Prefix notation calculator

This is a recursion based calculator written in MIPS assembly using the MARS mips simulator.

Supported Operations

Operator	Syntax	Description
+	+ a b	returns the result of a summed with b
-	- a b	returns the result of b subtracted from a
*	* a b	returns the result of a multiplied by b
/	/ a b	returns the result of a divided by b truncating the result to an integer
%	% a b	returns the remainder of a divided by b
&&	&& a b	returns 1 if both a and b are non-zero, 0 otherwise
||	|| a b	returns 0 if both a and b are zero, 1 otherwise
!	! a	returns 1 if a is zero, 0 otherwise
&	& a b	returns the result of a ANDed with b bitwise
|	| a b	returns the result of a ORed with b bitwise
~	~ a	returns a with all the bits inverted
^	^ a b	returns the result of a XORed with b bitwise
>>	>> a b	returns the result of shifting all the bits in a to the right b times with signed padding
<<	<< a b	returns the result of shifting all the bits in a to the left b times
==	== a b	returns 1 if a equals b, 0 otherwise
!=	!= a b	returns 1 if a does not equal b, 0 otherwise
<	< a b	returns 1 if a is less than b, 0 otherwise
<=	<= a b<	returns 1 if a is less than or equal to b, 0 otherwise
>	> a b	returns 1 if a is greater than b, 0 otherwise
>=	>= a b	returns 1 if a is greater than or equal to b, 0 otherwise
=	= A b	assigns b to A, then returns A
+=	+= A b	increments A by b, then returns A
-=	-= A b	decrements A by b, then returns A
*=	*= A b	multiplies A by b, then returns A
/=	/= A b	divides A by b, truncating to an integer, then returns A
%=	%= A b	assigns A to the remainder of A divided by b, then returns A
&=	&= A b	bitwise ANDs A with b, then returns A
|=	|= A b	bitwise ORs A with b, then returns A
^=	^= A b	bitwise XORs A with b, then returns A
++	++ A	increments A, then returns A
--	-- A	decrements A, then returns A
.	. a b	returns b

Variables are case sensitive and are single letters ([a-zA-Z])

Examples

+ 1 2: adds 1 and 2, returning 3 . = a 4 + a 8: assigns 4 to a, then adds a and 8, returning 12