README.md

Expression-Intepreter

Java Expression Intepreter made as an assignment.

This application is used to calculate arhitmetical expressions based on the following context-free grammar (N.B: "e" means void, for example, a statement list can be made of a statement alone or statement followed by a statement list):

	program → statement list

	statement list → statement statement list | e

	statement → variable def | expression def

	variable def → ( SET variable id expression )

	expression def → ( GET expression )

	expression → 	( ADD expression expression )

			| ( SUB expression expression )

			| ( MUL expression expression )

			| ( DIV expression expression )

			| number

			| variable id

	variable id → alpha list

	alpha list → alpha alpha list | alpha

	alpha → a | b | c | . . . | z | A | B | C | . . . | Z

	number → 0 | sigdigit rest

	sigdigit → 1 | . . . | 9

	rest → digit rest | e

	digit → 0 | sigdigit

###How to write an expression

These are some examples on how to use the grammar:

	(GET (ADD (MUL 14 10) 25)) 

	(SET var (MUL 10 5))

	(GET (DIV 1000 var))

	(SET var (MUL 10 20))

	(GET (DIV 1000 var))

###TODO

• Translate comments from Italian to English
• Polish the code (?)

###Documentation

See Main.java on how to use this Expression Interpreter