Changed the way to handle default tag in AST.

language/parser.cc

@@ -4,6 +4,7 @@ using namespace peglib;
 using namespace std;
 
 static auto g_grammar = R"(
+
     PROGRAM               <-  _ STATEMENTS
 
     STATEMENTS            <-  (EXPRESSION (';' _)?)*
@@ -53,12 +54,12 @@ static auto g_grammar = R"(
     EndOfLine             <-  '\r\n' / '\n' / '\r'
     EndOfFile             <-  !.
     Comment               <-  '/*' (!'*/' .)* '*/' /  ('#' / '//') (!(EndOfLine / EndOfFile) .)* (EndOfLine / EndOfFile)
+
 )";
 
 peg& get_parser()
 {
     static peg  parser;
-
     static bool initialized = false;
 
     if (!initialized) {
@@ -73,14 +74,17 @@ peg& get_parser()
         }
 
         parser.enable_ast({
+            /*
+               Definition,            Tag               Optimize
+             ---------------------- ------------------ ---------- */
             { "STATEMENTS",          Statements                   },
             { "WHILE",               While                        },
             { "ASSIGNMENT",          Assignment                   },
             { "IF",                  If                           },
             { "FUNCTION",            Function                     },
-            { "PARAMETERS",          Undefined               },
+            { "PARAMETERS",          Default                      },
             { "FUNCTION_CALL",       FunctionCall                 },
-            { "ARGUMENTS",           Undefined               },
+            { "ARGUMENTS",           Default                      },
             { "PRIMARY",             LogicalOr,         true      },
             { "LOGICAL_OR",          LogicalAnd,        true      },
             { "LOGICAL_AND",         Condition,         true      },
@@ -93,8 +97,7 @@ peg& get_parser()
             { "BOOLEAN",             Boolean                      },
             { "IDENTIFIER",          Identifier                   },
             { "INTERPOLATED_STRING", InterpolatedString           },
-        },
-        Undefined);
+        });
     }
 
     return parser;

language/parser.hpp

@@ -2,7 +2,7 @@
 
 enum AstTag
 {
-   Undefined,
+   Default = peglib::Ast::DefaultTag,
    Statements, While, If, FunctionCall, Assignment,
    LogicalOr, LogicalAnd, Condition, UnaryPlus, UnaryMinus, UnaryNot, BinExpresion,
    Identifier, InterpolatedString,

peglib.h

@@ -1834,6 +1834,8 @@ private:
 
 struct Ast
 {
+    static const int DefaultTag = -1;
+
     Ast(const char* _name, int _tag, const std::vector<std::shared_ptr<Ast>>& _nodes)
         : name(_name), tag(_tag), is_token(false), nodes(_nodes) {}
 
@@ -2031,16 +2033,16 @@ public:
         bool        optimize;
     };
 
-    peg& enable_ast(std::initializer_list<AstNodeInfo> list, int tag) {
+    peg& enable_ast(std::initializer_list<AstNodeInfo> list) {
         for (const auto& info: list) {
             ast_node(info);
         }
-        ast_end(tag);
+        ast_end();
         return *this;
     }
 
     peg& enable_ast() {
-        ast_end(-1);
+        ast_end();
         return *this;
     }
 
@@ -2073,21 +2075,21 @@ private:
         };
     }
 
-    void ast_end(int tag) {
+    void ast_end() {
         for (auto& x: *grammar_) {
             const auto& name = x.first;
             auto& def = x.second;
             auto& action = def.actions.front();
             if (!action) {
-                action = [tag, name](const SemanticValues& sv) {
+                action = [name](const SemanticValues& sv) {
                     if (sv.is_token()) {
-                        return std::make_shared<Ast>(name.c_str(), tag, std::string(sv.s, sv.n));
+                        return std::make_shared<Ast>(name.c_str(), Ast::DefaultTag, std::string(sv.s, sv.n));
                     }
                     if (sv.size() == 1) {
                         std::shared_ptr<Ast> ast = sv[0].get<std::shared_ptr<Ast>>();
                         return ast;
                     }
-                    return std::make_shared<Ast>(name.c_str(), tag, sv.map<std::shared_ptr<Ast>>());
+                    return std::make_shared<Ast>(name.c_str(), Ast::DefaultTag, sv.map<std::shared_ptr<Ast>>());
                 };
             }
         }