On 2012-Aug-31 09:50 , Programmingkid wrote:
Are you saying my-variable is better than myVariable?
Yes.
How do global variables get you in trouble in recursion? Do you have an example?
Not off-hand, we learn to avoid doing that. To construct one - let's take a method doing recursion properly, and break it:
\ Correct way, using stack manipulation : fibonacci ( fib -- return ) recursive dup 2 >= if ( fib ) dup 1- fibonnaci ( fib fib-1 ) swap 2 - fibonnaci ( fib-1 fib-2 ) + ( fib ) then ( fib ) ;
\ Incorrect way - using variable "fib", which will get overwritten during recursion 0 value fib; : fibonnaci ( fib -- return ) recursive to fib \ to avoid stack manipulation fib 2 < if fib exit then fib 1- fibonnaci ( fib-1) fib 2 - fibonnaci ( fib-1 fib-2 ) + ( fib ) ;
I am not familiar with this alarm level. Could you explain what it is?
In IEEE 1275, you can set an "alarm" for a device. This will be called asynchronously when the condition in question triggers (usually a timer expiring). If you were in the middle of something else using global variables, you can get in trouble if those global variables area also used in the alarm code. The Serial driver for openboot uses alarms, for example.