%{
#include <stdio.h>
#include <strings.h>
/* Declaracoes C diversas */
%}

%token PROGRAM DECLARATIONS STATEMENTS INTEGER BOOLEAN SET ARRAY SIZE TRUE FALSE FORWARD BACKWARD RRIGHT RLEFT 
%token PEN UP DOWN GOTO WHERE SUCC PREDD ISMEMBER ASK SAY IF THEN ELSE WHILE

%token SETA OR AND EQ NE LT GT LE GE

%token number
%token identifier
%token string

%%
Liss                 : PROGRAM identifier  '{' Body  '}'
                     ;
Body                 : DECLARATIONS Declarations STATEMENTS   Statements
                     ;
                     
Declarations         : Declaration
                     | Declarations Declaration
                     ;
                     
Declaration          : Variable_Declaration
                     ;

Variable_Declaration : Vars SETA Type ';'
                     ;
                     
Vars                 : Var
                     | Vars ',' Var
                     ;
                     
Var                  : identifier Value_Var
                     ;
                     
Value_Var            :
                     | '=' Inic_Var
                     ;
                     
Type                 : INTEGER
                     | BOOLEAN
                     | SET
                     | ARRAY SIZE number
                     ;
                     
Inic_Var             : Constant
                     | Array_Definition
                     | Set_Definition
                     ;
                     
Constant             : Sign number
                     | string
                     | TRUE
                     | FALSE
                     ;
                     
Sign                 :
                     | '+'
                     | '-'
                     ;
                     
Array_Definition     : '[' Array_Initialization ']'
                     ;
                     
Array_Initialization : Elem
                     | Array_Initialization ',' Elem
                     ;
                     
Elem                 : Sign number
                     ;
                     
Set_Definition       : '{' Set_Initialization '}'
                     ;
                     
Set_Initialization   :
                     | identifier '|' Expression
                     ;
                     
Statements           : Statement
                     | Statements Statement
                     ;
                     
Statement            : Turtle_Commands
                     | Assignment
                     | Conditional_Statement
                     | Iterative_Statement
                     ;
                     
Turtle_Commands      : Step
                     | Rotate
                     | Mode
                     | Dialogue
                     | Location
                     ;
                     
Step                 : FORWARD Expression
                     | BACKWARD Expression
                     ;
                     
Rotate               : RRIGHT
                     | RLEFT
                     ;
                     
Mode                 : PEN UP
                     | PEN DOWN
                     ;
                     
Dialogue             : Say_Statement
                     | Ask_Statement
                     ;
                     
Location             : GOTO number ',' number
                     | WHERE '?'
                     ;
                     
Assignment           : Variable '=' Expression
                     ;
                     
Variable             : identifier Array_Acess
                     ;
                     
Array_Acess          :
                     | '[' Expression ']'
                     ;
                     
Expression           : Single_Expression
                     | Expression Rel_Oper Single_Expression
                     ;
                     
Single_Expression    : Term
                     | Single_Expression Add_Op Term
                     ;
                     
Term                 : Factor
                     | Term Mul_Op Factor
                     ;
                     
Factor               : Constant
                     | Variable
                     | Set_Definition
                     | Member
                     | SuccOrPred
                     | '!' Expression
                     | '+' Expression
                     | '-' Expression
                     | '(' Expression ')'
                     ;
                     
Add_Op               : '+'
                     | '-'
                     | OR
                     ;

Mul_Op               : '*'
                     | '/'
                     | AND
                     ;

Rel_Op               : EQ
                     | NE
                     | LT
                     | GT
                     | LE
                     | GE
                     ;

SuccOrPred           : SuccPred identifier
                     ;
                     
SuccPred             : SUCC
                     | PRED
                     ;
                     
Member               : ISMEMBER '(' Expression ',' Variable ')'
                     ;
                     
Say_Statement        : SAY '(' Expression ')'
                     ;
                     
Ask_Statement        : ASK '(' string ',' Variable ')'
                     ;
                     
Conditional_Statement: IfThenElse_Stat
                     ;
                     
Iterative_Statement  : While_Stat
                     ;
                     
IfThenElse_Stat      : IF Expression  THEN '{' Statements '}' Else_Expression
                     ;
                     
Else_Expression      :
                     | ELSE '{' Statements '}'
                     ;
                     
While_Stat           : WHILE '(' Expression ')' '{' Statements '}'
                     ;
%%
void yyerror(char *s)
{
  fprintf(stderr, "ERRO: %s \n", s);
}

int main()
{
  yyparse();
  return(0);
}

%--------------------------------------------------------------------------


\end{document}