Design a compiler for the language whose grammar is given below. The minimum
requirement is to design the lexer, parser, and generate intermediate code in
the intermediate language .Please also implementing error recovery, some simple optimizations, like
reducing the number of temporaries etc.

 

program 	::= PROGRAM identifier;
		    {declarations} 
                    BEGIN  
                         statement-list 
                    END  
 
declaration-list::=     VAR variable-decl { , variable-decl }  ; 
variable-decl  ::=      identifier   [ := constant ]    
 
statement      ::=      IF "(" condition ")" THEN statement
                   		[ ELSE statement ]                | 
               		WHILE "(" condition ")" DO statement      | 
   			BEGIN statement-list END 		  |
               		ASKFOR  identifier                        | 
               		DISPLAY write-item { , write-item }       | 
   			identifier := expression 
 
statement-list  ::=      statement ; { statement ; } 
 
write-item     ::= expression | string 
string         ::= " any characters except " ..." 
 
condition      ::= expression relational-op expression 
relational-op  ::=  <  | >   
 
expression     ::= term      {  (+ | - )  term   } 
term           ::= factor      {  ( * | / ) factor } 
factor         ::=  [ + | - ] ( constant | identifier ) 
 
constant     ::= a number 			  Integers only
identifier     ::= A-Z { A-Z  _ 0-9  ? }          Usual Identifier syntax plus ?