rule
 std::pair<Token_Iterator, bool> Optional_Rule
     (Token_Iterator iter, Token_Iterator end, TokenPtr parent, bool keep, int new_id, struct Rule rule);
 
+std::pair<Token_Iterator, bool> Nop_Rule
+    (Token_Iterator iter, Token_Iterator end, TokenPtr parent, bool keep, int new_id, struct Rule rule);
+
 struct Rule {
     RuleImplPtr impl;
 
@@ -58,9 +63,9 @@ struct Rule {
     }
 
     Rule &operator=(const Rule &rule) {
-        //*impl = *(rule.impl);
+        int prev_id = impl->new_id;
-        impl->rule = rule.impl->rule;
+        *impl = *(rule.impl);
-        impl->keep = rule.impl->keep;
+        impl->new_id = prev_id;
 
         return *this;
     }
@@ -100,5 +105,6 @@ Rule Str(const std::string &text);
 Rule Id(int id);
 
 Rule Ign(Rule rule);
+Rule Nop(Rule rule);
 
 #endif /* LANGKIT_PARSER_HPP_ */

langkit/main.cpp

@@ -66,7 +66,6 @@ void parse(std::vector<TokenPtr> &tokens) {
 
     //Example: "def add(x,y)"
 
-
     Rule params;
     Rule block(TokenType::Scoped_Block);
     Rule rule(TokenType::Function_Def);
@@ -78,12 +77,13 @@ void parse(std::vector<TokenPtr> &tokens) {
     block = Ign(Str("{")) << ~return_statement << Ign(Str("}"));
     return_statement = Ign(Str("return")) << Id(TokenType::Identifier) << Str("+") << Id(TokenType::Identifier);
 
-
     /*
-    Rule rule, rule2;
+    Rule rule;
-    rule = rule2;
+    Rule rule2;
+    rule = Nop(rule2);
     rule2 = Str("Bob");
     */
+
     /*
     Rule rule(3);
     rule = Ign(Str("Bob")) << Str("Fred");