designP1.txt

Design of the Interpreter:
1. the program is divided into parts: Lexer (.h,.cpp) and Parser (.h, .cpp).
2. Lexer implements the functions checkNextToken() and skipNextToken() just as mentioned in the comments given by the Professor.
(checkNextToken() returns the same next token unless the skipNextToken() is called, which updates to the next token)
3. The responsibility of lexer is just to scan the input buffer and return the tokens whenever requested by parser.
4. The parser implements the grammar rules. The following are the grammar rules defined by me:
<ls>  :== <IR1>
<IR1> :== INT 
	 | ID 
	 | ( <IR1> . <IR1> ) 
	 | ( <IR1><IR2> 
	 | ()

<IR2> :== ) 
	 | [SPACE]<IR1><IR2>

The function corresponding to the rules of <IR1> is implemented in the function inputRoutine1() and the functions corresponding to the <IR2> is implemented in inputRoutine2.