start : program;

program : program unit 
	| unit
    ;

unit : var_declaration 
	| func_declaration
	| func_definition
    ;
	
func_declaration : type_specifier ID LPAREN parameter_list RPAREN SEMICOLON 
	| type_specifier ID LPAREN RPAREN SEMICOLON 
	;

func_definition : type_specifier ID LPAREN parameter_list RPAREN compound_statement 
	| type_specifier ID LPAREN RPAREN compound_statement 
	;

parameter_list : parameter_list COMMA type_specifier ID 
	| parameter_list COMMA type_specifier 
	| type_specifier ID 
	| type_specifier
	;

compound_statement : LCURL statements RCURL 
	| LCURL RCURL 
	;

var_declaration : type_specifier declaration_list SEMICOLON 
	;

type_specifier : INT
	| FLOAT
	| VOID
	;

declaration_list : declaration_list COMMA ID 
	| declaration_list COMMA ID LTHIRD CONST_INT RTHIRD
	| ID
	| ID LTHIRD CONST_INT RTHIRD
	;

statements : statement 
	| statements M
	;

statement : var_declaration
	| expression_statement
	| compound_statement
	| FOR LPAREN expression_statement M expression_statement M expression RPAREN M statement 
	| IF LPAREN expression P RPAREN M statement %prec LOWER_THAN_ELSE 
	| IF LPAREN expression P RPAREN M statement ELSE N M statement 
	| WHILE M LPAREN expression RPAREN M statement 
	| PRINTLN  LPAREN expression RPAREN SEMICOLON 
	| PRINT LPAREN expression RPAREN SEMICOLON 
	| RETURN expression SEMICOLON 
	| RETURN SEMICOLON
	| PRINTLN LPAREN CONST_STRING RPAREN SEMICOLON 
	| PRINT LPAREN CONST_STRING RPAREN SEMICOLON 
	| SCANINT LPAREN variable RPAREN SEMICOLON
	;


expression_statement : SEMICOLON 
	| expression SEMICOLON
	;

variable : ID
	| ID LTHIRD expression RTHIRD
	;

expression : logic_expression 
	| variable ASSIGNOP logic_expression
	;

logic_expression : rel_expression 
	| rel_expression LOGICOP M rel_expression
	;

rel_expression : simple_expression 
	| simple_expression RELOP simple_expression
	;

simple_expression : term 
	| simple_expression ADDOP term
	;

term : unary_expression 
	| term MULOP unary_expression 
	;

unary_expression : ADDOP unary_expression 
	| NOT unary_expression 
	| factor
	;

factor : variable 
	| ID LPAREN argument_list RPAREN 
	| LPAREN expression RPAREN
	| CONST_INT
	| CONST_FLOAT
	| variable INCOP
	| variable DECOP
	;

argument_list : arguments
	| 
	;

arguments : arguments COMMA logic_expression
	| logic_expression
	;

N : 
	; 

M : 
    ;

P :
    ;