%skeleton "lalr1.cc"
%defines
%define api.value.type variant
%define api.token.constructor
%code requires{
  #include "Node.hh"
}
%code{
  extern FILE yyin;
  unsigned int total = 0;
  #include <string>
  #define YY_DECL yy::parser::symbol_type yylex()
  YY_DECL;
  Node root;
  int Node::id = 0;
}


%token <std::string> SPACE
%token <std::string> EQUAL
%token <std::string> NUMBER
%token <std::string> ADD
%token <std::string> SUB
%token <std::string> MULT
%token <std::string> DIV
%token <std::string> ELE
%token <std::string> NEWLINE
%token <std::string> START
%token <std::string> FINISH
%token <std::string> VAR
%token <std::string> PRINT
%token <std::string> COMMA
%token <std::string> CITE
%token <std::string> FOR
%token <std::string> DO
%token <std::string> ENDLOOP
%token <std::string> READ
%token <std::string> TRUE
%token <std::string> FALSE
%token <std::string> MOD
%token <std::string> EQU
%token <std::string> IF
%token <std::string> THEN
%token <std::string> LIST
%token <std::string> LISTSTART
%token <std::string> LISTEND
%token <std::string> LISTRANGESTART
%token <std::string> LISTRANGEEND
%token <std::string> REPEAT
%token <std::string> UNTIL
%token <std::string> MORE
%token <std::string> LESS
%token <std::string> FUNCTION
%token <std::string> ELSE

//binop precedence
%left MORE LESS EQU COMMA
%left ADD SUB
%left MULT DIV MOD
%left ELE

%type <Node> chunk
%type <Node> exp
%type <Node> optblank
%type <Node> block
%type <Node> stat
%type <Node> prefixexp
%type <Node> field
%type <Node> var
%type <Node> functioncall
%type <Node> explist
%type <Node> args


%token END 0 "end of file"
%%

block : chunk                {$$ = Node("BLOCK", "");
                              $$.children.push_back($1);
                              root = $$;};
       | block NEWLINE chunk { $$ = $1;
                               $$.children.push_back($3);
                               root = $$;}


chunk :      { $$ = Node("CHUNK", "empty");}
      | stat { $$ = Node("CHUNK","has stat");
               $$.children.push_back($1);};


stat : field       { $$ = $1; }


optblank :                  {};
         | optblank SPACE   {};
         | optblank READ    {};



var : optblank VAR optblank {$$ = Node("VAR",$2);};

explist : exp {$$ = $1;};
        | explist COMMA optblank exp {$$ = $1;};

exp : optblank NUMBER optblank {$$ = Node("NUMBER",$2);};
    | prefixexp                {$$ = $1;};
    | functioncall      {$$ = $1;};
    | exp MORE exp  {$$ = Node("BINOP",">");
                     $$.children.push_back($1);
                     $$.children.push_back($3);};
    | exp LESS exp  {$$ = Node("BINOP","<");
                     $$.children.push_back($1);
                     $$.children.push_back($3);};
    | exp EQU exp   {$$ = Node("BINOP","==");
                     $$.children.push_back($1);
                     $$.children.push_back($3);};
    | exp ADD exp   {$$ = Node("BINOP","+");
                     $$.children.push_back($1);
                     $$.children.push_back($3);};
    | exp SUB exp   {$$ = Node("BINOP","-");
                     $$.children.push_back($1);
                     $$.children.push_back($3);};
    | exp MULT exp  {$$ = Node("BINOP","*");
                     $$.children.push_back($1);
                     $$.children.push_back($3);};
    | exp DIV exp   {$$ = Node("BINOP","/");
                     $$.children.push_back($1);
                     $$.children.push_back($3);};
    | exp MOD exp   {$$ = Node("BINOP","%");
                     $$.children.push_back($1);
                     $$.children.push_back($3);};
    | exp ELE exp   {$$ = Node("BINOP","^");
                     $$.children.push_back($1);
                     $$.children.push_back($3);};

args : START explist END {$$ = $2;};

prefixexp : var               {$$ = $1;};
          | optblank START exp FINISH optblank {$$ = $3;};

functioncall : prefixexp args {$$ = $1;};


field : exp           {$$ = $1;}
      | var EQUAL exp {$$ = Node("Assignment", "");
                       $$.children.push_back($1);
                       $$.children.push_back($3);};