I have this task where i'm working with a metacircular evaluator, and i define a new cond
like this:
(define cond 3)
As well as else
:
(define (else x) (/ x 2)
My question is why does this (below) actually work?
(cond ((= cond 2) 0)
(else (else 4)))
How does Scheme know which cond
is my defined cond and my else
, over the conditional cond
and else
?
(Feel free to edit the title, as i'm not sure how to formulate my question)
It depends on how you have implemented cond
in the metacircular evaluator. Usually it checks some operators for symbols like quote
and cond
and then do someething special. Thus cond
in operator position will be expanded as cond
while cond
in other circumstances would be evaluated as if it was a variable.