grammar

p_prime: program 
program: elements mainFunction

elements: structs elements| functions_or_declarations elements| classes elements | eps

structs: STRUCT ID '{' declarations_only '}' ';'

classes: CLASS ID '{' specifier ':' class_body '}' ';' 
specifier: private | public | protected
class_body: functions_or_declarations class_body | eps
functions_or_declarations: DTYPE ID next ';'
next: functions | declarations | eps

functions: '(' parameter_list ')' '{' declarations_only statement_list '}';
parameter_list: DTYPE ID id_prime | eps
id_prime: COMMA parameter_list| '[' NUMBER ']' id_prime | eps

mainFunction: MAIN '(' ')' '{' declarations_only statement_list '}';

declarations: identifier_list ';'| eps
declarations_only: DTYPE identifier_list ';' declarations_only | eps

identifier_list: ID id1;
id1: COMMA identifier_list |'[' NUMBER ']' id1| ;

statement_list: statement statement_list| ;
statement: assign_stat_or_function_call ';'| decision_stat | looping_stat| return_stat | input_stat | output_stat| switch_stat

assign_stat_or_function_call: ID assign_function_prime;

assign_function_prime: function_call|assign_stat;
function_call: '(' argument_list ')' | '.' ID f_prime 
f_prime: '.' f_prime| function_call
argument_list: identifier_list| eps

assign_stat:  '=' expression | '.' ID a_prime
a_prime: '.' a_prime | assign_stat

return_stat : RETURN factor ';' 

input_stat:CIN '>''>' ID input_prime ';' 
input_prime : '>' '>' ID input_prime| eps

output_stat: COUT '<' '<' LITERAL output_prime ';' | COUT '<' '<' NUMBER output_prime ';' | COUT '<' '<' ID output_prime ';' 
output_prime: '<' '<' LITERAL output_prime|'<' '<' ID output_prime|'<' '<' NUMBER output_prime| eps

assign_stat_only:  ID assign_stat_prime
assign_stat_prime: '=' expression | '.' assign_stat_only

expression: simple_expression eprime;

eprime: relop simple_expression| eps
simple_expression: term seprime
seprime: addop term seprime| eps
term: factor tprime
tprime: mulop factor tprime| eps
factor: ID|NUMBER

decision_stat: IF '(' expression ')' '{' statement_list '}' dprime
dprime: ELIF '(' expression ')' '{' statement_list '}' dprime | dp_prime 
dp_prime: ELSE '{' statement_list '}' | eps

switch_stat: SWITCH '(' ID ')' '{' case_stat '}'
case_stat: CASE NUMBER ':' statement_list break_stat case_stat | default | eps
break_stat: BREAK ';' | eps
default: DEFAULT ':' statement_list

looping_stat: WHILE '(' expression ')' '{' statement_list '}'| FOR '(' assign_stat_only ';' expression ';' assign_stat_only ')' '{' statement_list '}'

relop: '>'|'<'|'<' '='|'>' '=' | '!' '='
addop: '+'|'-'
mulop: '*' | '/' | '%'